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  • 301.
    Hartvig P., Bergström M., Långström B.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Use of positron emission tomography in analysing receptor function in vivo2001Article in journal (Other scientific)
  • 302.
    Hartvig, P
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nordberg, A
    Torstensson, R
    Sjöberg, P
    Fasth, K-J
    Långström, B.
    Interactions of a muscarinic cholinergic agonist with acetylcholine and dopamine receptors in the monkey brain studied by PET2002In: Dementia and Genetic Cognitive Disorders, no 13, p. 199-204Article in journal (Other scientific)
  • 303. Hartvig, Per
    et al.
    Neil, A
    Terenius, Lars
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Rimland, Annika
    Ulin, Johan
    Långström, Bengt
    Brain and plasma  kinetics of the opioid 11C-hydromorphone in two macaque species.,1989In: Pharmacology and toxicology., Vol. 65, p. 214-216Article in journal (Refereed)
  • 304. Hashemi, Payman
    et al.
    Zarjani, Razieh Afzari
    Abolghasemi, Mir Mehdi
    Olin, Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Agarose film coated glass slides for preparation of pH optical sensors2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 121, no 2, p. 396-400Article in journal (Refereed)
    Abstract [en]

    A method for preparation of optical sensors was developed by agarose film coating on aminosilanated glass slides. An optical pH sensor was accordingly prepared by epoxy activation of the agarose film, followed by chemical immobilization of Neutral Red dye. In an optimized coupling pH of 12 and a dye concentration of 10(-2) mol L-1 a pH sensor for a pH range of 2-8.5 was obtained. A theoretical equation was derived using the extended Henderson-Hasselbalch equation that reproduced the measured data well. The sensor was mounted in a flow cell and successfully applied for on-line pH measurements. The sensor responded rapidly to the pH changes with a response time of less than 2 min and reproducibility better than 0.40% (R.S.D.). In comparison to a stand-alone agarose membrane, the agarose coated glass slide showed better physical properties and easier handling and application but slightly slower response times. No evidence of leaching of the dye or any signal drift was observed.

  • 305.
    Hedberg, C
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Pinho, P
    Roth, P
    Andersson, PG
    Diels-Alder reaction of heterocyclic imine dienophiles2000In: JOURNAL OF ORGANIC CHEMISTRY, ISSN 0022-3263, Vol. 65, no 9, p. 2810-2812Article in journal (Refereed)
  • 306.
    Hedberg, Christian
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Design, Synthesis, Mechanistic Rationalization and Application of Asymmetric Transition-Metal Catalysts2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes mechanistic studies, rational ligand design, and synthesis of asymmetric transition metal catalysts. The topics addressed concerned [Papers I-VII]:

    [I] The asymmetric addition of diethyl zinc to N-(diphenylphosphinoyl)benzalimine catalyzed by bicyclic 2-azanorbornyl-3-methanols was studied. An efficient route to both diastereomers of new bicyclic 2-azanorbornyl-3-methanols with an additional chiral center was developed, in the best case 97% ee was obtained with these ligands. The experimental results were rationalized by a computational DFT-study.

    [II] An aza-Diels-Alder reaction of cyclopentadiene with chiral heterocyclic imines derived from (S)-1-phenylethylamine and different heteroaromatic aldehydes was developed. The cycloaddition proved to be highly diastereoselective and offers a very rapid access to possible biologically active compounds and interesting precursors for chiral (P,N)-ligands.

    [III] A convenient and high-yielding method for the preparation of (R)-tolterodine, utilizing a catalytic asymmetric Me-CBS reduction was developed. Highly enantio-enriched (R)-6-methyl-4-phenyl-3,4-dihydrochromen-2-one (94% ee) was recrystallized to yield practically enantiopure material (ee >99%) and converted to (R)-tolterodine in a four-step procedure.

    [IV] The reaction mechanism of the iridium-phosphanooxazoline-catalyzed hydrogenation of unfunctionalized olefins has been studied by means of DFT-calculations (B3LYP) and kinetic experiments. The calculations suggest that the reaction involves an unexpected IrIII-IrV catalytic cycle facilitated by coordination of a second equivalent of dihydrogen. On the basis of the proposed catalytic cycle, calculations were performed on a full system with 88 atoms. These calculations were also used to explain the enantioselectivity displayed by the catalyst.

    [V and VI] A new class of chiral (P,N)-ligands for the Ir-catalyzed asymmetric hydrogenation of aryl alkenes was developed. These new ligands proved to be highly efficient and tolerate a broad range of substrates. The enantiomeric excesses are, so far, the best reported and can be rationalized using the proposed selectivity model.

    [VII] The complex formed between the quincorine-amine, containing both a primary and a quinuclidine amino function, and [Cp*RuCl]4 catalyzes the hydrogenation of aromatic and aliphatic ketones in up to 90% ee approx. 24-times faster than previously reported Ru-diamine complexes. The reason for the lower but opposite stereoselectivity seen with the quincoridine-amine, as compared to the quincorine-amine, was rationalized by a kinetic and computational study of the mechanism. The theoretical calculations also revealed a significantly lower activation barrier for the alcohol mediated split of dihydrogen, as compared to the non-alchol mediated process. A finding of importance also for the diphosphine/diamine mediated enantioselective hydrogenation of ketones.

