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  • 1. Abrahamsson, Maria
    et al.
    Wolpher, Henriette
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Johansson, Olof
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Larsson, Jan
    Kritikos, Mikael
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Norrby, Per-Ola
    Bergquist, Jonas
    Sun, Licheng
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Hammarström, Leif
    A New Strategy for Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes. Synthesis, Photophysical and Electrochemical characterisation of Six Mononuclear Ruthenium(II) Bisterpyridine Type Complexes2005In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 9, p. 3215-3225Article in journal (Refereed)
    Abstract [en]

    The synthesis and characterization of six ruthenium(II) bistridentate polypyridyl complexes is described. These were designed on the basis of a new approach to increase the excited-state lifetime of ruthenium(II) bisterpyridine-type complexes. By the use of a bipyridylpyridyl methane ligand in place of terpyridine, the coordination environment of the metal ion becomes nearly octahedral and the rate of deactivation via ligand-field (i.e., metal-centered) states was reduced as shown by temperature-dependent emission lifetime studies. Still, the possibility to make quasi-linear donor−ruthenium−acceptor triads is maintained in the complexes. The most promising complex shows an excited-state lifetime of τ = 15 ns in alcohol solutions at room temperature, which should be compared to a lifetime of τ = 0.25 ns for [Ru(tpy)2]2+. The X-ray structure of the new complex indeed shows a more octahedral geometry than that of [Ru(tpy)2]2+. Most importantly, the high excited-state energy was retained, and thus, so was the potential high reactivity of the excited complex, which has not been the case with previously published strategies based on bistridentate complexes.

  • 2.
    Brisander, Magnus
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Synthesis and Structure of Novel G-Protein Coupled Receptor Ligands1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A method based on h6-arenetricarbonylchromium chemistry has been developed for the synthesis of enantiopure 4-alkylated 3-(dipropylamino)chromans. The stereochemistry of these new serotonergic ligands was determined by a combination of X-ray crystallography, NMR spectroscopy and chemical correlation. A single-crystal X-ray diffraction study of the hydrochloride salt of the exo-[h 6-(3R)-(dipropylamino)chroman]tricarbonylchromium complex served to determine its relative and absolute configuration, and also as an aid in rationalising the stereochemical outcome of the benzylic alkylations.

    The stereochemistry of five derivatives of the novel pentacyclic compound (R)-1,11-methyleneaporphine was studied by X-ray diffraction, and their rigid conformation is compared with that of previously published aporphine derivatives.

    The conformational preferences of two achiral antimuscarinic derivatives of 3-(2-furanyl)quinuclidin-2-ene were studied by experimental (X-ray crystallography) and theoretical methods (ab initio and molecular mechanics). Introduction of a phenyl group in the 3-position of the furan ring causes a steric interaction that changes the conformation and conjugation of the molecule as compared to the 5-phenyl substituted derivative.

    The relative and absolute configurations of the chiral antimuscarinic stereoisomers of 3-(2,3-dihydrobenzofuran-2-yl)quinuclidine were determined by X-ray diffraction.

  • 3.
    Burkhardt, Anja
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    Widmalm, Göran
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Cumpstey, Ian
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    (Z)-1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranos-3-ulose O-benzyloxime2009In: Acta Crystallographica Section E: Structure Reports Online, E-ISSN 1600-5368, Vol. E65, no Part 3, p. o633-o633Article in journal (Refereed)
  • 4.
    Carlson, Stefan
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    High pressure structural investigations using single crystal techniques: influence of pressure on Jahn-Teller distorted alkali manganese fluorides1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The results from high-pressure single-crystal X-ray diffraction studies of some ternary sodium transition metal fluorides are presented. The structures of NaMnF4, Na2MnF5, Na3MnF6 and Na3ScF6 have been investigated at high pressures, and in connection with these studies the Na5Mn3F14 structure has been investigated at ambient pressure. The compressibilities of these compounds are compared in terms of structural features such as atom packing, bulk moduli and Jahn-Teller effect. An introduction to high-pressure diffraction techniques using diamond anvil cells, DAC, is included.

    Bulk modulus data at pressures lower than 1 GPa show a much higher compressibility for NaMnF4 (B0 = 16 GPa) than for the other compounds (B0 = 46-56 GPa). A successively higher transition pressure for the collapse of the single crystals into polycrystalline specimens is observed in the series NaMnF4 (1.3 GPa), Na2MnF5 (3.0 GPa) and Na3MnF6 (4.0 GPa). This can be explained in terms of the different connectivity between corner-sharing MnF6 octahedra, since NaMnF4 contains two-dimensional layers of corner-connected octahedra, Na2MnF5 one-dimensional strings, and Na3MnF6 isolated octahedra.

    The transitions in the Mn3+-containing compounds (d4 ion) are shown to be dependent on structural changes due to the Jahn-Teller distortions of the MnF6 octahedra. Both X-ray diffraction and spectroscopic studies of Na3MnF6 show a reversible phase transition at 2.2 GPa, which implies a reorientation of the static prolate Jahn-Teller distortions of the co-ordination around Mn3+. The Na3ScF6 compound, containing Sc3+ (d0 ion), shows no such transitions. Preliminary investigations of NaMnF4, Na2MnF5 and Na3MnF6 by high-pressure powder techniques show that new polycrystalline phases are formed when the pressure is raised above that where the single crystals collapse.

