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  • 1. Aabloo, A
    et al.
    Klintenberg, M
    Thomas, John Oswald
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Molecular dynamics simulation of a polymer-inorganic interface.2000In: Electrochim.Acta, Vol. 45, p. 1425-Article in journal (Refereed)
  • 2. Aabloo, A.
    et al.
    Thomas, John Oswald
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Molecular dynamics simulation of lithium ion mobility in a PEO surface.2001In: Solid State Ionics, Vol. 143, p. 83-Article in journal (Refereed)
  • 3.
    Aabloo, A
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Thomas, John Oswald
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Molecular dynamics simulation of Nd3+ ions in a crystalline PEO surface1998In: ELECTROCHIMICA ACTA, ISSN 0013-4686, Vol. 43, no 10-11, p. 1361-1364Article in journal (Other scientific)
    Abstract [en]

    Poly(ethylene oxide) based electrolytes are systems in which ionic salts are dissolved into an amorphous EO matrix. Potentials developed earlier to model crystalline and amorphous bulk PEO systems are here used for the MD simulation at 400 K of the behavi

  • 4.
    Aabloo, A
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Thomas, John Oswald
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Molecular dynamics simulations of a poly(ethylene oxide) surface1997In: POLYMER, ISSN 0032-3861, Vol. 38, no 18, p. A47-A51Article in journal (Refereed)
    Abstract [en]

    Potentials developed earlier for crystalline and amorphous bulk PEO systems have been used for the MD simulation of a PEO surface model. The surface comprises the outer region of a 122 Angstrom-thick sheet of PEO in which the PEO, -(CH2-CH2-O)(n)- chains

  • 5.
    Aarik, J.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. oorganisk kemi.
    Aidla, A.
    Mändar, H.
    Uustare, T.
    Schuisky, M.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. oorganisk kemi.
    Hårsta, A.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. oorganisk kemi.
    Atomic layer growth of epitaxial TiO2 thin films from TiCl4 and H2O on a-Al2O3 substrates2002In: J. Cryst. Growth, no 242, p. 189-198Article in journal (Refereed)
  • 6.
    Aarik, J.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. oorganisk kemi.
    Sundqvist, J.
    Aidla, A.
    Lu, J.
    Sajavaara, T.
    Kukli, K.
    Hårsta, Anders
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. oorganisk kemi.
    Hafnium tetraiodide and oxygen as precursors for atomic layer deposition of hafnium oxide thin films2002In: Thin Solid Films, Vol. 418, p. 69-72Article in journal (Refereed)
  • 7.
    Abal, Joao P. K.
    et al.
    Univ Fed Rio Grande do Sul, Inst Fis, BR-91501970 Porto Alegre, RS, Brazil..
    Dillenburg, Rodrigo F.
    Univ Fed Rio Grande do Sul, Inst Fis, BR-91501970 Porto Alegre, RS, Brazil..
    Köhler, Mateus H.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Univ Fed Santa Maria, Dept Fis, BR-97105900 Santa Maria, RS, Brazil.
    Barbosa, Marcia C.
    Univ Fed Rio Grande do Sul, Inst Fis, BR-91501970 Porto Alegre, RS, Brazil..
    Molecular Dynamics Simulations of Water Anchored in Multilayered Nanoporous MoS2 Membranes: Implications for Desalination2021In: ACS Applied Nano Materials, E-ISSN 2574-0970, Vol. 4, no 10, p. 10467-10476Article in journal (Refereed)
    Abstract [en]

    One of the most promising applications in nano-science is the design of new materials to improve water permeability and selectivity of nanoporous membranes. Understanding the molecular architecture behind these fascinating structures and how it impacts the water flow is an intricate but a necessary task. We studied here the water flux through multi-layered nanoporous molybdenum disulfide (MLNMoS2) membranes with different nanopore sizes and lengths. Molecular dynamics simulations show that the permeability does not increase with the inverse of the membrane thickness, violating the classical hydrodynamic behavior. The data also reveal that water dynamics is slower than those observed in frictionless carbon nanotubes and multilayer graphene membranes, which we explain in terms of an anchor mechanism observed in between layers. We show that the membrane permeability is critically dependent on the nanopore architecture, bringing important insights into the manufacture of new desalination membranes.

  • 8.
    Abbas, Alaa
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Palladium-Catalysed Carbonylative Synthesis of Acylamidines2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 9. Abbrent, S
    et al.
    Plestil, J
    Hlavata, D
    Lindgren, Jan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Tegenfeldt, Jörgen
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Wendsjö, Å
    Crystallinity and morphology of PVdF-HFP based gel electrolytes.2001In: Polymer, Vol. 42, p. 1407-Article in journal (Refereed)
  • 10.
    Abbrent, Sabina
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Lithium ion interactions in polymer gel electrolytes: Effect on structure, dynamics and morphology2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Polymer electrolytes are an essential part of the modern all-solid lithium battery. Several properties, such as mechanical and thermal stability, good ionic conductivity and compatibility with other materials used in the battery are necessary for a successful material.

    This thesis is focused on the ionic interactions in two electrolyte systems, based on a cross-linked polyethylene oxide (nona(ethylene oxide)dimethacrylate) or a fluorinated copolymer (polyvinylidene fluoride-hexafluoropropylene). Changes of thermal properties and morphology of and coordination in the electrolyte on addition of a lithium salt (LiTFSI) and different types and concentrations of solvents are studied. These properties are shown to control the ionic conductivity of the resulting material, influencing the conductivity mechanism.

    The presumably inert polyvinylidene fluoride is shown to undergo large structural changes, where polar conformations of the polymer backbone appear on salt addition, inducing a different crystalline phase. The lithium cation in the polyethylene oxide based electrolyte can coordinate either to the polymer chain or to the solvent. In for example systems containing propylene carbonate, the lithium ion binds more strongly to the polymer than to the solvent. This is in contrast to the systems with dimethyl sulphoxide where the ion prefers the solvent. This variation in coordination also strongly affects the mobility of the cation, reflected both in diffusion constants and in conductivity data.

    A combination of techniques was necessary to use for a deeper understanding of these complex materials. Coordination has been studied by FTIR and high resolution NMR, dynamics by NMR diffusion measurements and impedance spectroscopy, and morphology by diffraction techniques and DSC.

  • 11. Abdala, Paula M
    et al.
    Safonova, Olga V
    Wiker, Geir
    van Beek, Wouter
    Emerich, Herman
    van Bokhoven, Jeroen A
    Sá, Jacinto
    Szlachetko, Jakub
    Nachtegaal, Maarten
    Scientific opportunities for heterogeneous catalysis research at the SuperXAS and SNBL beam lines.2012In: CHIMIA, ISSN 0009-4293, E-ISSN 2673-2424, Vol. 66, no 9, p. 699-705Article in journal (Refereed)
    Abstract [en]

    In this short review, we describe the complementary experimental capabilities for catalysis research at two beam lines available to the Swiss community, SuperXAS at SLS (Swiss Light Source, Villigen) and SNBL (Swiss Norwegian Beam lines) at ESRF (European Synchrotron Radiation Facility, Grenoble). Over the years, these two facilities have been developed to provide powerful techniques for structural studies under in situ and operando conditions. These techniques, X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and X-ray emission spectroscopy (XES) in combination with Raman or infrared spectroscopy provide new avenues for structure-performance studies of catalysts. Several exemplary studies are used to demonstrate the capability of these facilities.

