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  • 1. Abbasi, A.
    et al.
    Damian Risberg, Emilana
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Mink, Janos
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Persson, I.
    Sandström, Magnus
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sidorov, Y. V.
    Skripkin, Michail
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Ullström, A-S
    Crystallographic and Vibrational Spectroscopic Studies of Octakis(DMSO)lanthanoid(III) Iodides2007In: Inorganic Chemistry, Vol. 46, p. 7731-7741Article in journal (Refereed)
  • 2. Abbasi, A
    et al.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Beheshti, S
    Kianmehr, E
    Dimethyl 2-chloro-3-tosylmaleate2007In: Acta Crystallographica Section E, Vol. E63, p. o3774-Article in journal (Refereed)
  • 3. Abbasi, A
    et al.
    Golchoubian, H
    Khaniani, Y
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Badiei, A
    N,N'-Bis(2,6-dichlorobenzyl)ethylenediimine2007In: Acta Crystallographica Section E, Vol. E63, p. o3773-Article in journal (Refereed)
  • 4. Abbasi, A.
    et al.
    Habibian, M.
    Sandström, Magnus
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    mer-Trichloridotris(dimethyl sulfide-kS)-rhodium(III)2007In: Acta Crystallographica, Vol. E63, p. m1904-Article in journal (Refereed)
  • 5.
    Abbasi, Alireza
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Structural and Spectroscopic Studies of Solvated Metal Ions2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Crystallographic and spectroscopic studies have been performed of structures, coordination and chemical bonding for series of trivalent metal ions solvated by two oxygen-coordinating solvents, water and dimethyl sulfoxide (DMSO). The hydrated scandium(III) and lanthanoid(III) ions, La to Lu, are surrounded by tricapped trigonal prisms of aqua ligands in the isomorphous series of trifluoromethanesulfonates, [M(H2O)n](CF3SO3)3. For the smallest ions, M = Er, Tm, Yb, Lu, Sc, the hydration numbers decrease, n = 8.96(5), 8.8(1), 8.7(1), 8.5(1), 8.0(1), respectively, with decreasing size of the ion. The crystal structures at ambient temperature indicate randomly distributed vacancies of the capping oxygen atoms, and 2H solid-state NMR of the diamagnetic [M(H2O)n](CF3SO3)3, M = Sc, Lu, Y and La compounds revealed increasing mobility of the water ligands in the coordination sphere with increasing temperature, also for the fully nonahydrated LaIII and YIII ions. The stretching force constants of the Ln-O bonds, evaluated from vibrational spectroscopy, increased from 0.81 to 1.16 N cm-1 for the Ln-6O trigonal prism in a smooth correlation with the bond distances from La to Lu. For the capping Ln-3O bonds the increase from 0.49 to 0.65 N cm-1 reflects the increased ligand-ligand repulsion with decreasing ion size. This is also the reason for the water deficiency of the Er, Tm, Yb, Lu and Sc salts, and for [Sc(H2O)8.0](CF3SO3)3 the repulsion induced a phase transition at about 185 K that, by low temperature crystallography, was found to distort the coordination of water molecules toward a monocapped trigonal prism around the scandium(III) ion.

    All crystal structures of the octakis(dimethyl sulfoxide)lanthanoid(III) iodides comprise discrete [Ln(dmso)8]3+ complexes surrounded by iodide ions. The lanthanum(III) and praseodymium(III) compounds crystallize in the orthorhombic space group Pbca with more efficient packing than for the heavier and smaller ions in the lanthanoid series, which crystallize in the monoclinic space group P21/n. The group 13 metal ions, aluminium(III), gallium(III), indium(III), thallium(III), and also scandium(III) of group 3, form crystalline hexakis(dimethyl sulfoxide) solvates in the space group R 3, with octahedral MO6 coordination entities, which are increasingly compressed along one threefold axis for increasing ionic size. EXAFS measurements on the solvated ions display similar M-O bond distances in dimethyl sulfoxide solution as in the solid solvates. For all the solid dimethyl sulfoxide solvates the strength and nature of the metal-oxygen bond has been evaluated by normal coordinate analysis of vibrational spectra, and correlated with the S-O stretching vibrational mode.

    Distortions from regular octahedral six coordination are discussed for the hydrated isoelectronic soft mercury(II) and thallium(III) ions in the solid bisaquamercury(II) and trisaquatallium(III) trifluoromethanesulfonates, in terms of pseudo Jahn-Teller effects (PJTE). Mercury(II), generally more strongly influenced by PJTE distortions, displays a 2 + 4 Hg-O coordination forming chains that are held together in sheets by hydrogen bonds and in layers by van der Waals interactions, which explain the fragile structure of the crystals.