  • 5. Cong, D. Y.
    et al.
    Wang, Y. D.
    Xu, J. Z.
    Zuo, L.
    Zetterström, P.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Delaplane, R.
    Neutron diffraction study on crystal structure and phase transformation in Ni-Mn-Ga ferromagnetic shape memory alloys2007In: Powder Diffraction, ISSN 0885-7156, E-ISSN 1945-7413, Vol. 22, no 4, p. 307-311Article in journal (Refereed)
    Abstract [en]

    Crystal structure and phase transformation behaviors in two Ni-Mn-Ga ferromagnetic shape memory alloys (FSMAs) with compositions of Ni48Mn30Ga22 and Ni53Mn25Ga22 (at. %) as a function of temperature were investigated by in situ neutron diffraction experiments. Neutron diffraction technique proves to be highly efficient in characterizing structural transformation in Ni-Mn-Ga FSMAs, which consist of nearby elements in the periodic table. Our neutron results show that Ni48Mn30Ga22 has a cubic, L-21 Heusler structure from 373 to 293 K. Its crystal structure changes into a seven-layered orthorhombic martensitic structure when cooled to 243 K, and no further transformation is observed upon cooling to 19 K. Neutron diffraction results also show that Ni53Mn25Ga22 has a tetragonal 14/mmm martensitic structure from 20 to 403 K. A pre-transformation around room temperature is observed from an abrupt jump in unit-cell volume of Ni53Mn25Ga22, which corresponds with an endothermic peak detected in a heated DSC curve.

  • 6.
    Deiana, Luca
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Dziedzic, Pawel
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zhao, Gui-Ling
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Vesely, Jan
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Ibrahem, Ismail
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Rios, Ramón
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Córdova, Armando
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Catalytic asymmetric aziridination of α,β-unsaturated aldehydes2011In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 17, no 28, p. 7904-7917Article in journal (Refereed)
    Abstract [en]

    The development, scope, and application of the highly enantioselective organocatalytic aziridination of α,β-unsaturated aldehydes is presented. The aminocatalytic azirdination of α,β-unsaturated aldehydes enables the asymmetric formation of β-formyl aziridines with up to >19:1 d.r. and 99% ee. The aminocatalytic aziridination of α-monosubstituted enals gives access to terminal α-substituted-α-formyl aziridines in high yields and upto 99% ee. In the case of the organocatalytic aziridination of disubstituted α,β-unsaturated aldehydes, the transformations were highly diastereo- and enantioselective and give nearly enantiomerically pure β-formyl-functionalized aziridine products (99% ee). A highly enantioselective one-pot cascade sequence based on the combination of asymmetric amine and N-heterocycliccarbene catalysis (AHCC) is also disclosed. This one-pot three-component co-catalytic transformation between α,β-unsaturated aldehydes, hydroxylamine derivatives, and alcohols gives the corresponding N-tert-butoxycarbonyl and N-carbobenzyloxy-protected β-amino acid esters with ee values ranging from 92–99%. The mechanisms and stereochemistry of all these catalytic transformations are also discussed.

  • 7.
    Deiana, Luca
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zhao, Gui-Ling
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Leijonmarck, Hans
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Lehmann, Christian W.
    Córdova, Armando
    Stockholm University, Faculty of Science, Department of Organic Chemistry. Mid Sweden University, Sweden.
    Direct Catalytic Asymmetric Synthesis of Pyrazolidine Derivatives2012In: ChemistryOpen, ISSN 2191-1363, Vol. 1, no 3, p. 134-139Article in journal (Refereed)
    Abstract [en]

    A highly enantioselective, metal-free cascade reaction between di-1,2-N-protected hydrazine and α,β-unsaturated aldehydes is disclosed. The catalytic, asymmetric cascade transformation is a direct entry to 3-hydroxypyrazolidine and 3-allylpyrazolidine derivatives in one step and two steps, respectively, with >19:1 d.r. and 98–99 % ee using simple chiral pyrrolidines as catalysts.

  • 8.
    Eriksson, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    2,2’,6,6’-Tetrachloro-4,4’-propane-2,2-diyldiphenol, 2,2’,6-tribromo-4,4’-propane-2,2-diyldi phenol and 2,2’,6,6’-tetrabromo-4,4’-propane-2,2-diyldiphenol2001In: Acta crystallographica Section C, ISSN 0108-2701, Vol. 57, no 11, p. 1308-1312Article in journal (Refereed)
    Abstract [en]

    Three flame retardants with very similar molecular structures showing three different packing patterns have been studied. The crystal structure of 2,2',6,6'-tetrachloro-4,4'-propane-2,2-diyldiphenol, C15H12Cl4O2, can be described as a packing of sheets. The packing shows a very short intermolecular ClCl contact distance of 3.094  (2)  Å between pairs of molecules inside each sheet. The crystal structure of 2,2',6-tribromo-4,4'-propane-2,2-diyldiphenol, C15H13Br3O2, can be described as a packing of doubly stranded helical square tubes. These square helices are interconnected through BrBr contacts between different helices. Finally, a previously known structure, 2,2',6,6'-tetrabromo-4,4'-propane-2,2-diyldiphenol [Simonov, Cheban, Rotaru & Bels'skii (1986). Kristallografiya, 31, 397-399], C15H12Br4O2, which is the most commonly used flame retardant and which has twofold rotational symmetry, has been refined in the correct absolute configuration. The structure shows large differences from the chloro analogue with regard to packing, van der Waals distances and hydrogen-bond distances.