  • 12.
    Abd-El Azeem, Hoda H.
    et al.
    Menoufia Univ, Fac Sci, Dept Zool, Shibin Al Kawm 32512, Egypt..
    Osman, Gamalat Y.
    Menoufia Univ, Fac Sci, Dept Zool, Shibin Al Kawm 32512, Egypt..
    El-Seedi, Hesham
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi. Jiangsu Univ, Int Res Ctr Food Nutr & Safety, Zhenjiang 212013, Jiangsu, Peoples R China.;Jiangsu Univ, Jiangsu Educ Dept, Int Joint Res Lab Intelligent Agr & Agriprod Proc, Zhenjiang 212013, Jiangsu, Peoples R China.;Menoufia Univ, Fac Sci, Dept Chem, Shibin Al Kawm 32512, Egypt..
    Fallatah, Ahmed M.
    Taif Univ, Coll Sci, Dept Chem, POB 11099, Taif 21944, Saudi Arabia..
    Khalifa, Shaden A. M.
    Stockholm Univ, Wenner Gren Inst, Dept Mol Biosci, SE-10691 Stockholm, Sweden..
    Gharib, Mohamed M.
    Menoufia Univ, Fac Sci, Dept Bot, Shibin Al Kawm 32512, Egypt..
    Antifungal Activity of Soft Tissue Extract from the Garden Snail Helix aspersa (Gastropoda, Mollusca)2022In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 27, no 10, article id 3170Article in journal (Refereed)
    Abstract [en]

    Gastropods comprise approximately 80% of molluscans, of which land snails are used variably as food and traditional medicines due to their high protein content. Moreover, different components from land snails exhibit antimicrobial activities. In this study, we evaluated the antifungal activity of soft tissue extracts from Helix aspersa against Candida albicans, Aspergillus flavus, and Aspergillus brasiliensis by identifying extract components using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Two concentrations of three extracts (methanol, acetone, and acetic acid) showed antifungal activity. Both acetone (1 g/3 mL) and acetic acid extracts (1 g/mL) significantly inhibited C. albicans growth (p = 0.0001, 5.2 +/- 0.2 mm and p = 0.02, 69.7 +/- 0.6 mm, respectively). A. flavus and A. brasiliensis growth were inhibited by all extracts at 1 g/mL, while inhibition was observed for acetic acid extracts against A. brasiliensis (p = 0.02, 50.3 +/- 3.5 mm). The highest growth inhibition was observed for A. flavus using acetic acid and acetone extracts (inhibition zones = 38 +/- 1.7 mm and 3.1 +/- 0.7 mm, respectively). LC-MS-MS studies on methanol and acetone extracts identified 11-alpha-acetoxyprogesterone with a parent mass of 372.50800 m/z and 287.43500 m/z for luteolin. Methanol extracts contained hesperidin with a parent mass of 611.25400 m/z, whereas linoleic acid and genistein (parent mass = 280.4 and 271.48900 m/z, respectively) were the main metabolites.

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  • 13.
    Abdel-Baset, T. A.
    et al.
    Taibah Univ, Fac Sci, Dept Phys, Yanbu 46423, Saudi Arabia.;Fayoum Univ, Fac Sci, Dept Phys, Al Fayyum 63514, Egypt..
    Abdel-Hafiez, Mahmoud
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Effect of metal dopant on structural and magnetic properties of ZnO nanoparticles2021In: Journal of materials science. Materials in electronics, ISSN 0957-4522, E-ISSN 1573-482X, Vol. 32, no 12, p. 16153-16165Article in journal (Refereed)
    Abstract [en]

    Zn1-xRxO (R = Li, Mg, Cr, Mn, Fe and Cd) were obtained by using co-precipitation synthesis technique with constant weight percent of 3% from R ions. The phase composition, crystal structure, morphology, density functional theory (DFT), and magnetic properties were examined to comprehend the influence of Zn2+ partial substitution with R ions. X-ray diffraction shows that the ZnO lattice parameters were slightly affected by R doping and the doped sample crystallinity is enhanced. Our results show that introducing Cr, Mn and Fe along with Mg into ZnO induces a clear magnetic moment without any apparent distortion in the structural morphology. The spatial configuration of dopant atoms is determined from first-principles calculations, giving a better understanding of the position of the dopant atom responsible for the magnetism. The magnetic moments obtained from our calculations are 3.67, 5.0, and 4.33 mu B per dopant atom for Cr, Mn, and Fe, respectively, which agree with the experimental values. While Cr and Fe tend to form clusters, Mn has more propensity to remain evenly distributed within the system, avoiding cluster-derived magnetism.

  • 14.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden;Assiut Univ, Dept Chem, Adv Multifunct Mat Lab, Assiut 71515, Egypt.
    El-Zohry, Ahmed M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Cong, Jiayan
    KTH Royal Inst Technol, Dept Chem, Appl Phys Chem, Tekn Ringen 30, S-10044 Stockholm, Sweden.
    Thersleff, Thomas
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden.
    Karlsson, Martin
    KTH Royal Inst Technol, Dept Chem, Appl Phys Chem, Tekn Ringen 30, S-10044 Stockholm, Sweden.
    Kloo, Lars
    KTH Royal Inst Technol, Dept Chem, Appl Phys Chem, Tekn Ringen 30, S-10044 Stockholm, Sweden.
    Zou, Xiaodong
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden.
    Towards implementing hierarchical porous zeolitic imidazolate frameworks in dye-sensitized solar cells2019In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 6, no 7, article id 190723Article in journal (Refereed)
    Abstract [en]

    A one-pot method for encapsulation of dye, which can be applied for dye-sensitized solar cells (DSSCs), and synthesis of hierarchical porous zeolitic imidazolate frameworks (ZIF-8), is reported. The size of the encapsulated dye tunes the mesoporosity and surface area of ZIF-8. The mesopore size, Langmuir surface area and pore volume are 15 nm, 960-1500 m(2). g(-1) and 0.36-0.61 cm(3). g(-1), respectively. After encapsulation into ZIF-8, the dyes show longer emission lifetimes (greater than 4-8-fold) as compared to the corresponding non-encapsulated dyes, due to suppression of aggregation, and torsional motions.

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  • 15.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Huang, Zhehao
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    El-Zohry, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Zheng, Haoquan
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Zou, Xiaodong
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    A Fast and Scalable Approach for Synthesis of Hierarchical Porous Zeolitic Imidazolate Frameworks and One-Pot Encapsulation of Target Molecules2017In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 15, p. 9139-9146Article in journal (Refereed)
    Abstract [en]

    A trimethylamine (TEA)-assisted synthesis approach that combines the preparation of hierarchical porous zeolitic, imidazolate framework ZIF-8, nanoparticles and one-pot encapsulation of target molecules is presented. Two dye molecules, rhodamine B (RhB) and methylene blue (MB), and one protein (bovine serum albumin, BSA) were, tested as the target molecules. The addition of TEA into the solution of zinc nitrate promoted the formation of ZnO nanocrystals, which rapidly transformed to ZIF-8 nanoparticles after the addition of the linker 2-methylimidazole (Hmim): Hierarchical porous dye@ZIF-8 nanoparticles with high crystallinity, large BET surface areas (1300-2500 m(2)/g), and large pore Volatiles (0.5-1.0 cm(3)/g) could be synthesized. The synthesis procedure was fast (down to 2 min) and scalable. The Hmim/Zn ratio could be greatly reduced (down to 2:1) compared to previously reported ones. The surface areas, and the mesopore size, structure, and density could be modified by changing the TEA or dye concentrations, or by postsynthetic treatment using reflux in methanol. This synthesis and one-pot encapsulation approach is simple and can be readily scaled Up. The photophysical properties such as lifetime and photostability of the dyes could be tuned via encapsulation. The lifetimes of the encapsulated dyes were increased by 3-27-fold for RhB@ZIF-8 and by 20-fold for MB@ZIF-8, compared to those of the corresponding free dyes. The synthesis approach is general, which was successfully applied for encapsulation of protein BSA. It could also be extended for the synthesis of hierarchical porous cobalt-based ZIP (dye@ZIF-67).

  • 16.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden;Assiut Univ, Dept Chem, Assiut 71515, Egypt.
    Wilk-Kozubek, Magdalena
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden;PORT Polish Ctr Technol Dev, Dept Nanotechnol, 147 Stablowicka St, PL-54066 Wroclaw, Poland.
    El-Zohry, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Gomez, Antonio Bermejo
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Valiente, Alejandro
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Martin-Matute, Belen
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Mudring, Anja-Verena
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Zou, Xiaodong
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Luminescence properties of a family of lanthanide metal-organic frameworks2019In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 279, p. 400-406Article in journal (Refereed)
    Abstract [en]

    Two isostructural series of lanthanide metal-organic frameworks denoted as SUMOF-7II (Ln) and SUMOF-7IIB (Ln) (Ln = La, Ce, Pr, Nd, Sm, Eu, and Gd) were synthesized using4,4',4 ''-(pyridine-2,4,6-triyl)tris(benzoic acid) (H(3)L2) and a mixture of H(3)L2 and 4,4',4 ''-(benzene-1,3,5-triyl)tris(benzoic acid) (H3BTB) as linkers, respectively. Both series were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal analysis (TGA), and photoluminescence spectroscopy. Photoluminescence measurements show that Eu-MOFs demonstrate a red emission while Pr- and Nd-MOFs display an emission in the near-infrared (NIR) range. On the other hand, La-, Ce-, Sm- and Gd-MOFs exhibit only a ligand-centered emission. The average luminescence lifetimes in the SUMOF-7IIB series are 1.3-1.4-fold longer than the corresponding ones in the SUMOF-7II series. SUMOF-7IIs show a good photo- and thermal stability. Altogether, the properties of SUMOF-7II and SUMOF-7IIB render them promising materials for applications including sensing, biosensing, and telecommunications.

