uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 46) Show all publications
Calard, F., Wani, I. H., Hayat, A., Jarrosson, T., Lere-Porte, J.-P., Jafri, S. H., . . . Orthaber, A. (2017). Designing sterically demanding thiolate coated AuNPs for electrical characterization of BPDT in a NP-molecule-nanoelectrode platform. MOLECULAR SYSTEMS DESIGN & ENGINEERING, 2(2), 133-139.
Open this publication in new window or tab >>Designing sterically demanding thiolate coated AuNPs for electrical characterization of BPDT in a NP-molecule-nanoelectrode platform
Show others...
2017 (English)In: MOLECULAR SYSTEMS DESIGN & ENGINEERING, ISSN 2058-9689, Vol. 2, no 2, p. 133-139Article in journal (Refereed) Published
Abstract [en]

Molecular electronics with single or few molecules requires a stable metal-molecule nanojunction platform. Herein, we report the design and synthesis of gold nanoparticles coated with sterically demanding thiol ligands that are essential to fabricate a versatile and stable nanoelectrode-molecule-nanoparticle platform suitable for electrical characterization of small organic molecules. By combining.-tetraphenylmethane ether functionalized alkyl thioacetate and alkyl thiols, we prepared highly stable gold nanoparticles in a one-phase reaction providing simple and efficient purification. This robust preparation gives highly pure nanoparticles in very high yields (up to 90%) with long-time shelf stability. The synthesis in this work has superior reproducibility compared to previous synthesis processes that are currently being used for such molecular electronics platforms. Electron microscopy confirms the formation of uniform and small nanoparticles in the range of 5 to 7 nm. These nanoparticles with different ligand surface coverages were placed in a 20 nm nanoelectrode setup using dielectrophoretic forces. This setup was utilized to characterize the conductivity of the molecular wire 4,4'-biphenyldithiol introduced via ligand placeexchange under ambient conditions.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2017
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-323512 (URN)10.1039/c6me00095a (DOI)000400987200003 ()
Available from: 2017-06-14 Created: 2017-06-14 Last updated: 2017-06-14Bibliographically approved
Blunder, M., Orthaber, A., Bauer, R., Bucar, F. & Kunert, O. (2017). Efficient identification of flavones, flavanones and their glycosides in routine analysis via off-line combination of sensitive NMR and HPLC experiments. Food Chemistry, 218, 600-609.
Open this publication in new window or tab >>Efficient identification of flavones, flavanones and their glycosides in routine analysis via off-line combination of sensitive NMR and HPLC experiments
Show others...
2017 (English)In: Food Chemistry, ISSN 0308-8146, E-ISSN 1873-7072, Vol. 218, p. 600-609Article in journal (Refereed) Published
Abstract [en]

We present a standardized, straightforward and efficient approach applicable in routine analysis of flavonoids combining sensitive NMR and HPLC experiments. The determination of the relative configuration of sugar moieties usually requires the acquisition of 13C NMR shift values. We use a combination of HPLC and sensitive NMR experiments (1D-proton, 2D-HSQC) for the unique identification of known flavones, flavanones, flavonols and their glycosides. Owing to their broad range of polarity, we developed HPLC and UHPLC methods (H2O/MeOH/MeCN/HCOOH) which we applied and validated by analyzing 46 common flavones and flavanones and exemplified for four plant extracts. A searchable data base is provided with full data comprising complete proton and carbon resonance assignments, expansions of HSQC-spectra, HPLC parameters (retention time, relative retention factor), UV/Vis and mass spectral data of all compounds, which enables a rapid identification and routine analysis of flavones and flavanones from plant extracts and other products in nutrition and food chemistry.

Keyword
NMR, Flavones, Flavanones, HPLC, MS, Data base
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-306576 (URN)10.1016/j.foodchem.2016.09.077 (DOI)000386409700078 ()27719955 (PubMedID)
Available from: 2016-10-28 Created: 2016-10-28 Last updated: 2017-12-28Bibliographically approved
Morales Salazar, D., Mijangos, E., Pullen, S., Gao, M. & Orthaber, A. (2017). Functional small-molecules & polymers containing P[double bond, length as m-dash]C and As[double bond, length as m-dash]C bonds as hybrid π-conjugated materials. Chemical Communications, 53(6), 1120-1123.
Open this publication in new window or tab >>Functional small-molecules & polymers containing P[double bond, length as m-dash]C and As[double bond, length as m-dash]C bonds as hybrid π-conjugated materials
Show others...
2017 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 6, p. 1120-1123Article in journal (Refereed) Published
Abstract [en]