  • 9.
    Eriksson, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    Jakobsson, Eva
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    Decabromodiphenyl ether1999In: Acta crystallographica Section C, ISSN 0108-2701, Vol. 55, no 12, p. 2169-2171Article in journal (Refereed)
    Abstract [en]

    Bis(pentabromophenyl) ether, C12Br100, shows strangedifferences in the endocyclic angles between the twodifferent rings, although they are both substituted inthe same manner. Several short van der Waals contact distances give clues to the anomalous endocyclic anglesand some hints to the formation of decompositionproducts. We suggest that the intermolecular Br...Brcontacts contribute to the distortions of the ring systems.Usually distortions of this kind would be explained fromhighly anisotropic TLS behaviour, but the data from thetitle compound do not show any conclusive TLS effects.

  • 10.
    Eriksson, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Marsh, G
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Bergman, Å
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    3,4,5,6-Tetrabromo phenyl-2,3,4,5,6-pentabromo phenyl ether, C12HBr9O, 2,4,5,6-tetrabromo phenyl-2,3,4,5,6-pentabromo phenyl ether, C12HBr9O and 2,3,5,6-tetrabromo phenyl-2,3,4,5,6-pentabromo phenyl ether, C12HBr9O2004Manuscript (preprint) (Other (popular science, discussion, etc.))
  • 11.
    Ertan, Anne
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Structural studies of dipyridylmethane based ligands and metal complexes1995Doctoral thesis, comprehensive summary (Other academic)
  • 12.
    Gao, Chuanbo
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Izquierdo-Barba, Isabel
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Nakase, Ikuhiko
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Mesostructured silica based delivery system for a drug with a peptide as a cell-penetrating vector2009In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 122, no 1-3, p. 201-207Article in journal (Refereed)
    Abstract [en]

    A drug delivery system using mesostructured silica as a reservoir has been developed for the storage and controlled release of a drug with a cell-penetrating peptide (CPP) as a vector. We use fluorescein isothiocyanate (FITC) as the drug model and octaarginine (R8) as a vector to endow the drug with cell-penetrating property. The mesostructured silica reservoir system was prepared by using a one-pot liquid?crystal templating method, which is suitable for the encapsulation of intact FITC-R8 conjugates and sustained release of drugs without hampering their properties. The hydrophobic poly(propyl oxide) (PPO) shell of the pore-filling Pluronic F127 and the electrostatic interaction between R8 and siloxide ions on the pore walls act as the diffusion-limiting factors of the FITC-R8 conjugate. A sigmoidal in vitro release of FITC-R8 from mesostructured silica into phosphate buffered saline (PBS, pH 7.4) was observed and the typical release duration was 5 days at 37 ‹C. Release from the reservoir yielded significant elongation in duration of the FITC signals in DU145 cells by confocal microscopic analysis, compared with a single administration of FITC-R8.

     

  • 13.
    Gao, Weiming
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Åkermark, Torbjörn
    Li, Mingrun
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Sun, Licheng
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Attachment of a hydrogen-bonding carboxylate side chain to an [FeFe]-hydrogenase model complex: Influence on the catalytic mechanism2010In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 16, no 8, p. 2537-2546Article in journal (Refereed)
    Abstract [en]

    Azapropanedithiolate (adt)-bridged model complexes of [FeFe]-hydrogenase bearing a carboxylic acid functionality have been designed with the aim of decreasing the potential for reduction of protons to hydrogen. Protonation of the bisphosphine complexes 46 has been studied by in situ IR and NMR spectroscopy, which revealed that protonation with triflic acid most likely takes place first at the N-bridge for complex 4 but at the FeFe bond for complexes 5 and 6. Using an excess of acid, the diprotonated species could also be observed, but none of the protonated species was sufficiently stable to be isolated in a pure state. Electrochemical studies have provided an insight into the catalytic mechanisms under strongly acidic conditions, and have also shown that complexes 3 and 6 are electro-active in aqueous solution even in the absence of acid, presumably due to hydrogen bonding. Hydrogen evolution, driven by visible light, has been observed for three-component systems consisting of [Ru(bpy)3]2+, complex 1, 2, or 3, and ascorbic acid in CH3CN/D2O solution by on-line mass spectrometry.

  • 14. Gardestedt, Caroline
    et al.
    Plea, Mama
    Nilsson, Gertrud
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Jacks, Birgitta
    Jacks, Gunnar
    Zinc in Soils, Crops, and Meals in the Niger Inland Delta, Mali2009In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 38, no 6, p. 334-338Article in journal (Refereed)
    Abstract [en]

    Zinc deficiency is a problem in developing countries and not least so in Africa. This concerns both agriculture and human food provision. Zinc deficiency in soils may severely decrease yields, whereas insufficient zinc in food intake primarily affects the immune defense, notably in children. The present investigation concerned zinc availability in soils, crops, and food in the Niger inland delta in Mali. Agricultural soils are largely deficient in plant-available zinc, however, soils in close vicinity to habitation show elevated zinc concentrations. The zinc concentrations in crops are low; in rice, they are about half of reference ranges. Zinc intake assessed from a number of sampled meals was about half the recommended requirement. When zinc concentration is higher phytate was also high, which made the zinc less available. In spite of a recorded sufficient intake of iron, anemia is common and is most likely because of the high phytate concentration in the cereal-dominated diet. Increasing zinc and iron availability would be possible through the use of malting, fermentation, and soaking in food preparation. Finally, in the long run, any trace element deficiency, especially that of zinc in agricultural soils needs to be amended by addition of appropriate amounts in commercial fertilizers.