  • 17. Abdel-Hamid, Mohammed K
    et al.
    Macgregor, Kylie A
    Odell, Luke R
    Chau, Ngoc
    Mariana, Anna
    Whiting, Ainslie
    Robinson, Phillip J
    McCluskey, Adam
    1,8-Naphthalimide derivatives: new leads against dynamin I GTPase activity.2015In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 13, no 29Article in journal (Refereed)
    Abstract [en]

    Fragment-based in silico screening against dynamin I (dynI) GTPase activity identified the 1,8-naphthalimide framework as a potential scaffold for the design of new inhibitors targeting the GTP binding pocket of dynI. Structure-based design, synthesis and subsequent optimization resulted in the development of a library of 1,8-naphthalimide derivatives, called the Naphthaladyn™ series, with compounds 23 and 29 being the most active (IC50 of 19.1 ± 0.3 and 18.5 ± 1.7 μM respectively). Compound 29 showed effective inhibition of clathrin-mediated endocytosis (IC50(CME) 66 μM). The results introduce 29 as an optimised GTP-competitive lead Naphthaladyn™ compound for the further development of naphthalimide-based dynI GTPase inhibitors.

  • 18.
    Abdelki, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Fused deposition modeling of API-loaded mesoporous magnesium carbonate2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis, the incorporation of drug loaded mesoporous magnesium carbonate as an excipient for the additive manufacturing of oral tablets by fused deposition modeling was investigated. Cinnarizine, a BCS class II drug, was loaded into the pores of the mesoporous material via a soaking method, corresponding to a drug loading of 8.68 wt%. DSC measurements on the loaded material suggested that the drug was partially crystallized after incorporation, meanwhile the XRD diffractogram implied that the drug was in a state lacking long range order. The drug loaded material was combined with two pharmaceutical polymers, Aquasolve LG and Klucel ELF, and extruded into filaments with a single screw extruder. Filaments of Klucel ELF and drug loaded Upsalite (30:70 wt% ratio) were successfully implemented for the printing oral tablets, in contrast to the Aquasolve LG based filaments which were difficult to print due to thickness variations and non-uniform material distributions. The drug content obtained by TGA suggested drug loadings of 7.71 wt% and 2.23 wt% in the drug loaded Upsalite and tablets respectively. Dissolution studies using an USP II apparatus showed a slower API-release from the tablets in comparison to the crystalline drug, most probably due to slow diffusion of drug species through the polymeric matrix. For future studies, pharmaceutical polymers with higher aqueous solubility should be investigated in order to thoroughly examine the potential of utilizing the immediate release property of Upsalite.

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  • 19.
    Abdellah, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. South Valley Univ, Qena Fac Sci, Dept Chem, Qena 83523, Egypt..
    El-Zohry, Ahmed M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Antila, Liisa J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Windle, Christopher D.
    Univ Cambridge, Dept Chem, Christian Doppler Lab Sustainable SynGas Chem, Lensfield Rd, Cambridge CB2 1EW, England..
    Reisner, Erwin
    Univ Cambridge, Dept Chem, Christian Doppler Lab Sustainable SynGas Chem, Lensfield Rd, Cambridge CB2 1EW, England..
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Time-Resolved IR Spectroscopy Reveals a. Mechanism with TiO2 as a Reversible Electron Acceptor in a TiO2-Re Catalyst System for CO2 Photoreduction2017In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 139, no 3, p. 1226-1232Article in journal (Refereed)
    Abstract [en]

    Attaching the phosphonated molecular catalyst [(ReBr)-Br-I(bpy)-(CO)(3)](0) to the wide-bandgap semiconductor TiO2 strongly enhances the rate of visible-light-driven reduction of CO2 to CO in dimethylformamide with triethanolamine (TEOA) as sacrificial electron donor. Herein, we show by transient mid-IR spectroscopy that the mechanism of catalyst photoreduction is initiated by ultrafast electron injection into TiO2, followed by rapid (ps-ns) and sequential two-electron oxidation of TEOA that is coordinated to the Re center. The injected electrons can be stored in the conduction band of TiO2 on an ms-s time scale, and we propose that they lead to further reduction of the Re catalyst and completion of the catalytic cycle. Thus, the excited Re catalyst gives away one electron and would eventually get three electrons back. The function of an electron reservoir would represent a role for TiO2 in photocatalytic CO2 reduction that has previously not been considered. We propose that the increase in photocatalytic activity upon heterogenization of the catalyst to TiO2 is due to the slow charge recombination and the high oxidative power of the Re-II species after electron injection as compared to the excited MLCT state of the unbound Re catalyst or when immobilized on ZrO2, which results in a more efficient reaction with TEOA.

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  • 20.
    Abdellah, Mohamed
    et al.
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden.;South Valley Univ, Qena Fac Sci, Dept Chem, Qena 83523, Egypt..
    Poulsen, Felipe
    Univ Copenhagen, Dept Chem, DK-2100 Copenhagen, Denmark..
    Zhu, Qiushi
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden..
    Zhu, Nan
    Tech Univ Denmark, Dept Chem, Kemitorvet Bldg 207, DK-2800 Lyngby, Denmark.;Dalian Univ Technol, Zhang Dayu Sch Chem, Dalian 116024, Peoples R China..
    Zidek, Karel
    Acad Sci Czech Republ, Inst Plasma Phys, Reg Ctr Special Opt & Optoelect Syst TOPTEC, Za Slovankou 1782-3, Prague 18200 8, Czech Republic..
    Chabera, Pavel
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden..
    Corti, Annamaria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hansen, Thorsten
    Univ Copenhagen, Dept Chem, DK-2100 Copenhagen, Denmark..
    Chi, Qijin
    Tech Univ Denmark, Dept Chem, Kemitorvet Bldg 207, DK-2800 Lyngby, Denmark..
    Canton, Sophie E.
    DESY, Attosecond Sci Grp, Notkestr 85, D-22607 Hamburg, Germany.;ELI HU Nonprofit Ltd, ELI ALPS, Dugonics Ter 13, H-6720 Szeged, Hungary..
    Zheng, Kaibo
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden.;Qatar Univ, Coll Engn, Gas Proc Ctr, POB 2713, Doha, Qatar..
    Pullerits, Tonu
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden..
    Drastic difference between hole and electron injection through the gradient shell of CdxSeyZn1−xS1−y quantum dots2017In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 34, p. 12503-12508Article in journal (Refereed)
    Abstract [en]

    Ultrafast fluorescence spectroscopy was used to investigate the hole injection in CdxSeyZn1-xS1-y gradient core-shell quantum dot (CSQD) sensitized p-type NiO photocathodes. A series of CSQDs with a wide range of shell thicknesses was studied. Complementary photoelectrochemical cell measurements were carried out to confirm that the hole injection from the active core through the gradient shell to NiO takes place. The hole injection from the valence band of the QDs to NiO depends much less on the shell thickness when compared to the corresponding electron injection to n-type semiconductor (ZnO). We simulate the charge carrier tunneling through the potential barrier due to the gradient shell by numerically solving the Schrodinger equation. The details of the band alignment determining the potential barrier are obtained from X-ray spectroscopy measurements. The observed drastic differences between the hole and electron injection are consistent with a model where the hole effective mass decreases, while the gradient shell thickness increases.

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  • 21.
    Abdellah, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. South Valley Univ, Qena Fac Sci, Dept Chem, Qena 83523, Egypt.
    Zhang, Shihuai
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Wang, Mei
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Competitive Hole Transfer from CdSe Quantum Dots to Thiol Ligands in CdSe-Cobaloxime Sensitized NiO Films Used as Photocathodes for H-2 Evolution2017In: ACS Energy Letters, E-ISSN 2380-8195, Vol. 2, no 11, p. 2576-2580Article in journal (Refereed)
    Abstract [en]

    Quantum dot (QD) sensitized NiO photocathodes rely on efficient photoinduced hole injection into the NiO valence band. A system of a mesoporous NiO film co-sensitized with CdSe QDs and a molecular proton reduction catalyst was studied. While successful electron transfer from the excited QDs to the catalyst is observed, most of the photogenerated holes are instead quenched very rapidly (ps) by hole trapping at the surface thiols of the capping agent used as linker molecules. We confirmed our conclusion by first using a thiol free capping agent and second varying the thiol concentration on the QD's surface. The later resulted in faster hole trapping as the thiol concentration increased. We suggest that this hole trapping by the linker limits the H-2 yield for this photocathode in a device.

