March 1999 issue
cif-access (metal-organic compounds)
The structure of catena-poly[[[di-μ-acetato-1:2κ4O:O'-diaqua-2κ2O-calciumcopper]-di-μ-acetato-1:2'κ4O:O] hexahydrate], originally determined twice at room temperature, has been redetermined at 173K. There are no significant differences between these structures.
Two molybdenum centers are bridged by an oxo group in a compound in which the metal atoms are chiral centers coordinated to two chlorides, two oxo groups and two phosphorus ligands (PMe3 and OPMe3) situated cis to one another.
cif-access (organic compounds)
The reaction of o-phthalaldehyde with (R)-(–)-2-aminobutanol yielded an unexpected rearrangement product, an N-substituted isoindoline-1-one, 2-(1-hydroxybut-2-yl)isoindolin-1-one.
In the title compound, the piperazine ring adopts a half-chair conformation and the best plane through it forms a dihedral angle of 79.4(1)° with the phenyl ring. In the solid state, the molecules exist as centrosymmetrically N—H⋯S hydrogen-bonded dimers.
In the crystal structure of the title taxoid, taxa-4(20),11-diene-2α,5α,10β,14β-tetrayl 2α,5α,10β-triacetate 14β-(2-methylbutyrate), left-hand ring A has a distorted boat, central ring B a boat–chair and right-hand ring C a distorted chair conformation. The terpenoid core is folded in a cage-type conformation, with the butyrate side chain in a trans,trans,gauche,gauche,trans conformation.
Pb9.85(VO4)6I1.7 belongs to the vanadinite family and is stoichiometrically deficient in lead iodide.
The title vanadium oxide bronze crystallizes in the monoclinic system with an original structure built up of layers formed by VO5 square pyramids and VO4 tetrahedra parallel to the (010) plane, with the Na atoms lying between these layers.
The three-dimensional framework of strontium bis[oxovanadium(IV)] bis(phosphate) consists of infinite [VO3]∞ chains linked through PO4 tetrahedra. In the [VO3]∞ chains, the VO6 octahedra share their corners.
The crystal structure of dicalcium bis(oxonium) decavanadate hexadecahydrate has been determined by X-ray analysis. The main feature of the structure is the [V10O28]6- anion, built up from ten distorted edge-sharing VO6 octahedra with well established structures. Each Ca2+ ion is surrounded by seven water molecules in the form of a distorted pentagonal bipyramid.