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  • 201. Gao, Weiming
    et al.
    Ekström, Jesper
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Liu, Jianhui
    Chen, Changneng
    Eriksson, Lars
    Department of Physical, Inorganic and Structural Chemistry.
    Weng, Linhong
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Licheng
    Binuclear iron-sulfur complexes with bidentate phosphine ligands as active site models of Fe-hydrogenase and their catalytic proton reduction2007In: Inorganic Chemistry, ISSN 0020-1669, Vol. 46, no 6, p. 1981-1991Article in journal (Refereed)
  • 202.
    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.

  • 203. Garcia-Bennett, AE.
    et al.
    Brohede, U.
    Hodgkins, R.
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Strømme, M.
    A mechanistic study of the formation of mesoporous structures from in situ ac conductivity measurements2007In: Langmuir, Vol. 23, no 19, p. 9875-9881Article in journal (Refereed)
  • 204. Garcia-Bennett, Alfonso E.
    et al.
    Che, Shunai
    Miyasaka, Keiichi
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sakamoto, Yasuhiro
    Ohsuna, Tetsu
    Liu, Zheng
    Terasaki, Osamu
    Studies of anionic surfactant templated mesoporous structures by electron microscopy2005In: Studies in Surface Science and Catalysis, ISSN 0167-2991, Vol. 156, p. 11-18Article in journal (Refereed)
  • 205. Garcia-Bennett, Alfonso E.
    et al.
    Miyasaka, Keiichi
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Che, Shunai
    Terasaki, Osamu
    Structural solution of mesocaged material AMS-82004In: Chemistry of Materials, ISSN 0897-4756, Vol. 16, p. 3597-3605Article in journal (Refereed)
  • 206. 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.

  • 207.
    Georgieva, Elka R.
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Narvaez, Ana Julia
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Hedin, Niklas
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Secondary structure conversions of Mycobacterium tuberculosis ribonucleotide reductase protein R2 under varying pH and temperature conditions2008In: Biophysical Chemistry, Vol. 137, no 43-48Article in journal (Refereed)
    Abstract [en]

    The structural properties of Mycobacterium tuberculosis (Mtb) ribonucleotide reductase R2 protein were studied under varying pH and temperature conditions by circular dichroism (CD) spectroscopy as well as dynamic light scattering (DLS). Under physiological conditions this protein has a high alpha-helical content, similar to the corresponding protein from other species, e.g. mouse. Decreasing the pH induced significant structure conversions. When pH was below 6.5 an aggregated structure was observed and reached a maximum at pH 4. The aggregated state of this protein was verified by DLS and was found to be rich in beta-structure. This amyloid-like structure transformed into a molten globule state with high temperature stability (between 25 and 80 degrees C) at pH below 3. The corresponding mouse protein R2 under similar conditions showed no evidence of an aggregated state around pH 4.

  • 208.
    Ghalebani, Leila
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Probing Dynamics of Oligosaccharides by Interference Phenomena in NMR Relaxation2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Oligosaccharides (carbohydrates) are a large class of biological molecules that are important as energy sources in the human body and have enormously varied biological functions. It is generally believed that biological activities of carbohydrates are related to their internal dynamics. The dynamic properties of some oligosaccharides in solution are studied in this thesis, by NMR relaxation. We have employed relaxation interference effects to investigate the conformational dynamics within oligosaccharides (in-tramolecular dynamics) and paramagnetic relaxation enhancement (PRE) as an experimental tool to study intermolecular dynamics. Most of the thesis concerns the dynamics of the methylene group in the two possibly mobile parts of the oligosaccharide: in the exocyclic hydroxymethyl moiety and in the glycosidic linkage position. To perform conformational dynamic studies, the more traditional auto-relaxation pa-rameters are combined with the relaxation interference terms or the cross-correlated relaxation rates (CCRRs). Some experimental schemes based on the initial-rate technique were developed for measuring CCRRs. The techniques are useful for labelled sugars as well as naturally abundant ones. Furthermore, various dynamical models ranging from the Lipari–Szabo approach to several more informative and complicated models such as the two-site jump model, restricted internal rotation and slowly relaxing local structure (SRLS), have been employed to interpret our experimental data. We have combined and com-pared different models; we have also developed a novel approach to existing models, by scaling dipolar coupling constants (DCC), to extract the dynamic behaviour and structural properties of the system. We found that the auto- and cross-correlated relaxation data analyses yield a consistent picture of the dynam-ics in all cases. Additionally, our investigations show that CCRRs are practically important for verifica-tion of certain dynamical and structural information that is difficult to be determined by other means. Moreover, the anisotropy of the carbon-13 chemical shielding tensor in the methylene group has been estimated, using the interference between dipole-dipole and chemical shift anisotropy.