  • 15.
    Helmle, Olga
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Molecular recognition in the solid state: crystal structure studies of selected inclusion compounds of host molecules with roof-shaped skeleton1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This survey presents the results of single-crystal X-ray diffraction investigations of nine selected organic heteromolecular complexes in terms of the molecular recognition concept. The host molecules of the studied inclusion compounds have the 9,10-dihydro-9,10-ethanoanthracene moiety in common, to which various sensor groups possessing both proton donor and acceptor abilities are attached. The guests are small, uncharged organic molecules with different capabilities for hydrogen bonding. The present studies have provided information about non-covalent interactions in heteromolecular crystals and have evidenced the existence of a compromise/balance between the requirements of dense packing and directional-dependent intermolecular interactions. It has been shown that even supposedly weak interactions may play a structure-determining role in the absence of stronger intermolecular forces. The use of graph sets in the description of the observed hydrogen bonding patterns was found to be an efficient tool in the visualization of their common and different features. The geometry of the studied host molecules may be affected by the host/guest or host/host recognition modes. The observed conformational flexibility of the host molecules seems to be one of the factors responsible for their clathrate formation capability.

  • 16. Hemamala, U. L. C.
    et al.
    El-Ghussein, F.
    Muthu, D. V. S.
    Andersen, A. M. Krogh
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Carlson, S.
    Ouyang, L.
    Kruger, M. B.
    High-pressure Raman and infrared study of ZrV2O72007In: Solid State Communications, ISSN 0038-1098, E-ISSN 1879-2766, Vol. 141, no 12, p. 680-684Article in journal (Refereed)
    Abstract [en]

    The room-temperature Raman and infrared spectra of zirconium vanadate (ZrV2O7) were observed up to pressures of 12 GPa and 5.7 GPa, respectively. The frequencies of the optically active modes at ambient pressure were calculated using direct methods and compared with experimental values. Average mode Gruneisen parameters were calculated for the Raman and infrared active modes. Changes in the spectra under pressure indicate a phase transition at similar to 1.6 GPa, which is consistent with the previously observed a (cubic) to (pseudo-tetragonal) phase transition, and changes in the spectra at similar to 4 GPa are consistent with an irreversible transformation to an amorphous structure. 

  • 17. Lee, Myeong H.
    et al.
    Björling, T.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Hauback, B. C.
    Utsumi, T.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Moser, D.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Bull, D.
    Noreus, Dag
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Sankey, Otto F.
    Haeussermann, Ulrich
    Crystal structure, electronic structure, and vibrational properties of MAlSiH (M=Ca,Sr,Ba): Hydrogenation-induced semiconductors from the AlB2-type alloys MAlSi2008In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 78, no 19, p. 195209-Article in journal (Refereed)
    Abstract [en]

    Superconducting AlB2-type silicides CaAlSi, SrAlSi, and BaAlSi (MAlSi) absorb hydrogen and form semiconducting monohydrides where hydrogen is exclusively attached to Al. This induces a metal-nonmetal transition which is accompanied with only a minor rearrangement of the metal atoms. We report the synthesis and structure determination of CaAlSiH and BaAlSiH as well as a first-principles study of the electronic structure and vibrational property changes associated with the metal-nonmetal transition. We find that incorporation of H in MAlSi removes the partly occupied antibonding pi(*) band responsible for metallic behavior and turns it into an energetically low-lying Al-H bonding band. The fully occupied bonding pi band in MAlSi changes to a weakly dispersed band with Si p(z) (lone-pair) character in the hydrides, which becomes located below the Fermi level. The soft phonon mode in MAlSi pivotal for the superconducting properties stiffens considerably in the hydride. This mode is associated with the out-of-plane Al-Si vibration and is most affected by the formation of the Al-H bond. The mode of the Al-Si in-plane vibration, however, is unaffected, indicating that the Al-Si bond is equally strong in the metallic precursor and the semiconducting hydride. Al-H modes for MAlSiH are weakly dispersed. The frequencies of the stretching mode are around 1200 cm(-1) and virtually invariant to the M environment, indicating a covalent but weak Al-H interaction, which is interpreted as a dative bond from hydridic hydrogen to Al [Al <- H1-].

  • 18. Manyar, Haresh G.
    et al.
    Gianotti, Enrica
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Terasaki, Osamu
    Coluccia, Salvatore
    Tumbiolo, Simonetta
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Active Biocatalysts Based on Pepsin Immobilized in Mesoporous SBA-152008In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 112, no 46, p. 18110-18116Article in journal (Refereed)
    Abstract [en]

    Porcine pepsin was immobilized inside the SBA-15 mesoporous silica system through physical adsorption. A grafting step with 3-aminopropryltriethoxysilane (APTES) was performed to reduce the pore openings of the host material, in order to minimize the enzyme leaching. A detailed physical chemical characterization of hybrid materials was performed. The catalytic activity of the hybrid bioinorganic material, tested with two different substrates (hemoglobin and Z-L-glutamyl-L-tyrosine dipeptide), confirmed that pepsin was located inside the pore/channels of the silica material and that the grafting process did not affect the enzyme structure. The immobilized pepsin has maintained the necessary degree of freedom to fulfill its catalytic activity. The reusability of the so-called bioreactor was also investigated.