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  • 22.
    Abdel-Magied, Ahmed F.
    et al.
    KTH Royal Inst Technol, Dept Chem Engn, S-100 44 Stockholm, Sweden.;Nucl Mat Author, POB 530,El Maadi, Cairo, Egypt..
    Ashour, Radwa M.
    KTH Royal Inst Technol, Dept Chem Engn, S-100 44 Stockholm, Sweden.;Nucl Mat Author, POB 530,El Maadi, Cairo, Egypt..
    Fu, Le
    Cent South Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China..
    Dowaidar, Moataz
    King Fahd Univ Petr & Minerals KFUPM, Dept Bioengn, Dhahran 31261, Saudi Arabia..
    Xia, Wei
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Material Science.
    Forsberg, Kerstin
    KTH Royal Inst Technol, Dept Chem Engn, S-100 44 Stockholm, Sweden..
    Abdelhamid, Hani Nasser
    Assiut Univ, Dept Chem, Adv Multifunct Mat Lab, Assiut 71515, Egypt.;Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden..
    Magnetic metal-organic frameworks for efficient removal of cadmium(II), and lead(II) from aqueous solution2022In: Journal of Environmental Chemical Engineering, E-ISSN 2213-3437, Vol. 10, no 3, article id 107467Article in journal (Refereed)
    Abstract [en]

    Efficient and convenient methods for the removal of toxic heavy metal ions especially Cd(II) and Pb(II) from aqueous solutions is of great importance due to their serious threat to public health and the ecological system. In this study, two magnetic metal-organic frameworks (namely: Fe3O4@ZIF-8, and Fe3O4@UiO-66-NH2) were synthesized, fully characterized, and applied for the adsorption of Cd(II) and Pb(II) from aqueous solutions. The adsorption efficiencies for the prepared nanocomposites are strongly dependent on the pH of the aqueous solution. The maximum adsorption capacities of Fe3O4@UiO-66-NH2, and Fe3O4@ZIF-8 at pH 6.0 were calculated to be 714.3 mg.g(-), and 370 mg.g(-1) for Cd(II), respectively, and 833.3 mg.g(-1), and 666.7 mg.g(-1) for Pb(II), respectively. The adsorption process follows a pseudo-second-order model and fit the Langmuir isotherm model. Moreover, the thermodynamic studies revealed that the adsorption process is endothermic, and spontaneous in nature. A plausible adsorption mechanism was discussed in detail. The magnetic adsorbents: Fe3O4@ZIF-8, and Fe3O4@UiO-66-NH2 showed excellent reusability, maintaining the same efficiency for at least four consecutive cycles. These results reveal the potential use of magnetic Fe3O4@ZIF-8, and Fe3O4@UiO-66-NH2 as efficient adsorbents in removing Cd(II) and Pb(II) from aqueous solutions.

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  • 23.
    Abdelmoniem, Amr M.
    et al.
    Cairo Univ, Dept Chem, Fac Sci, Giza, Egypt.
    Elnagdi, Mohamed H.
    Cairo Univ, Giza, Egypt;Kuwait Univ, Safat, Kuwait.
    Elsehemy, Mohamed S.
    Cairo Univ, Dept Chem, Fac Pharm, Giza, Egypt.
    El-Seedi, Hesham R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi. Menoufia Univ, Dept Chem, Fac Sci, Shibin Al Kawm 32512, Egypt.
    Abdelhamid, Ismail A.
    Cairo Univ, Dept Chem, Fac Sci, Giza, Egypt.
    Synthesis, Chemistry and Utilities of Diaminoazoles with Special Reference to 3,5-Diaminopyrazoles2018In: Current Organic Synthesis, ISSN 1570-1794, E-ISSN 1875-6271, Vol. 15, no 4, p. 487-514Article, review/survey (Refereed)
    Abstract [en]

    Background: Although the chemistry of heteroaromatic monoamino azoles has been surveyed more than once in the last decade, the chemistry of the di- and triaminoazoles has not been reviewed. In this article we will survey the synthesis, chemistry and utility of the diaminoazoles. In this review, the chemistry of the diaminoazoles as well as their most important utilities will be surveyed. Objective: The review focuses on recent progress in diaminoazoles (i.e. diaminopyrazoles, diaminoimidazoles, diaminotriazoles and diaminothiazole) with especial references to diaminopyrazoles. The synthesis as well as pharmaceutical utilities are reported. There are several methods for synthesis of diaminopyrazoles. 3,5-Diaminopyrazole and its derivatives are prepared through the reaction of malononitrile or arylhydrazononitrile with hydrazine derivatives. 3,4-Diaminopyrazoles are prepared via nitration of 3-aminopyrazole with subsequent reduction of the produced compound. The diaminopyrazoles have several applications in cosmetic and pharmaceutical industries. They also have useful utilities as a constituent in oxidative hair dyes. Conclusion: We managed to report the common methods for the synthesis of diaminoazoles with especial reference to aminopyrazoles that are prepared through the reaction of malononitrile or hydrazononitriles with hydrazine derivatives. Some important applications that include pharmaceutical utilities such as hair dye constituents are reported.

  • 24.
    Abdi, Zahra
    et al.
    Inst Adv Studies Basic Sci IASBS, Dept Chem, Zanjan 4513766731, Iran..
    Bagheri, Robabeh
    Soochow Univ, Sch Phys Sci & Technol, Coll Energy, Soochow Inst Energy & Mat Innovat, Suzhou 215006, Peoples R China.;Soochow Univ, Key Lab Adv Carbon Mat & Wearable Energy Technol, Suzhou 215006, Peoples R China..
    Reza Mohammadi, Mohammad
    Univ Sistan & Baluchestan, Dept Phys, Zahedan 9816745845, Iran..
    Song, Zhenlun
    Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, Surface Dept, Surface Protect Res Grp, 519 Zhuangshi Rd, Ningbo 315201, Peoples R China..
    Görlin, Mikaela
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Dau, Holger
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany..
    Najafpour, Mohammad Mahdi
    Inst Adv Studies Basic Sci IASBS, Dept Chem, Zanjan 4513766731, Iran..
    In Situ Synthesis of Manganese Oxide as an Oxygen-Evolving Catalyst: A New Strategy2021In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 27, no 4, p. 1330-1336Article in journal (Refereed)
    Abstract [en]

    All studies on oxygen-evolution reaction by Mn oxides in the presence of cerium(IV) ammonium nitrate (CAN) have been so far carried out by synthesizing Mn oxides in the first step. And then, followed by the investigation of the Mn oxides in the presence of oxidants for oxygen-evolution reaction (OER). This paper presents a case study of a new and promising strategy for in situ catalyst synthesis by the adding Mn-II to either CAN or KMnO4/CAN solution, resulting in the formation of Mn-based catalysts for OER. The catalysts were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. Both compounds contained nano-sized particles that catalyzed OER in the presence of CAN. The turnover frequencies for both catalysts were 0.02 (mmolO2 /mol(Mn).

  • 25. Abdi-Jalebi, Mojtaba
    et al.
    Andaji-Garmaroudi, Zahra
    Cacovich, Stefania
    Stavrakas, Camille
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Richter, Johannes M.
    Alsari, Mejd
    Booker, Edward P.
    Hutter, Eline M.
    Pearson, Andrew J.
    Lilliu, Samuele
    Savenije, Tom J.
    Rensmo, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Divitini, Giorgio
    Ducati, Caterina
    Friend, Richard H.
    Stranks, Samuel D.
    Maximizing and stabilizing luminescence from halide perovskites with potassium passivation2018In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 555, p. 497-501Article in journal (Refereed)
    Abstract [en]

    Metal halide perovskites are of great interest for various high-performance optoelectronic applications. The ability to tune the perovskite bandgap continuously by modifying the chemical composition opens up applications for perovskites as coloured emitters, in building-integrated photovoltaics, and as components of tandem photovoltaics to increase the power conversion efficiency. Nevertheless, performance is limited by non-radiative losses, with luminescence yields in state-of-the-art perovskite solar cells still far from 100 per cent under standard solar illumination conditions. Furthermore, in mixed halide perovskite systems designed for continuous bandgap tunability2 (bandgaps of approximately 1.7 to 1.9 electronvolts), photoinduced ion segregation leads to bandgap instabilities. Here we demonstrate substantial mitigation of both non-radiative losses and photoinduced ion migration in perovskite films and interfaces by decorating the surfaces and grain boundaries with passivating potassium halide layers. We demonstrate external photoluminescence quantum yields of 66 per cent, which translate to internal yields that exceed 95 per cent. The high luminescence yields are achieved while maintaining high mobilities of more than 40 square centimetres per volt per second, providing the elusive combination of both high luminescence and excellent charge transport. When interfaced with electrodes in a solar cell device stack, the external luminescence yield—a quantity that must be maximized to obtain high efficiency—remains as high as 15 per cent, indicating very clean interfaces. We also demonstrate the inhibition of transient photoinduced ion-migration processes across a wide range of mixed halide perovskite bandgaps in materials that exhibit bandgap instabilities when unpassivated. We validate these results in fully operating solar cells. Our work represents an important advance in the construction of tunable metal halide perovskite films and interfaces that can approach the efficiency limits in tandem solar cells, coloured-light-emitting diodes and other optoelectronic applications.

