Structural Science

 

Acta Cryst. (2000). B56, 173-182  [ doi:10.1107/S0108768199012586 ]

A five-dimensional structural investigation of the misfit layer compound [Bi_0.87SrO₂]₂[CoO₂]_1.82

H. Leligny, D. Grebille, O. Pérez, A. C. Masset, M. Hervieu and B. Raveau

Synopsis: A structural study of the misfit layer compound [BiSrO][CoO] was carried out from single-crystal X-ray diffraction data. The main results concern both the existence of vacant bismuth sites regularly distributed in the crystal and the setting up of strong bonds between the [BiSrO] and [CoO] subsystems.

Online April 2000

 

Acta Cryst. (2000). B56, 183-188  [ doi:10.1107/S0108768199012951 ]

Structure of the defect perovskite Ce_1/3NbO₃: a redetermination by electron and neutron powder diffraction

C. Bridges, J. E. Greedan and J. Barbier

Synopsis: The crystal structure of the defect perovskite Ce_1/3NbO₃ has been re-examined by neutron powder and electron diffraction. The structure is described in P2/m, rather than the previously reported Pmmm. The reduction in symmetry arises from subtle tilting of NbO₆ octahedra, which was not detected by X-ray diffraction data.

Online April 2000

 

Acta Cryst. (2000). B56, 189-196  [ doi:10.1107/S0108768199015311 ]

High-pressure transformations of NbO₂F

S. Carlson, A.-K. Larsson and F. E. Rohrer

Synopsis: High-pressure synchrotron X-ray powder diffraction data show a cubic to rhombohedral transition for NbO₂F between ambient pressure and 0.47 GPa. At pressures above 18 GPa the structure becomes X-ray amorphous.

Online April 2000

 

Acta Cryst. (2000). B56, 197-203  [ doi:10.1107/S0108768199015529 ]

Electron density of KNiF₃: analysis of the atomic interactions

V. Tsirelson, Y. Ivanov, E. Zhurova, V. Zhurov and K. Tanaka

Synopsis: Atomic interactions in the perovskite KNiF₃ are examined in terms of the topological analysis of the electron density. Comparison with the classical crystal chemistry description has been performed.

Online April 2000

 

Acta Cryst. (2000). B56, 204-209  [ doi:10.1107/S0108768199014846 ]

Structure of the alums. I. On the sulfate group disorder in the -alums

S. C. Nyburg, J. W. Steed, S. Aleksovska and V. M. Petrusevski

Synopsis: The crystal structures at room (296 K) and low (173 K) temperature of several -alums have been refined by single-crystal X-ray structure analysis. In all the -alums studied a disorder of the sulfate group is evident, but the degree of disorder decreases with lowering of the temperature.

Online April 2000

 

Acta Cryst. (2000). B56, 210-214  [ doi:10.1107/S0108768199012677 ]

Two phases of {[CsPH(⁶-2,4,6-^tBu₃C₆H₂)]₂(³-toluene)_0.5}_x: their structures and interconversions

T. E. Concolino, K.-C. Lam, I. A. Guzei, A. L. Rheingold and G. W. Rabe

Synopsis: The crystal structure of {[CsPH(⁶-2,4,6-^tBu₃C₆H₂)]₂(³-toluene)_0.5}_x has been shown to undergo a reversible solid-state, order-disorder phase transition at 278 (2) K. This transformation results in the doubling of a unit-cell vector, resulting in the doubling of the unit cell of the system.

Online April 2000

 

Acta Cryst. (2000). B56, 215-225  [ doi:10.1107/S0108768199013622 ]

X-ray diffraction study of the phase transitions of (CH₃)₄NCdCl₃ between 293 and 80 K: a quantitative analysis of the ferroelastic domains distribution below 118 K

I. Peral, G. Madariaga, A. Pérez-Etxebarria and T. Breczewski

Synopsis: The X-ray diffraction study of the chain compound [N(CH)][CdCl] in the range 80-293 K is reported. A maximum entropy model for the disorder of the organic groups at room temperature is proposed. A quantitative analysis of the domain structure in the low-temperature phases (stable below 118 and 104 K, respectively) is given.