  • 6. Abbasi, Alireza
    et al.
    Adib, Mehdi
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Dimethyl 3-(tert-butylamino)-5-oxo-7-phenyl-1H,5H-pyrazolo[1,2-a]pyrazole-1,2-dicarboxylate2007In: Acta Crystallographica Section E, Vol. E63, p. o2115–o2116-Article in journal (Refereed)
  • 7. Abbasi, Alireza
    et al.
    Damian Risberg, Emiliana
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Mink, Janos
    Persson, Ingmar
    Sandström, Magnus
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Sidorov, Yurii V.
    Skripkin, Mikhail Yu.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Ullström, Ann-Sofi
    Crystallographic and Vibrational Spectroscopic Studies of Octakis(dimethyl sulfoxide)lanthanoid(III) Iodides2007In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 46, no 19, p. 7731-7741Article in journal (Refereed)
    Abstract [en]

    The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysprosium(III), erbium(III), and lutetium(III) iodides crystallize in the monoclinic space group P21/n (No. 14) with Z = 4, while the octakis(DMSO) iodides of the larger lanthanum(III), cerium(III), and praseodymium(III) ions crystallize in the orthorhombic space group Pbca (No. 61), Z = 8. In all [Ln(OS(Me2)8]I3 compounds the lanthanoid(III) ions coordinate eight DMSO oxygen atoms in a distorted square antiprism. Up to three of the DMSO ligands were found to be disordered and were described by two alternative configurations related by a twist around the metal−oxygen (Ln−O) bond. To resolve the atomic positions and achieve reliable Ln−O bond distances, complete semirigid DMSO molecules with restrained geometry and partial occupancy were refined for the alternative sites. This disorder model was also applied on previously collected data for the monoclinic octakis(DMSO)yttrium(III) iodide. At ambient temperature, the eight Ln−O bond distances are distributed over a range of about 0.1 Å. The average value increases from Ln−O 2.30, 2.34, 2.34, 2.36, 2.38, 2.40 to 2.43 Å (Ln = Lu, Er, Y, Dy, Gd, Sm, and Nd) for the monoclinic [Ln(OSMe2)8]I3 structures, and from 2.44, 2.47 to 2.49 Å (Ln = Pr, Ce, and La) for the orthorhombic structures, respectively. The average of the La−O and Nd−O bond distances remained unchanged at 100 K, 2.49 and 2.43 Å, respectively. Despite longer bond distances and larger Ln−O−S angles, the cell volumes are smaller for the orthorhombic structures (Ln = Pr, Ce, and La) than for the monoclinic structure with Ln = Nd, showing a more efficient packing arrangement. Raman and IR absorption spectra for the [Ln(OS(CH3)2)8]I3 (Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Er, Lu, and Y) compounds, also deuterated for La and Y, have been recorded and analyzed by means of normal coordinate methods. The force constants for the Ln−O and S−O stretching modes in the complexes increase with decreasing Ln−O bond distance and show increasing polarization of the bonds for the smaller and heavier lanthanoid(III) ions.

  • 8.
    Abbasi, Alireza
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lindqvist-Reis, Patric
    Eriksson, Lars
    Sandström, Dick
    Lidin, Sven
    Persson, Ingmar
    Sandström, Magnus
    Highly hydrated cations: Deficiency, mobility and coordination of water in crystalline nonahydrated scandium(III), yttrium(III) and lanthanoid(III) trifluoromethanesulfonate2005In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 11, no 14, p. 4065-4077Article in journal (Refereed)
    Abstract [en]

    Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped trigonal prism in a large number of crystalline hydrates. Water deficiency, randomly distributed over the capping positions, was found for the smallest metal ions in the isomorphous nonahydrated trifluoromethanesulfonates, [M(H2O)(n)]CF3SO3)(3), in which M=Sc-III, Lu-III, Yb-III, Tm-III or Er-III. The hydration number n increases (n=8.0(1), 8.4(1), 8.7(1), 8.8(1) and 8.96(5), respectively) with increasing ionic size. Deuterium (H-2) solid-state NMR spectroscopy revealed fast positional exchange between the coordinated capping and prism water molecules; this exchange started at temperatures higher than about 280 K for lutetium(m) and below 268 K for scandium(m). Similar positional exchange for the fully nonahydrated yttrium(m) and lanthanum(m) compounds started at higher temperatures, over about 330 and 360 K, respectively. An exchange mechanism is proposed that can exchange equatorial and capping water molecules within the restrictions of the crystal lattice, even for fully hydrated lanthanoid(III) ions. Phase transitions occurred for all the water-deficient compounds at; 185 K. The hydrated scandium(III) trifluoromethanesulfonate transforms reversibly (Delta H degrees= -0.80(1) kJ mol(-1) on cooling) to a trigonal unit cell that is almost nine times larger, with the scandium ion surrounded by seven fully occupied and two partly occupied oxygen atom positions in a distorted capped trigonal prism. The hydrogen bonding to the trifluoromethanesulfonate anions stabilises the trigonal prism of water ligands, even for the crowded hydration sphere of the smallest metal ions in the series. Implications for the Lewis acid catalytic activity of the hydrated scandium(III) and lanthanoid(III) trifluoromethanesulfonates for organic syntheses performed in aqueous media are discussed.

