Acta Crystallographica Section B

Structural Science

Volume 54, Part 2 (April 1998)

Cover illustration: Space filling representation of the hydrated anionic framework formed by trimesic acid around piles of cobalticinium cations in crystalline [(C5H5)2Co][(H3TMA)(H2TMA)].2H2O. Graphics (picture or drawing) obtained using SCHAKAL by E. Keller, University of Freiburg, Germany. Courtesy of D. Braga and F. Grepioni

• topical reviews
• research papers
• short communications
• books received

topical reviews

Acta Cryst. (1998). B54, 97-108    [doi:10.1107/S010876819701879X]

Superstructure Ordering of Intermetallics: B8 Structures in the Pseudo-Cubic Regime

S. Lidin

Synopsis: The class of B8-type compounds (structure types NiAs, Ni₂In and to some extent MnP and Co₂Si, and superstructures thereof) has attracted interest throughout the history of crystallography. Today, there is renewed interest in this topic from the point of view of modulated structures and structured diffuse scattering.

research papers

Acta Cryst. (1998). B54, 109-114    [doi:10.1107/S010876819700726X]

Structure Refinement of Monoclinic Astrophyllite

N. Shi, Z. Ma, G. Li, N. A. Yamnova and D. Yu. Pushcharovsky

Synopsis: The crystal structure of monoclinic astrophyllite, whose chemical composition and crystal structure are different from astrophyllite (triclinic system), has been redetermined.

Acta Cryst. (1998). B54, 115-120    [doi:10.1107/S010876819701152X]

-K₂SO₄-Type Isomorphs: Prediction of Structures and Refinement of Rb₂CrO₄

S. Aleksovska, S. C. Nyburg, Lj. Pejov and V. M. Petrusevski

Synopsis: Using ionic radii and calculated Mulliken charge densities it is possible to predict cell parameters and atomic coordinates for members of an isostructural series. For the -K₂SO₄ series, predictions agree well with experiment, except for an early structure determination of Rb₂CrO₄. New X-ray data give a structure in close accord with that predicted. Parameters are predicted for the, as yet, undetermined structures of Rb₂MnO₄ and Rb₂FeO₄.

Acta Cryst. (1998). B54, 121-128    [doi:10.1107/S0108768197011956]

Neutron and X-ray Diffraction Study of the Thermal Motion in K₂PtCl₆ as a Function of Temperature

J. Schefer, D. Schwarzenbach, P. Fischer, Th. Koetzle, F. K. Larsen, S. Haussühl, M. Rüdlinger, G. McIntyre, H. Birkedal and H.-B. Bürgi

Synopsis: The structure and atomic thermal motions of K₂PtCl₆ are studied as functions of temperature between 8 and 380 K with 11 neutron and X-ray single crystal and powder data sets.

Acta Cryst. (1998). B54, 129-138    [doi:10.1107/S0108768197010124]

Chain, Sheet and Framework Structures in the Adducts of Phenylphosphonic Acid with 4,4'-Bipyridyl (1/1), Piperazine (2/1) and 1,4-Diazabicyclo[2.2.2]octane (2/1)

G. Ferguson, C. Glidewell, R. M. Gregson and P. R. Meehan

Synopsis: Phenylphosphonic acid forms a stem-and-leaves motif in its 1:1 adduct with 4,4'-bipyridyl, where the acid-dimer motif is retained; in its 2:1 adduct with piperazine, where sheets are formed, again the acid-dimer motif is retained. The 2:1 adduct with DABCO shows retention of the acid-chain motif in a three-dimensional framework structure.