    List of papers
    1. A Theoretical and Experimental Study of the Asymmetric Addition of Dialkylzinc to N-(diphenylphosphinoyl)benzalimine
    Open this publication in new window or tab >>A Theoretical and Experimental Study of the Asymmetric Addition of Dialkylzinc to N-(diphenylphosphinoyl)benzalimine
    Show others...
    1999 In: Chemistry-A European Journal, ISSN 0947-6539, Vol. 5, no 6, p. 1692-1699Article in journal (Refereed) Published
    Abstract
    Identifiers
    urn:nbn:se:uu:diva-92875 (URN)
    Available from: 2005-04-07 Created: 2005-04-07 Last updated: 2016-08-17Bibliographically approved
    2. Diels-Alder Reaction of Heterocyclic Imine Dienophiles
    Open this publication in new window or tab >>Diels-Alder Reaction of Heterocyclic Imine Dienophiles
    2000 In: Journal of Organic Chemistry, ISSN 0022-3263, Vol. 65, no 9, p. 2810-2812Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-92876 (URN)
    Available from: 2005-04-07 Created: 2005-04-07Bibliographically approved
    3. Catalytic Asymmetric Total Synthesis of Muscarinic Receptor Antagonist (R)-Tolterodine
    Open this publication in new window or tab >>Catalytic Asymmetric Total Synthesis of Muscarinic Receptor Antagonist (R)-Tolterodine
    2005 (English)In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 347, no 5, p. 662-666Article in journal (Refereed) Published
    Abstract [en]

    A convenient and high yielding method for the preparation of (R)-tolterodine, utilizing a catalytic asymmetric Me-CBS reduction was developed. Highly enantioenriched (R)-6-methyl-4-phenyl-3,4-dihydrochromen-2-one (94% ee) was recrystallized to yield practically enantiopure material (ee >99%) and converted to (R)-tolterodine in a four-step procedure. The configuration of the crucial stereocenter was preserved during the synthesis and the obtained product was identified by chiral HPLC to be the (R)-tolterodine enantiomer.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-92877 (URN)10.1002/adsc.200404234 (DOI)
    Available from: 2005-04-07 Created: 2005-04-07 Last updated: 2017-12-14Bibliographically approved
    4. New Mechanistic Insights into the Iridium-Phosphanooxazoline Catalyzed Hydrogenation of Unfunctionalized Olefins: A DFT and Kinetic Study
    Open this publication in new window or tab >>New Mechanistic Insights into the Iridium-Phosphanooxazoline Catalyzed Hydrogenation of Unfunctionalized Olefins: A DFT and Kinetic Study
    2003 In: Chemistry-A European Journal, ISSN 0022-3263, Vol. 9, no 1, p. 339-347Article in journal (Refereed) Published
    Abstract
    Identifiers
    urn:nbn:se:uu:diva-92878 (URN)
    Available from: 2005-04-07 Created: 2005-04-07 Last updated: 2016-08-17Bibliographically approved
    5. Rationally Designed Ligands for Asymmetric Iridium-Catalyzed Hydrogenation of Olefins
    Open this publication in new window or tab >>Rationally Designed Ligands for Asymmetric Iridium-Catalyzed Hydrogenation of Olefins
    Show others...
    2004 In: Journal of the American Chemical Society, ISSN 0002-7863, Vol. 126, no 44, p. 14308-14309Article in journal (Refereed) Published
    Abstract
    Identifiers
    urn:nbn:se:uu:diva-92879 (URN)
    Available from: 2005-04-07 Created: 2005-04-07 Last updated: 2016-08-17Bibliographically approved
    6. Origin of Enantioselectivity in Ir-Catalyzed Asymmetric Hydrogenation of Tri-Substituted Olefins
    Open this publication in new window or tab >>Origin of Enantioselectivity in Ir-Catalyzed Asymmetric Hydrogenation of Tri-Substituted Olefins
    Show others...
    Manuscript (Other academic)
    Abstract
    Identifiers
    urn:nbn:se:uu:diva-92880 (URN)
    Available from: 2005-04-07 Created: 2005-04-07 Last updated: 2016-08-17Bibliographically approved
    7. Mechanistic Insights into the Phosphine free RuCp*-Diamine Catalyzed Hydrogenation of Arylketones: An Experimental and Theoretical Study
    Open this publication in new window or tab >>Mechanistic Insights into the Phosphine free RuCp*-Diamine Catalyzed Hydrogenation of Arylketones: An Experimental and Theoretical Study
    Show others...
    In: Journal of the American Chemical Society, ISSN 0002-7863Article in journal (Refereed) Submitted
    Abstract
    Identifiers
    urn:nbn:se:uu:diva-92881 (URN)
    Available from: 2005-04-07 Created: 2005-04-07 Last updated: 2016-08-17Bibliographically approved
  • 307. Hedberg, Christian
    et al.
    Källström, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Arvidsson, Per
    Andersson, Pher
    Brandt, Peter
    Mechanistic Insights into the Phosphine free RuCp*-Diamine Catalyzed Hy-drogenation of Arylketones: Experimental and Theoretical Evidence for an Alcohol-Mediated Dihydrogen Activation2005In: Journal of the American Chemical Society, ISSN 0002-7863, Vol. 127, no 43, p. 15083-15090Article in journal (Refereed)
    Abstract
  • 308.
    Hedberg, Christian
    et al.
    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.
    Källström, Klas
    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.
    Arvidsson, Per
    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.
    Brandt, Peter
    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.
    Mechanistic Insights into the Phosphine-Free RuCp*-Diamine-Catalyzed Hydrogenation of Aryl Ketones: Experimental and Theoretical Evidence for an Alcohol-Mediated Dihydrogen Activation2005In: J. Am. Chem. Soc., no 127, p. 15083-15090Article in journal (Refereed)
    Abstract
  • 309.
    Hedberg, Christian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Källström, Klas
    Arvidsson, Per I.
    Andersson, Pher G.
    Brandt, Peter
    Mechanistic Insights into the Phosphine free RuCp*-Diamine Catalyzed Hydrogenation of Arylketones: An Experimental and Theoretical StudyIn: Journal of the American Chemical Society, ISSN 0002-7863Article in journal (Refereed)
    Abstract
  • 310.
    Hedberg, Christian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Källström, Klas
    Brandt, Peter
    Bayer, Annette
    Andersson, Pher G.
    Origin of Enantioselectivity in Ir-Catalyzed Asymmetric Hydrogenation of Tri-Substituted OlefinsManuscript (Other academic)
    Abstract
  • 311. Hedberg, Christian
    et al.
    Källström, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Brandt, Peter
    Hansen, Lars-Kristian
    Andersson, Pher
    Asymmetric Hydrogenation of Trisubstituted Olefins with Iridium-Phosphine Thiazole Complexes: A Further Investigation of the Ligand Structure2006In: Journal of the American Chemical Society, ISSN 0002-7863, Vol. 128, no 9, p. 2995-3001Article in journal (Refereed)
    Abstract
  • 312.
    Hedberg, Christian
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Pinho, Pedro
    Roth, Peter
    Andersson, Pher G.
    Diels-Alder Reaction of Heterocyclic Imine Dienophiles2000In: Journal of Organic Chemistry, ISSN 0022-3263, Vol. 65, no 9, p. 2810-2812Article in journal (Refereed)
  • 313.
    Hedberg, Elisabeth
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Synthesis of 18F- and 76Br-labelled oligonucleotide and nucleoside derivatives1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With the aim of developing synthetic routes to oligodeoxynucleotides and analogues labelled with the positron-emitting radionuclides 18F and 76Br (half-lives 1.8 and 16.2 h, respectively), a number of compounds containing amine-reactive electrophiles were synthesised and used in preparation of oligodeoxynucleotide derivatives labelled in the 5´-position. Some 76Br-labelled nucleoside derivatives, which might be useful in the preparation of oligodeoxynucleotides containing a 5-[76Br]bromouracil unit, were also synthesised.