    This thesis also discusses using the PRE to investigate sugar dynamics relative to a paramagnetic MRI contrast agent in solution, which might be important in medicine. We have studied the intramolecu-lar dynamics of the trisaccharide raffinose in the presence of a gadolinium complex. We also investigated the effect of translational diffusion instead of rotational diffusion, which is normally more important in NMR. The paramagnetically enhanced spin–lattice relaxation rates of aqueous protons over a wide range of magnetic fields and of carbon-13 and protons of the sugar at high fields have been measured. The nuclear magnetic relaxation dispersion of water protons and the PREs of proton and carbon in the sugar are interpreted in terms of the model recently developed in our laboratory, allowing both outer- and inner-sphere PREs for water protons, but allowing only the outer sphere PRE for nuclei in the sugar. We found that the relative diffusion has a stronger effect on the PRE than the electron spin relaxation.

  • 209.
    Ghalebani, Leila
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Bernatowicz, P.
    Nikkhou Aski, Sahar
    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.
    Cross-correlated and conventional dipolar carbon-13 relaxation in methylene groups in small, symmetric molecules2007In: Concept in Magnetic Resonance Part A, Vol. 30A, p. 100-115Article in journal (Refereed)
  • 210.
    Ghalebani, Leila
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Bernatowicz, Piotr
    Nikkhou Aski, Sahar
    Kowalewski, Jozef
    Cross-correlated and conventional dipolar carbon-13 relaxation in methylene groups in small, symmetric molecules2007In: Concepts in Magnetic Resonance, Part A: Bridging Education and Research, ISSN 1546-6086, Vol. 30A, no 2, p. 100-115Article in journal (Refereed)
  • 211.
    Ghalebani, Leila
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Kotsyubynskyy, Dmytro
    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.
    NMR relaxation interference effects and internal dynamics in γ-cyclodextrin2008In: Journal of magnetic resonance, ISSN 1090-7807, E-ISSN 1096-0856, Vol. 195, no 1, p. 1-8Article in journal (Refereed)
    Abstract [en]

    Multiple-magnetic field (9.4, 14.1 and 21.1 T) measurements of 13C spin–lattice and spin–spin relaxation rates, the heteronuclear Overhauser enhancement and cross-correlated relaxation rates (CCRRs) in the methylene groups are reported for γ-cyclodextrin in water/dimethylsulfoxide solution at 323 and 343 K. The CCRRs are obtained from differences in the initial relaxation rates of the components of the CH2 triplet in the 13C spectra. The relaxation data are analyzed using the Lipari–Szabo approach and a novel modification of the two-site jump model. According to the latter model, inclusion of the dipolar (CH,CH) cross-correlated longitudinal and transverse relaxation is important for estimating the rate of the conformational jumps in the hydroxymethyl group. Using the dynamic information from the jump model, we have also used the differences in the initial relaxation rates for the triplet components to estimate the anisotropy of the chemical shielding tensor.

  • 212.
    Ghalebani, Leila
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Kotsyubynskyy, Dmytro
    Kowalewski, Jozef
    Olsson, Ulrika
    Widmalm, Göran
    NMR relaxation study of the motional dynamics of methylene groups in oligosaccharides by applying Slowly Relaxing Local Structure modelManuscript (Other academic)
  • 213.
    Ghalebani, Leila
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Kruk, Danuta
    Kowalewski, Jozef
    Nuclear spin relaxation study of aqueous raffinose solution in the presence of a gadolinium contrast agent2005In: Magnetic Resonance in Chemistry, ISSN 0749-1581, Vol. 43, no 3, p. 235-239Article in journal (Refereed)
  • 214. Golosovsky, IV
    et al.
    Salazar-Alvarez, G
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lopez-Ortega, A
    Gonzalez, MA
    Sort, J
    Estrader, M
    Surinach, S
    Baro, MD
    Nogues, J
    Magnetic Proximity Effect Features in Antiferromagnetic/FerrimagneticCore-Shell Nanoparticles2009In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 102, no 24, p. 247201-Article in journal (Refereed)
  • 215.
    GRINS, Jekabs
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    SVENSSON, Gunnar
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    SYNTHESIS OF OXYNITRIDE PEROVSKITES [AZRXTA1-XO2+XN1-X, A=CA, SR, BA AND 0-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-1]1994In: Materials research bulletin, ISSN 0025-5408, E-ISSN 1873-4227, Vol. 29, no 7, p. 801-809Article in journal (Refereed)
    Abstract [en]