Acta Cryst. (1998). B54, 139-150    [doi:10.1107/S0108768197010136]

Crystal Engineering Using Bis- and Tris-phenols. Adducts with 1,4,8,11-Tetraazacyclotetradecane (Cyclam): Isolated Ladders in the Adduct with 4,4'-Thiodiphenol, Tethered Ladders in the Adduct with 4,4'-Sulfonyldiphenol and Two Interwoven Three-Dimensional Networks in the Adduct with 1,1,1-Tris(4-hydroxyphenyl)ethane

G. Ferguson, C. Glidewell, R. M. Gregson and P. R. Meehan

Synopsis: The 2:1 adducts formed between 4,4'-thiodiphenol or 4,4'-sulfonyldiphenol with cyclam take the form of supramolecular ladders, with chains of diphenol anions forming the uprights and [cyclamH₂]²⁺ cations the rungs; with CH₃C(C₆H₄OH)₃, cyclam forms a three-dimensional interwoven structure without void spaces.

Acta Cryst. (1998). B54, 151-161    [doi:10.1107/S0108768197010148]

Formation of One-Dimensional Chains, Two-Dimensional Bilayers and a Three-Dimensional Diamondoid Architecture in Hydrogen-Bonded Adducts of 4,4'-Biphenol with 1,4-Diazabicyclo[2.2.2]octane and 1,2-Diaminoethane

G. Ferguson, C. Glidewell, R. M. Gregson, P. R. Meehan and I. L. J. Patterson

Synopsis: 4,4^'-Biphenol forms simple chains in its 1:1 adduct with 1,4-diazabicyclo[2.2.2]octane, two-dimensional sheets in its methanol-solvated 2:1 adduct with 1,2-diaminoethane and a three-dimensional diamondoid architecture in its 1:1 adduct with 1,2-diaminoethane.

Acta Cryst. (1998). B54, 162-173    [doi:10.1107/S010876819701149X]

Pseudoacids. I. 4- and 5-Oxoacids

E. J. Valente, J. F. Fuller and J. D. Ball

Synopsis: Pseudoacids are cyclic oxoacids or lactols formed in favorable cases by intramolecular reaction of carboxylic acid and aldehyde or ketone functions. The resulting nominal C-O bonds from the former aldehydo or keto carbon differ in length by ~0.08Å, based on disparities in oxyanion leaving-group basicities.

Acta Cryst. (1998). B54, 174-179    [doi:10.1107/S0108768197012007]

Low-Temperature Synchrotron Radiation Study of a Twinned Disordered Crystal of Bis(4,4'-bromophenyl)-61,61-diyl Methano Fullerene C₆₀

B. B. Iversen, A. Darovsky, R. Bolotovsky and P. Coppens

Synopsis: Combined use of synchrotron radiation and area-detector technology allows the structure of a twinned crystal containing two isomers of the title compound to be solved.

Acta Cryst. (1998). B54, 180-192    [doi:10.1107/S0108768196014498]

Hydrogen-Bonded Urea-Anion Host Lattices. 6. New Inclusion Compounds of Urea with Tetra-n-propylammonium Halides

Q. Li and T. C. W. Mak

Synopsis: The novel inclusion complex 2(n-C₃H₇)₄N⁺F^-.7(NH₂)₂CO.- 3H₂O contains a channel framework built from urea ribbons that are bridged by fluoride ions, water molecules and other urea molecules. The complexes (n-C₃H₇)₄N⁺Cl^-.y(NH₂)₂CO (y = 2, 3) feature layer and channel-type urea-chloride host lattices, respectively, whereas the isomorphous compounds (n-C₃H₇)₄N⁺- X^-.3(NH₂)₂CO.H₂O (X = Br, I) exhibit a channel-type host lattice built of corrugated urea layers and centrosymmetric cyclic (H₂O-X^-)₂ units.

short communications

Acta Cryst. (1998). B54, 193-195    [doi:10.1107/S0108768197012949]

Towards extinction-free experimental diffraction data on Al₂O₃

H. Graafsma, M. Souhassou, A. Puig-Molina, S. Harkema, C. Lecomte and Å. Kvick

Synopsis: Virtually extinction-free 58 keV (0.214 Å) synchrotron radiation data on Al₂O₃ produce high-quality deformation electron density maps, which compare very well with theoretical maps.

books received

Acta Cryst. (1998). B54, 196    [doi:10.1107/S010876819809990X]

Molecular Toxicology by P. D. Josephy

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