  • 9.
    Abbasi, Alireza
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Skripkin, Mikhail
    Damian, Emiliana
    Mink, Janos
    Ullström, Ann-Sofi
    Persson, Ingmar
    Sidorov, Yurii
    Sandström, Magnus
    Crystallographic, vibratioal spectroscopic and force field studies of octakis(dimethyl sulfoxide)lanthanide(III) solvatesManuscript (Other academic)
  • 10. Abrahamsson, Maria
    et al.
    Lundqvist, Maria J.
    Wolpher, Henriette
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Johansson, Olof
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Eriksson, Lars
    Department of Physical, Inorganic and Structural Chemistry.
    Bergquist, Jonas
    Rasmussen, Torben
    Becker, Hans-Christian
    Hammarström, Leif
    Norrby, Per-Ola
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Persson, Petter
    Steric influence on the excited-state lifetimes of ruthenium complexes with bipyridyl-alkanylene-pyridyl ligands2008In: Inorganic Chemistry, ISSN 0020-1669, Vol. 47, no 9, p. 3540-3548Article in journal (Refereed)
  • 11. 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.

  • 12.
    Ahlford, Katrin
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Ekström, Jesper
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zaitsev, Alexey B.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Ryberg, Per
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Adolfsson, Hans
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Asymmetric Transfer Hydrogenation of Ketones Catalyzed by Amino Acid Derived Rhodium Complexes: On the Origin of Enantioselectivity and Enantioswitchability2009In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 15, no 42, p. 11197-11209Article in journal (Refereed)
    Abstract [en]

    Amino acid based thioamides, hydroxamic acids, and hydrazides have been evaluated as ligands in the rhodium-catalyzed asymmetric transfer hydrogenation of ketones in 2-propanol. Catalysts containing thioamide ligands derived from L-valine were found to selectively generate the product with an R configuration (95 % ee), whereas the corresponding L-valine-based hydroxamic acids or hydrazides facilitated the formation of the (S)-alcohols (97 and 91 % ee, respectively). The catalytic reduction was examined by performing a structure–activity correlation investigation with differently functionalized or substituted ligands and the results obtained indicate that the major difference between the thioamide and hydroxamic acid based catalysts is the coordination mode of the ligands. Kinetic experiments were performed and the rate constants for the reduction reactions were determined by using rhodium–arene catalysts derived from amino acid thioamide and hydroxamic acid ligands. The data obtained show that the thioamide-based catalyst systems demonstrate a pseudo-first-order dependence on the substrate, whereas pseudo-zero-order dependence was observed for the hydroxamic acid containing catalysts. Furthermore, the kinetic experiments revealed that the rate-limiting steps of the two catalytic systems differ. From the data obtained in the structure–activity correlation investigation and along with the kinetic investigation it was concluded that the enantioswitchable nature of the catalysts studied originates from different ligand coordination, which affects the rate-limiting step of the catalytic reduction reaction.

  • 13. Ahniyaz, A
    et al.
    Bergstrom, Lennart
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sakamoto, Y
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Tuning the aspect ratio of ceria nanorods and nanodumbbells by a face-specific growth and dissolution process2008In: Crystal Growth & Design, Vol. 8, p. 1798-1800Article in journal (Refereed)
  • 14. Ahniyaz, A.
    et al.
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Bergström, Lennart
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Magnetic Field-Induced Assembly of Oriented Superlattices from Maghemite Nanocubes2007In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 104, p. 17570-17574Article in journal (Refereed)
  • 15.
    Akhtar, Farid
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Vasiliev, Petr
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Bergström, Lennart
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Hierarchically Porous Ceramics from Diatomite Powders by Pulsed Current Processing2009In: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 92, no 2, p. 338-343Article in journal (Refereed)
    Abstract [en]

    Hierarchically porous ceramic monoliths have been fabricated by pulsed current processing (PCP) of diatomite powders. The partial sintering behavior of the porous diatomite powders during PCP or spark plasma sintering was evaluated at temperatures between 600 degrees and 850 degrees C. Scanning electron microscopy and mercury porosimetry measurements showed that the PCP method was able to bond the diatomite powder together into relatively strong monoliths without significantly destroying the internal pores of the diatomite powder at a temperature range of 700 degrees-750 degrees C. Little fusion at the particle contact points occurred at temperatures below 650 degrees C while the powder showed partial melting and collapse of both the interparticle pores and the internal structure at temperatures above 800 degrees C.

  • 16.
    Akhtar, Tashfeen
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Eriksson, Lars
    Department of Physical, Inorganic and Structural Chemistry.
    Cumpstey, Ian
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Unusual synthesis of carbohydrate sec-sec ether-linked pseudodisaccharides2008In: Carbohydrate Research, ISSN 0008-6215, Vol. 343, no 12, p. 2094-2100Article in journal (Refereed)
  • 17.
    al-Karadaghi, Salam
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Refined crystal structures of Zn(II)- and Cu(II)-alcohol dehydrogenase: a comparative study1993Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The crystal structure of the ternary complex of horse liver alcohol dehydrogenase (LADH) with the coenzyme NADH and inhibitor dimethyl sulphoxide (DMSO) (space group PI) has been refined by simulated annealing with molecular dynamics and restrained positional refinement using the program system XPLOR. The resulting crystallographic R- factor is 17. 1 V, for 62 440 reflections in the resolution range 10.0 to 1.8 A.

    The structure of the active site Cut 11)-substituted LADH complex with NADH and DMSO (space group P2^ ) was solved by molecular replacement and refined to a crystallographic R-factor of 15.6 for 40 796 reflections in the resolution range 12.0 to 2.1 A.