    Solid solution perovskite phases AZrxTa1-xO2+xN1-x, with A = Ca, Sr, Ba and 0 less-than-or-equal-to x less-than-or-equal-to 1 have been synthesised by ammonolysis of mixtures of Ta-Zr gels and ACO3. The gels were made by the sol-gel technique using TaCl5 and Zr-n-propoxide as precursors. The perovskite phases have been characterised by X-ray powder diffraction and elemental analysis for one composition from each subsystem has been performed. The Ca compounds were found to be orthorhombic for all x. The orthorhombic GdFeO3 type perovskite structure was verified for the composition CaZr0.52Ta0.48O2.52N0.48 by a Rietveld refinement to R(F) = 2.3 %, using CuKalpa1 X-ray powder diffractometer data. According to X-ray powder diffraction data, the Sr compounds are orthorhombic for x greater-than-or-equal-to 0.60 and cubic for lower x values. The Ba compounds were found to be cubic for all x.

  • 216.
    Grippa, Alexander
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Structural investigation of Nb-based layer sulfides2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this work we have investigated the intercalation of electron-donors between NbS2 slabs in Nb-based layer sulfides.

    Two series of Sr substituted Nb-based misfit sulfides belonging to the 1.5Q/1H and 1Q/1H series of misfit layer compounds have been synthesised. For large lanthanides (Ln=La, Ce), only the 1Q/1H compounds formed whereas for smaller lanthanides and yttrium, both types of phases can be obtained. The crystal structure of misfit sulfide (Pr0.55Sr0.45S)1.15NbS2 has been refined using the composite approach. In the Q-slab, Pr-atoms are partly replaced by Sr with a random distribution over one cation position. The crystal structure of misfit sulfide [(Sm1/3Sr2/3S)1.5]1.15NbS2 belonging to the 1.5Q/1H series have also been determined. The obtained results suggest a preferred occupancy of the cation positions in the slab where Sr atoms mainly occupy positions on the exterior of the slab while Sm atoms are in the center of the slab. The (La1-xSrxS)1.15NbS2 solid solution (0.1<x<0.9) has also been studied. It was found that the maximum value of Sr substitution is 40-50% and therefore, the minimal value of charge transfer to stabilize this structure type is about 0.6ē per Nb atom.

    An attempt to synthesize SrxNbS2 (0.1≤x≤0.5) intercalates was made but single phases were not obtained and increasing the temperature from 1000оС to 1100оС leads to the decomposition of these intercalates. Single crystals of Sr0.22Nb1.05S2 and Sr0.23NbS2 were found and their structures were determined. The structures belong to two different types of packings with statistical distribution of Sr between layers.

    A new superconducting sulfide, "EuNb2S5", was investigated by ED and HREM and its structure model consisting of Nb7S14 and (Eu3S4)2 slabs alternating along the c-axis is suggested. An attempt to suggest a model for the structure of "SrNb2S5" by means of X-ray single crystal diffraction was made. The proposed structure consists of two types of slabs: a Nb7S14 and a [Sr6(NbS4)2S] slab with niobium in tetrahedral coordination. It is shown that "SrNb2S5" and "EuNb2S5" are have similar structures.

    For the first time, single crystals of the complex sulfide BaNb0.9S3 have also been studied by means of X-ray single crystal diffraction. The single crystal refinement and EDX analysis showed the existence of cation vacancies at the niobium position. BaNb0.9S3 has also been studied by ED and no superstructure was found which implies that and the vacancies are statistically distributed.

    No improvement of the magnetic properties of the studied compounds was observed in comparison to NbS2.

  • 217.
    Grippa, Alexander Yu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    D'yachenko, Oleg G.
    Abakumov, Artiom M.
    Antipov, Eugeny V.
    Crystal Structure of BaNb0.9S32001In: Crystallography Reports, ISSN 1063-7745, Vol. 46, no 3, p. 373-376Article in journal (Refereed)
    Abstract [en]

    Single crystals of the composition BaNb[sub 0.9]S[sub 3] have been synthesized from the BaS, Nb, and S mixture and the BaCl[sub 2] flux at 900°C. The BaNb[sub 0.9]S[sub 3] structure was refined by X-ray single-crystal and electron diffraction data. The compound is crystallized in the sp. gr P6[sub 3]/mmc (z = 2) with the unit-cell parameters a = 6.839(1) Å and c = 5.745(1) Å. It was established that the cationic vacancies in the niobium positions are statistically distributed over the structure.

