CHEMICAL AND STRUCTURAL INVESTIGATIONS ON BISMUTH COMPLEXES OF 2,6-DIACETYLPYRIDINE BIS(2-THENOYLHYDRAZONE) AND 2,6-DIACETYLPYRIDINE BIS(THIOSEMICARBAZONE)

Bismuth complexes with the polydentate ligands 2,6-diacetylpyridine bis(2-thenoylhydrazone) (H2dapt) and 2,6-diacetylpyridine bis(thiosemicarbazone) (H2dapts) were synthesized and characterized by means of i.r. spectroscopy and X-ray crystal analysis. In the complex [Bi(dapt)(OH)].dmso.H2O (1) (dmso = dimethyl sulphoxide) the co-ordination of the carbonyl and azomethine groups is in agreement with the shift of the amide I and II bands to lower and higher frequencies respectively. For [Bi(dapts)(N3)].0.5dmso (2) the strong band at 2 025 cm-1 is in accord with co-ordination of the azide group, and involvement of the sulphur atom in the co-ordination is evidenced by the negative shift of the band from 1 250 to 1 180 cm-1. The crystals of (1) and (2) are monoclinic, space group P2(1)/n, with lattice constants: (1), a = 14.763(7), b = 10.844(6), c = 16.590(7) angstrom, beta = 105.03(3)-degrees, Z = 4, and R = 0.0483; (2) a = 21.112(9), b = 11.939(7), c = 7.333(6) angstrom, beta = 97.86(6)-degrees, Z = 2 for a double formula, and R = 0.0546. In both compounds the geometry around bismuth is pentagonal pyramidal with the base occupied by the organic ligand and the apical site occupied by the OH- and N- groups for (1) and (2) respectively.