    The refinement of the two structures demonstrated that the conformational transition from the open to the closed form of LADH induces asymmetry between the two subunits of the dimer. The asymmetry is a result of a relative shift of the catalytic domains with respect to each other. In the Cutll)-substituted LADH the catalytic domains are also rotated relative to each other by an angle of 1.2°.

    The coordination geometry of the Cu(II) and Zn(II) ions in the active site is compared. The distances from the metal to the protein ligands (Cys46, His67 and Cysl74) are similar for both the Zn(II) and Cu(II) ions. The distances of the oxygen of the inhibitor DMSO to the Cu(II) ion in the two subunits of the enzyme are 3.12 A and 3.44 A, which are considerably larger than the respective distances to the Zn(II) ion - 2. 19 A and 2.15 A. The coordination geometry of the Cut II) ion in LADH is closely related to that of the blue (type I) copper proteins.

  • 18.
    Almqvist, Jonas
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Structural modeling of membrane transporter proteins2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A fundamental process of all living organisms - the transport of molecules across cellular membranes through membrane transport proteins - is investigated.

    After a brief review of general properties of biological membranes follows a recollection of the major methods of membrane transport that Nature utilizes (Chapter 1). This is followed by a description of important experimental (Chapter 2) and theoretical methods (Chapter 3) for structural studies of membrane proteins. The findings on membrane protein transport in papers I-IV are then summarized (Chapter 4) and important findings are discussed. The remaining text is a discussion on relevant theoretical and experimental methods.

  • 19.
    Almqvist, Jonas
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Huang, Yafei
    Hovmöller, Sven
    Wang, Da-Neng
    Homology Modeling of the Human Microsomal Glucose 6-Phosphate Transporter Explains the Mutations That Cause the Glycogen Storage Disease Type Ib2004In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 43, p. 9289-9297Article in journal (Refereed)
  • 20.
    Almqvist, Jonas
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Huang, Yafei
    Laaksonen, A
    Wang, Da-Neng
    Hovmöller, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Docking and homology modeling explain inhibition of the human vesicular glutamate transporters2007In: Protein Science, ISSN 0961-8368, E-ISSN 1469-896X, Vol. 16, no 9, p. 1819-1829Article in journal (Refereed)
    Abstract [en]

    As membrane transporter proteins, VGLUT1-3 mediate the uptake of glutamate into synaptic vesicles at presynaptic nerve terminals of excitatory neural cells. This function is crucial for exocytosis and the role of glutamate as the major excitatory neurotransmitter in the central nervous system. The three transporters, sharing 76% amino acid sequence identity in humans, are highly homologous but differ in regional expression in the brain. Although little is known regarding their three- dimensional structures, hydropathy analysis on these proteins predicts 12 transmembrane segments connected by loops, a topology similar to other members in the major facilitator superfamily, where VGLUT1-3 have been phylogenetically classified. In this work, we present a three- dimensional model for the human VGLUT1 protein based on its distant bacterial homolog in the same superfamily, the glycerol- 3-phosphate transporter from Escherichia coli. This structural model, stable during molecular dynamics simulations in phospholipid bilayers solvated by water, reveals amino acid residues that face its pore and are likely to affect substrate translocation. Docking of VGLUT1 substrates to this pore localizes two different binding sites, to which inhibitors also bind with an overall trend in binding affinity that is in agreement with previously published experimental data.

  • 21.
    Almqvist, Jonas
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Laaksonen, A
    Hovmöller, Sven
    Huang, Y
    Computational modeling explains substrate binding in microsomal glucose-6-phosphate transportManuscript (Other academic)
  • 22. Altomare, Angela
    et al.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Werner, Per-Erik
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Advances in powder pattern indexing: N-TREOR092009In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 42, p. 768-775Article in journal (Refereed)
    Abstract [en]

    Powder pattern indexing can still be a challenge, despite the great recent advances in theoretical approaches, computer speed and experimental devices. More plausible unit cells, belonging to different crystal systems, are frequently found by the indexing programs, and recognition of the correct one may not be trivial. The task is, however, of extreme importance: in case of failure a lot of effort and computing time may be wasted. The classical figures of merit for estimating the unit-cell reliability {i.e.M20 [de Wolff (1968). J. Appl. Cryst.1, 108–113] and FN [Smith & Snyder (1979). J. Appl. Cryst.12, 60–65]} sometimes fail. For this reason, a new figure of merit has been introduced in N-TREOR09, the updated version of the indexing package N-TREOR [Altomare, Giacovazzo, Guagliardi, Moliterni, Rizzi & Werner (2000). J. Appl. Cryst. 33, 1180–1186], combining the information supplied by M20 with additional parameters such as the number of unindexed lines, the degree of overlap in the pattern (the so-called number of statistically independent observations), the symmetry deriving from the automatic evaluation of the extinction group, and the agreement between the calculated and observed profiles. The use of the new parameters requires a dramatic modification of the procedures used worldwide: in the approach presented here, extinction symbol and unit-cell determination are simultaneously estimated. N-TREOR09 benefits also from an improved indexing procedure in the triclinic system and has been integrated into EXPO2009, the updated version of EXPO2004 [Altomare, Caliandro, Camalli, Cuocci, Giacovazzo, Moliterni & Rizzi (2004). J. Appl. Cryst. 37, 1025–1028]. The application of the new procedure to a large set of test structures is described.