Stable phospha- and arsaalkenes were used to synthesize polymers containing unsaturated P[double bond, length as m-dash]C and As[double bond, length as m-dash]C moieties. The composition, chemical environment, structure, optical, and electronic properties of the monomers and polymers were elucidated. The incorporation of the heteroatom-carbon double bonded units efficiently perturbs the optoelectronics and solid state features of both monomeric and polymeric scaffolds. Proof-of principle work supports their responsive character through post-functionalisation and electrochromic behaviour. To the best of our knowledge, this is the first example of a polymer containing arsenic-carbon double bonds.

National Category
Organic Chemistry Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-312610 (URN)10.1039/c6cc08736a (DOI)000393978300026 ()28054056 (PubMedID)
Funder
Lars Hierta Memorial FoundationStiftelsen Olle Engkvist ByggmästareSwedish Research Council, 2013-4763
Available from: 2017-01-12 Created: 2017-01-12 Last updated: 2017-11-29Bibliographically approved
Xiong, R., Bornhof, A.-B., Arkhypchuk, A., Orthaber, A. & Borbas, E. (2017). Furan- and Thiophene-Based Auxochromes Red-shift Chlorin Absorptions and Enable Oxidative Chlorin Polymerizations. Chemistry - A European Journal, 23(17), 4089-4095.
Open this publication in new window or tab >>Furan- and Thiophene-Based Auxochromes Red-shift Chlorin Absorptions and Enable Oxidative Chlorin Polymerizations
Show others...
2017 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, no 17, p. 4089-4095Article in journal (Refereed) Published
Abstract [en]

The de novo syntheses of chemically stable chlorins with five-membered heterocyclic (furane, thiophene, formylfurane and formylthiophene) substituents in selected meso- and beta-positions are reported. Heterocycle incorporation in the 3- and 13-positions shifted the chlorin absorption and emission to the red (up to lambdaem =680 nm), thus these readily incorporated substituents function analogously to auxochromes present in chlorophylls, for example, formyl and vinyl groups. Photophysical, theoretical and X-ray crystallographic experiments revealed small but significant differences between the behavior of the furan- and the thiophene-based auxochromes. Four regioisomeric bis-thienylchlorins (3,10; 3,13, 3,15 and 10,15) were oxidatively electropolymerized; the chlorin monomer geometry had a profound impact on the polymerization efficiency and the electrochemical properties of the resulting material. Chemical co-polymerization of 3,13-bis-thienylchlorin with 3-hexylthiophene yielded an organic-soluble red-emitting polymer.

Keyword
chlorins, electrochemistry, photophysics, polymerization, porphyrinoids
National Category
Organic Chemistry
Research subject
Chemistry with specialization in Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-317978 (URN)10.1002/chem.201604655 (DOI)000399312700011 ()27859811 (PubMedID)
Funder
Stiftelsen Olle Engkvist ByggmästareSwedish Research Council, 2013-4655Swedish Research Council, 2013-4763
Available from: 2017-03-22 Created: 2017-03-22 Last updated: 2017-12-28Bibliographically approved
Gupta, A. K., Akkarasamiyo, S. & Orthaber, A. (2017). Rich Coordination Chemistry of pi-Acceptor Dibenzoarsole Ligands. Inorganic Chemistry, 56(8), 4504-4511.
Open this publication in new window or tab >>Rich Coordination Chemistry of pi-Acceptor Dibenzoarsole Ligands
2017 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 8, p. 4504-4511Article in journal (Refereed) Published
Abstract [en]

A series of dibenzoarsole (also known as 9-arsafluorene) derivatives have been prepared, and their coordination chemistry has been investigated. The different ligand topology and the arsenic substituents govern the reactivity of the ligands. We report various crystal structures of palladium and platinum complexes derived from this family of ligands. The biphenyl backbone of the bridged bidentate ligands allows very flexible coordination. We have also studied the application of an allylic Pd complex in nucleophilic substitution reactions, revealing that the benzoarsole substituent is susceptible to metal insertion.

