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  • 1.
    Alexander, James N.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Novel detection schemes and high resolution separations in microcolumn liquid separations1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Three micro detectors were developed and studied using micro-liquidchromatography (micro-LC). An evaporative light scattering detector (ELSD) nebulizer was developed for use with flow rates ranging from 0.5 to 10 µL/min. The parameters that affect analyte response were investigated and the most influential were capillary tip position and nebulization gas flow rate. One unique advantage of thismicro detector is that it can be operated at ambient conditions which allows for the analysis of semi-volatile compounds.

    A radio activity monitor (RAM) flow cell was developed for use at 3 µL/min and was designed for coupling to mass spectrometry (MS). The parameters that affect analyte response and band broadening were studied. Reducing the solid scintillant particle size to 9 µm and efficiently packing the solid cells allowed for direct coupling to MS without compromising the chromatographic separation.

    A nano-electrospray ionization (BSI) source for MS was developed and coupled to nano-LC and capillary electrophoresis (CE). This source incorporated a 50 µm i.d. stainless steel tip that was coupled to the separation capillary. At flow rates of 100 nL/min a stable electrospray was achieved.

    A multi-use separations system was developed for isocratic and gradient elution micro-LC, capillary electrochromatography (CEC), and pressure CEC (PEC). The details of the system and studies on peak area and retention time repeatability are reported. Comparisons are made between nano-LC and CEC. On average, column efficiency is 57% greater for CEC compared to nano-LC using the same nanocolumn.

  • 2.
    Alexander, JN
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Poli, JB
    Markides, KE
    Evaluation of automated isocratic and gradient nano-liquid chromatography and capillary electrochromatography1999In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 71, no 13, p. 2398-2409Article in journal (Refereed)
    Abstract [en]

    An automated liquid nano-separation system has been developed for nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) using both isocratic and gradient elution, One fused-silica nanocolumn, typically 75 mu m i x 39 cm (25 cm ef

  • 3.
    Alfredsson, Maria
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Polar molecules in crystalline and surface environments: From first principles1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With the knowledge of the composition and structure of a chemical system, be it a molecule, a two-dimensional surface or a three-dimensional crystal, it is now possible to predict the specific properties of the compound under consideration via computational studies. Molecular and periodic Hartree-Fock and DFT calculations have been used as a tool to study polar molecules and how their properties respond to the molecular environment in a crystal or on an ionic surface. The investigation covers a range of molecules (HF, HC1, HCN, H2O, OH-, OH., N2, CO and LiF) with different net charges, dipole moments and polarisibility, and a range of crystals and crystalline surfaces: hydrogen-bonded, ionic and ferroelectric.

    The step-wise build up of the molecular properties (geometries, energies, dipole moments, vibrational frequencies etc.) has been investigated. It was found that sorne molecular properties converge quickly towards the crystal value, others more slowly. Molecules adsorbed on a solid surface were studied as a function of adsorptionenergy, substrate and surface coverage. For the ionic surfaces studied here it was found that the properties of the chemi- and physisorbed molecules are as sensitive to the surface coverage as to the adsorption of the ad-molecule to the surface. The vibrational frequency shift of the ad-molecule has been given special attention.

    Finally the spontaneous polarisation in two ferroelectric crystals was calculated within the Berry-phase approach.

  • 4. Alonso, D A
    et al.
    Bertilsson, S K
    Johnsson, S Y
    Nordin, S J M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Organic Chemistry.
    Södergren, M J
    Andersson, Pher G
    New Expidient Route to Both Enantiomers of Nonproteinogenic Amino Acid Derivatives from the Unsaturated 2-Aza-bicyclo Moiety. D. A1999In: J. Org. Chem., Vol. 64, p. 2276-Article in journal (Refereed)
  • 5. Alonso, D A
    et al.
    Nordin, S J M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Organic Chemistry.
    Andersson, Pher G
    Highly Diastereoselective Reaction of 2-Azanorbornyl Enolates with Electrophiles. D. A1999In: Org. Lett., Vol. 1, p. 1595-Article in journal (Refereed)
  • 6. Alonso, D A
    et al.
    Nordin, S J M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Organic Chemistry.
    Roth, P
    Tarnai, T
    Thommen, M
    Pittelkow, U
    Andersson, Pher G
    2-Azanorbornyl alcohols: Very efficient Ligands for Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation of Aromatic Ketones. D. A1999In: J. Org. Chem., Vol. 65, p. 3116-Article in journal (Refereed)
  • 7.
    Alonso, DA
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nordin, SJM
    Andersson, PG
    Highly diastereoselective reaction of 2-azanorbornyl enolates with electrophiles1999In: ORGANIC LETTERS, ISSN 1523-7060, Vol. 1, no 10, p. 1595-1597Article in journal (Refereed)
    Abstract [en]