  • 23.
    Andersson, Linnéa
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry. Oorganisk kemi.
    Exploring expandable microspheres as a novel pore former in gel-cast macroporous alumina2008Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Expandable microspheres have been explored as sacrificial templates for the production of macroporous ceramics. Concentrated alumina powder suspensions that contain expandable microspheres have been consolidated by gel-casting. The temperature range for the setting of the monomers and cross-linkers in the gel-casting system was tailored to allow the gas-filled polymer spheres to expand before the surrounding powder body became rigid. It has been demonstrated that it is possible to tune and tailor the porosity up to 86 % and the pore size distribution from 15 up to 150 micrometers by controlling the amount and size of the expandable microspheres. Scanning electron microscopy showed that the porosity became more and more open as the total porosity increased. This was corroborated by a preliminary study by X-ray µ Computed Tomography, which showed a very high connectivity between the pores, in a macroporous alumina body with a high porosity. The connectivity was reduced when alumina particles were deposited as a homogenous coating of on the expandable microspheres by a layer-by-layer coating process. The expandable microspheres has the advantage that a relatively low amount of organic material results in a large pore volume, which allow rapid and facile burn-out. It was demonstrated that the temperature induced expansion of the microspheres, and the associated increase of the suspension volume could be used as a novel casting method to yield macroporous alumina bodies with complex shapes. Ceramics produced with this method could find application ranging from bone scaffolds to low mass kiln furniture.

  • 24.
    Andersson, Linnéa
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Bergström, Lennart
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Gas-filled microspheres as an expandable sacrificial template for direct casting of complex-shaped macroporous ceramics2008In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 28, no 15, p. 2815-2821Article in journal (Refereed)
    Abstract [en]

    Expandable microspheres have been used as a sacrificial template to produce macroporous ceramic materials by a gel-casting process. The temperature range for the gel-casting process has been tuned to allow the gas-filled polymer spheres to expand prior to the setting of the powder body. It is demonstrated that by controlling the amount and size of the expandable microspheres it is possible to tune and tailor the porosity up to 86% and the pore size distribution from 15 up to 150 mu m. The expandable microspheres add a relatively low amount of organic material that allows rapid and facile burn-out. The temperature-induced expansion of the microspheres and the associated volume increase of the suspension has been used as a simple zero-pressure near-net shaping method to yield complex-shaped macroporous alumina bodies.

  • 25.
    Andersson, Nina
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Mesostructured materials: Synthesis towards applications2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A new class of materials with well-defined structures on mesoscopic (2-50 nm) length scales has attracted considerable interest during the last decade. These mesostructured mataterials are formed from the self-assembly of amphiphillic molecules and inorganic precursors. The aim of this thesis has been to develop preparation methods that are scalable, and at the same time allow for efficient structural control coupled with possibility to incorporate different functionalities.

    Two different industrial processes for production of particles with spherical morphology were successfully tailored for synthesis of well-ordered mesostructured particles. An existing spray drying method for a fast and continuous production was further developed, and for the first time, an emulsion-based method was implemented. The latter method resulted in superior control of both particle size and internal mesostructure.

    Mesostructured photochromic pigments were synthesised by incorporating photochromic dyes in the organic domains of the surfactant templated inorganic/organic mesostructured silica particles. The pigments were produced using a one-pot synthesis method employing an aerosol reactor, allowing control over both the internal mesostructure and the dye content. We show that transparent photochromic films can be prepared using latex binders and conventional coating technology.

    Mesoporous magnetic carrier materials were prepared by adding iron oxide nanoparticles during either the emulsion- or aerosol processing. The surfactant templated silica matrix displayed well-ordered internal pore architecture with limited pore blocking caused by the incorporated iron oxide nanoparticles. The iron oxide content was precisely controlled, and the magnetic properties were preserved during the processing. Finally we demonstrate that these materials can be used to magnetically separate water-soluble dyes from solution.

  • 26.
    Andersson, Nina
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Alberius, Peter
    Aerosol based synthesis of mesostructured particles using ammonia gas as a condensation promoterIn: Microporous and Mesoporous MaterialsArticle in journal (Refereed)
  • 27.
    Andersson, Nina
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Alberius, Peter
    Skov Pedersen, Jan
    Bergström, Lennart
    Structural features and adsorption behaviour of mesoporous silica particles formed from droplets generated in a spraying chamber2004In: Microporous and Mesoporous Materials, ISSN 1387-1811, Vol. 72, no 1-3, p. 175-183Article in journal (Refereed)
  • 28.
    Andersson, Nina
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Alberius, Peter
    Örtegren, Jonas
    Lindgern, Mikael
    Bergström, Lennart
    Photochromic mesostructured silica pigments dispersed in latex films2005In: Journal of Materials Chemistry, ISSN 0959-9428, Vol. 15, no 34, p. 3507-3513Article in journal (Refereed)
  • 29.
    Andersson, Nina
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Corkery, Robert
    Alberius, Peter
    One-Pot Synthesis of Well-Ordered Mesoporous Magnetic Carriers2007In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 17, p. 2700-2705Article in journal (Refereed)
    Abstract [en]