  • 26.
    Abdi-Jalebi, Mojtaba
    et al.
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Pazoki, Meysam
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Dar, M. Ibrahim
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, Lausanne, Switzerland.
    Alsari, Mejd
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Sadhanala, Aditya
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Diyitini, Giorgio
    Univ Cambridge, Dept Mat Sci & Met, Charles Babbage Rd, Cambridge, England.
    Imani, Roghayeh
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lilliu, Samuele
    Univ Sheffield, Dept Phys & Astron, Sheffield, S Yorkshire, England; UAE Ctr Crystallog, Dubai, U Arab Emirates.
    Kullgren, Jolla
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Rensmo, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Gratzel, Michael
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, Lausanne, Switzerland.
    Friend, Richard H.
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Dedoping of Lead Halide Perovskites Incorporating Monovalent Cations2018In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 7, p. 7301-7311Article in journal (Refereed)
    Abstract [en]

    We report significant improvements in the optoelectronic properties of lead halide perovskites with the addition of monovalent ions with ionic radii close to Pb2+. We investigate the chemical distribution and electronic structure of solution processed CH3NH3PbI3 perovskite structures containing Na+, Cu+, and Ag+, which are lower valence metal ions than Pb2+ but have similar ionic radii. Synchrotron X-ray diffraction reveals a pronounced shift in the main perovskite peaks for the monovalent cation-based films, suggesting incorporation of these cations into the perovskite lattice as well as a preferential crystal growth in Ag+ containing perovskite structures. Furthermore, the synchrotron X-ray photoelectron measurements show a significant change in the valence band position for Cu- and Ag-doped films, although the perovskite bandgap remains the same, indicating a shift in the Fermi level position toward the middle of the bandgap. Such a shift infers that incorporation of these monovalent cations dedope the n-type perovskite films when formed without added cations. This dedoping effect leads to cleaner bandgaps as reflected by the lower energetic disorder in the monovalent cation-doped perovskite thin films as compared to pristine films. We also find that in contrast to Ag+ and Cu+, Na+ locates mainly at the grain boundaries and surfaces. Our theoretical calculations confirm the observed shifts in X-ray diffraction peaks and Fermi level as well as absence of intrabandgap states upon energetically favorable doping of perovskite lattice by the monovalent cations. We also model a significant change in the local structure, chemical bonding of metal-halide, and the electronic structure in the doped perovskites. In summary, our work highlights the local chemistry and influence of monovalent cation dopants on crystallization and the electronic structure in the doped perovskite thin films.

  • 27. Abdin, Amir
    et al.
    Feyzabi, Kaveh
    Hellman, Oskar
    Nordström, Henrietta
    Rasa, Dilman
    Thaung Tolförs, Gustav
    Öqvist, Per-Olof
    Methods to create compressive stress in high strength steel components2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Residual compressive stresses can be used to increase the lifetime of parts under cyclic stress as they negate the applied tensile stresses that cause crack initiation and propagation in the material. The goal of this project was to investigate methods to induce stresses, their advantages and disadvantages as well as depth and magnitude of induced stresses, and also to find methods of analyzing the induced residual stresses. This was done on behalf of Epiroc Drilling Tools AB in order for them to induce stresses on the insides of their long, narrow and hollow rods, where stress induction is difficult. Shot peening was used as a reference as that is the method currently in use by the company. The results show that the two most promising methods are cavitation peening and laser shock peening; two relatively new methods with large magnitudes and depth of induced stress as well as a great capability of inducing stresses on the hard-to-reach insides of the rods. Ultrasonic needle peening, ultrasonic shot peening as well as induction hardening, cryogenic treatment and friction stir processing were also investigated. Methods of analyzing the stresses include X-ray diffraction and slitting, hole drilling and ultrasonic methods.

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  • 28. Abdissa, Negera
    et al.
    Fangfang, Pan
    Gruhonjic, Amra
    Gräfenstein, Jürgen
    Fitzpatrick, Paul A
    Landberg, Göran
    Rissanen, Kari
    Yenesew, Abiy
    Erdelyi, Mate
    Naphthalene Derivatives from the Roots of Pentas parvifolia and Pentas bussei.2016In: Journal of natural products (Print), ISSN 0163-3864, E-ISSN 1520-6025, Vol. 79, no 9, p. 2181-2187Article in journal (Refereed)
    Abstract [en]

    The phytochemical investigation of the CH2Cl2/MeOH (1:1) extract of the roots of Pentas parvifolia led to the isolation of three new naphthalenes, parvinaphthols A (1), B (2), and C (3), two known anthraquinones, and five known naphthalene derivatives. Similar investigation of the roots of Pentas bussei afforded a new polycyclic naphthalene, busseihydroquinone E (4), a new 2,2'-binaphthralenyl-1,1'-dione, busseihydroquinone F (5), and five known naphthalenes. All purified metabolites were characterized by NMR and MS data analyses, whereas the absolute configurations of 3 and 4 were determined by single-crystal X-ray diffraction studies. The E-geometry of compound 5 was supported by DFT-based chemical shift calculations. Compounds 2-4 showed marginal cytotoxicity against the MDA-MB-231 human triple-negative breast cancer cell line with IC50 values ranging from 62.3 to 129.6 μM.

  • 29. Abdissa, Negera
    et al.
    Induli, Martha
    Fitzpatrick, Paul
    Alao, John Patrick
    Sunnerhagen, Per
    Landberg, Göran
    Yenesew, Abiy
    Erdelyi, Mate
    Cytotoxic quinones from the roots of Aloe dawei.2014In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 19, no 3, p. 3264-3273Article in journal (Refereed)
    Abstract [en]

    Seven naphthoquinones and nine anthraquinones were isolated from the roots of Aloe dawei by chromatographic separation. The purified metabolites were identified by NMR and MS analyses. Out of the sixteen quinones, 6-hydroxy-3,5-dimethoxy-2-methyl-1,4-naphthoquinone is a new compound. Two of the isolates, 5,8-dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione and 1-hydroxy-8-methoxy-3-methylanthraquinone showed high cytotoxic activity (IC₅₀ 1.15 and 4.85 µM) on MCF-7 breast cancer cells, whereas the others showed moderate to low cytotoxic activity against MDA-MB-231 (ER Negative) and MCF-7 (ER Positive) cancer cells.

  • 30.
    Abdulla, Beyar
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Nanocellulose surface functionalization for in-situ growth of zeolitic imidazolate framework 67 and 82020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master’s thesis was conducted at the Department of Nanotechnology and Functional Materials at Ångström Laboratory as part of an on-going project to develop hybrid nanocomposites from Cladophora cellulose and a sub-type of metal-organic frameworks; zeolitic imidazolate frameworks (ZIFs). By utilizing a state-of-the-art interfacial synthesis approach, in-situ growth of ZIF particles on the cellulose could be achieved. TEMPO-mediated oxidation was diligently used to achieve cellulose nanofibers with carboxylate groups on their surfaces. These were ion-exchanged to promote growth of ZIF particles in a nanocellulose solution and lastly, metal ions and organic linkers which the ZIFs are composed of were added to the surface functionalized and ion-exchanged nanocellulose solution to promote ZIF growth. By vacuum filtration, mechanical pressing and furnace drying; freestanding nanopapers were obtained. A core-shell morphology between the nanocellulose and ZIF crystals was desired and by adjusting the metal ion concentration, a change in morphologies was expected. The nanocomposites were investigated with several relevant analytical tools to confirm presence, attachment and in-situ growth of ZIF crystal particles upon the surface of the fine nanocellulose fibers. Both the CNF@ZIF-67 and CNF@ZIF-8 nanocomposites were successfully prepared as nanopapers with superior surface areas and thermal properties compared to pure TEMPO-oxidized cellulose nanopapers. The CNF@ZIFs showcased hierarchical porosities, stemming from the micro- and mesoporous ZIFs and nanocellulose, respectively. Also, it was demonstrated that CNF@ZIF-8 selectively adsorbed CO2 over N2. Partial formation of core-shell structure could be obtained, although a relationship between increased metal ions and ZIF particle morphology could not wholly be observed.