  • 19. Mayoral, Alvaro
    et al.
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Anderson, Paul. A.
    Synthesis of copper chloride nanowires by thermal treatment in the presence of zeolite X2010In: CrystEngComm, E-ISSN 1466-8033, Vol. 12, no 10, p. 3012-3018Article in journal (Refereed)
    Abstract [en]

    Copper(I) chloride nanowires have been synthesized by heating the salt in the presence of copper zeolite X (FAU structure type). Their structure and composition were studied by powder X-ray diffraction, transmission electron microscopy and energy dispersive X-ray spectroscopy. Wire growth was found to be dependent on a number of factors, the most important being the temperature of the reaction. The mechanism of wire growth, involving the occlusion of CuCl within the zeolite pores, is discussed.

  • 20.
    Miyasaka, Keiichi
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Neimark, Alex V
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Density Functional Theory of in Situ Synchrotron Powder X-ray Diffraction on Mesoporous Crystals: Argon Adsorption on MCM-412009In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 113, no 3, p. 791-794Article in journal (Refereed)
    Abstract [en]

    Bioactive microspheres with ordered mesoporous structure have been synthesized by means of the evaporation-induced self-assembly (EISA) method and following an aerosol-assisted route. The bioactive microspheres belong to the SiO2-CaO-P2O5 systems, and the mesoporous structure closely depends on the structure-directing agent as well as its interaction with the Ca2+ cations during the mesophase formation. Among the different tested surfactants, the triblock copolymer F127 leads to hexagonal ordered structures for low CaO contents, P123 leads to wormlike mesoporous structures for any CaO content, whereas the ionic surfactant cetyltrimethyl ammonium bromide (C16TAB) does not produce accessible mesopores at the external surface, for any CaO content. All the mesoporous SiO2-CaO-P2O5 microspheres develop an apatite like layer when reacting with simulated body fluid. Preliminary tests indicate the capability to load and release triclosan with kinetic profiles that depend on the pore structure, thus showing interesting features to be used in periodontal regenerative surgery and infection profilaxis

  • 21.
    Nilsson, Göran
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Inorganic Chemistry.
    Svensson, Gunnar
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Crystal Structure of BaNb6.3(1)Ti3.6(1)O16 containing Nb6O12, fused Ti3O13 Clusters and Ti3O10 Units2000In: Zeitschrift für Anorganische und Allgemeines Chemie, ISSN 0044-2313, E-ISSN 1521-3749, Vol. 626, no 1, p. 160-172Article in journal (Refereed)
    Abstract [en]

    A new phase, BaNb6.3(1)Ti3.6(1)O16, has been synthesised. Electron diffraction studies indicate an hexagonal substructure with unit cell parameters a ≈ 8.9 Å and c ≈ 9.5 Å. In some of the ED patterns superstructure reflections are present, indicating a supercell with a = √3 · asub and c = csub. However, X-ray single-crystal diffraction studies of a crystallite yielding reflections corresponding to the supercell revealed it to be monoclinic, with the unit cell parameters a = 26.811(2) Å, b = 15.4798(2) Å, c = 9.414(2) Å, β = γ = 90° and α = 90.0(3)°. The average crystal structure was refined, using the subcell with a = 8.937(2) Å, b = 15.479(2) Å, c = 9.414(2) Å, β = γ = 90° and α = 90.0(3)°, space group Cm11, and Z = 4, to RI = 3.24% and RwI = 3.44%. The structure can be described as an hexagonal close packing layers of Nb6 octahedra, Ba, and O atoms (A1, A2) and layers of O atoms (B1, B2), appearing in the packing sequence: A1B1A2B2. The Nb6 octahedra are found in isolated Nb6O12O6 clusters, and the Ti atoms in Ti3O13 and Ti3O10 units in octahedral and tetrahedral voids formed by O atoms, respectively. The Ti positions were found to be only partly occupied. Microanalysis indicates that some Nb atoms are located in the Ti3 triangles. A model is presented that interprets these not fully occupied Ti3 triangles as a result of a superimposing of three different structures. Two of these consist of two fused Ti3O13 units, forming an Ti6O19 unit, and a Ti3O10 unit, while the third consists of alternating Ti3O13 units.

  • 22.
    Ramstadius, Clinton
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Hekmat, Omid
    Department of Biochemistry, Lund University.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Stålbrand, Henrik
    Department of Biochemistry, Lund University.
    Cumpstey, Ian
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    β-Mannosidase and β-hexosaminidase inhibitors: synthesis of 1,2-bis-epi-valienamine and 1-epi-2-acetamido-2-deoxy-valienamine from D-mannose2009In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 20, no 6-8, p. 795-807Article in journal (Refereed)
    Abstract [en]

    A partially protected C-5C-5a unsaturated carbasugar with α-lyxo configuration is synthesised in five steps and 26% overall yield from a known mannose-derived hemiacetal, using ring-closing metathesis as a key step. This carbasugar is converted into valienamine derivatives with β-lyxo (i.e., corresponding to β-manno at C-1–C-4), α-lyxo (i.e., corresponding to α-manno at C-1–C-4) and β-2-acetamido-2-deoxy-xylo (i.e., corresponding to β-GlcNAc at C-1–C-4) configurations. This is the first report of the synthesis of the β-lyxo compound, 1,2-bis-epi-valienamine, which was found to inhibit Cellulomonas fimi β-mannosidase (CfMan2A) with Ki 140 μM. We report the crystal structures of three protected C-5C-5a unsaturated carbasugars with lyxo configuration.