Online April 2000

 

Acta Cryst. (2000). B56, 226-233  [ doi:10.1107/S0108768199014500 ]

Packing effects on the geometry of neutral platinum(II) complexes due to solvate molecules: the structure of trans-dichlorobis(triphenylarsine)platinum(II)

M. H. Johansson, S. Otto, A. Roodt and Å Oskarsson

Synopsis: Four different solvates of trans-[PtCl₂(AsPh₃)₂] have been obtained and their different geometries are analysed by half-normal probability plots and root-mean-square calculations.

Online April 2000

 

Acta Cryst. (2000). B56, 234-244  [ doi:10.1107/S0108768199005790 ]

Dimorphism and inclusion compounds of N,N'-di(benzenesulfonyl)-p-phenylenediamine

N. Nagel, H. Bock and P. Eller

Synopsis: The crystal structures, phase transformation behavior and crystallization conditions of two polymorphs, as well as two solvates, of N,N'-di(benzenesulfonyl)-p-phenylenediamine are investigated and discussed.

Online April 2000

 

Acta Cryst. (2000). B56, 245-253  [ doi:10.1107/S0108768199012008 ]

Direct observation of deuterium migration in crystalline-state reaction by single-crystal neutron diffraction. II. 3-1 Photoisomerization of a cobaloxime complex

T. Ohhara, J. Harada, Y. Ohashi, I. Tanaka, S. Kumazawa and N. Niimura

Synopsis: Single crystal neutron diffraction analysis of photo-exposed (3-cyanopropyl-d₂^,)-[(R)-1-phenylethylamine-d₁₁]bis(dimethylglyoximato-d₁₄)cobalt(III) revealed that the crystalline-state 3-1 photoisomerization of the 3-cyanopropyl group proceeded in two steps, 3-2 and 2-1 isomerizations. Moreover, it was indicated that the 2-1 process was irreversible.

Online April 2000

 

Acta Cryst. (2000). B56, 254-260  [ doi:10.1107/S0108768199012318 ]

Short N⁺-HPh hydrogen bonds in ammonium tetraphenylborate characterized by neutron diffraction

T. Steiner and S. A. Mason

Synopsis: In the neutron diffraction crystal structure of ammonium tetraphenylborate, all N-H vectors of the ammonium ion are involved in short N-HPh hydrogen bonds with NM(Ph) separations of 3.023 Å. The H-atom displacement parameters are very high.

Online April 2000

 

Acta Cryst. (2000). B56, 261-272  [ doi:10.1107/S0108768199012860 ]

Hydrogen-bonding behaviour of benzene-1,2,4,5-tetracarboxylic acid: supramolecular structures of different dimensionality in the 2:1 adducts formed with 4,4'-bipyridyl and hexamethylenetetramine

A. J. Lough, P. S. Wheatley, G. Ferguson and C. Glidewell

Synopsis: Benzene-1,2,4,5-tetracarboxylic acid forms 2:1 adducts with 4,4'-bipyridyl and with hexamethylenetetramine: the 4,4'-bipyridyl adduct contains a chain-of-rings built from (C₁₀H₉N₂)⁺ and (C₁₀H₄O₈)^2- ions, while in the hexamethylenetetramine adduct the dominant structural motif is a three-component aggregate [(C₆H₁₃N₄)⁺][(C₁₀H₄O₈)^2-][(C₆H₁₃N₄)⁺]. In each compound the primary structural motifs are further linked by soft C-HO hydrogen bonds.

Online April 2000

 

Acta Cryst. (2000). B56, 273-286  [ doi:10.1107/S0108768199013051 ]

Oligosiloxanediols as building blocks for supramolecular chemistry: hydrogen-bonded adducts with amines form supramolecular structures in zero, one and two dimensions

B. O'Leary, T. R. Spalding, G. Ferguson and C. Glidewell

Synopsis: Oligosiloxanediols HO(SiPh₂O)_nH (n = 2 or 3) form hydrogen-bonded adducts with the following cyclic and cage amines: pyridine, pyrimidine, pyrazine, 2,2'-bipyridyl and hexamethylenetetramine. The structures exhibit molecular aggregation in zero, one or two dimensions by means of O-HO, O-HN and C-HO hydrogen bonds.