    The novel compounds 4-([18F]fluoromethyl)phenyl isothiocyanate and N-succinimidyl 4-[76Br]bromobenzoate were prepared in 13-15% and 45-60% isolated radiochemical yields, respectively. The previously reported N-succinimidyl [18F]fluorobenzoate was prepared by a modified procedure. The reactions of these compounds with oligodeoxynucleotides and phosphorothioate oligodeoxynucleotides (6- to 30-mers) modified in the 5´-position with a hexylamine group were investigated. With regard to chemical stability, an aromatic position of the halogen was found superior in the conditions of the oligodeoxynucleotide labelling reaction. Using the 18F- and 76Br-labelled succinimidyl esters, labelled oligodeoxynucleotidesand phosphorothioate oligodeoxynucleotides were obtained in 5-19% isolated radiochemical yield.

    The 76Br-labelled nucleoside 5-[76Br]bromo-2´-deoxyuridine was prepared in 60% isolated radiochemical yield. The corresponding phosphoramidite derivative 5´-O-[bis(4-methoxyphenyl)-phenylmethyI]-5-[76Br]bromo-2´-deoxyuridine 3´-[(2-cyanoethyl)-bis(1-methylethyl)phosphoramidite], was synthesised in 19-24% radio-chemical yield.

  • 314. Hederos, Sofia
    et al.
    Broo, Kerstin S
    Jakobsson, Emma
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology. Chemistry, Department of Biochemistry and Organic Chemistry, Biochemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology. ICM.
    Kleywegt, Gerard J
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology. Chemistry, Department of Biochemistry and Organic Chemistry, Biochemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology. ICM.
    Mannervik, Bengt
    Department of Biochemistry. Chemistry, Department of Biochemistry and Organic Chemistry, Biochemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Baltzer, Lars
    Department of Chemistry. Chemistry, Department of Biochemistry and Organic Chemistry, Biochemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Molecular Biology.
    Incorporation of a single His residue by rational design enables thiol-ester hydrolysis by human glutathione transferase A1-1.2004In: Proc Natl Acad Sci U S A, ISSN 0027-8424, Vol. 101, no 36, p. 13163-7Article in journal (Refereed)
    Abstract [en]

    A strategy for rational enzyme design is reported and illustrated by the engineering of a protein catalyst for thiol-ester hydrolysis. Five mutants of human glutathione (GSH; gamma-Glu-Cys-Gly) transferase A1-1 were designed in the search for a catalyst and to provide a set of proteins from which the reaction mechanism could be elucidated. The single mutant A216H catalyzed the hydrolysis of the S-benzoyl ester of GSH under turnover conditions with a k(cat)/K(M) of 156 M(-1) x min(-1), and a catalytic proficiency of >10(7) M(-1) when compared with the first-order rate constant of the uncatalyzed reaction. The wild-type enzyme did not hydrolyze the substrate, and thus, the introduction of a single histidine residue transformed the wild-type enzyme into a turnover system for thiol-ester hydrolysis. By kinetic analysis of single, double, and triple mutants, as well as from studies of reaction products, it was established that the enzyme A216H catalyzes the hydrolysis of the thiol-ester substrate by a mechanism that includes an acyl intermediate at the side chain of Y9. Kinetic measurements and the crystal structure of the A216H GSH complex provided compelling evidence that H216 acts as a general-base catalyst. The introduction of a single His residue into human GSH transferase A1-1 created an unprecedented enzymatic function, suggesting a strategy that may be of broad applicability in the design of new enzymes. The protein catalyst has the hallmarks of a native enzyme and is expected to catalyze various hydrolytic, as well as transesterification, reactions.

  • 315.
    Heldin, E
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Ion-Pair Chromatography2000In: Academic Press, p. 2358-2368Article in journal (Refereed)
  • 316.
    Henssen, Cecile
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Synthesis of DNA Intercalating Compounds for Nuclide Therapy2000Licentiate thesis, monograph (Other scientific)
  • 317.
    Herlin, G.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Persson, B.
    Bergström, M.
    Långström, B.
    Aspelin, P.
    11C-harmine as a potential PET tracer for ductal pancreas cancer-in vitro studies2003In: Eur. Radiol., Vol. 13, no 459, p. 729-733Article in journal (Refereed)
  • 318.
    Hermansson, K.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Thomas, J. O.
    Olovsson, I.
    Hydrogen bond studies. CXXXVIII. Neutron diffraction studies of LiNO 3.3H 2O at 120 and 295K1980In: Acta Crystallogr. B, Struct. Crystallogr. Cryst. Chem. (Denmark), ISSN 0567-7408, Vol. B36, p. 1032-1040Article in journal (Refereed)
    Abstract [en]

