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, dibenzoylmethanate), entraps solvent molecules upon crystallization. Six clathrates of four structural types have been studied by single-crystal X-ray diffraction (guest, 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, monoclinic, C2/c, Z = 8; (TV) chlorobenzene, 1:1, monoclinic, C2/c, Z = 8; (V) chloroform, 1:2, monoclinic, P2(1)/n, Z = 2; (VI) tetrahydrofuran, 1:2, monoclinic, 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 are consistent with wan der Weals type of packing. The complex unit is formed by octahedral coordination to nickel of four oxygen and two nitrogen atoms from two chelate DBM and two pyridine molecules, respectively. In all seven compounds the host complex is tuans-configured. Complexes of similar composition 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 complex unit, and they do not form inclusion compounds with above guests.