Online April 2000

 

Acta Cryst. (2000). B56, 287-298  [ doi:10.1107/S0108768199014032 ]

3,6,9,16,19,22-Hexaazatricyclo[22.2.2.2^11,14]triconta-1(26),11(29),12,14(30),24,27-hexaene, C₂₄H₃₈N₆, as a building block in supramolecular chemistry: structures in two and three dimensions

C. Glidewell, G. Ferguson, R. M. Gregson and A. J. Lough

Synopsis: The adducts of the hexaaza macrocycle C₂₄H₃₈N₆ with 4,4'-sulfonyldiphenol and with 4,4'-biphenol are both salts containing centrosymmetric (C₂₄H₄₀N₆)²⁺ cations which exhibit a variety of different conformations. Extensive hydrogen bonding links the molecular components into sheets in the 4,4'-sulfonyldiphenol adduct and into a three-dimensional framework in the 4,4'-biphenol adduct.

Online April 2000

 

Acta Cryst. (2000). B56, 299-309  [ doi:10.1107/S0108768199013634 ]

Anisotropic crystal structure distortion of the monoclinic polymorph of acetaminophen at high hydrostatic pressures

E. V. Boldyreva, T. P. Shakhtshneider, M. A. Vasilchenko, H. Ahsbahs and H. Uchtmann

Synopsis: Despite the overall decrease in the molar volume with pressure, the structure expanded in particular crystallographic directions. The anisotropy of structural distortion was analysed in detail in relation to the pressure-induced changes in the molecular conformations, to the compression of the hydrogen-bond network and to the changes in the orientation of molecules with respect to each other in the pleated sheets in the structure.

Online April 2000

 

Acta Cryst. (2000). B56, 310-316  [ doi:10.1107/S0108768199014044 ]

Bulk modulus and high-pressure crystal structures of tetrakis(trimethylsilyl)methane C[Si(CH₃)₃]₄ determined by X-ray powder diffraction

R. E. Dinnebier, S. Carlson and S. van Smaalen

Synopsis: The pressure dependence of the crystal structure of cubic tetrakis(trimethylsilyl)methane C[Si(CH₃)₃]₄ is reported, as determined from high-resolution X-ray powder diffraction at room temperature. The material undergoes three phase transitions up to a pressure of 16.0 GPa.

Online April 2000

 

Acta Cryst. (2000). B56, 317-321  [ doi:10.1107/S0108768199014020 ]

Molecular analysis of the -polymorphic form of trielaidin: crystal structure at low temperature

C. Culot, B. Norberg, G. Evrard and F. Durant

Synopsis: The polymorphism of trielaidin, a trans unsaturated triglyceride, was analyzed and the crystal structure of the -form was solved at low temperature.

Online April 2000

 

Acta Cryst. (2000). B56, 322-331  [ doi:10.1107/S0108768199014494 ]

Structure of the inclusion complex of -cyclodextrin with 1,12-dodecanedioic acid using synchrotron radiation data; a detailed dimeric -cyclodextrin structure

S. Makedonopoulou and I. M. Mavridis

Synopsis: The quality of the data made possible the location of the H atoms of the dimeric host. Thus, it was revealed for the first time that the host monomers self-assemble through hydrogen bonds of the O3 hydroxyl groups only.

Online April 2000

 

Acta Cryst. (2000). B56, 332  [ doi:10.1107/S0108768100003992 ]

Structure and thermal behavior of the new superprotonic conductor Cs₂(HSO₄)(H₂PO₄). Erratum

C. R. I. Chisholm and S. M. Haile

Synopsis: Erratum to Acta Cryst. (1999). B55, 937-946.

Online April 2000

 

Acta Cryst. (2000). B56, 333-334  [ doi:10.1107/S0108768199016900 ]

The weak hydrogen bond in structural chemistry and biology

Online April 2000