  • 23.
    Ruan, Juanfang
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Wu, Peng
    Slater, Ben
    Zhao, Zhonglin
    Wu, Leilei
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Structural Characterization of Interlayer Expanded Zeolite Prepared From Ferrierite Lamellar Precursor2009In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 21, no 13, p. 2904-2911Article in journal (Refereed)
    Abstract [en]

    A novel methodology was successfully developed to expand the structure of zeolitic lamellar precursors through molecular alkoxysilylation. The method has been applied to PREFER (lamellar precursor of ferrierite). As a result, a novel crystalline interlayer expanded zeolite named as IEZ-FER (IEZ is the abbreviation of interlayer expanded zeolite) with enlarged distance perpendicular to the layer was synthesized through interlayer molecular alkoxysilylation. In this paper, the structure of IEZ- FER has been comprehensively studied by various means such as electron diffraction, high-resolution electron microscopy (HREM) and structure modeling. Our studies provide evidence that IEZ-FER preserves the pentasil layers corresponding to that found in the known three-dimensional (3D) FER zeolite, but it also shows a distinct expansion of the layer spacing (?5 A ? ). The newly formed channel system is distinct from that of the known 3D FER structure,which has 8-membered ring (MR) and 10MR pores along the [010] and [001] directions, respectively; IEZ-FER exhibits 10MR and 12MR pores along the [010] and [001] directions, respectively, in the interlayer space, which can be shown to explain the expansion in between layers. Furthermore, the formation of the large pores could be realized by the insertion of monolayer of Si species between the layers, and it explains the unique interlayer cross-linkages (Si(OH)(SiO2)3 and Si(OH)2(SiO2)2) present in the interlayer.

  • 24. Rusanova, D.
    et al.
    Christensen, K. E.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Persson, I.
    Pike, K. J.
    Antzutkin, O. N.
    Zou, X.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Dupree, R.
    Forsling, W.
    Copper(I) O,O '-dialkyldithiophosphate clusters: EXAFS, NMR and X-ray diffraction studies2007In: Journal of coordination chemistry (Print), ISSN 0095-8972, E-ISSN 1029-0389, Vol. 60, no 5, p. 517-525Article in journal (Refereed)
    Abstract [en]

    Copper K- edge EXAFS data for six polycrystalline cubic cluster compounds, {Cu-8[ S2P(OR)(2)](6)(mu(8)- S)} with R= Et, Pr-n, Pr-i, Bu-n, Bu-i and Am-i, show that the architecture of their Cu-8(S2P)(2)S cores is fairly rigid and independent of both length and branching of the alkyl chain, and that the structure of the cluster is maintained in acetone solution. Solid- state P-31 CP-MAS and static Cu-65 NMR data for {Cu-8[S2P(O-n Pr)(2)] 6(mu(8)- S)} and {Cu-8[S2P(OEt)(2)](6) mu(8)- S)} show similarities in the icosahedral O,O'- dialkyldithiophosphate shells and in the `cubic' copper cores in these cluster compounds. The crystal structure of {Cu-8[S2P(O-n Pr)(2)](6) (mu(8)- S)} was resolved using single- crystal X- ray diffraction.

  • 25.
    Sahoo, Suman
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Lundberg, Helena
    Ahlsten, Nanna
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Martín-Matute, Belén
    Heterogeneous Rh-Catalyzed Reactions of Allylic Alcohols2009Conference paper (Other academic)
    Abstract [en]

    The development of metal-catalyzed reactions that are atom-economical, environmentally benign, and highly selective and that take place under mild reaction conditions is of extreme importance. The isomerization of allylic alcohols to the corresponding carbonyl compounds can be catalyzed by transition metal complexes. We have shown before that this transformation involves the formation of metal enolates. When this isomerization is performed under homogeneous conditions in the presence of an electrophile, a new C-C bond is formed in a regioselective manner.

    1 Here, we present our studies towards the use of immobilized transition metal complexes as heterogeneous catalysts in tandem transformations of allylic alcohols. Different strategies and supports for the immobilization have been compared in this study.