    A highly diastereoselective reaction of 2-azanorbornyl enolates with electrophiles has been studied. Deprotonation of 4 with LDA at low temperature affords the corresponding exocyclic lithium enolate 5, which reacts with different electrophiles such as al

  • 8.
    Alonso, Diego A
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Brandt, P
    Nordin, Sofia J M
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Andersson, Pher G
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Ru(arene)(amino alcohol)-Catalyzed Transfer Hydrogenation of Ketones: Mechanism and Origin of Enantioselectivity1999In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 121, no 41, p. 9580-9588Article in journal (Refereed)
    Abstract [en]

    The mechanism of the Ru(arene)(amino alcohol)-catalyzed transfer hydrogenation of ketones using isopropyl alcohol as the hydrogen source has been studied by means of hybrid density functional methods (B3PW91). Three mechanistic alternatives were evaluated, and it was shown that the reaction takes place via a six-membered transition state, where a metal-bound hydride and a proton of a coordinated amine are transferred simultaneously to the ketone. Further calculations provided a general rationale for the rate of the reaction by comparison of steric effects in the ground and transition states of the ruthenium hydride complex. It was found that the TS has a strong preference for planarity, and this in turn is dependent on the conformational behavior of the O,N-linkage of the amino alcohol ligand. Finally, a general model, rationalizing the enantioselectivity of the reaction, was developed. Experimental studies of both rate and enantioselectivity were used in order to support the computational results.

  • 9. Alonso, Diego
    et al.
    Bertilsson, Sophie
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Johnsson, Sandra
    Nordin, Sofia
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Södergren, Mikael
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    New Expedient Route to Both Enantiomers of Nonproteinogenic a-Amino Acid Derivatives from the Unsaturated 2-Aza-Bicyclo Moiety1999In: J. Org. Chem., no 64, p. 2276-2280Article in journal (Refereed)
  • 10. Alonso, Diego
    et al.
    Brandt, Peter
    Nordin, Sofia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Andersson, Pher
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Ru(arene)(amino alcohol)-Catalyzed Transfer Hydrogenation of Ketones: Mechanism and Origin of Enantioselectivity1999In: J. Am. Chem. Soc., no 121, p. 9580-9588Article in journal (Refereed)
    Abstract
  • 11. Barnidge, David
    et al.
    Nilsson, Stefan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, Karin
    A design for low-flow sheathless electrospray emitters1999In: Analytical Chemistry, ISSN 0003-2700, Vol. 71, no 19, p. 4115-4118Article in journal (Refereed)
  • 12. Barnidge, David
    et al.
    Nilsson, Stefan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Rapp, Håkan
    Hjort, Klas
    Markides, Karin
    Metallized sheathless electrospray emitters for use in capillary electrophoresis orthogonal time-of-flight mass spectrometry1999In: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, Vol. 13, no 11, p. 994-1002Article in journal (Refereed)
  • 13.
    Barnidge, DR
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nilsson, S
    Markides, KE
    A design for low-flow sheathless electrospray emitters1999In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 71, no 19, p. 4115-4118Article in journal (Refereed)
    Abstract [en]

    An extremely simple design has been developed for producing durable sheathless electrospray emitters that give highly stable electrospray for unlimited lifetimes. The emitters can be fashioned from any style fused-silica capillary and are ideally suited

  • 14.
    Barnidge, DR
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nilsson, S
    Markides, KE
    Rapp, H
    Hjort, K
    Metallized sheathless electrospray emitters for use in capillary electrophoresis orthogonal time-of-flight mass spectrometry1999In: RAPID COMMUNICATIONS IN MASS SPECTROMETRY, ISSN 0951-4198, Vol. 13, no 11, p. 994-1002Article in journal (Refereed)
    Abstract [en]

    Chromiun-gold coated fused silica emitters for electrospray ionization have been fabricated with lifetimes upwards of 100 hours. The coating on these emitters is extremely durable withstanding electrical discharges, abrasion and mechanical stress, Usable

  • 15.
    Berg, Helena
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    The rational design of lithium insertion materials for battery applications1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The transition-metal oxide spine1 LiMn2O4 is a promising cathode material for high-capacity lithium-ion batteries. Structure-property relationships pertaining to the electrochemical cycling behaviour of LiMn2O4 have been studied. The techniques exploited have been in situ X-ray and neutron diffraction, in combination with quantum-mechanical band-structure calculations. The results obtained lay the ground for an improved basis for designing new insertion materials.