    The facile preparation of a mesoporous magnetic carrier technology is demonstrated. The micron-sized spherical mesostructured particles are prepared using a newly-developed, one-step, combined emulsion and solvent evaporation (ESE) method. The surfactant-templated silica matrix display a well-ordered internal pore architecture. Very limited pore blocking, and only to a limited degree disordered- or worm-like structures are observed, induced by the iron oxide nanoparticles added to provide the superparamagnetic properties.The iron oxide content was precisely controlled, and the magnetic properties were well preserved during the process. Finally we demonstrate the applicability of the magnetically separable mesoporous material as an adsorbent for specific dissolved materials from dilute aqueous solutions.

  • 30.
    Andersson, Nina
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Kronberg, Bengt
    Corkery, Robert
    Alberius, Peter
    Combined Emulsion and Solvent Evaporation (ESE) Synthesis Route to Well-Ordered Mesoporous Materials2007In: Langmuir, ISSN 0743-7463, Vol. 23, no 3, p. 1459-1464Article in journal (Refereed)
  • 31. Arcos, D.
    et al.
    Lopez-Noriega, A.
    Ruiz-Hernandez, E.
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Vallet-Reg, M.
    Ordered Mesoporous Microspheres for Bone Grafting and Drug Delivery2009In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 21, no 6, p. 1000-1009Article 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.

     

  • 32.
    Aski, Sahar Nikkhou
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lo, Andy Y H
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Edén, Mattias
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Kowalewski, Jozef
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Brotin, Thierry
    Dutasta, Jean-Pierre
    Studies of Inclusion Complexes of Dichloromethane in Cryptophanes by Exchange Kinetics and 13C NMR in Solution and the Solid State2008In: Journal of Physical Chemistry C, Vol. 112, p. 13873-13881Article in journal (Refereed)
    Abstract [en]

    Cryptophanes are molecular hosts having high binding affinities for small, neutral molecules in weakly polar solvents. We have previously studied dichloromethane as a guest inside the cavity of cryptophane-E (cryptophane-333), in solution as well as in the solid state. Here, we present a solution 13C relaxation study of dichloromethane as the guest molecule complexed in the cavity of two smaller hosts: cryptophane-A (cryptophane-222) and cryptophane-223. Carbon-13 relaxation measurements were performed for both guest and host molecules. Exchange kinetics have to be explicitly taken into consideration in order to derive 13C relaxation properties of the bound guest. Rate coefficients were measured using proton 1D-exchange experiments. We have also investigated dichloromethane complexed in the cavity of cryptophane-233 in the solid state, by estimating the motionally averaged 13C-1H dipolar interactions from recoupling experiments under magic angle spinning (MAS) conditions. The measurements for the three cryptophanes provide a consistent set of results for the extent of rotational freedom of the guest inside the host cavities.

  • 33.
    Aski, Sahar Nikkhou
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Takacs, Zoltan
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Kowalewski, Jozef
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Inclusion complexes of cryptophane–E with dichloromethane and chloroform: A thermodynamic and kinetic study using the 1D-EXSY NMR method2008In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 46, no 12, p. 1135-1140Article in journal (Refereed)
    Abstract [en]

    Complexation equilibria and kinetics of exchange of chloroform and dichloromethane molecules between the cavity of cryptophane-E and bulk solution were investigated using NMR methods. Using one dimensional magnetization transfer (1D-EXSY type sequence), chemical exchange rates were measured in different temperature ranges, limited by the equilibrium constant values of the complexes and the boiling points of the guest substances. From the kinetic data, activation energies were calculated using the Arrhenius equation. From the temperature dependence of the association constant data, the enthalpy and entropy of complexation were estimated and compared with values for similar complexes of other cryptophanes.

  • 34. Atluri, Rambabu
    et al.
    Garcia Bennett, Alfonso E
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Hydrothermal Phase Transformation of Bicontinuous Cubic Mesoporous Material AMS-62008In: Chemistry of Materials, Vol. 20, no 12, p. 3857–3866-Article in journal (Refereed)
    Abstract [en]

    The controlled synthesis of ordered anionic surfactant templated mesoporous silica with cubic Ia3d̅ structure (AMS-6) is reported via prolonged periods of hydrothermal treatment (HT). The cubic Ia3d̅ mesophase transforms to hexagonal p6mm after 8 days of HT at 100 °C. Surprisingly, the hexagonal phase is stable only for a limited period after which a reversal to the cubic Ia3d̅ mesostructure is observed. Characterization methods such as powder X-ray diffraction (XRD), electron microscopy (SEM, TEM), N2-isotherms, magic-angle spinning (MAS) 29Si NMR spectroscopy, and thermogravimetric analysis (TGA) have been employed to follow structural and textural changes of the materials prepared. Data show that the resultant mesostructure and its textural properties are highly dependent on the period of HT with less unit-cell shrinkage on calcination after extensive HT. Furthermore, evidence of two different solid−solid phase mechanisms during HT is presented. The initial transition is consistent with a restructuring of the surfactant packing and a depletion of the organic moieties from the organo-silica wall as evident from 29Si NMR spectroscopy. The return to the bicontinuous cubic phase is driven by changes in charge matching at the organic−inorganic interface as a result of increases in the polymerization of the silica wall. The textural properties, and in particular the presence or absence of surface porosity, has been controlled through variations in hydrothermal treatment. These are associated with specific growth directions of cubic AMS-6 crystals. The synthetic method described allows us to easily prepare phase pure and intermediate mesostructured nanoparticles.

