January 1999 issue
cif-access (metal-organic compounds)
In the crystals of μ-[N:N';N:N'-bis(2-chloro-1,3-xylyl)bis(di-aza-18-crown-6)]disilver(I) bis(trifluoromethanesulfonate), each AgI ion is coordinated primarily by two N atoms in an almost linear fashion and further coordinated by four weaker contacts to the O atoms of the diaza-18-crown-6 unit.
cif-access (inorganic compounds)
The Fe atom is coordinated to the exocyclic double bonds of the organic ligand and the carbonyl groups in a pentagonal fashion, with the carbonyl groups in a piano-chair conformation. The Fe—C distances correspond generally to those of the butadiene analogue [Mills & Robinson (1963). Acta Cryst. 16, 758–761].
cif-access (organic compounds)
The crystal structure of (2SR,5RR,6RR,9SR)-1,2,5,6,9,10-hexachlorodecane, prepared by chlorine addition to the double bonds of 1,5,9-decatriene, is presented. The molecule has C2 symmetry.
The title compound is used as a raw material for the esterification of aliphatic and aromatic mono- and polyfunctional alcohols. Mono-, di- and triazido compounds, which are applied, for example, in the process of lithographic structuring of polymers, are prepared in the same way.
The title compound belongs to the group of [3.2.2]propellanes. The bond angles inside the cyclobutane and cyclobutene units involving the C1 and C2 atoms of the central bridge are less than 90°.
The molecular structures of the title compounds are similar to each other and suggest almost no electron transfer from the dithiacyclopentene-2-thione or 2-one group to the indandione group.
The two phenyl rings make a dihedral angle of 73.5(1)°, indicating the non-planarity of the molecule. The orientation of the methanesulfonanilide moiety with respect to the phenyl ring is given by the C—S—N—C torsion angle of -69.2(2)°. Molecules are linked into pairs by N—H⋯O hydrogen bonding over an inversion centre.
The Rietveld refinement of a barium titanate, Ba4Ti12O27, which is isostructural with Ba4Al2Ti10O27 and Ba4ZnTi11O27, is reported. The structure is rather compact, with narrow channels along the b axis.
The isomorphous title compounds are newly discovered double-anion salts containing ZnCl42– and NO3– ions. The structure consists of rows of nitrate ions parallel to a, surrounded by cylinders of cations, which in turn are surrounded by concentric cylinders of tetrachlorozincate ions.
The bloedite-type title compound consists of parallel layers built up of MgO2(H2O)4 and NaO4(H2O)2 octahedra. Layers are interconnected through SO4 tetrahedra and hydrogen bonds.
In the title salt, the anion has the Anderson structure with crystallographic 3m symmetry. The unique cation site is occupied by disordered Na+ and Co2+ ions. The anions form layers perpendicular to the c axis which are separated by double layers of cations.
A powder diffraction study of BaCaGa4O8 reveals that GaO4 tetrahedra are arranged in a derivative structure of tridymite. The type of arrangement of GaO4 tetrahedra has not been found previously among compounds with the stuffed tridymite structure.