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  • 31. Abdurahman, Samir
    et al.
    Youssefi, Masoud
    Höglund, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Vahlne, Anders
    Characterization of the invariable residue 51 mutations of human immunodeficiency virus type 1 capsid protein on in vitro CA assembly and infectivity2007In: Retrovirology, E-ISSN 1742-4690, Vol. 4, p. 69-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The mature HIV-1 conical core formation proceeds through highly regulated protease cleavage of the Gag precursor, which ultimately leads to substantial rearrangements of the capsid (CAp24) molecule involving both inter- and intra-molecular contacts of the CAp24 molecules. In this aspect, Asp51 which is located in the N-terminal domain of HIV-1 CAp24 plays an important role by forming a salt-bridge with the free imino terminus Pro1 following proteolytic cleavage and liberation of the CAp24 protein from the Pr55Gag precursor. Thus, previous substitution mutation of Asp51 to alanine (D51A) has shown to be lethal and that this invariable residue was found essential for tube formation in vitro, virus replication and virus capsid formation. RESULTS: We extended the above investigation by introducing three different D51 substitution mutations (D51N, D51E, and D51Q) into both prokaryotic and eukaryotic expression systems and studied their effects on in vitro capsid assembly and virus infectivity. Two substitution mutations (D51E and D51N) had no substantial effect on in vitro capsid assembly, yet they impaired viral infectivity and particle production. In contrast, the D51Q mutant was defective both for in vitro capsid assembly and for virus replication in cell culture. CONCLUSION: These results show that substitutions of D51 with glutamate, glutamine, or asparagine, three amino acid residues that are structurally related to aspartate, could partially rescue both in vitro capsid assembly and intra-cellular CAp24 production but not replication of the virus in cultured cells.

  • 32. Abe, Ryu
    et al.
    Bajada, Mark
    Beller, Matthias
    Bocarsly, Andrew B.
    Butt, Julea N.
    Cassiola, Flavia
    Domcke, Wolfgang
    Durrant, James R.
    Gavrielides, Stelios
    Grätzel, Michael
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hatzell, Marta C.
    König, Burkhard
    Kudo, Akihiko
    Kuehnel, Moritz F.
    Lage, Ava
    Lee, Chong-Yong
    Maneiro, Marcelino
    Minteer, Shelley D.
    Paris, Aubrey R.
    Plumeré, Nicolas
    Reek, Joost N. H.
    Reisner, Erwin
    Roy, Souvik
    Schnedermann, Christoph
    Shankar, Ravi
    Shylin, Sergii I.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Smith, Wilson A.
    Soo, Han Sen
    Wagner, Andreas
    Wielend, Dominik
    Beyond artificial photosynthesis: general discussion2019In: Faraday discussions, ISSN 1359-6640, E-ISSN 1364-5498, Vol. 215, p. 422-438Article in journal (Other (popular science, discussion, etc.))
  • 33. Abi Ghaida, Fatima
    et al.
    Brinkert, Katharina
    Chen, Ping
    DeBeer, Serena
    Hoffman, Brian M.
    Holland, Patrick L.
    Laxmi, Shoba
    MacFarlane, Doug
    Peters, Jonas C.
    Peters, John W.
    Pickett, Christopher J.
    Seefeldt, Lance C.
    Shylin, Sergii I.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Stephens, Ifan E. L.
    Vincent, Kylie A.
    Wang, Qianru
    Westhead, Olivia
    Enzymatic N2 activation: general discussion2023In: Faraday discussions, ISSN 1359-6640, E-ISSN 1364-5498, Vol. 243, p. 287-295Article in journal (Other (popular science, discussion, etc.))
  • 34.
    Aboulfadl, Hisham
    et al.
    Chalmers Univ Technol, Dept Phys, Div Microstruct Phys, S-41296 Gothenburg, Sweden..
    Sopiha, Kostiantyn
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Keller, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Larsen, Jes K
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Scragg, Jonathan J.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Persson, Clas
    Univ Oslo, Ctr Mat Sci & Nanotechnol, Dept Phys, N-0316 Oslo, Norway.;KTH Royal Inst Technol, Dept Mat Sci & Engn, Div Appl Mat Phys, S-10044 Stockholm, Sweden..
    Thuvander, Mattias
    Chalmers Univ Technol, Dept Phys, Div Microstruct Phys, S-41296 Gothenburg, Sweden..
    Edoff, Marika
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Alkali Dispersion in (Ag,Cu)(In,Ga)Se-2 Thin Film Solar Cells-Insight from Theory and Experiment2021In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 13, no 6, p. 7188-7199Article in journal (Refereed)
    Abstract [en]

    Silver alloying of Cu(In,Ga)Se-2 absorbers for thin film photovoltaics offers improvements in open-circuit voltage, especially when combined with optimal alkali-treatments and certain Ga concentrations. The relationship between alkali distribution in the absorber and Ag alloying is investigated here, combining experimental and theoretical studies. Atom probe tomography analysis is implemented to quantify the local composition in grain interiors and at grain boundaries. The Na concentration in the bulk increases up to similar to 60 ppm for [Ag]/([Ag] + [Cu]) = 0.2 compared to similar to 20 ppm for films without Ag and up to similar to 200 ppm for [Ag]/([Ag] + [Cu]) = 1.0. First-principles calculations were employed to evaluate the formation energies of alkali-on-group-I defects (where group-I refers to Ag and Cu) in (Ag,Cu)(In,Ga)Se-2 as a function of the Ag and Ga contents. The computational results demonstrate strong agreement with the nanoscale analysis results, revealing a clear trend of increased alkali bulk solubility with the Ag concentration. The present study, therefore, provides a more nuanced understanding of the role of Ag in the enhanced performance of the respective photovoltaic devices.

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  • 35.
    Aboye, Teshome L.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Burman, Robert
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Göransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Synthesis, Cyclization and Oxidative folding of backbone engineered Cyclotides2010Conference paper (Refereed)
  • 36.
    Aboye, Teshome Leta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Clark, Richard J.
    University of Queensland, Institute for Molecular Bioscience.
    Burman, Robert
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Craik, David J.
    University of Queensland, Institute for Molecular Bioscience.
    Göransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Synthesis and Oxidative Folding of Cyclic Cystine Knot Peptides: Towards Backbone Engineering2010In: Peptides 2010: Tales of Peptides Proceedings of the Thirty-First European Peptide Symposium / [ed] Michal Lebl, Morten Meldal, Knud J. Jensen, Thomas Høeg-Jensen, European Peptide Society , 2010, p. 142-143Conference paper (Refereed)
  • 37.
    Aboye, Teshome Leta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Clark, Richard J.
    University of Queensland, Institute for Molecular Bioscience.
    Craik, David J.
    University of Queensland, Institute for Molecular Bioscience.
    Göransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Synthesis and folding of the circular cystine knotted cyclotide cycloviolacin O22008In: Peptides 2008: Chemistry of Peptides in Life Science Technology and MedicineProceedings of The Thirtieth European Peptide Symposium / [ed] Hilkka Lankinen, The Finnish Peptide Society and The European Peptide Society , 2008, p. 280-281Conference paper (Refereed)
  • 38.
    Abrahamsson, Malin L. A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Berglund Baudin, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Tran, A.
    Philouze, C.
    Berg, K.
    Raymond-Johansson, Mary Katherine
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Sun, L.
    Åkermark, B.
    Styring, S.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Ruthenium-Manganese Complexes for Artificial Photosynthesis: Factors Controlling Intramolecular Electron Transfer and Excited State Quenching Reactions2002In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 41, no 6, p. 1534-1544Article in journal (Refereed)
    Abstract [en]

    Continuing our work toward a system mimicking the electron-transfer steps from manganese to P(680)(+) in photosystem II (PS II), we report a series of ruthenium(II)-manganese(II) complexes that display intramolecular electron transfer from manganese(II) to photooxidized ruthenium(III). The electron-transfer rate constant (k(ET)) values span a large range, 1 x 10(5)-2 x 10(7) s(-1), and we have investigated different factors that are responsible for the variation. The reorganization energies determined experimentally (lambda = 1.5-2.0 eV) are larger than expected for solvent reorganization in complexes of similar size in polar solvents (typically lambda approximately 1.0 eV). This result indicates that the inner reorganization energy is relatively large and, consequently, that at moderate driving force values manganese complexes are not fast donors. Both the type of manganese ligand and the link between the two metals are shown to be of great importance to the electron-transfer rate. In contrast, we show that the quenching of the excited state of the ruthenium(II) moiety by manganese(II) in this series of complexes mainly depends on the distance between the metals. However, by synthetically modifying the sensitizer so that the lowest metal-to-ligand charge transfer state was localized on the nonbridging ruthenium(II) ligands, we could reduce the quenching rate constant in one complex by a factor of 700 without changing the bridging ligand. Still, the manganese(II)-ruthenium(III) electron-transfer rate constant was not reduced. Consequently, the modification resulted in a complex with very favorable properties.