  • 35.
    Atluri, Rambabu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Garcia-Bennett, Alfonso E.
    Non-Surfactant Supramolecular Templating Synthesis of Ordered Mesoporous Silica2009In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 131, no 9, p. 3189-3191Article in journal (Refereed)
    Abstract [en]

    Hoogsteen-bonded tetrads and pentamers are formed by a large variety of organic molecules through H-donor and acceptor groups capable of inducing self-organization to form columnar and hexagonal mesophases. The biological importance of such macromolecular structures is exemplified by the assembly of guanosine-rich groups of telomere units and their implication in chromosomal replication. Folic acid is composed of a pterin group, chemically and structurally similar to guanine, conjugated to an l-glutamate moiety via a p-amino benzoic acid. Our aim has been to develop a delivery vehicle for folic acid and at the same time provide a novel synthetic route for ordered mesoporous materials without the use of amphiphilic surfactants. We present a new nonsurfactant route for the synthesis of highly ordered mesoporous materials, based on the supramolecular templating of stacked arrays of the tetramer-forming pterin groups of folic acid under a variety of synthetic conditions. This method leads to hexagonally ordered mesoporous structures with gyroid, spherical, and chiral morphologies with pores on the order of 25−30 Å in diameter and surface areas above 1000 m2/g. More importantly circular dichroism studies reveal that the folate template possesses a chiral signature within the pores in the as-synthesized solid and that chirality is transferred from the folate template to the pore surface via the aminopropyl triethoxysilane costructure directing agent used in the supramolecular assembly. This novel templating approach for ordered mesoporous materials breaks the hegemony of surfactant micellar systems for the preparation of these exciting high surface area solids and opens new opportunities for structural control, design of pore geometry, and novel applications.

  • 36.
    Aydin, Juhanes
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Kumar, K. Senthil
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Eriksson, Lars
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Szabó, Kálmán J.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Palladium pincer complex-catalyzed condensation of sulfonimines and isocyanoacetate to imidazoline derivatives. Dependence of the stereoselectivity on the ligand effects2007In: Advanced Synthesis & Catalysis, ISSN 1615-4150, Vol. 349, no 17-18, p. 2585-2594Article in journal (Refereed)
  • 37. Baerlocher, C.
    et al.
    Gramm, F.
    Massüger, L.
    McCusker, L. B.
    He, Z.B.
    Hovmöller, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Structure of the Polycrystalline Zeolite Catalyst IM-5 Solved by Enhanced Charge Flipping2007In: Science, Vol. 315, p. 1113-1116Article in journal (Refereed)
  • 38. Banenzoue, Charles
    et al.
    Ponou, Simeon
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Inorganic Chemistry.
    Lambi, John Ngolui
    Non-isovalent substitution in a Zintl phase with the TiNiSi type structure, CaMg1-xAgxGe [x=0.13 (3)]2009In: Acta Crystallographica Section E: Structure Reports Online, ISSN 1600-5368, E-ISSN 1600-5368, Vol. 65, p. i90-U56Article in journal (Refereed)
    Abstract [en]

    Single crystals of the title Ag-substituted calcium magnesium germanide, CaMg1-xAgxGe [x = 0.13 (3)] were obtained from the reaction of the corresponding elements at high temperature. The compound crystallizes with the TiNiSi structure type (Pearson code oP12) and represents an Ag-substituted derivative of the Zintl phase CaMgGe in which a small fraction of the divalent Mg atoms have been replaced by monovalent Ag atoms. All three atoms in the asymmetric unit (Ca, Mg/Ag, Ge) occupy special positions with the same site symmetry (.m.). Although the end member CaAgGe has been reported in an isomorphic superstructure of the same TiNiSi type, higher Ag content in solid solutions could not be achieved due to competitive formation of other, perhaps more stable, phases.