  • 218.
    Grippa, Alexander Yu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lidin, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    D'yachenko, Oleg G.
    Rupasov, Dmitry P.
    Antipov, Eugeny V.
    Synthesis and study of Sr-substituted misfit layer sulfides2005In: Materials Research Bulletin, ISSN 0025-5408, Vol. 40, no 1, p. 79-91Article in journal (Refereed)
    Abstract [en]

    Two series of [(Ln1/3Sr2/3S)1.5]1.15NbS2 (1.5Q/1H) and (Ln1−xSrxS)1+yNbS2 (1Q/1H) misfit layer sulfides have been synthesised and studied by X-ray powder and single crystal diffraction, EDX-analysis and magnetic measurements. For the early lanthanides (Ln = La, Ce) only the (Ln1−xSrxS)1+yNbS2 (x < 0.40–0.45, y = 0.15–0.17) compounds were formed whereas for late lanthanides (Ln = Pr, Nd, Sm, Gd–Er, Yb, Lu), and yttrium, both types of phases can be obtained. The crystal structure of (Pr0.55Sr0.45S)1.15NbS2 has been refined on the basis of X-ray single crystal data using the superspace approach. It consists of double layers [Pr0.55Sr0.45S] of NaCl-type (Q-part: a = 5.799(3) Å, b = 5.810(2) Å, c = 23.331(9) Å, z = 4) and NbS2-sandwiches (H-part: a = 3.332(3) Å), z = 8, yielding a q-vector q = (α 0 0), α = 0.74) alternating along the c-direction. The superspace group pair is Fm2m (α 0 0):Fm2m (α 0 0) (No. 42.7). The refinement converged to Rw(obs) = 0.069. According to the structure refinement and EDX-analysis data in the [Pr0.55Sr0.45S]-slab almost half of the Pr-atoms are randomly replaced by Sr. The minimal formal value of charge transfer from the Q- to the H-part of the structure necessary to stabilise the misfit Nb-based layer sulfides has been estimated as about 0.6 ē per Nb atom.

  • 219.
    Grippa, Alexander Yu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lidin, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Svensson, Gunnar
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Rupasov, Dmitry P.
    Khasanova, Nellie R.
    D'yachenko, Oleg G.
    Antipov, Eugeny V.
    New strontium and rare earth-based mixed niobium misfit sulfides2003In: Solid State Sciences, Vol. 5, no 3, p. 495-502Article in journal (Refereed)
    Abstract [en]

    New niobium-based misfit sulfides [(Ln1/3Sr2/3S)1.5]1.15NbS2 (Ln=Sm, Tb) have been synthesized from a mixture of SrS, Ln2S3, Nb(m), and S in evacuated and sealed silica tubes by annealing at 1000 °C for 144 h under a sulfur partial pressure of 49.3 kPa. The compounds have been characterized by EDX analysis, X-ray single crystal and powder diffraction, electron diffraction, and magnetic susceptibility measurements. Both sulfides have misfit structures with orthorhombic symmetry for the (Ln1/3Sr2/3S)1.5 (Ln=Sm, Tb) and NbS2 subsystems. The lattice parameters for the different subsystems are: for the Sm-based sulfide [(Sm1/3Sr2/3S)1.5]: a=5.7953(9) Å, b=5.8007(5) Å, c=14.957(2) Å and [NbS2]: a=3.3420(7) Å, b=5.8008(5) Å, c=14.955(2) Å, and for the Tb-based sulfide [(Tb1/3Sr2/3S)1.5]: a=5.769(2) Å, b=5.7766(7) Å, c=14.906(2) Å and [NbS2]: a=3.340(1) Å, b=5.7769(8) Å, c=14.905(2) Å. The [(Sm1/3Sr2/3S)1.5]1.15NbS2 crystal structure has been refined from X-ray single crystal data. It belongs to the 1.5Q/1H homologue type where the (Sm1/3Sr2/3S)1.5 part is a three-atoms-thick slab. Sr-cations are mainly located at the exterior of the slab whereas Sm preferably occupy the positions at its center. Both compounds exhibit paramagnetic temperature dependence down to 2 K.

  • 220.
    Gustafsson, Mikaela
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Li, Zhongyue
    Zhu, Guangshan
    Qiu, Shilun
    Grins, Jekabs
    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.
    A porous chiral lanthanide metal-organic framework with high thermal stability2008In: Zeolites and related materials: Trends, targets and challenges: Proceedings of the 4th International FEZA Conference, Vol. 174, Part A / [ed] Antoine Gédéon, Pascale Massiani and Florence Babonneau, Amsterdam: Elsevier, 2008, p. 451-454Conference paper (Refereed)
    Abstract [en]

    A metal-organic framework Nd(BTC)(H2O)·DMF (1), which is isostructural with reported Dy(BTC)(H2O)·DMF [1], Tb(BTC)(H2O)1.5·(DMF) (MOF-76) [2] and Eu(BTC)(H2O)·1.5H2O [3], is synthesized. The compound 1 was characterized by SEM/EDS, TGA and in situ PXRD. The structure was determined by single crystal X-ray diffraction. Compound 1 crystallizes in a chiral space group P43, with a = 10.4278(4) and c = 14.2602(12) Å. The structure contains 1D chiral -Nd-O-C-O-Nd- chains linked by the phenyl groups of BTC ligands. The 3D framework contains circular channels along the [001] direction and is stable up to 400°C.

