SYNTHESIS AND SPECTROSCOPIC INVESTIGATIONS OF SOME BINUCLEAR ORGANOTIN(IV) COMPLEXES OF MALONOBIS(SALICYLIDENEHYDRAZIDE) AND CRYSTAL-STRUCTURE STUDY OF [(C2H5)2SN]2[OC6H4CH=NNCO]2CH2

The Schiff base, [HOC6H4CH=NNHCO]2CH2 [H4L]. derived from the condensa tion of salicylaldehyde and malonodihydrazide, reacted with organotin chlorides to yield binuclear complexes of the type R2Sn[L]SnR2, where R=CH3-, C2H5-, C4H9-, C6H5-, CH3CO2CH2CH2-, and C6H5CH2-. The complexe s were characterized and the structure assigned on the basis of their elemental analysis, IR, H-1, C-13, Sn-119 NMR spectral, and X-ray crys tallographic data. In these complexes, the ligand functions as a flexi bly bridging tetrabasic hexadentate moiety binding two tin atoms throu gh ONO donor atoms and both tin atoms are in trigonal bipyramidal envi ronment. A single crystal diffraction study of the complex, [(C2H5)2Sn ]2(OC6H4CH=NNCO)2CH2, confirms the structure to be binuclear. The crys tals are monoclinic, space group I2/a with a=12.312(2), b=11.526(2), c =18.858(2) angstrom, beta=94.69(2)-degrees, volume=2667.1(7) angstrom3 . Z=4, D(c)=1.718 g cm-3. The final discrepancy factors are R=0.042, R (w)=0.055 for 1698 observed reflections. Half of the molecule is bridg ed to the other half by two fold symmetry via C(13) atom. The tin atom has distorted trigonal bipyramidal coordination with two oxygens occu pying axial positions while two ethyl groups and azomethine nitrogen o ccupy the equatorial positions. The two ethyl groups coordinated to ti n are cis to each other.