  • 39.
    Batra, Vidya S
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Urbonaite, S
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Svensson, G
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Characterisation of unburned carbon in bagasse fly ash2008In: Fuel, Vol. 87, p. 2972-2976Article in journal (Refereed)
  • 40. Becker, R.
    et al.
    Berger, H.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    A new modification of Cu3(SeO3)2Cl2: an oxohalide with an unusual CuII coordination polyhedron2007In: Acta Crystallographica, Vol. C63Article in journal (Refereed)
  • 41. Becker, R.
    et al.
    Berger, H.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Monoclinic Cu3(SeO3)(2)Cl2: an oxohalide with an unusual CuO4Cl trigonal-bipyramidal coordination2007In: Acta Crystallographica Section C-Crystal Structure Communications, Vol. 63, p. 14-16Article in journal (Refereed)
  • 42. Becker, R
    et al.
    Johnsson, M
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Berger, H
    Prester, M
    Zivkovic, I
    Drobac, D
    Miljak, M
    Herak, M
    Crystal structure and magnetic properties of Co7(TeO3)(4)Br6 - a new cobalt tellurite bromide2006In: Solid State Sciences, Vol. 8, p. 836-842Article in journal (Refereed)
  • 43. Becker, R.
    et al.
    Prester, M.
    Berger, H.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Drobac, D.
    Zivkovic, I.
    Crystal structure and magnetic properties of the new cobalt tellurite2007In: Solid State Sciences, Vol. 9, p. 223-230Article in journal (Refereed)
  • 44.
    Becker, Richard
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Terminating species and Lewis acid-base preference in oxohalides – a new route to low-dimensional compounds2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is based upon synthesis and structure determination of new transition metal oxo-halide compounds, which includes p-element cations that have a stereochemically active lone pair. A synthesis concept has been developed, which uses several different structural features to increase the possibility to yield a low-dimensional arrangement of transition metal cations. A total of 17 new compounds has been synthesised and their structures have been determined via single-crystal X-ray diffraction. The halides and the stereochemically active lone-pairs will typically act as terminating species segregating into regions of non-bonding volumes, which may take the form of 2D layers, 1D channels or Euclidean spheres. The transition metals that have been used for this work are copper, cobalt and iron. The Hard-Soft-Acid-Base principle has been utilized to match strong Lewis acids to strong Lewis bases and weak acids to weak bases. All compounds show tendencies towards low-dimensionality; they all have sheets of transition metal cations arranged into layers, where the layers most often are connected via weak dispersion forces.

  • 45.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Berger, Helmuth
    Johnsson, Mats
    Prester, Mladen
    Marohnic, Zeljko
    Miljak, Marko
    Herak, Mirta
    Crystal Structure and Magnetic Properties of Co2TeO3Cl2 and Co2TeO3Br22006In: Journal of Solid State Chemistry, ISSN 0022-4596, Vol. 179, no 3, p. 836-842Article in journal (Refereed)
  • 46.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Crystal Structure of Cu3Bi(TeO3)2O2Cl: a Kagomé lattice type compound2005In: Solid State Sciences, ISSN 1293-2558, Vol. 7, no 4, p. 375-380Article in journal (Refereed)
  • 47.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Three new tellurite halides with unusual Te4+ coordinations and iron honeycomb lattice variants2007In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 180, no 5, p. 1750-1758Article in journal (Refereed)
    Abstract [en]

    The crystal structure of three new iron and copper-iron tellurite halides are presented; (I) Cu3Fe8Te12O32Cl10 that crystallizes in the orthorhombic space group Pmmn, (II) Fe8Te12O32Cl3Br3 that crystallizes in the monoclinic space group P21/c, and (III) Fe5(TeO3)6Cl2 that crystallizes in the triclinic space group P-1. The crystal structures were solved from single crystal X-ray diffraction data. All three compounds have layered crystal structures where the Fe atoms form variants of the honeycomb lattice. Highly unusual Te4+ coordination polyhedra are exemplified: [TeO3+1E], [TeO3XE], [TeO3+1XE], and [TeO3X2E] (X=halide ion, E=the lone–pair valence electrons). The crystal structures contain large non-bonding volumes occupied by the stereochemically active lone–pair electrons on Te4+.

  • 48.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Berger, Helmuth
    Crystal Structure of the New Cobalt Tellurite Chloride Co5Te4O11Cl42007In: Zeitschrift für Anorganische und Allgemeines Chemie, ISSN 0044-2313, E-ISSN 1521-3749, Vol. 633, no 3, p. 422-424Article in journal (Refereed)
    Abstract [en]

    The crystal structure of the new compound Co5Te4O11Cl4 is described. It crystallizes in the triclinic system, space group P-1 with the unit cell parameters a = 822.26(8) pm, b = 1029.7(1) pm, c = 1031.1(1) pm, = 110.80(1)°, β = 97.950(9)°, = 98.260(9)° and Z = 2. The structure is layered along the bc–plane and built by [CoO5Cl], [CoO4Cl2] and [CoO4Cl] polyhedra sandwiched by [TeO3E] and [TeO4E] polyhedra. The layers can be regarded as infinite molecules without any net charge and only weak van der Waals forces connect them to each other. The halides and the lone-pair, E, of TeIV protrude from the layers.

  • 49.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Berger, Helmuth
    Monoclinic Cu3(SeO3)2Cl2: an oxohalide with an unusual CuO4Cl trigonal bipyramidal coordination2007In: Acta Crystallographica Section C: Crystal Structure Communications, ISSN 0108-2701, Vol. C63, no 1, p. i4-i6Article in journal (Refereed)
  • 50.
    Becker, Richard
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Johnsson, Mats
    Berger, Helmuth
    Prester, Mladen
    Zivkovic, Ivica
    Drobac, Djuro
    Miljak, Marko
    Herak, Mirta
    Crystal structure and magnetic properties of Co7(TeO3)4Br6 – a new cobalt tellurite bromide2006In: Solid State Sciences, ISSN 1293-2558, Vol. 8, no 7, p. 836-842Article in journal (Refereed)
1234567 1 - 50 of 683
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