    For pt.CXXXVII see ibid., vol.B35, p.2384 (1979). LiNO 3.3H 2O has been studied by neutron diffraction at 120 and 295 K. The final R(w.F 2) values are 4.5% (120K) and 4.9% (295K). The crystal structure found in a previous room-temperature X-ray study is confirmed: one water molecule is involved in six hydrogen bonds; the other independent water molecule in the structure has a tetrahedral environment comprising two Li + ions and two medium-strong hydrogen bonds. The four different O...O hydrogen-bond lengths increase by 0.02-0.03 Aring going from 120 to 295K. The mean-square amplitudes of vibration for the N and O atoms are found to be closely proportional to temperature. For the H and Li atoms the vibrational amplitudes are less sensitive to temperature. Crystal data: space group Cmcm, Z=4; at 120K a=6.713 (7), b=12.669 (4), c=5.968 (5) Aring; at 295K a=6.8018 (4), b=12.7132 (9), c=5.9990 (4) Aring.

  • 319.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    A neutron diffraction determination of the structure of deuterated aluminium nitrate nonahydrate, Al(NO 3) 3.9D 2O1983In: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. C39, p. 925-930Article in journal (Refereed)
    Abstract [en]

    Mr=393.26, monoclinic, P2 1/ c, a=13.8937 (14), b=9.6258 (7), c=10.9127 (7) Aring, beta=95.66 (1)deg, V=1452.3 (2) Aring 3, T=295K [the cell parameters were determined from the refinement of 39 theta values from a Guinier-Hagg X-ray powder film (Cr Kalpha radiation, lambda=2.28975 Aring, using a CoP 3 standard: a=7.70778 Aring)], Z=4, Dx=1.80 Mg m -3, final Rw( F2)=0.069 for all 4480 independent reflections collected out to sintheta/lambda=0.69 Aring -1. The crystal structure of Al(NO 3) 3.9D 2O has been studied by three-dimensional neutron diffraction data collected at 295K. The asymmetric unit contains Al(D 2O) 63+ octahedra, NO 3- ions and three D 2O molecules which are not coordinated to Al 3+ ions. All nine water molecules in the formula unit are crystallographically independent and the 19 hydrogen bonds donated have O...O distances in the range 2.650 (2)-3.054 (2) Aring. The hydrogen bonds donated by the D 2O molecules which are coordinated to Al 3+ ions are shorter than the other hydrogen bonds. A distinct correlation exists between the O-D and D...O distances.

  • 320.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    A simulated X-ray diffraction study of liquid water: Beyond the spherical-atom approximation1996In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 260, no 1-2, p. 229-235Article in journal (Refereed)
    Abstract [en]

    The total electron density of a water molecule differs significantly from the superposition of the O + H + H spherical-atom densities by way of bonding and lone-pair electron charge accumulations. Such non-spherical electron density features on neighbouring molecules typically lie in the range 2-4 Angstrom apart in liquid water. Their influence on the diffracted coherent X-ray intensity for liquid water has been simulated, based on molecular dynamics data and non-spherical atomic electron deformation functions, for the water molecule. It is found that in the liquid water sample, the deformation densities on different molecules interfere significantly in the scattering process, but the effect is largely eliminated because of statistical cancellations over Q vector directions and time, The result is that the influence from the deformation densities on g(r) is large for intramolecular distances, but small for intermolecular distances.

  • 321.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    ABINITIO CALCULATIONS OF THE FUNDAMENTAL OH FREQUENCY OF BOUND OH- IONS1991In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 95, no 5, p. 3578-3588Article in journal (Refereed)
    Abstract [en]

    In contrast to the OH stretching frequencies of bound H2O molecules, which are always found at lower wave numbers compared to the free molecule, the experimentally determined frequency of the OH- ion can be either lower or higher than the free-ion value. Optimized geometries and fundamental stretching frequency of OH- have been calculated here by ab initio methods at the Hartree-Fock and second-order Moller-Plesset levels for a number of cation-OH-, HOH...OH-, cation-OH-.q-, and cation-OH-.OH2 complexes for Li+, Mg2+, and Al3+. The importance of electrostatic effects on the OH- frequency has been assessed by comparison with calculations of different point-charge and homogenous-field OH- systems. As long as the interaction is not dominated by electronic overlap, the frequency shift is found to be largely determined by electrostatic forces: with increasing field strength the OH- frequency rises to a maximum and then decreases. The OH- dipole moment and Mulliken charges vary monotonically with the field strength, whereas the equilibrium OH distance goes through a minimum and the bond electron density through a maximum. In strongly polarizing fields, such as in the optimized Al3+.OH- and Mg2+.OH-...OH2 systems, the OH- frequency falls below the free-ion value. Ar experimentally observed frequency downshift for an OH- ion in the condensed phase cannot be used as a criterion for the existence of H bonding. The OH- ion acts as an H-bond donor only when strongly polarized by a neighbor on its oxygen side.