  • 221.
    Hakeem, A. S.
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Daucé, R.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Leonova, E.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Edén, M.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Z.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, J.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Esmaeilzadeh, S.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Silicate glasses with unprecedented high nitrogen and electropositive metal contents obtained by using metals as precursors2005In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 17, p. 2214-2216Article in journal (Refereed)
    Abstract [en]

     

     

  • 222.
    Hakeem, Abbas Saeed
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Novel Route of Oxynitride Glass Synthesis and Characterisation of Glasses in the Ln-Si-O-N and Ln-Si-Al-O-N Systems2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The present work has been primarily focused on the glass forming region in the La-Si-O-N system, and attempts have been made to find glass forming regions by adopting a new synthesis route to produce glasses in oxynitride system. This goal can be attained by adding a network modifier in its metallic form instead of as an oxide. In this kind of synthesis, the metallic modifier reacts with nitrogen, which gives a strongly exothermic reaction at particular temperature. The resulting sudden increase in the temperature of the system enables the mixture to react with other components at an early stage of the synthesis. This also provides a high degree of mixing in the melt, and results in larger glass forming regions than reported until now (Figure A shows La from 30 to 62 e/o and nitrogen from 9 of 68 e/o in the La-Si-O-N system). The better property values (Tg-Tc, hardness and refractive index) were achieved over the whole compositional range in the systems.

    Similarly, glasses containing Al were prepared in the Ln-Si-Al-O-N system, where Ln = La, Sm, Gd, Ho, Dy, and in the Ln-Si-O-N system, with Ln = Pr, Sm, Gd, Dy. Both systems were examined to study the properties at various nitrogen contents, which can be as high as 70 e/o. Glasses were prepared from one particular glass composition in the Pr-Si-O-N system by replacing Pr with various other La components, in order to study the effect of lanthanide substitution on the properties.

    Figure A. The solid line encloses the glass forming region in the La-Si-O-N system, as determined in the present work. The dotted line represent the glass forming region according to the literature; details are given in figure 11.

    A new synthesis route has extended the glass forming region, allowing a detailed study of properties such as hardness, glass transition temperature (Tg), glass crystallization temperature (Tc), density and refractive index. Comprehensive studies of properties may give better understanding of the glass structure. The glass transition temperatures range from 950 to 1100°C, and crystallization temperatures from 1050 to 1250°C; the hardness can be as high as 12 GPa and the refractive index attains the value 2.3 in the La-Si-O-N system. Hardness and refractive index were measured in both glass systems (Ln-Si-O-N and Ln-Si-Al-O-N) when substituting cations, and a detailed study of replacing La with Pr in the La-Si-O-N system yielded substantial effects on the properties of the glasses.

    Higher values of hardness were found: ~13 GPa when applying load of one kg, and an increase with decreasing cation radius was noted in both the Ln-Si-O-N and the Ln-Si-Al-O-N system, containing of 63 and 61 e/o nitrogen, respectively. The hardness increases as the lanthanide ionic radius decreases, and becomes as high as 13.5 GPa in the Dy-Si-O-N system, and the refractive index is 2.3 in the La-Si-O-N system. A linear increase in the properties Tg-Tc, hardness and refractive index with increasing Pr content was found in the Pr-(La)-Si-O-N system.

