Modified metal dibenzoylmethanates and their clathrates. Part I. Clathration ability of dipyridinebis(dibenzoylmetlhanato)nickel(II), a novel metal-complex host

The title complex, [NiPy2(DBM)(2)] (DBM = C6H6CO CHCOC6H5, dibenzoylmethana te), entraps solvent molecules upon crystallization. Six clathrates of four structural types have been studied by single-crystal X-ray diffraction (gu est, host:guest molar ratio, crystal system, space group, formula units per unit cell): (I) carbon tetrachloride, 1:2 orthorhombic, P2(1)2(1)2(1), Z = 4; (II) pyridine, 1:2, monoclinic, C2/c, Z = 8; (III) benzene, 1:1, monocl inic, C2/c, Z = 8; (TV) chlorobenzene, 1:1, monoclinic, C2/c, Z = 8; (V) ch loroform, 1:2, monoclinic, P2(1)/n, Z = 2; (VI) tetrahydrofuran, 1:2, monoc linic, P21/n, Z = 2. A nonclathrate form of the complex (VII) was obtained from acetone; it is triclinic, P (1) over bar, Z = 1. The compounds I-VII a re consistent with wan der Weals type of packing. The complex unit is forme d by octahedral coordination to nickel of four oxygen and two nitrogen atom s from two chelate DBM and two pyridine molecules, respectively. In all sev en compounds the host complex is tuans-configured. Complexes of similar com position but with Zn (VIII) and Cd (IX) replacing Ni have been also studied for comparison: they are monoclinic, P2(1), Z = 2, with a cis-configured c omplex unit, and they do not form inclusion compounds with above guests.