  • 322.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    COMPUTER-SIMULATION AND ABINITIO CALCULATIONS OF SOME PROPERTIES OF LITHIUM FORMATE MONOHYDRATE1988In: Zeitschrift fur Kristallographie, ISSN 0044-2968, Vol. 182, no 1-4, p. 130-132Article in journal (Other academic)
  • 323.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    COORDINATION EFFECTS ON THE STRETCHING VIBRATION OF THE OH- ION1993In: Chemical Physics, ISSN 0301-0104, E-ISSN 1873-4421, Vol. 170, no 2, p. 177-184Article in journal (Refereed)
    Abstract [en]

    IR and Raman measurements on crystalline hydroxides reported in the literature have shown that both frequency upshifts and downshifts with respect to the free-ion frequency occur. Here the fundamental stretching vibrational frequency of a bound OH- ion in different point charge environments has been examined by ab initio calculations at the MP2 level. For a given geometry of a q+ . OH- . q- complex, the ab initio frequency is found to vary in a systematic way as the electric field is increased: the frequency increases, passes through a maximum and then decreases. Both the value of the maximum frequency and the field strength at which it occurs are highly dependent on the geometry of the complex. Only the field component parallel to the OH- axis is effective in changing the OH frequency. The arc-like shape of the frequency versus field correlation curves ''explains'' the large degree of non-additivity found for the environment-induced frequency shifts. H-bonds donated by the OH- ion may, or may not, lead to a frequency downshift, depending on the other neighbours present. It is also shown that a model which explicitly takes the field inhomogeneity into account (by a simple polynomial in E(parallel-to), (E(parallel-to))2, E(parallel-to)', (E(parallel-to)')2 and cross-terms, evaluated at two different ''probing sites'' in the ion), manages to represent the OH- frequency shift for an ''arbitrary'' point-charge environment.

  • 324.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    ELECTRIC-FIELD EFFECTS ON THE OH VIBRATIONAL FREQUENCY AND INFRARED-ABSORPTION INTENSITY FOR WATER1993In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 99, no 2, p. 861-868Article in journal (Refereed)
    Abstract [en]

    The variations of the anharmonic OH frequency and the infrared absorption intensity with field strength have been calculated for the uncoupled OH stretching vibration of a water molecule in a static, homogeneous electric field using ab initio methods at the MP4 level with a nearly saturated basis set. The OH frequency is found to be virtually independent of the field components perpendicular to the vibrating OH bond. For the parallel component, the frequency vs field curve is close to quadratic, with a maximum for a slightly negative (directed from H to 0) field strength. The external field perturbation, defined as V(ext)(E(parallel-to), r(OH)) = V(tot)(E(parallel-to), r(OH)) - V(free)(r(OH)), is found to be closely linear in r(OH), except when the field strength Ell is both large and negative. The linear external force constant is almost perfectly accounted for by the sum of two terms, -E(parallel-to).dmu(parallel-to)free/dr(OH) and -1/2.E(parallel-to).partial derivative mu(parallel-to)induced/partial derivative r(OH). These derivatives are quite insensitive to the choice of basis-set. The partial derivative mu(parallel-to)induced/partial derivative r(OH) derivative is approximately proportional to E(parallel-to), and gives rise to the arclike shape of the frequency vs field curve. The frequency maximum occurs where partial derivative mu(parallel-to)tot/partial derivative r(OH) almost-equal-to 0. It is the sign of dmu(parallel-to)free/dr(OH) which determines that the frequency maximum occurs at a negative field strength for water (but at a positive field strength for OH-, for example), i.e., that a frequency red-shift (blue-shift for OH-) occurs when the molecule is bound. The linear relationship between the infrared absorption intensity and frequency of the water OH vibration is derived.

  • 325.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    ELECTRON REARRANGEMENT FOR THE WATER MOLECULE IN DIFFERENT ENVIRONMENTS1985In: Acta Crystallographica Section B: Structural Science, ISSN 0108-7681, E-ISSN 1600-5740, Vol. 41, no JUN, p. 161-169Article in journal (Refereed)
  • 326.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    FROM CLUSTER TO CRYSTAL - ABINITIO CALCULATIONS OF THE OH- FREQUENCY IN LITHIUM HYDROXIDE MONOHYDRATE1992In: Chemical Physics, ISSN 0301-0104, E-ISSN 1873-4421, Vol. 159, no 1, p. 67-73Article in journal (Refereed)
    Abstract [en]

    The fundamental O-H stretching frequency of the OH- ion in crystalline LiOH.H2O has been calculated by ab initio methods at the MP2 level. The experimental and calculated wavenumbers are 3575 and 3602 cm-1, respectively. This frequency is shown to result from a delicate balance of several important interactions between the OH- ion and its surroundings: the two cations in the (Li+)2.OH- cluster produce an upshift of 75 cm-1 with respect to the isolated ion, while the whole nearest-neighbour cluster, (Li+)2(H2O)2.OH-.OH-, gives a frequency downshift of -570 cm-1. The crystal field outside the nearest-neighbour cluster produces an upshift of 610 cm-1. This behaviour conforms well with the frequency versus field correlation curves calculated for simple hydroxide point charge complexes.

  • 327.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    INFLUENCE OF RIGID-BODY MOTION ON THE DEFORMATION ELECTRON-DENSITY OF H2O1983In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 99, no 4, p. 295-300Article in journal (Refereed)
  • 328.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    INTERMOLECULAR INTERACTIONS IN CRYSTALLINE HYDRATES - WHAT CAN A CRYSTALLOGRAPHER LEARN FROM THEORETICAL CALCULATIONS1987In: ACTA CHEM SCAND A, ISSN 0302-4377, Vol. 41, no 10, p. 513-526Article in journal (Refereed)
  • 329.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    MANY-BODY EFFECTS IN TETRAHEDRAL WATER CLUSTERS1988In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 89, no 4, p. 2149-2159Article in journal (Refereed)
  • 330.
    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)
  • 331.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    O-H BONDS IN ELECTRIC-FIELDS - ELECTRON-DENSITIES AND VIBRATIONAL FREQUENCY-SHIFTS1995In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 233, no 4, p. 376-382Article in journal (Refereed)
    Abstract [en]

    The changes in the electron density distribution caused by varying the O-H bond length for HDO and OH- in uniform electric fields are investigated and related to the frequency shifts for the uncoupled O-H stretching vibration. Numerical integration of difference density maps, Delta rho=rho(r(OH)+Delta r(OH))-rho(r(OH)), reproduces the electronic contribution to theta mu(parallel to)(total)/theta r(OH), if the integration is carried out to a distance of approximate to 3.5 Angstrom from the O atom. The frequency shift Delta nu, is proportional to -E(parallel to) X[d mu(parallel to)(permanent)(r(OH))/dr(OH)]-1/2E(parallel to)[theta mu(parallel to)(induced)(E(parallel to), r(OH))/theta r(OH)] and electron density maps corresponding to the electronic parts of these terms are presented. Experimentally it has been found that the OH- ion shows a frequency upshift when bound in a moderately strong field, while water molecules show a downshift. The electron density maps show why d mu(parallel to)(permanent)(r(OH))/dr(OH) is positive for HDO and negative for OH-, resulting in a downshift for bound water an an upshift for bound OH-. For positive fields, theta mu(parallel to)(induced)/theta r(OH) is positive for both HDO and OH- and gives a downshift contribution.