  • 223.
    Hakeem, Abbas Saeed
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, J.
    Esmaeilzadeh, S.
    La–Si–O–N glasses: Part I: Extension of the glass forming region2007In: J.Eur.Ceram. Soc, Vol. 27, p. 4773-4781Article in journal (Refereed)
  • 224.
    Hakeem, Abbas Saeed
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Grins, J.
    Esmaeilzadeh, S.
    La-Si-O-N glasses: Part II: Vickers hardness and refractive index2007In: J.Eur.Ceram.Soc, Vol. 27, p. 4783-4787Article in journal (Refereed)
  • 225. Hakeem, A.S.
    et al.
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Esmaeilzadeh, Saeid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    La-Si-O-N glasses. Part I: Extension of the glass forming region in the La-Si-O-N system2007In: Journal of the European Ceramic Society, Vol. 27, no 16, p. 4773-4781Article in journal (Refereed)
  • 226. Hakeem, A.S.
    et al.
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Esmaeilzadeh, Saeid
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    -Si-O-N glasses. Part II: Vickers hardness and refractive index2007In: Journal of the European Ceramic Society, Vol. 27, no 16, p. 4783-4787Article in journal (Refereed)
  • 227.
    Han, Lu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Ruan, Juanfang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Li, Yongsheng
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Che, Shunai
    Synthesis and Characterization of the Amphoteric Amino Acid Bifunctional Mesoporous Silica2007In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 19, no 11, p. 2860-2867Article in journal (Refereed)
  • 228.
    Han, Lu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Che, Shunai
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Insight Into the Defects of Cage-Type Silica Mesoporous Crystals with Fd(3)over-arm Symmetry: TEM Observations and a New Proposal of "Polyhedron Packing" for the Crystals  2009In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 15, no 12, p. 2818-2825Article in journal (Refereed)
  • 229.
    Han, Lu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Li, Y.
    Che, S.
    Synthesis of carboxylic group functionalized mesoporous silicas (CFMSs) with various structures2007In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 17, p. 1216-1221Article in journal (Refereed)
  • 230. Han, Yu
    et al.
    Zhang, Daliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Chng, Leng Leng
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zhao, Lan
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Ying, Jackie Y.
    A tri-continuous mesoporous material IBN-9 with the silica pore wall following a hexagonal minimal surface2009In: Nature Chemistry, ISSN 1755-4349, Vol. 1, p. 123-127Article in journal (Refereed)
    Abstract [en]

    Ordered porous materials with unique pore structures and pore sizes in the mesoporous range (2–50 nm) have many applications in catalysis, separation and drug delivery. Extensive research has resulted in mesoporous materials with onedimensional, cage-like and bi-continuous pore structures. Three families of bi-continuous mesoporous materials have been made, with two interwoven but unconnected channels, corresponding to the liquid crystal phases used as templates. Here we report a three-dimensional hexagonal mesoporous silica, IBN-9, with a tri-continuous pore structure that is synthesized using a specially designed cationic surfactant template. IBN-9 consists of three identical continuous interpenetrating channels, which are separated by a silica wall that follows a hexagonal minimal surface. Such a tri-continuous mesostructure was predicted mathematically, but until now has not been observed in real materials.

    Keywords: mesoporous structure, electron microscopy, self-assembly

  • 231. He, Z.B.
    et al.
    Zou, Xiaodong
    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.
    Oleynikov, P.
    Kuo, K.H.
    Structure determination of the hexagonal quasicrystal approximant my'-(Al,Si)4Cr by the strong reflections approach2007In: Ultramicroscopy, Vol. 107, p. 495-500Article in journal (Refereed)
  • 232.
    Hedin, Niklas
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    DeMartin, GJ.
    Roth, WJ.
    Strohmaier, K.
    Reyes, SC.
    PFG NMR Self-Diffusion of Small Hydrocarbons in High Silica DDR, CHA and LTA Structures2007In: Microporous and Mesoporous MaterialsArticle in journal (Refereed)
  • 233.
    Hedin, Niklas
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    DeMartin, GJ
    Strohmaier, K.
    Reyes, SC.
    PFG NMR self-diffusion of propylene in ITQ-29, CaA and NaCaA: window size and cation effects2007In: Microporous and Mesoporous Materials, Vol. 98, no 1-3, p. 182-188Article in journal (Refereed)
  • 234.
    Hedin, Niklas
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Ng, JBS
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Stilbs, P
    Spectral Deconvolution of NMR Cross Polarization Data Sets2009In: Solid State Nuclear Magnetic Resonance, ISSN 0926-2040, E-ISSN 1527-3326, Vol. 35, p. 208-213Article in journal (Refereed)
    Abstract [en]

    The COmponent-REsolved (CORE) strategy has been employed, for the first time to solid state NMR spectroscopy. CORE was used to extract two time-dependent spectral components in 24 Si-29(H-1) NMR spectra, recorded on a meso-structured silica material under conditions of cross polarization evolution. No prior assumptions were made about the component bandshapes, which were both found to be skewed to higher chemical shifts. For the silica fragments close to protons this skewness could be rationalized by a distribution of the degree of condensation in the silica network; however, for the other component the non-Gaussian shape was unexpected. We expect that the same strategy could be applied to a range of experiments in solid-state NMR spectroscopy, where spectral distributions or kinetic parameters need to be accurately extracted

  • 235.
    Hedman, Fredrik
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Algorithms for Molecular Dynamics Simulations2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Methods for performing large-scale parallel Molecular Dynamics(MD) simulations are investigated. A perspective on the field of parallel MD simulations is given. Hardware and software aspects are characterized and the interplay between the two is briefly discussed.