National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-322810 (URN)10.1021/acs.inorgchem.7b00100 (DOI)000399625600030 ()28345894 (PubMedID)
Available from: 2017-06-08 Created: 2017-06-08 Last updated: 2017-06-08Bibliographically approved
El Nahhas, A., Shameem, M. A., Chabera, P., Uhlig, J. & Orthaber, A. (2017). Synthesis and Characterization of Cyclopentadithiophene Heterofulvenes: Design Tools for Light-Activated Processes. Chemistry - A European Journal, 23(24), 5673-5677.
Open this publication in new window or tab >>Synthesis and Characterization of Cyclopentadithiophene Heterofulvenes: Design Tools for Light-Activated Processes
Show others...
2017 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, no 24, p. 5673-5677Article in journal (Refereed) Published
Abstract [en]

The development of new materials for solar-to-energy conversion should consider stability, ease of fabrication, and beneficial photophysical properties. In this context, a set of novel -conjugated building blocks, with phospha- and arsaalkenes possessing a unique dithienyl annulated heterofulvenoid core, have been prepared as air- and moisture-stable sensitizers. These compounds unify electron-donor and -acceptor moieties, making them potential candidates for light-harvesting applications. Optical characterization of these systems was performed by steady-state and time-resolved absorption spectroscopy, supported by time-dependent DFT calculations. Tuning of the optical properties of these systems can be achieved by varying the pnictogen element at the bridgehead position, giving a bathochromic shift of approximate to 40nm and coordinating the phosphaalkene towards gold Au-I centers. The latter results in a approximate to 2000-fold extension of the approximate to 10ps lifetime of uncoordinated systems well into the ns regime.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2017
Keyword
arsaalkene, electrochemistry, main group elements, phosphaalkene, pnictogens, time-resolved spectroscopy
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-322721 (URN)10.1002/chem.201700917 (DOI)000400044400006 ()28248442 (PubMedID)
Funder
Swedish Research Council, 2013-4763Knut and Alice Wallenberg FoundationÅForsk (Ångpanneföreningen's Foundation for Research and Development)
Available from: 2017-05-29 Created: 2017-05-29 Last updated: 2017-05-29Bibliographically approved
Arkhypchuk, A. I., Orthaber, A. & Borbas, K. E. (2017). Synthesis and Characterization of Ferrocenyl Chlorins, 1,1'-Ferrocene-Linked Chlorin Dimers, and their BODIPY Analogues. Inorganic Chemistry, 56(5), 3044-3054.
Open this publication in new window or tab >>Synthesis and Characterization of Ferrocenyl Chlorins, 1,1'-Ferrocene-Linked Chlorin Dimers, and their BODIPY Analogues
2017 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 5, p. 3044-3054Article in journal (Refereed) Published
Abstract [en]

We present the synthesis and characterization of meso-ferrocenyl-substituted hydroporphyrins (chlorins) and 1,1' -linked chlorin dimers. The dipyrromethane chlorin precursors were also transformed into Fc-substituted BODIPYs and 1,1'-ferrocenyl-linked BODIPY dimers. The chlorin dimers were studied by 1D and 2D NMR experiments and DFT calculations, which showed that their solution structures were dependent on the central metal. Monomeric and dimeric Ni(II) chlorins had similar H-1 NMR spectra. Monomeric and dimeric free base, Zn(II), and Pd(II) chlorins, on the other hand, showed significantly more different spectra. The eclipsed conformer of the free base chlorin dimer was calculated to be energetically more favored than the open form. The chlorin and BODIPY fluorescence emissions were quenched in the Fcsubstituted compounds; these could be recovered by oxidation of the Fe(II) center. Cyclic voltammetry showed up to five oxidation waves for the free base chlorin dimer, which suggests that the macrocycles were not behaving independently of each other.

National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-320661 (URN)10.1021/acs.inorgchem.6b03158 (DOI)000395847300076 ()28186734 (PubMedID)
Funder
Swedish Research Council, 2013-4655Stiftelsen Olle Engkvist Byggmästare
Available from: 2017-06-30 Created: 2017-06-30 Last updated: 2017-06-30Bibliographically approved
Xiong, R., Arkhypchuk, A. I., Kovacs, D., Orthaber, A. & Borbas, K. E. (2016). Directly linked hydroporphyrin dimers. Chemical Communications, 52(58), 9056-9058.
Open this publication in new window or tab >>Directly linked hydroporphyrin dimers
Show others...
2016 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 52, no 58, p. 9056-9058Article in journal (Refereed) Published
Abstract [en]

Directly linked hydroporphyrin (chlorin) dimers were accessed regioselectively from bromochlorins. Versatile 15-borylated chlorins were prepared in excellent yield via Miyaura borylation. Suzuki coupling yielded meso-beta-linked homo- and heterodimers, and meso-blinked dimers. The photophysical and electrochemical properties of the dimers are reported.