    Substitution of Mn by Ni in LiMn2O4 and by Li in Li1+xMn2-xO4 give qualitatively different results: Ni is found to replace Mn directly, while Li takes up entirely new sites not observed earlier. Band-structure calculations have been used to better understand the crystallographically observed x-dependence of the Li1+xMn2-xO4 structure, and the underlying mechanisms of lithium-ion extraction/insertion.

    Quantitative observation of charge passed through the cell has also been related to the amount of lithium extracted to indicate possible sources of irreversible capacity loss, and how synthesis technique can influence cell performance.

    The LiMn2O4 structure has also been studied by neutron diffraction after treatment in strong-acid solutions, where Li ® H ion-exchange has been observed to take place. This process has strong implications for the dissolution of Mn2+ ions from the cathode into the electrolyte, especially at elevated temperatures, and the related corrosion process occurring at the cathode surface.

  • 16. Berglof, T
    et al.
    Jonsall, G
    Markides, KE
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Selectivity in supercritical fluid extraction: Recovery of pesticides from model matrices1999In: JOURNAL OF CHROMATOGRAPHIC SCIENCE, ISSN 0021-9665, Vol. 37, no 10, p. 400-406Article in journal (Refereed)
  • 17.
    Bertilsson, Sophie
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Tedenborg, Lars
    Alonso, Diego
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Chiral N, N' - and N,O-Bidentate Anionic Ligands. Preparation, Metal Complexation, and Evalution in the Asymmetric Aziridination of Olefins1999In: Organometallics, no 18, p. 1281-1286Article in journal (Refereed)
  • 18.
    Bjorefors, F
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Gadomska, J
    Donten, M
    Nyholm, L
    Stojek, Z
    Influence of mixed diffusional, migrational, and convective mass transport on the response of a wall-tube microelectrode in a flow injection system1999In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 71, no 21, p. 4926-4931Article in journal (Refereed)
    Abstract [en]

    The current response of a 10-mu m walt-tube microelectrode in a now injection system under the conditions of low ionic strength has been examined experimentally for several redox systems such as ferrocene in methanol, undiluted methanol, and water in ace

  • 19.
    Bjorefors, F
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nyholm, L
    Donten, M
    Stojek, Z
    Amperometric determination of the water content in acetone, butter and margarine using a wall-tube platinum microelectrode in a flow injection system1999In: ANALYST, ISSN 0003-2654, Vol. 124, no 2, p. 143-146Article in journal (Refereed)
    Abstract [en]

    Amperometric determinations of the water content in acetone, butter and margarine were performed using a wall-tube platinum microelectrode in combination with a flow injection system. For the butter and margarine samples, acetone containing small amounts

  • 20.
    Björefors, Fredrik
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Fundamental investigations and applications of microelectrode based detections in flowing solutions1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The influence of diffusional, migrational and convective mass transport at microelectrodes employed for voltammetric and amperometric detection in flowing solutions has been investigated. Special attention was paid to the influence of convection on the IR drop in organic solvents and on the transport of reaction products between individual electrode bands of microarray electrodes. A flow injection system was also designed to study the stability of mercury films coated on microelectrodes for the purpose of stripping analysis.

    Increased influence of convection, obtained by altering the flow rate or by changing the position of the microelectrode in a wall-tube flow cell, at low support ratios in organic solvents was found to result in decreased currents as a consequence of the inability to maintain a sufficient amount of ions at the vicinity of the microelectrode surface. Successful determinations of the water content in butter and margarine could be performed in an acetone based flow injection system, provided that the detection potential was chosen to accommodate the different support ratios in the injected solutions.

    The degree of redox cycling at interdigitated microarray electrodes was found to increase if the flow rate was reduced from 20 to 2 µl/min. Even at these low flow rates, the degree of redox cycling in stationary solutions was, however, always larger compared to the values obtained under the influence of convection. A microarray electrode was also employed to improve the selectivity in the detection of poorly separated species in capillary electrophoresis.