  • 332.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    REDSHIFTS AND BLUESHIFTS OF OH VIBRATIONS1993In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 45, no 6, p. 747-758Article in journal (Refereed)
    Abstract [en]

    Ab initio calculations of potential energy, dipole moment, equilibrium OH distance, force constants, and anharmonic frequencies, and correlation between these quantities, are presented for a water molecule and an OH- ion in a uniform electric field of varying field strength. It is explained why a bound H2O molecule in nature always experiences a frequency downshift with respect to the free molecule, and a bound OH-1 ion, either a downshift or an upshift. The frequency-field variation is well accounted for by the expression DELTAnu(OH) is-proportional-to -E(parallel-to) . (dmu(parallel-to)free/dr(OH) + 1/2 . partial derivative mu(parallel-to)induced/partial derivative r(OH)). A frequency maximum occurs at the field strength where partial derivative mu(parallel-to)tot/partial derivative r(OH) is similar to 0. Two cases can be discerned: (1) the frequency maximum falls at a positive field strength when dmu(parallel-to)free/dr(OH) is positive (this is the situation for OH-), and (2) the maximum frequency falls at a negative field when dmu(parallel-to)free/dr(OH) is negative (this occurs for water). In general, for an OH bond in a bonding situation where the intermolecular interactions are dominated by electrostatic forces, the nonlinearity of the frequency shift with respect to an applied field is governed by how close to the frequency maximum one is, i.e., by both dmu(parallel-to)free/dr(OH) and partial derivative mu(parallel-to)induced/partial derivative r(OH). Correlation curves between the external linear force constant, k(ext), and r(OH,e) are closely linear over the whole field range studied here, whereas the frequency vs. r(OH,e) and force constants vs. r(OH,e) correlation curves form two approximately linear, parallel branches, corresponding to ''before'' and ''after'' the maximum in the frequency vs. field curves. Each branch of the nu vs. r(OH,e) curves has a slope of approximately -16,000 cm-1/angstrom.

  • 333.
    HERMANSSON, KERSTI
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    THE WATER FLIP BARRIER IN THE LI+HCOO-.H2O CRYSTAL FROM ABINITIO AND MOLECULAR MECHANICS CALCULATIONS1989In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 91, no 1, p. 368-375Article in journal (Refereed)
  • 334.
    HERMANSSON, KERSTI
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    KNUTS, SÖREN
    LINDGREN, JAN
    THE OH VIBRATIONAL-SPECTRUM OF LIQUID WATER FROM COMBINED ABINITIO AND MONTE-CARLO CALCULATIONS1991In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 95, no 10, p. 7486-7496Article in journal (Refereed)
    Abstract [en]

    The infrared vibrational OH stretching spectrum of isotopically isolated HDO molecules in liquid water has been calculated by ab initio methods at the MP2 level for a number of geometrical configurations taken from a Monte Carlo simulation. Each vibrating water molecule with its environment was described by a pentamer supermolecule, surrounded by a large number of point charges representing polarized water molecules. The anharmonic stretching potentials (MP2 force constants up to fifth order) for 40 uncoupled OH water vibrators were calculated. The average computed r(e) distance found for liquid water is 0.01 angstrom longer than the free-water value. The frequencies were obtained by solving the one-dimensional Schrodinger equation variationally for each OH potential curve. Using the squared dipole moment derivatives, which vary by a factor of 7 over the frequency band, the density-of-states histograms were converted to intensities. The resulting computed average frequency downshift is approximately 260 cm-1, compared to approximately 310 cm-1 (experimental), with a bandwidth in good agreement with experiment. The remaining discrepancy between theoretical and experimental frequency shifts is to a large part due to the charge transfer within the water clusters. This charge transfer gives rise to an electrostatic field which, at the site of the vibrating H atom, counteracts the downshift induced by the other environmental effects. The agreement between experiment and theory is very satisfactory when this charge transfer effect is corrected for or when point-charge embedded heptamer clusters are considered.

  • 335.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lindgren, Jan
    AN ABINITIO STUDY OF ANHARMONIC POTENTIAL-ENERGY SURFACES FOR BOUND WATER-MOLECULES1988In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 146, no 5, p. 459-464Article in journal (Refereed)
  • 336.
    HERMANSSON, KERSTI
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    LINDGREN, JAN
    PROBST, MICHAEL M
    NONADDITIVITY OF OH FREQUENCY-SHIFTS IN ION WATER-SYSTEMS1995In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 233, no 4, p. 371-375Article in journal (Refereed)
    Abstract [en]

    The intramolecular OH stretching frequency shift observed for water on formation of 'cation-water...H-bond acceptor' complexes is highly non additive. The uncoupled OH frequency shift has been calculated by ab initio methods for q(+)-OH2 and OH2...q(-) complexes of different geometries and for a series of Mg2+.(H2O)(n)...(H2O)(m) complexes, and we argue that the non-additivity (cooperativity) of the frequency shifts is largely a consequence of the parabolic shape of the frequency versus electric field curves.