    A method for performing ab initio MD is described; the method essentially recomputes the interaction potential at each time-step. It has been tested on a system of liquid water by comparing results with other simulation methods and experimental results. Different strategies for parallelization are explored.

    Furthermore, data-parallel methods for short-range and long-range interactions on massively parallel platforms are described and compared.

    Next, a method for treating electrostatic interactions in MD simulations is developed. It combines the traditional Ewald summation technique with the nonuniform Fast Fourier transform---ENUF for short. The method scales as N log N, where N is the number of charges in the system. ENUF has a behavior very similar to Ewald summation and can be easily and efficiently implemented in existing simulation programs.

    Finally, an outlook is given and some directions for further developments are suggested.

  • 236.
    Hedman, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Laaksonen, Aatto
    A Data-parallel Molecular Dynamics Method for Liquids with Coulombic Interactions1995In: Molecular Simulation, ISSN 0892-7022, Vol. 14, no 4-5, p. 235-244Article in journal (Refereed)
  • 237.
    Hedman, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Laaksonen, Aatto
    A Parallel Quantum Mechanical MD Simulation1998In: Molecular Simulation, ISSN 0892-7022, Vol. 20, no 5, p. 265-284Article in journal (Refereed)
  • 238.
    Hedman, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Laaksonen, Aatto
    Data Parallel Large-Scale Molecular Dynamics for Liquids1993In: International Journal of Quantum Chemistry, ISSN 0020-7608, Vol. 46, no 1, p. 27-38Article in journal (Refereed)
  • 239.
    Hedman, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Laaksonen, Aatto
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Physical Chemistry.
    Ewald Summation Based on Nonuniform Fast Fourier Transform2006In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 425, no 1-3, p. 142-147Article in journal (Refereed)
    Abstract [en]

    We present a novel approach, that combines the traditional Ewald summation technique with the nonuniform Fast Fourier transform to calculate the electrostatic energies and forces in molecular computer simulations. The method can easily be implemented in existing simulation programs. We report here some results from our implementation, where we utilize widely available libraries, and demonstrate the accuracy, and expected computational complexity of our approach.

  • 240.
    Hedman, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Laaksonen, Aatto
    Parallel aspects of quantum molecular dynamics simulations of liquids2000In: Computer Physics Communications, ISSN 0010-4655, Vol. 128, no 1-2, p. 284-294Article in journal (Refereed)
  • 241.
    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.

  • 242. 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. 

  • 243. Hoeche, T.
    et al.
    Shen, Zhijian
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Nygren, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zhang, J.
    Van Aken, P. A.
    Heyroth, F.
    Uecker, R.
    Internal strain formed in oxide ceramics upon spark-plasma sintering2007In: Philosophical Magazine, Vol. 87, no 28-30, p. 4555-4566Article in journal (Refereed)
  • 244.
    Hovmöller, Sven
    et al.
    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.
    Electron crystallography: imaging and single crystal diffraction on powders2008In: Acta Crystallographica A, Vol. 64, p. 149-160Article in journal (Refereed)
  • 245.
    Hu, Wei-kang
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Noreus, Dag
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Metal hydrides as bi-functional catalysts for hydrogen generation and oxidation in reversible MH-air fuel cells.2009In: Electrochemistry Communications, Vol. 11, no 11, p. 2212-Article in journal (Refereed)
    Abstract [en]

    Two kinds of metal hydride alloys as the bi-functional catalyst concept for hydrogen generation and oxidation in hydrogen-diffusion electrodes were investigated. The AB5-type hydride electrode shows much higher catalytic activities than the Zr-based AB2-type hydride electrode. However, the activity of Zr-based hydride electrodes can be improved only after removal of zirconium oxides on surface by a 1.0 M HF solution. The experiments demonstrated that the both metal-hydride hydrogen-diffusion electrodes for cycles of hydrogen generation (12 h) and oxidation (12 h) had good stability under the current densities of 100 and 50 mA/cm2, respectively. The results also showed that small amounts of oxygen below 500 ppm and moisture up to 145,000 ppm in the hydrogen gas have little effect on the activity. It indicated that the hydride alloys as the non-noble-metal bi-functional catalysts in a reversible MH-air fuel cell have potential applications.