    By employing a flow injection system, it was found that the stability of mercury films plated on platinum and carbon fibre microelectrodes could be improved as potential control could be maintained during solution exchange and between individual experiments. Stripping voltammetric determinations of nickel at nM concentrations and of copper in a low ionic strength solution was demonstrated in the flow injection system.

  • 21. Brandt, Peter
    et al.
    Hedberg, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Lawonn, Klaus
    Pinho, Pedro
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Andersson, Pher
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    A Theoretical and Experimental Study of the Asymmetric Addition of Dialkylzinc to N-(Diphenylphosphinoyl)benzalimine1999In: Chem. Eur. J., no 5, p. 1692-1699Article in journal (Refereed)
    Abstract
  • 22. Brandt, Peter
    et al.
    Hedberg, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lawonn, Klaus
    Pinho, Pedro
    Andersson, Pher G.
    A Theoretical and Experimental Study of the Asymmetric Addition of Dialkylzinc to N-(diphenylphosphinoyl)benzalimine1999In: Chemistry-A European Journal, ISSN 0947-6539, Vol. 5, no 6, p. 1692-1699Article in journal (Refereed)
    Abstract
  • 23.
    El-Seedi, Hesham R
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Gohil, Suresh
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Perera, Premila
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Torssell, Kurt B G
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Bohlin, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Cyclopeptide alkaloids from Heisteria nitida1999In: Phytochemistry, ISSN 0031-9422, E-ISSN 1873-3700, Vol. 52, no 8, p. 1739-1744Article in journal (Refereed)
  • 24.
    Eriksson, A
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nyholm, L
    A comparison of the electrochemical properties of some azosalicylic acids at glassy carbon electrodes by cyclic and hydrodynamic voltammetry1999In: ELECTROCHIMICA ACTA, ISSN 0013-4686, Vol. 44, no 23, p. 4029-4040Article in journal (Refereed)
    Abstract [en]

    The electrochemical properties of a number of azosalicylic acid derivatives have been compared at glassy carbon electrodes using cyclic and hydrodynamic voltammetry. The reduction of all studied compounds, except one, was found to be irreversible giving

  • 25. Forngren, Benita H
    et al.
    Samskog, Jenny
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Analytical Chemistry.
    Gustavsson, Sven Åke
    Tyrefors, Niklas
    Markides, Karin E
    Långström, Bengt
    Reversed-phase ion-pair chromatography coupled to electrospray ionisation mass spectrometry by on-line removal of the counter-ions1999In: J Chromatogr A, Vol. 854, no 1-2, p. 155-162Article in journal (Refereed)
  • 26.
    Forngren, BH
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Samskog, J
    Gustavsson, SA
    Tyrefors, N
    Markides, KE
    Langstrom, B
    Reversed-phase ion-pair chromatography coupled to electrospray ionisation mass spectrometry by on-line removal of the counter-ions1999In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 854, no 1-2, p. 155-162Article in journal (Refereed)
    Abstract [en]

    A strong anion-exchanger was used as a trapping column to perform on-line coupling of ion-pair chromatography with electrospray ionisation mass spectrometry. Ion-pairing reagents were used to retain polar analytes of low molecular mass away from the solv

  • 27.
    Göransson, Kenneth
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Structure and stability trends in the platinum metal-silicon systems1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The stability of group 8-10 silicides has been studied by LMTO-ASA band structurecalculations. In the Rh-Si and Ir-Si systems the lowest calculated heat of formation isfound in compounds near the equiatomic composition. Model calculations forsuperstructures in bcc and fcc solid solutions show that in group 8 and 9 silicides thebcc based structures have a maximum in stability near 50% Si. In group 10 systemsthe energy minimum is shifted to lower Si contents and the minimum is less clearlydeveloped.

    The heats of formation in monosilicides are predicted to have a minimum for metalatoms from group 9.

    Calculated one electron densities of states are in good agreement with spectroscopicmeasurements and confirm the generally accepted picture of silicide stability. Themain stabilising factor is metal d - silicon p bonding. With increasing Si contents or group number of the metal atoms dp antibonding states become increasingly filled. A stabilising effect in the highest occupied states is metal-silicon pp interactions and insilicon rich compounds also silicon-silicon pp interactions.