  • 26.
    Samec, Joseph S. M.
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Éll, Alida H.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Åberg, Jenny B.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Privalov, Timofei
    Kungliga Tekniska Högskolan.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    Bäckvall, Jan-Erling
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Mechanistic Study of Hydrogen Transfer to Imines from a Hydroxycyclopentadienyl Ruthenium Hydride. Experimental Support for a Mechanism Involving Coordination of Imine to Ruthenium Prior to Hydrogen Transfer2006In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 128, no 44, p. 14293-14305Article in journal (Refereed)
    Abstract [en]

    Reaction of [2,3,4,5-Ph4(η5-C4COH)Ru(CO)2H] (2) with different imines afforded ruthenium amine complexes at low temperatures. At higher temperatures in the presence of 2, the complexes decomposed to give [Ru2(CO)4(μ-H)(C4Ph4COHOCC4Ph4)] (1) and free amine. Electron-rich imines gave ruthenium amine complexes with 2 at a lower temperature than did electron-deficient imines. The negligible deuterium isotope effect (kRuHOH/kRuDOD = 1.05) observed in the reaction of 2 with N-phenyl[1-(4-methoxyphenyl)ethylidene]amine (12) shows that neither hydride (RuH) nor proton (OH) is transferred to the imine in the rate-determining step. In the dehydrogenation of N-phenyl-1-phenylethylamine (4) to the corresponding imine 8 by [2,3,4,5-Ph4(η4-C4CO)Ru(CO)2] (A), the kinetic isotope effects observed support a stepwise hydrogen transfer where the isotope effect for C−H cleavage (kCHNH/kCDNH = 3.24) is equal to the combined (C−H, N−H) isotope effect (kCHNH/kCDND = 3.26). Hydrogenation of N-methyl(1-phenylethylidene)amine (14) by 2 in the presence of the external amine trap N-methyl-1-(4-methoxyphenyl)ethylamine (16) afforded 90−100% of complex [2,3,4,5-Ph4(η4-C4CO)]Ru(CO)2NH(CH3)(CHPhCH3) (15), which is the complex between ruthenium and the amine newly generated from the imine. At −80 °C the reaction of hydride 2 with 4-BnNH-C6H9=NPh (18), with an internal amine trap, only afforded [2,3,4,5-Ph44-C4CO)](CO)2RuNH(Ph)(C6H10-4-NHBn) (19), where the ruthenium binds to the amine originating from the imine, showing that neither complex A nor the diamine is formed. Above −8 °C complex 19 rearranged to the thermodynamically more stable [Ph4(η4-C4CO)](CO)2RuNH(Bn)(C6H10-4-NHPh) (20). These results are consistent with an inner sphere mechanism in which the substrate coordinates to ruthenium prior to hydrogen transfer and are difficult to explain with the outer sphere pathway previously proposed.

  • 27.
    Shu, Nanjiang
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Zhou, Tuping
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Hovmöller, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Prediction of zinc-binding sites in proteins from sequence2008In: Bioinformatics, ISSN 1367-4803, E-ISSN 1367-4811, Vol. 24, no 6, p. 775-782Article in journal (Refereed)
    Abstract [en]

    MOTIVATION: Motivated by the abundance, importance and unique functionality of zinc, both biologically and physiologically, we have developed an improved method for the prediction of zinc-binding sites in proteins from their amino acid sequences. RESULTS: By combining support vector machine (SVM) and homology-based predictions, our method predicts zinc-binding Cys, His, Asp and Glu with 75% precision (86% for Cys and His only) at 50% recall according to a 5-fold cross-validation on a non-redundant set of protein chains from the Protein Data Bank (PDB) (2727 chains, 235 of which bind zinc). Consequently, our method predicts zinc-binding Cys and His with 10% higher precision at different recall levels compared to a recently published method when tested on the same dataset. AVAILABILITY: The program is available for download at www.fos.su.se/~nanjiang/zincpred/download/

  • 28. Skobridis, Konstantinos
    et al.
    Theodorou, Vassiliki
    Alivertis, Dimitrios
    Seichter, Wilhelm
    Weber, Edwin
    Csoregh, Ingeborg
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Crystalline complexes of 2,2 '-bis(9-hydroxy-9-fluorenyl) biphenyl host with oligofunctional and conjugate functional group guests2007In: Supramolecular chemistry (Print), ISSN 1061-0278, E-ISSN 1029-0478, Vol. 19, no 6, p. 373-382Article in journal (Refereed)
    Abstract [en]

    Four crystalline inclusion compounds of the 2,20-bis( 9hydroxy- 9- fluorenyl) biphenyl host 1, containing diethylene glycol ( 1: 1) ( 1a), bis( 2- aminoethyl) amine ( 1: 1) ( 1b), methacrylic acid ( 1: 1) ( 1c) and 2- cyclopenten- 1- one ( 1: 2) ( 1d), have been studied by X- ray diffraction analysis from single crystals. Departure from the expectation, the multifunctional and conjugate functional guest molecules, potentially being able to offer multiple H donor-/ acceptorships or other modes of polar interaction due to the conjugation, do not result in the formation of infinitely connected networks in the crystal structures. Instead of this, discrete 2: 2 host - guest aggregates ( 1a, 1b), guest dimers ( 1c) and rather conventional host - guest units ( 1d) are found. Hence, inherent shielding effects of the host molecule owing to the fluorenyl moieties and the presence of a strong intramolecular hydrogen bond, impeding multiple intermolecular association, are not overcome by the merits of the guest molecules, showing that the host compound 1 is superior by structural constancy in its crystalline inclusions.