  • 246. Huang, Congcong
    et al.
    Wikfeldt, K. Thor
    Stockholm University, Faculty of Science, Department of Physics.
    Tokushima, Takashi
    Nordlund, Dennis
    Harada, Yoshi
    Bergmann, Uwe
    Niebuhr, Marc
    Weiss, T. M.
    Horikawa, Yoshi
    Leetmaa, Mikael
    Stockholm University, Faculty of Science, Department of Physics.
    Ljungberg, Mathias P.
    Stockholm University, Faculty of Science, Department of Physics.
    Takahashi, Osamu
    Lenz, Annika
    Ojamäe, Lars
    Lyubartsev, Alexander
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Physical Chemistry.
    Shin, Shik
    Pettersson, Lars G. M.
    Stockholm University, Faculty of Science, Department of Physics.
    Nilsson, Anders
    Stockholm University, Faculty of Science, Department of Physics.
    The Inhomogeneous Structure of Water at Ambient Conditions2009In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 106, p. 15214-15218Article in journal (Refereed)
    Abstract [en]

    Small-angle X-ray scattering (SAXS) is used to demonstrate the presence of density fluctuations in ambient water on a physical length-scale of ≈1 nm; this is retained with decreasing temperature while the magnitude is enhanced. In contrast, the magnitude of fluctuations in a normal liquid, such as CCl4, exhibits no enhancement with decreasing temperature, as is also the case for water from molecular dynamics simulations under ambient conditions. Based on X-ray emission spectroscopy and X-ray Raman scattering data we propose that the density difference contrast in SAXS is due to fluctuations between tetrahedral-like and hydrogen-bond distorted structures related to, respectively, low and high density water. We combine our experimental observations to propose a model of water as a temperature-dependent, fluctuating equilibrium between the two types of local structures driven by incommensurate requirements for minimizing enthalpy (strong near-tetrahedral hydrogen-bonds) and maximizing entropy (nondirectional H-bonds and disorder). The present results provide experimental evidence that the extreme differences anticipated in the hydrogen-bonding environment in the deeply supercooled regime surprisingly remain in bulk water even at conditions ranging from ambient up to close to the boiling point.

  • 247.
    Hugonin, Zuzana
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    "Chemical scissors" - a shortcut to the low-dimensional world2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A number of oxo-halide compounds have been prepared and studied. The antimony Sb3+ cation shows great flexibility in adopting coordination numbers of three or four, and, since this ion carries a stereochemically active lone-pair of electrons (E), both coordinations are one-sided. This flexibility, combined with the behaviour of the unshared electron pair, offers the possibility of a wide range of original structures to form.

    If late transition metals are introduced into a lone-pair element − oxo-halide system, it is observed that the resulting structure is primarily divided into an oxygen/lone-pair element part and a halogen/transition metal part. In the majority of examples of such structures, the border between these two regions is a non-bonding volume occupied by terminal halide ions and lone-pairs of electrons. Furthermore, the halide ion – lone-pair combination acts as “chemical scissors” to reduce the dimensionality of the structure, and as a consequence the transition metals are usually forced to form chains or layers in the structures.

    This thesis studies some previously known Sb3+ − O − X (X = Cl, Br, I) compounds that lack accurate structure solution or their crystal structures remain unknown, and new compounds where a transition metal is introduced into simple antimony oxo-halide system. In all the compounds the structures formed are based on the nature of the Sb3+ cation, the behaviour of its unshared electron pair and how the structures utilize the lone-pair and halide surfaces. These compounds are examples of the concept of “chemical scissors” and the dimensionality of their structures are analysed.

  • 248.
    Hugonin, Zuzana
    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.
    Lidin, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sb35O44Cu20Br37 – one structure, two temperature dependencies2007In: Solid State SciencesArticle in journal (Refereed)
  • 249.
    Hugonin, Zuzana
    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.
    Lidin, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sb35O44Cu20Br37 - one structure, two temperature dependencies2008In: Solid State Sciences, Vol. 10, p. 160-167Article in journal (Refereed)
  • 250. Hugonin, Zuzana
    et al.
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lidin, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
     Two for the price of one  resolvable polymorphism in a single crystalof a- and b-Sb3O4I2009In: Solid State Sciences, ISSN 1293-2558, E-ISSN 1873-3085, Vol. 11, no 1, p. 24-28Article in journal (Refereed)
    Abstract [en]

    The title compound forms as biphasic single crystals containing the &#61537;&#61485; and &#61538; polymorphs. The structure of both polymorphs was solved and refined from single crystal X-ray data in a simultaneous refinement. The structures consist of rods of composition Sb3O4 separated by isolated iodine ions. The two phases differ only in the next nearest neighbour arrangement. The orthorhombic &#61537;-phase crystallizes in space group Pbn21, and the monoclinic &#61538;-phase in space group P21/n

2345678 201 - 250 of 691
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