  • 28.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Molecules in crystals - What makes them different?1999In: IMPLICATIONS OF MOLECULAR AND MATERIALS STRUCTURE FOR NEW TECHNOLOGIES, 1999, p. 101-117Conference paper (Refereed)
  • 29.
    Hyllbrant, B
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Tyrefors, N
    Langstrom, B
    Markides, KE
    Packed capillary column liquid chromatography coupled to mass spectrometry by a simple modification of an electrospray interface1999In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 11, no 5, p. 353-358Article in journal (Refereed)
    Abstract [en]

    When packed capillary columns are coupled to electrospray mass spectrometry, care must be taken to reduce the dead volumes of the detector connections. In this work, the coupling between the column and the detector was made with a 20-mu m i fused silica

  • 30.
    Hyllbrant, B
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Tyrefors, N
    Markides, KE
    Langstrom, B
    On the use of liquid chromatography with radio- and ultraviolet absorbance detection coupled to mass spectrometry for improved sensitivity and selectivity in determination of specific radioactivity of radiopharmaceuticaIs1999In: JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS, ISSN 0731-7085, Vol. 20, no 3, p. 493-501Article in journal (Refereed)
    Abstract [en]

    Pneumatically assisted electrospray mass spectrometry was evaluated as a complementary detection technique to UV absorbance, for determination of specific radioactivity of tracer molecules to be used in positron emission tomography. Tracers labelled with

  • 31.
    Johannesson, Petra
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Lindeberg, Gunnar
    Tong, Weimin
    Gogoll, Adolf
    Karlen, Anders
    Hallberg, Anders
    A flexible regioselective method for bicyclization of peptides.1999In: Peptides for the New Millennium, Proceedings of the American Peptide Symposium, 16th, Minneapolis, MN, United States, 1999, p. 153-154Conference paper (Other scientific)
  • 32.
    Juvancz, Z
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Jicsinszky, L
    Chiral analysis of metoprolol and its by-products by capillary electrophoresis1999In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 11, no 10, p. 716-722Article in journal (Refereed)
    Abstract [en]

    The enantiomers of metoprolol, a frequently used beta-blocker, have different physiological effects, which makes their chiral separation necessary. The separation of the main product from its by-products and their chiral separation were also aims of this

  • 33.
    Langstrom, B
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Kihlberg, T
    Bergstrom, M
    Antoni, Gunnar
    Bjorkman, M
    Forngren, BH
    Forngren, T
    Hartvig, P
    Markides, K
    Yngve, U
    Ogren, M
    Compounds labelled with short-lived beta(+)-emitting radionuclides and some applications in life sciences. The importance of time as a parameter1999In: ACTA CHEMICA SCANDINAVICA, ISSN 0904-213X, Vol. 53, no 9, p. 651-669Article in journal (Refereed)
    Abstract [en]

    Some examples of recent development of the synthesis of compounds labelled with short-lived beta(+)-emitting radionuclides will be discussed with an emphasis on the importance of time in selecting a synthetic strategy. Furthermore the use of such labelle

  • 34.
    Liu, Hui-Ping
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Magnetic ordering and crystal structure in selected transition- metal compounds1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Applications of magnetic materials are inherently related to their crystal, magnetic and electronic structures. In this thesis, experimental and theoretical methods have been focused on magnetic bulk materials from novel chemical synthesis, to X-ray diffraction for initial phase characterisation, and crystal and magnetic structure studies to explain their complex magnetic properties. A selection of materials was studied, ranging from 3d transition-metal phosphides to rare-earth transition-metal intermetallics. Several techniques (including X-ray and neutron diffraction, magnetisation measurements,Mössbauer spectroscopy and first principles, electronic structure calculations) were combined to obtain a unified picture.

    In the (Fe1-xCox)3P compounds (x<0.37), a dependence of structure and ferromagnetic properties on Co concentration was demonstrated. The situation for the (Fe1-xMnx)3P system is more complex and has been studied at both ends of the composition range. At the Fe-rich end (x<0.25), the compounds exhibit ferromagnetic ordering, while at the Mn-rich end (x≥0.67), an antiferromagnetic coupling was discovered. The majority of the experimental results are supported by theoretical calculations.

    Magnetic ordering in the TbNi5-xCux system was determined, starting with the incommensurate modulated helimagnetic structure for the binary compound TbNi5, and going over to the collinear ferromagnetic structure for the Cu-substituted pseudo-binary system.