  • 39.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Microsecond (MLCT)-M-3 excited state lifetimes in bis-tridentate Ru(II)-complexes: significant reductions of non-radiative rate constants2017In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 46, no 39, p. 13314-13321Article in journal (Refereed)
    Abstract [en]

    In this paper we report the photophysical properties of a series of bis-tridentate Ru-II-complexes, based on the dqp-ligand (dqp = 2,6-di(quinolin-8-yl) pyridine), which display several microsecond long excited state lifetimes for triplet metal-to-ligand charge transfer ((MLCT)-M-3) at room temperature. Temperature dependence of the excited state lifetimes for [Ru(dqp)(2)](2+) and [Ru(dqp)(ttpy)](2+) (ttpy = 4'-tolyl-2,2': 6', 2 ''-terpyridine) is reported and radiative and non-radiative rate constants for the whole series are reported and discussed. We can confirm previous assumptions that the near-octahedricity of the bis-dqp complexes dramatically slows down activated decay at room temperature, as compared to most other and less long-lived bis-tridentate RuII-complexes, such as [Ru(tpy)(2)](2+) with tau = 0.25 ns at room temperature (tpy = 2,2': 6', 2 ''-terpyridine). Moreover, the direct non-radiative decay to the ground state is comparatively slow for similar to 700 nm room-temperature emission when considering the energy-gap law. Analysis of the 77 K emission spectra suggests that this effect is not primarily due to smaller excited state distortion than that for comparable complexes. Instead, an analysis of the photophysical parameters suggests a weaker singlet-triplet mixing in the MLCT state, which slows down both radiative and non-radiative decay.

  • 40.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science, Chemical Physics.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science, Chemical Physics.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science, Chemical Physics.
    Bonnefous, Celine
    Chamchoumis, Charles
    Thummel, Randolph
    Six-membered Ring Chelate Complexes of Ru(II): Structural and photophysical effects2007In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 46, no 24, p. 10354-10364Article in journal (Refereed)
    Abstract [en]

    The structural and photophysical properties of Ru(II)−polypyridyl complexes with five- and six-membered chelate rings were studied for two bis-tridentate and two tris-bidentate complexes. The photophysical effect of introducing a six-membered chelate ring is most pronounced for the tridentate complex, leading to a room-temperature excited-state lifetime of 810 ns, a substantial increase from 180 ns for the five-membered chelate ring model complex. Contrasting this, the effect is the opposite in tris-bidentate complexes, in which the lifetime decreases from 430 ns to around 1 ns in going from a five-membered to six-membered chelate ring. All of the complexes were studied spectroscopically at both 80 K and ambient temperatures, and the temperature dependence of the excited-state lifetime was investigated for both of the bis-tridentate complexes. The main reason for the long excited-state lifetime in the six-membered chelate ring bis-tridentate complex was found to be a strong retardation of the activated decay via metal-centered states, largely due to an increased ligand field splitting due to the complex having a more-octahedral geometry.

  • 41.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science, Chemical Physics.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science, Chemical Physics.
    Tocher, Derek
    Nag, Samik
    Datta, Dipankar
    Modulation of the lowest metal-to-ligand charge-transfer state in [Ru(bpy)(2)(N-N)](2+) systems by changing the N-N from hydrazone to azine: Photophysical Consequences2006In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 45, no 23, p. 9580-9586Article in journal (Refereed)
    Abstract [en]

    Two Ru( II) complexes, [ Ru( bpy) L-2]( ClO4) 2 ( 1) and [ Ru( bpy)(2)L']( BF4) 2 ( 2), where bpy is 2,2'-bipyridine, L is diacetyl dihydrazone, and L' 1: 2 is the condensate of L and acetone, are synthesized. From X-ray crystal structures, both are found to contain distorted octahedral RuN62+ cores. NMR spectra show that the cations in 1 and 2 possess a C-2 axis in solution. They display the expected metal-to-ligand charge transfer ( (MLCT)-M-1) band in the 400 - 500 nm region. Complex 1 is nonemissive at room temperature in solution as well as at 80 K. In contrast, complex 2 gives rise to an appreciable emission upon excitation at 440 nm. The room-temperature emission is centered at 730 nm ( lambda(max)(em)) with a quantum yield ( em) of 0.002 and a lifetime ( tau(em)) of 42 ns in an air-equilibrated methanol - ethanol solution. At 80 K, Phi(em) = 0.007 and tau(em)= 178 ns, with a lambda(max)(em) of 690 nm, which is close to the 0 - 0 transition, indicating an (MLCT)-M-3 excited-state energy of 1.80 eV. The radiative rate constant ( 5 x 10(4) s(-1)) at room temperature and 80 K is almost temperature independent. From spectroelectrochemistry, it is found that bpy is easiest to reduce in 2 and that L is easiest in 1. The implications of this are that in 2 the lowest (MLCT)-M-3 state is localized on a bpy ligand and in 1 it is localized on L. Transient absorption results also support these assignments. As a consequence, even though 2 shows a fairly strong and long-lived emission from a Ru( II) -> bpy CT state, the Ru( II) -> L CT state in 1 shows no detectable emission even at 80 K.

  • 42.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Jäger, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Kumar, Rohan J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Österman, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Persson, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Johansson, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond 3MLCT State Lifetimes: Sensitizers for Rod-Like Molecular Arrays2008In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 130, no 46, p. 15533-15542Article in journal (Refereed)
    Abstract [en]

    A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DFT calculations performed on the parent [Ru(dqp) 2](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)2](2+) (tpy is 2,2':6',2"-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((3)MLCT) state that has a very long lifetime (tau = 3 micros). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (3)MLCT state lifetime of 5.5 micros was demonstrated for the homoleptic complex based on dqpCO2Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics.

  • 43.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Jäger, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Österman, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Eriksson, Lars
    Persson, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Johansson, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    A 3.0 mu s room temperature excited state lifetime of a bistridentate Ru-II-polypyridine complex for rod-like molecular arrays2006In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 128, no 39, p. 12616-12617Article in journal (Refereed)
    Abstract [en]

    A bistridentate RuII-polypyridine complex [Ru(bqp)2]2+ (bqp = 2,6-bis(8'-quinolinyl)pyridine) has been prepared, which has a coordination geometry much closer to a perfect octahedron than the typical Ru(terpyridine)2-type complex. Thus, the complex displays a 3.0 mus lifetime of the lowest excited metal-to-ligand charge transfer (3MLCT) state at room temperature. This is, to the best of our knowledge, the longest MLCT state lifetime reported for a RuII-polypyridyl complex at room temperature. The structure allows for the future construction of rod-like, isomer-free molecular arrays by substitution of donor and acceptor moieties on the central pyridine units. This makes it a promising photosensitizer for applications in molecular devices for artificial photosynthesis and molecular electronics.

  • 44.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Lundqvist, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Wolpher, Henriette
    Johansson, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Eriksson, Lars
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Rasmussen, Torben
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Norrby, Per-Ola
    Åkermark, Björn
    Persson, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Steric influence on the excited-state lifetimes of ruthenium complexes with bipyridyl-alkanylene-pyridyl ligands.2008In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 47, no 9, p. 3540-3548Article in journal (Refereed)
    Abstract [en]

    The structural effect on the metal-to-ligand charge transfer (MLCT) excited-state lifetime has been investigated in bis-tridentate Ru(II)-polypyridyl complexes based on the terpyridine-like ligands [6-(2,2'-bipyridyl)](2-pyridyl)methane (1) and 2-[6-(2,2'-bipyridyl)]-2-(2-pyridyl)propane (2). A homoleptic ([Ru(2)(2)](2+)) and a heteroleptic complex ([Ru(ttpy)(2)](2+)) based on the new ligand 2 have been prepared and their photophysical and structural properties studied experimentally and theoretically and compared to the results for the previously reported [Ru(1)(2)](2+). The excited-state lifetime of the homoleptic Ru-II complex with the isopropylene-bridged ligand 2 was found to be 50 times shorter than that of the corresponding homoleptic Ru-II complex of ligand 1, containing a methylene bridge. A comparison of the ground-state geometries of the two homoleptic complexes shows that steric interactions involving the isopropylene bridges make the coordination to the central Ru-II ion less octahedral in [Ru(2)(2)](2+) than in [Ru(1)(2))(2+). Calculations indicate that the structural differences in these complexes influence their ligand field splittings as well as the relative stabilities of the triplet metal-to-ligand charge transfer ((MLCT)-M-3) and metal-centered ((MC)-M-3) excited states. The large difference in measured excited-state lifetimes for the two homoleptic Ru-II complexes is attributed to a strong influence of steric interactions on the ligand field strength, which in turn affects the activation barriers for thermal conversion from (MLCT)-M-3 states to short-lived (MC)-M-3 states.