National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:uu:diva-300581 (URN)10.1039/c6cc00516k (DOI)000379431000018 ()26859412 (PubMedID)
Funder
Swedish Research Council, 2013-4655Stiftelsen Olle Engkvist Byggmästare
Available from: 2016-08-09 Created: 2016-08-09 Last updated: 2017-11-28Bibliographically approved
Das, B., Orthaber, A., Ott, S. & Thapper, A. (2016). Iron Pentapyridyl Complexes as Molecular WaterOxidation Catalysts: Strong Influence of a Chloride Ligandand pH in Altering the Mechanism. ChemSusChem, 9(10), 1178-1186.
Open this publication in new window or tab >>Iron Pentapyridyl Complexes as Molecular WaterOxidation Catalysts: Strong Influence of a Chloride Ligandand pH in Altering the Mechanism
2016 (English)In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 9, no 10, p. 1178-1186Article in journal (Refereed) Published
Abstract [en]

The development of molecular water oxidation catalysts basedon earth-abundant, non-noble metals is essential for artificial photosynthesis research. Iron, which is the most abundant transition metal in the earth's crust, is a prospective candidate for this purpose. Herein, we report two iron complexes based on the polypyridyl ligand Py5OH (Py5OH=pyridine-2,6-diylbis[di(pyridin-2-yl)methanol]) that can catalyse water oxidation to produce O2 in RuIII-induced (at pH 8, highest turnover number (TON)=26.5; turnover frequency (TOF)=2.2 s-1), CeIV-induced(at pH 1.5 highest TON=16; TOF=0.75 s-1) and photo-induced(at pH 8, highest TON=43.5; TOF=0.6 s-1) reactions. A chloride ligand in one of the iron complexes is shown to affect the activity strongly, improve stability and, thereby, the performance at pH 8 but it inhibits oxygen evolution at pH 1.5. The observations are consistent with a change in mechanism for catalytic water oxidation with the Fe(Py5OH) complexes between acidic (CeIV) and near-neutral pH (RuIII).

Keyword
homogeneous catalysis, iron, oxidation, reaction mechanisms, water splitting
National Category
Inorganic Chemistry
Research subject
Chemistry with specialization in Molecular Biomimetics
Identifiers
urn:nbn:se:uu:diva-292976 (URN)10.1002/cssc.201600052 (DOI)000378635500016 ()27114078 (PubMedID)
Funder
Knut and Alice Wallenberg Foundation, 2011.0067Swedish Energy Agency, 11674-5Swedish Research Council
Available from: 2016-05-11 Created: 2016-05-11 Last updated: 2017-11-30Bibliographically approved
Esfandiarfard, K., Arkhypchuk, A. I., Orthaber, A. & Ott, S. (2016). Synthesis of the first metal-free phosphanylphosphonate and its use in the "phospha-Wittig-Horner" reaction. Dalton Transactions, 45(5), 2201-2207.
Open this publication in new window or tab >>Synthesis of the first metal-free phosphanylphosphonate and its use in the "phospha-Wittig-Horner" reaction
2016 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 45, no 5, p. 2201-2207Article in journal (Refereed) Published
Abstract [en]

The synthesis of the first phophanylphosphonate, Mes*PH-PO(OEt)(2) (2-H), in which the P(III) centre is not coordinated by a M(CO)(5) (M = W, Mo, Cr) fragment is reported. The title compound reacts with LDA under the formation of 2-Li which is best described as the enolate form with a high double bond character between the two phosphorus centres. 2-Li is shown to engage in the phospha-Wittig-Horner reaction and converts aldehydes into phosphaalkenes that are metal-free and thus available for future manipulations at the phophorus lone pair. Using a selection of aldehydes with aliphatic, aromatic or vinylic substituents as substrates, phosphaalkene formation proceeds in high yields and high E-selectivity. The selectivity is however compromised during purification on standard silica which was found to promote E/Z isomerization.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-280913 (URN)10.1039/c5dt03686k (DOI)000369413700046 ()26574885 (PubMedID)
Funder
Swedish Research Council
Available from: 2016-03-16 Created: 2016-03-16 Last updated: 2017-11-30Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5403-9902

Search in DiVA

Show all publications