    The phase stability investigation of CePt2Sn2 was made using in situ X-ray powder diffraction with respect to tetragonal and monoclinic modifications. The crystal structures were determined by the Rietveld refinement method.

  • 35.
    Matysik, FM
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Bjorefors, F
    Nyholm, L
    Application of microband array electrodes for end-column electrochemical detection in capillary electrophoresis1999In: ANALYTICA CHIMICA ACTA, ISSN 0003-2670, Vol. 385, no 1-3, p. 409-415Article in journal (Refereed)
    Abstract [en]

    Microfabricated arrays consisting of four individually addressable band electrodes have been used for end-column electrochemical detection in capillary electrophoresis (CE), The commercially available array was positioned 75-300 mu m from the capillary o

  • 36.
    Matysik, FM
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nyholm, L
    Markides, KE
    Comparison of mu m and mm sized disk electrodes for end-column electrochemical detection in capillary electrophoresis1999In: FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY, ISSN 0937-0633, Vol. 363, no 3, p. 231-235Article in journal (Refereed)
    Abstract [en]

    End-column electrochemical detection based on either the use of a 25 mu m microdisk electrode or a 0.5 mm macrodisk electrode has been compared with respect to performance and influence on non-aqueous capillary electrophoretic separations. Despite the mu

  • 37.
    Mårtensson, Per
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Atomic layer epitaxy of copper1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The high electric and thermal conductivity of copper has made it to a prime candidate as interconnect material in future integrated circuits. In this thesis, Atomic Layer Epitaxy has been used to deposit thin copper films on a variety of substrates, using both CuCl and Cu(II)2,2,6,6-tetramethyl-3,5-heptanedionate, Cu(thd)2, as precursors and hydrogen as reducing agent. Besides the experimental work, this thesis also comprises a large theoretical investigation where calculations based on Density Functional Theory has been performed in order to elucidate the deposition mechanisms in the CuCl/H2 process.

    Experiments showed that highly pure copper with low resistivity could be selectively deposited in the Cu(thd)2 process on Pt/Pd seeded substrates at temperatures below 300 °C. At higher temperatures, a selectivity was lost due to a thermal decomposition of the precursor, The selectivity was explained by the high catalytic activity of the seedlayer.

    Copper deposition by means of the CuCl/H2 process was kinetically controlled with an activation energy of approximately 85 kJmol-1 in the reduction step. Calculations showed that the rate determining step was the surface reaction between hydrogen and CuCl.

  • 38.
    Naeslund, Charlottta
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Synthesis of biomolecules for nuclide therapy: Studies on amino acids, nucleosides and isoquinolines1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nuclide therapy for cancer is based on the selective delivery of nuclide bearing compounds to tumour cells. Radionuclides, such as 125I, may be used, as well as stable isotopes, such as 10B, which is activated on site by an external neutron source. The second methodology is used in Boron Neutron Capture Therapy, which utilises the cytotoxic effect from the neutron capture reaction 10B(n,α)7Li. With this background in mind, nuclide bearing amino acids, nucleosides, and isoquinolines have been synthesised.

    Carborane containing analogues of phenylalanine were asymmetrically synthesised using Oppolzer's camphor-derived chiral handle. The (R)- and (S)-[3-(1,7-dicarba-closo-dodecaborane(12)-1-yl)-2-aminopropanoic acid] (meta-carboranylalanine), were obtained in >99 % enantiomeric purity. The (S)-Boc-ortho-carboranylalanine was obtained in two steps from (2S,2'S)-N-(3'(1",2"-dicarba-closo-dodecaborane(12)-1"-yl)-2'-aminopropanoyl)bornane-10,2-sultam.

    Three carborane containing thymidine derivatives 3'-O-(o-carboran-1-ylmethyl)thymidine, 7-(thymidine-3'-ylmethyl)dodecahydro-7,8-dicarba-nino-undecaborate, and 3'-O-(p-carboran-1-ylpropyl)thymidine were synthesised from thymidine. In vitro evaluation regarding enzymatic phosphorylation is described.