  • 45.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Wolpher, Henriette
    Johansson, Olof
    Larsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Kritikos, Mikael
    Eriksson, Lars
    Norrby, Per-Ola
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Sun, Licheng
    Åkermark, Björn
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    A New Strategy for the Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes: Synthesis and Photophysical and Electrochemical Characterization of Six Mononuclear Ruthenium(II) Bisterpyridine-Type Complexes2005In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 9, p. 3215-3225Article in journal (Refereed)
  • 46.
    Abramsson, Mia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Biophysical Characterization of Hit Compounds against a Structurally Dynamic Protein for Drug Discovery2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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  • 47.
    Abramsson, Mia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Production and characterization of Acetylcholine Binding Protein2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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    fulltext
  • 48.
    Abramsson, Mia L.
    et al.
    Karolinska Inst, Dept Microbiol Tumor & Cell Biol, S-17165 Stockholm, Sweden..
    Sahin, Cagla
    Karolinska Inst, Dept Microbiol Tumor & Cell Biol, S-17165 Stockholm, Sweden.;Univ Copenhagen, Linderstrom Lang Ctr Prot Sci, Dept Biol, DK-2200 Copenhagen, Denmark.;OMass Therapeut, SchrOdinger Bldg,Oxford Sci Pk, Oxford OX4 4GE, England..
    Hopper, Jonathan T. S.
    Univ Oxford, Dept Chem, Oxford OX1 3QZ, England..
    Branca, Rui M. M.
    Sci Life Lab, Dept Oncol Pathol, S-17165 Stockholm, Sweden.;Karolinska Inst, S-17165 Stockholm, Sweden..
    Danielsson, Jens
    Stockholm Univ, Dept Biochem & Biophys, S-10691 Stockholm, Sweden..
    Xu, Mingming
    Stockholm Univ, Dept Biochem & Biophys, S-10691 Stockholm, Sweden..
    Chandler, Shane A.
    Univ Oxford, Dept Chem, Oxford OX1 3QZ, England..
    Osterlund, Nicklas
    Stockholm Univ, Dept Biochem & Biophys, S-10691 Stockholm, Sweden..
    Ilag, Leopold L.
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Leppert, Axel
    Karolinska Inst, Dept Biosci & Nutr, S-14183 Huddinge, Sweden..
    Costeira-Paulo, Joana
    Uppsala Univ, Dept Chem BMC, S-75123 Uppsala, Sweden..
    Lang, Lisa
    Stockholm Univ, Dept Biochem & Biophys, S-10691 Stockholm, Sweden..
    Teilum, Kaare
    Univ Copenhagen, Linderstrom Lang Ctr Prot Sci, Dept Biol, DK-2200 Copenhagen, Denmark..
    Laganowsky, Arthur
    Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA..
    Benesch, Justin L. P.
    Univ Oxford, Dept Chem, Oxford OX1 3QZ, England..
    Oliveberg, Mikael
    Stockholm Univ, Dept Biochem & Biophys, S-10691 Stockholm, Sweden..
    Robinson, Carol, V
    Univ Oxford, Dept Chem, Oxford OX1 3QZ, England..
    Marklund, Erik
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Allison, Timothy M.
    Univ Canterbury, Biomol Interact Ctr, Sch Phys & Chem Sci, Christchurch 8140, New Zealand..
    Winther, Jakob R.
    Univ Copenhagen, Linderstrom Lang Ctr Prot Sci, Dept Biol, DK-2200 Copenhagen, Denmark..
    Landreh, Michael
    Karolinska Inst, Dept Microbiol Tumor & Cell Biol, S-17165 Stockholm, Sweden..
    Charge Engineering Reveals the Roles of Ionizable Side Chains in Electrospray Ionization Mass Spectrometry2021In: JACS Au, E-ISSN 2691-3704, Vol. 1, no 12, p. 2385-2393Article in journal (Refereed)
    Abstract [en]

    In solution, the charge of a protein is intricately linked to its stability, but electrospray ionization distorts this connection, potentially limiting the ability of native mass spectrometry to inform about protein structure and dynamics. How the behavior of intact proteins in the gas phase depends on the presence and distribution of ionizable surface residues has been difficult to answer because multiple chargeable sites are present in virtually all proteins. Turning to protein engineering, we show that ionizable side chains are completely dispensable for charging under native conditions, but if present, they are preferential protonation sites. The absence of ionizable side chains results in identical charge state distributions under native-like and denaturing conditions, while coexisting conformers can be distinguished using ion mobility separation. An excess of ionizable side chains, on the other hand, effectively modulates protein ion stability. In fact, moving a single ionizable group can dramatically alter the gas-phase conformation of a protein ion. We conclude that although the sum of the charges is governed solely by Coulombic terms, their locations affect the stability of the protein in the gas phase.

  • 49.
    Abrashev, Miroslav V.
    et al.
    Univ Sofia St Kliment Ohridski, Fac Phys, Sofia 1164, Bulgaria.
    Chernev, Petko
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Kubella, Paul
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Mohammadi, Mohammad Reza
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany;Univ Sistan & Baluchestan, Dept Phys, Zahedan 9816745845, Iran.
    Pasquini, Chiara
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Dau, Holger
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Zaharieva, Ivelina
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Origin of the heat-induced improvement of catalytic activity and stability of MnOx electrocatalysts for water oxidation2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 28, p. 17022-17036Article in journal (Refereed)
    Abstract [en]

    Catalysis of the oxygen evolution reaction (OER) by earth-abundant materials in the near-neutral pH regime is of great interest as it is the key reaction for non-fossil fuel production. To address the pertinent stability problems and insufficiently understood structure-activity relations, we investigate the influence of moderate annealing (100-300 degrees C for 20 min) for two types of electrodeposited Mn oxide films with contrasting properties. Upon annealing, the originally inactive and structurally well-ordered Oxide 1 of birnessite type became as OER active as the non-heated Oxide 2, which has a highly disordered atomic structure. Oxide 2 also improved its activity upon heating, but more important is the stability improvement: the operation time increased by about two orders of magnitude (in 0.1 M KPi at pH 7). Aiming at atomistic understanding, electrochemical methods including quantitative analysis of impedance spectra, X-ray spectroscopy (XANES and EXAFS), and adapted optical spectroscopies (infrared, UV-vis and Raman) identified structure-reactivity relations. Oxide structures featuring both di-mu-oxo bridged Mn ions and (close to) linear mono-mu-oxo Mn3+-O-Mn4+ connectivity seem to be a prerequisite for OER activity. The latter motif likely stabilizes Mn3+ ions at higher potentials and promotes electron/hole hopping, a feature related to electrical conductivity and reflected in the strongly accelerated rates of Mn oxidation and O-2 formation. Poor charge mobility, which may result from a low level of Mn3+ ions at high potentials, likely promotes inactivation after prolonged operation. Oxide structures related to the perovskite-like zeta-Mn2O3 were formed after the heating of Oxide 2 and could favour stabilization of Mn ions in oxidation states lower than +4. This rare phase was previously found only at high pressure (20 GPa) and temperature (1200 degrees C) and this is the first report where it was stable under ambient conditions.

  • 50. Abu-samha, M.
    et al.
    Børve, K. J.
    Harnes, J.
    Bergersen, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    What Can C1s Photoelectron Spectroscopy Tell about Structure and Bonding in Clusters of Methanol and Methyl Chloride?2007In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 111, no 37, p. 8903-8909Article in journal (Refereed)
    Abstract [en]

    Single-component clusters of methanol and methyl chloride have been produced by adiabatic expansion, and their carbon Is photoelectron spectra were recorded using synchrotron radiation and a high-resolution electron analyzer. The experimental spectra are interpreted by means of theoretical models based on molecular dynamics simulations. The data are used to explore to what extent core-level photoelectron spectra may provide information on the bonding mechanism and the geometric structure of clusters of polar molecules. The results indicate that the cluster-to-monomer shift in ionization energy and also the width of the cluster peak may be used to distinguish between hydrogen bonding and weaker electrostatic interactions. Moreover, the larger width of the cluster peak in methanol clusters as compared to methyl chloride clusters is partly due to the structured surface of methanol clusters. Theoretical modeling greatly facilitates the analysis of core-level photoelectron spectra of molecular clusters.

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