  • 337.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lindgren, Jan
    Ågren, Hans
    THEORETICAL-STUDIES OF IR INTENSITIES IN ZN2+OH2 AND MG2+OH21986In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 57, no 4, p. 857-863Article in journal (Refereed)
  • 338.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lunell, S.
    The theoretical electron density in lithium hydroxide monohydrate1982In: Acta Crystallogr. B, Struct. Crystallogr. Cryst. Chem. (Denmark), ISSN 0567-7408, Vol. B38, p. 2563-2569Article in journal (Refereed)
    Abstract [en]

    The electron density in LiOH.H 2O has been determined by ab initio MO-LCAO-SCF calculations. All nearest neighbours to the H 2O molecule and the OH - ion, respectively, have been included explicitly in the calculations; next-nearest and more-distant neighbours have been simulated by point charges. The theoretical electron density maps are compared with experimental maps with good overall agreement. The influence of intermolecular bonding in the crystal is found to be twofold. Firstly, the overall polarization of the H 2O molecule and the OH - ion is increased significantly. Secondly, the electron density around the O nuclei in H 2O and OH - is rearranged, leading to the decrease of density in the lone-pair directions. The reasons for this decrease are discussed in some detail.

  • 339.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lunell, Sten
    ELECTRON-DENSITY OF H2O IN A CRYSTALLINE ENVIRONMENT1981In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 80, no 1, p. 64-68Article in journal (Refereed)
  • 340.
    HERMANSSON, KERSTI
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    OJAMAE, LARS
    ON THE ROLE OF ELECTRIC-FIELDS FOR PROTON-TRANSFER IN WATER1995In: Solid State Ionics, ISSN 0167-2738, E-ISSN 1872-7689, Vol. 77, p. 34-42Article in journal (Refereed)
    Abstract [en]

    The influence of uniform and non-uniform electric fields on one-dimensional proton transfer curves for (H2O)(2), H5O2+ and H3O2- has been examined using quantum-mechanical ab initio calculations. Both liquid-state and solid-state environments are discussed. For the charged complexes the transfer barrier is removed or greatly reduced by a field as small as 0.005 a.u. (2.5 X 10(7) V/cm). Local field fluctuations of this size are easily produced in condensed aqueous systems at room temperature. For the asymmetric single-well potential of an (H2O)(2) complex, a field ten times larger is needed to move the minimum from one side to the other across the O ... O bond. Such local fields can be achieved in ionic aqueous systems. The energy barrier for proton transfer in ice Ih has been computed using a periodic Hartree-Fock approach; the barrier for a fully concerted proton transfer is similar to 60 kJ/mol.

  • 341.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Ojamäe, Lars
    From Molecule to Cluster to Bulk - Water OH Vibrations in Different Surroundings1992In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 42, no 5, p. 1251-1270Article, review/survey (Refereed)
    Abstract [en]

    Vibrational spectra for the O-H stretching motion of HDO molecules in different surroundings have been calculated by quantum mechanical ab initio methods and compared with experimental spectra. The free water molecule, water chains, and ion-water clusters are discussed. Solvent effects on OH vibrations in liquid water have been calculated as well as "in-crystal" OH frequencies in some ice and ionic crystalline hydrate structures. The importance of nonadditivity effects, electron correlation (at the MP2 level), and long-range interactions for the total frequency downshift is demonstrated. It is shown that the inclusion of these effects, in conjunction with a variational quantum mechanical treatment of the anharmonic vibrational stretching motion (force constants up to the fourth order), yields vibrational frequencies in quantitative agreement with experiment for a wide range of aqueous systems.

  • 342.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Olovsson, Ivar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lunell, Sten
    CATION INFLUENCE ON THE STRUCTURE AND ELECTRON-DENSITY OF WATER IN SOME MEN+.H2O COMPLEXES1984In: THEOR CHIM ACTA, ISSN 0040-5744, Vol. 64, no 4, p. 265-276Article in journal (Refereed)
  • 343.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Tellgren, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    A deformation electron density study of potassium hydrogen diformate1989In: Acta Crystallographica Section B: Structural Science, ISSN 0108-7681, E-ISSN 1600-5740, Vol. B45, p. 252-257Article in journal (Refereed)
    Abstract [en]

    KH(HCOO) 2, Mr=130.144, orthorhombic, Pbca, a=17.703(8), b=7.349(4), c=7.302(3) Aring, V=950.1(8) Aring 3, Z=8, Dx=1.820(1) g cm -3, lambda(Mo Kalpha)=0.71069 Aring, mu x(calc.)=0.973 mm -1, F(000)=528, T=120 K, R( F2)=0.033 for 2109 unique reflexions. The deformation electron density in KH(HCOO) 2 has been studied by means of experimental X- N maps obtained at 120 K. The electron distributions in the two chemically similar but crystallographically nonequivalent formate groups are discussed and correlated with bond order. The density distribution in the short intermolecular O-H. . . bond [2.437(1) Aring] is compared with experimental and theoretical maps in related compounds.

  • 344.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Tellgren, Roland
    Lehmann, Mogens S.
    Neutron diffraction studies of potassium hydrogen diformate, KH(HCOO) 2, at 120 and 295K1983In: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. C39, p. 1507-1510Article in journal (Refereed)
    Abstract [en]

    Mr=130.144, orthorhombic, Pbca, Z=8; at 120K a=17.705(8), b=7.349(4), c=7.302(3) Aring, V=950.1(8) Aring 3, Dx=1.820(1) g cm -3; at 295K, a=17.7079(9), b=7.5096(4), c=7.3774(4) Aring, V=981.05(9) Aring 3, Dx=1.7623(2) g cm -3. The crystal structure has been investigated by neutron diffraction at 120K (lambda=0.7228 Aring) and 295K (lambda=1.210 Aring); final R( F2) values are 0.041 (1418 reflections) and 0.065 (1365 reflections), respectively. The short intermolecular O...O hydrogen bond [2.437(1) Aring at 120K] is found to be asymmetrical [O-H 1.167(1), H...O 1.270(1) Aring] even though the bonding situations around the two formate groups are quite similar.