    Three iodo-analogues of the peripheral benzodiazepine receptor (PBR) ligand PK 11195, namely the isoquinoline derivatives N-Methyl-N-(1-methylpropyl)-1-(2-iodo phenyl)isoquinoline-3-carboxamide, N-Methyl-N-(1-methylpropyl)-1-(3-iodophenyl) isoquinoline-3-carboxamide, and N-Methyl-N-(1-methylpropyl)-1-(4-iodophenyl)isoquinoline -3-carboxamide were synthesised and radiolabelled with 125I.

    The carborane containing isoquinoline derivative N-Methyl-N-(1-methylpropyl)-l-[2'-(l"-7"-dicarba-closo-dodecaborane(12)-l"-yl)ethyl]isoquinoline-3-carboxamide was synthesised as a potential PBR-ligand.

  • 39.
    Noren, L
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Oorganisk kemi.
    Berger, R
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Oorganisk kemi.
    On the transformation of T1Cu(5)Se(3) to o-T1Cu(4)Se(3)1999In: J Alloys Comp, Vol. 288, no 1-2, p. 110-116Article in journal (Refereed)
    Abstract [en]

    A study on the transformation of TlCu5Se3 to the metastable orthorhombic form of TlCu4Se3 upon copper leaching has been conducted using neutron powder diffraction at 10 K and 293 K. The occupancy of the various copper sites in the TlCu5Se3 structure was investigated with Rietveld profile refinement techniques in combination with elemental analysis. The results indicate that mainly one of the three copper sites in the parent compound is affected during the extraction process.

  • 40.
    Noresson, Barbro
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Analytisk kemi.
    Analytical properties of an agarose-iminodiacetate chelating adsorbent used for the preconcentration of trace metal ions in water prior to the determination by ICP-AES1999Licentiate thesis, monograph (Other scientific)
  • 41.
    Palmgren, Andreas
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Palladium(II)-catalyzed 1,4-oxidations of 1,3-dienes: Development of an asymmetric version and synthetic applications1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis the development of an asymmetric version and synthetic applications of the Pd(II)-catalyzed 1,4-oxidation of conjugated dienes are described. The thesis is divided into four parts:

    (i) The first part concerns the design and synthesis of chiral p-benzoquinones as ligands in the Pd(II)-catalyzed 1,4-diacetoxylation. A p-benzoquinone substituted with a tert-butyl group and a chiral sulfoxide was found to be the best ligand. Optimization of the reaction conditions yielded an enantiomeric excess of 45%.

    (ii) The asymmetric version of the Pd(II)-catalyzed 1,4-dialkoxylation was also examined. In this case a C2-symmetric p-benzoquinone, with aminoalcohols as chiral units, was the best ligand employed in the reaction, and gave enantioselectivities up to 54% ee. The mechanism of the reaction is discussed.

    (iii) The synthesis of various heterocyclic compounds utilizing the intramolecular version of the 1,4-oxidation is described. In this study hydroxyl or nitrogen groups were used as the internal nucleophile and various alcohols were employed as the second nucleophile. Both spirocycles and fused heterocycles were obtained. When the hydroxyl group was used as the internal nucleophile the products were generated in good to excellent yield with high regio- and stereoselectivities. With nitrogen as the internal nucleophile the regioselectivity was found to be dependent on the nature of the second nucleophile.

    (iv) In the last part of the thesis the synthesis of epibatidine and its phenyl analogues are described. Here, one of the key-steps is the Pd(II)-catalyzed 1,4-chloroacetoxylation of aryl substituted 1,3-cyclohexadienes giving only one regio- and stereoisomer in moderate to good yields. Another key-step is a stereoselective hydrogenation, which afforded the required 1,2-cis or 1,2-trans relationship between the nitrogen and the aryl substituent.

  • 42.
    Persson, Anders
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Stereo- and enantioselective synthesis using palladium, ruthenium and enzyme catalysis1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis the use of palladium and ruthenium, with the latter in combination with enzymes, as selective catalysts in the transformation of organic substrates is discussed. The thesis is divided into two parts.

    The first part concerns the use of palladium(II) as a catalyst for the 1,4-oxidation of conjugated dienes using allylsilanes and carboxylic acids as internal nucleophiles. The reaction employing allylsilanes has been studied with two different reoxidation systems, p- benzoquinone and copper(II) chloride. By using the former oxidant highly stereoselective reactions took place, whereas the use of copper(II) chloride gave mixtures of isomeric products. It was demonstrated,by isolation and characterization of (p- allyl)palladium intermediates, that the allylsilane reacted as a nucleophile on the diene. The reactions using carboxylic acids as nucleophiles were conducted with the internal nucleophile connected to the side chain in the 2-position of the diene, giving six-membered lactones in good yields. High stereoselectivities across the diene were obtained, but in some cases the regioselectivity was lower and the 1,2-addition product wasformed.

