December 2000 issue
The new non-linear optical crystals LiKB4O7 and LiRbB4O7 contain two kinds of anionic groups, namely (B3O8)7− and (B5O10)5−. The (B3O8)7− chains parallel to the  direction are interconnected by sharing O atoms with (B5O10)5− groups.
electronic papers (inorganic compounds)
The crystal structure of low-temperature Na4Ti5O12 has been determined and refined from X-ray and neutron powder diffraction data at 295 K. The O and Na atoms form a distorted close-packed structure, where Ti atoms occupy octahedral sites.
electronic papers (metal-organic compounds)
Amido complexes of titanium are useful reagents in a variety of syntheses and as precursors for chemical vapor deposition of TiN. The title compound crystallizes with one molecule in the asymmetric unit. The neutral complex shows an unusual fivefold coordination of the titanium centre.
The central structural motif of the [Ti2(SC6H5)9]− anion features a face-sharing bi-octahedron. The charge is balanced by a [Li(C4H8O)4]+ cation.
The title compound has a doubly methoxo-bridged centrosymmetric copper dimer cation involving two tridentate bis(pyrazolyl)amine ligands. The geometry of each CuII atom is a distorted square pyramid. The Cu⋯Cu distance is 3.058 (1) Å.
In the title complex, the U atom is surrounded by seven O atoms giving a distorted pentagonal bipyramidal geometry. The U—Ouranyl and U—Odbm distances (dbm is 1,3-diphenylpropane-1,3-dionate) are in the ranges 1.760 (6)–1.776 (5) and 2.308 (4)–2.417 (4) Å, respectively, while the U—Osulfoxide distance is 2.427 (4) Å.
In the title compound, both central Ag and B atoms lie on twofold axes and exhibit tetrahedral geometries. There seems to be no trigonal–tetrahedral disorder, as is prevalent in the analogous Au complex.
The previously unknown title compound is a centrosymmetric linear trinuclear nickel(II) complex, where the Ni atoms are in an octahedral coordination and the ligand heteroatoms act so as to model amino acid residues.
The title compound contains two Sn atoms in the asymmetric unit, that complexed by NMP exhibiting an octahedral and the other showing a trigonal–bipyramidal geometry. The most important features are three different Sn—Br bond lengths at both Sn atoms.
In the title complex, the Pb centre has a distorted octahedral coordination with four μ2-Br ligands and two bridging 4,4-bipyridine (bipy) ligands in trans positions. The bipy group acts as a linear bifunctional bridge forming chains in the direction of the b axis. Pairs of bridging bromides join these into two-dimensional layers.
The structure of the title compound at 150 K is essentially identical to that determined at room temperature, with the expected reduction in cell-axis length.
In the title compound, a distorted octahedral CoIII complex shows an orientational disorder such that the positions of the nitro and aqua ligands are exchanged. As a result, the averaged structure has an inversion centre at the Co atom.
In the title compound, a distorted octahedral CoIII complex shows an orientational disorder such that the positions of the nitro and chloro ligands are exchanged with 84:16% occupancy. The O atoms of the nitrate ion are disordered over two sites.
In the title compound, two independent CoIII complexes with a distorted octahedral coordination show an orientational disorder. As a result, the averaged structure has inversion centres at the Co atoms. The perchlorate O atoms are disordered over two sites.
The structure of the title compound has been determined and shows structural parameters comparable to those of the previously reported 3,5-bis(trifluoromethyl)pyrazole analogue.
The title complex forms a three-dimensional network directed by alternating hydrogen-bonding and π–π interactions.
The title molecule is dimeric and the O atoms of the trimethylsiloxy groups bridge the two Al atoms to form a four-membered ring.
electronic papers (organic compounds)
The title molecule has approximate Cs symmetry. The dithiane ring adopts a chair conformation with the acetyl substituent in an axial orientation. A weak intermolecular C—H⋯O hydrogen bond (H⋯O 2.39 Å) involves the H atom at the 2-position of the ring.
Myoporum bontioides is a folk medicinal plant from the northwest of China. The EtOH extract from the dried root of Myoporum bontioides was chromatographed to give furanoeudesmane-B. The relative stereochemistry has been determined.