  • 29.
    Sun, Junliang
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Bonneau, Charlotte
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Cantín, Á
    Corma, A
    Díaz-Cabanas, M.J
    Moliner, M
    Zhang, Daliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Li, Mingrun
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    The ITQ-37 mesoporous chiral zeolite2009In: Nature, Vol. 458, p. 1154-1157Article in journal (Refereed)
    Abstract [en]

    The synthesis of crystalline molecular sieves with pore dimensions that fill the gap between microporous and mesoporous materials is a matter of fundamental and industrial interest. The preparation of zeolitic materials with extralarge pores and chiral frameworks would permit many new applications. Two important steps in this direction include the synthesis of ITQ-33, a stable zeolite with 18 × 10 × 10 ring windows, and the synthesis of SU-32, which has an intrinsically chiral zeolite structure and where each crystal exhibits only one handedness. Here we present a germanosilicate zeolite (ITQ-37) with extralarge 30-ring windows. Its structure was determined by combining selected area electron diffraction (SAED) and powder X-ray diffraction (PXRD) in a charge-flipping algorithm. The framework follows the SrSi2 (srs) minimal net and forms two unique cavities, each of which is connected to three other cavities to form a gyroidal channel system. These cavities comprise the enantiomorphous srs net of the framework. ITQ-37 is the first chiral zeolite with one single gyroidal channel. It has the lowest framework density (10.3 T atoms per 1,000 Å3) of all existing 4-coordinated crystalline oxide frameworks, and the pore volume of the corresponding silica polymorph would be 0.38 cm3 g-1.

    Keywords: srs-net, powder X-ray, charge flipping, electron microscopy

  • 30.
    Tran, Lien-Hoa
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, department of Structural Chemistry.
    Sun, Licheng
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    A New Square Planar Mn(III) Complex for Catalytic Epoxidation of Stilbene2008In: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 693, p. 1150-1153Article in journal (Refereed)
  • 31.
    Ullah, Farman
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zhao, Gui-Ling
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Deiana, Luca
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zhu, Mingzhao
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Dziedzic, Pawel
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Ibrahem, Ismail
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Hammar, Peter
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry. Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Córdova, Armando
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Enantioselective organocatalytic conjugate addition of fluorocarbon nucleophiles to α,β-unsaturated aldehydes2009In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 15, no 39, p. 10013-10017Article in journal (Refereed)
    Abstract [en]

    A highly chemo- and enantioselective organocatalytic addition of fluorocarbon nucleophiles, such as 1-fluoro-bis(phenylsulfonyl)methane, toα,β-unsaturated aldehydes is presented (see scheme). The reactions are catalyzed by simple chiral amines and give access to optically active fluorine derivatives in good yields and up to 95 % ee. Notably, the methodology can be applied to the formation of a chiral quaternary carbon center bearing a fluorine atom with high enantioselectivity.

  • 32.
    Westdahl, Marianne
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Non-single crystal X-ray diffraction methods: applications to zink-compounds and polymers1996Doctoral thesis, comprehensive summary (Other academic)
  • 33. Xu, W. Z.
    et al.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry. Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    Huang, Z. T.
    Zheng, Q. Y.
    Molecular encapsulation of a discrete (H2O)(32) cluster with S-6 symmetry in an organic crystalline supermolecule2009In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 2, p. 171-173Article in journal (Refereed)
    Abstract [en]

    A discrete S-6-symmetrical (H2O)(32) cluster was encapsulated in the cavity of an organic co-crystalline supermolecule constructed by the co-crystallization of guanidinium and benzenetribenzoate ions through hydrogen bonds, pi-pi and cation-pi interactions.

  • 34. Yang, Chia-Min
    et al.
    Lin, Ching-Yi
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Huang, Wei-Chia
    Chang, Li-Ling
    2D-Rectangular c2mm mesoporous silica nanoparticles with tunable elliptical channels and lattice dimensions2008In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 45, p. 5969-5971Article in journal (Refereed)
    Abstract [en]

    Mesoporous silica nanoparticles with a two-dimensional center-rectangular (plane group c2mm) lattice and coiled elliptical channels have been synthesized; the new synthetic route also allows simple control over the lattice dimensions and the elliptical shape of the channels.

  • 35.
    Zhao, Gui-Ling
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Dziedzic, Pawel
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Ullah, Farman
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Department of Structural Chemistry.
    Córdova, Armando
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Organocatalytic enantioselective domino synthesis of highly functionalized cyclohexanes with an all-carbon quaternary stereocenter2009In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 50, no 26, p. 3458-3462Article in journal (Refereed)
    Abstract [en]

    A highly enantioselective organocatalytic domino Michael/aldol reaction is presented. The reaction is catalyzed by chiral amines and gives access to highly functionalized cyclohexanes with one all-carbon quaternary stereocenter and multiple chiral stereocenters in high yields and 83–98% ee.

  • 36.
    Zhao, Gui-Ling
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Ullah, Farman
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Luca, Deiana
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Lin, Shuangzheng
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zhang, Qiong
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Ibrahem, Ismail
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Dziedzic, Pawel
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Córdova, Armando
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Dynamic kinetic asymmetric transformation (DYKAT) by combined amine- and transition-metal-catalyzed enantioselective cycloisomerization2010In: Chemistry: a European Journal, ISSN 0947-6539, Vol. 16, no 5, p. 1585-1591Article in journal (Refereed)
  • 37.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    3D structure determination from HRTEM and electron diffraction tomography2009Conference paper (Other (popular science, discussion, etc.))
  • 38.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    3D Structure determination of novel porous materials by electron crystallography2009Other (Other academic)
1 - 38 of 38
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