    In the second part, studies of the combination of a ruthenium-catalyzed racemization with an enantioselective enzymatic acylation, in order to achieve a dynamic kinetic resolution ofsecondary alcohols, are described. It was found that the combination of a lipase from Candida antarctica, a stable ruthenium(II)-catalyst and a specifically designed acyl donor gave enantiomerically pure secondary acetates in good yields. Application of the reaction to symmetric diols gave enantiomerically pure diacetates in good yields and with high diastereoselectivities.

  • 43.
    Pihlström, Tuija
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Analytical Chemistry.
    Österdahl, Bengt-Göran
    Analysis of pesticide residues in fruit and vegetables after cleanup with solid-phase extraction using ENV+ (polystyrene-divinylbenzene) cartridges1999In: Journal of Agricultural and Fod Chemistry, Vol. 47, no 7, p. 2549-2552Article in journal (Refereed)
  • 44.
    Pinho, Pedro
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    A novel synthesis of chiral cyclopentyl- and cyclohexyl-amines1999In: Chem. Commun., no 597-598Article in journal (Refereed)
  • 45.
    Richard, Åse
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science. Fasta tillståndets elektronik. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Klett, Oliver
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Strandman, Carola
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science. Fasta tillståndets elektronik. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Bäcklund, Ylva
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science. Fasta tillståndets elektronik. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Nyholm, L
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Design of a Chip Based Microanalytical Fluidic System Based on Electrochemical Detection using Redox Cycling1999In: Proc Int Eng Congress and Exposition, Nashville, Tenessee, Nov 14-19, 1999, 1999Conference paper (Other academic)
  • 46. Richard, Åse
    et al.
    Klett, Oliver
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Strandman, Carola
    Bäcklund, Ylva
    Nyholm, Leif
    Design of a Chip Based Microanalytical Fluidic System Based on Electrochemical Detection Using Redox Cycling1999In: MEMS-Proceedings of the ASME International Mechanical Engineering, Congress and Exposition, Vol. 1, no 1, p. 511-516Article in journal (Refereed)
  • 47.
    Riesinger, SW
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Lofstedt, J
    Pettersson-Fasth, H
    Backvall, JE
    A general approach to indolizidine alkaloids from 1-benzyloxy-5-(p-toluenesulfonamido)-3-alken-2-ols: Synthesis of (+)-monomorine I1999In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, ISSN 1434-193X, no 12, p. 3277-3280Article in journal (Refereed)
    Abstract [en]

    A versatile method for the preparation of indolizidine alkaloids from 1-benzyloxy-5-(p-toluenesulfonamido)-3-alken-2-ols as stereodefined key intermediates has been developed. The utility of this approach was demonstrated by the synthesis of (+)-monomorin

  • 48.
    Selditz, U
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nilsson, S
    Barnidge, D
    Markides, KE
    ESI/TOF-MS detection for microseparation techniques1999In: CHIMIA, ISSN 0009-4293, Vol. 53, no 10, p. 506-510Article in journal (Refereed)
    Abstract [en]

    The choice of electrospray ionisation/time-of-flight mass spectrometry (ESI/TOF-MS) as mass analyser for combination with microseparation techniques, such as mu LC, CE and CEC, may be recommended due to the features that present-day TOF-MS instruments ha

  • 49. Selditz, Ulrike
    et al.
    Nilsson, Stefan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Barnidge, David
    Markides, Karin
    MS detection for microseparation techniques1999In: Chimia, ISSN 0009-4293, Vol. 53, no 10, p. 506-510Article in journal (Refereed)
  • 50.
    Senorans, FJ
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Nyholm, L
    Determination of tocopherols and vitamin A in vegetable oils using packed capillary column supercritical fluid chromatography with electrochemical detection1999In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 11, no 5, p. 385-391Article in journal (Refereed)
    Abstract [en]

    A recently developed microelectrochemical detector for packed capillary column supercritical fluid chromatography (pcSFC) has been applied to determine nanogram amounts of tocopherols and vitamin A in vegetable oil samples. With this procedure, no remova

12 1 - 50 of 61
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