  • 345.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Thomas, J. O.
    The experimental electron density in lithium hydroxide monohydrate1982In: Acta Crystallogr. B, Struct. Crystallogr. Cryst. Chem. (Denmark), ISSN 0567-7408, Vol. B38, p. 2555-2563Article in journal (Refereed)
    Abstract [en]

    The deformation electron density has been studied in LiOH.H 2O at 295K using a combination of X-ray and neutron diffraction data. Notoriously high extinction was present in the neutron data. Despite an attempt to reduce this by shock-cooling, the subsequent refinement of an extinction correction met with only partial success. Limited use was thus made of the neutron data in the determination of static multipole deformation density maps. The resulting peak maximum in the O-H bonds of the water molecule is 0.66 e Aring -3, and of the OH - ion 0.49 e Aring -3. Lower peaks are observed in the lone-pair regions: 0.22 e Aring -3 for H 2O and 0.27 e Aring -3 for OH -. These are to be compared with the results of theoretical ab initio calculations given by Hermansson and Lunnell (1982).

  • 346.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Thomas, J. O.
    Olovsson, I.
    Hydrogen bond studies. CXX. An X-ray determination of the crystal structure of LiNO 3.3H 2O1977In: Acta Crystallogr. B, Struct. Crystallogr. Cryst. Chem. (Denmark), ISSN 0567-7408, Vol. B33, p. 2857-2861Article in journal (Refereed)
    Abstract [en]

    For pt.CXIX see Z. Naturforsch. a, vol.32, p.134 (1977). The crystal structure of lithium nitrate trihydrate, LiNO 3.3H 2O, has been determined by X-ray diffraction at 295K. The crystal is orthorhombic, space group Cmcm, a=6.8018 (4), b=12.7132 (9), c=5.9990 (4) Aring, V=518.75 Aring 3, Z=4. The nitrate ions, Li + ions and one of the two crystallographically non-equivalent water molecules lie in a mirror plane and are bonded to atoms in adjacent planes through the second water molecule. The Li + ion is octahedrally surrounded by six O atoms, four belonging to water molecules and two to nitrate ions. The two non-equivalent water molecules are present in the structure in distinctly different bonding situations. One is bonded to two Li + ions and is the donor of two hydrogen bonds. The other is involved in six hydrogen bonds: the O atom accepts two hydrogen bonds, and both protons are involved in bifurcated hydrogen bonds.

  • 347.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Thomas, John O.
    The structure and electron deformation density of LiNO 2.H 2O at 295K1983In: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. C39, p. 930-936Article in journal (Refereed)
    Abstract [en]

    Mr=70.959, monoclinic, P2 1/ c, Z=4, a=3.3387 (3), b=14.2980 (10), c=6.3961 (5) Aring, beta=105.10 (1)deg, V=294.79 (4) Aring 3, Dx=1.60 Mg m -3, Mo Kalpha, lambda=0.71069 Aring, mu calc=0.154 mm -1, T=295 K, F(000)=144. Two data sets were collected out to sintheta/lambda=0.91 Aring -1: one on a twinned crystal, the other on a single crystal. Positional and thermal parameters from the two data sets show only random deviations. Somewhat high Rw( F2) values of 0.084 and 0.081, respectively, resulted from the refinement of a spherical-atom model. This reflects the inadequacies of such a model. Introduction of multipolar deformation functions for the single-crystal data set brought the Rw( F2) value down to 0.029. The crystal contains one independent Li + ion with fivefold coordination, a tetrahedrally coordinated H 2O molecule and an NO 2- ion which accepts two medium-strength hydrogen bonds [O-H...O 2.755 (1); O-H...N 2.890 (1) Aring] and has three Li +-O contacts. The static deformation density for the NO 2- ion shows N-O bond maxima of 0.50 e Aring -3; O lone-pair maxima of 0.20-0.30 e Aring -3 are situated in the molecular planes at approximately 90deg to the N-O bonds. The lone-pair density associated with the water O is markedly asymmetric; no support for this effect has been found in theoretical model calculations, however.

  • 348.
    Hermansson, Kersti
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Thomas, John O.
    Olovsson, Ivar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Deformation electron density of lithium nitrate trihydrate, LiNO 3.3H 2O, at 120 and 295K1984In: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, E-ISSN 1600-5759, Vol. C40, p. 341-342Article in journal (Refereed)
    Abstract [en]

    Mr=123.00, orthorhombic, Cmcm, Z=4; at 120K, a=6.713 (7), b=12.669 (4), c=5.968 (5) Aring, V=507.7 (7) Aring 3; at 295K, a=6.8018 (4), b=12.7132 (9), c=5.9990 (4), V=518.75 (6) Aring 3; m.p.=303.1K, Dx=1.575 g cm -3 (295K), f(000)=256; X-ray data (Mo Kalpha, lambda=0.71069 Aring) have been collected at 120K; final wR( F2) values 0.064 from conventional spherical-atom refinement and 0.033 from deformation refinement. The deformation electron density of LiNO 3.3H 2O has been studied at 120K (new data) and 295K in order to compare static and dynamic deformation maps derived at two temperatures. A combination of X-ray and neutron data has been used both for the X- N and the multipolar expansion maps. The N-O bond peaks are elongated perpendicular to the molecular plane. The water molecules show well developed deformation features and the hydrogen-bond density is consistent with what is usually observed for medium-strong hydrogen bonds.

  • 349.
    Hilmersson, G
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Davidsson, Ö
    Arvidsson, P.I.
    2On the Mechanism of Internal ortho-Lithiation in a Mixed Complex Between n-BuLi and a Chiral Lithium Amide22002In: Helv. Chim. Acta, no 85, p. 3814-3822Article in journal (Other scientific)
  • 350.
    Hoja-Lukowicz, D
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Cialczyk, D
    Bergquist, J
    Litynska, A
    Laidler, P
    High-mannosetype oligosaccharides from human placental arylsulfatase A are core fucosylated as confirmed by MALDI MS2000In: Glycobiology, Vol. 10, no 6, p. 551-557Article in journal (Refereed)
45678910 301 - 350 of 851
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