CADMIUM(II) COMPLEXES OF 2,6-DIACETYLPYRIDINE BIS-AND MONOTHIOSEMICARBAZONES - THE CRYSTAL-STRUCTURE OF AQUODICHLORO(2,6-DIACETYLPYRIDINE MONOTHIOSEMICARBAZONE-N,N',O,S)CADMIUM(II) MONOHYDRATE

The reactions of cadmium(II) acetate and cadmium(II) chloride with 2,6 -diacetylpyridinebis(thiosemicarbazone) (H2L1) afforded the complexes [CdL1] and [CdC1(2)(H2L1)] respectively. The mother liquor of the chlo ride reaction also afforded [CdCl2(HL2)(H2O)]. H2O, where HL2 is 2,6-d iacetylpyridine monothiosemicarbazone. [CdCl2(HL2)(H2O)]. H2O is ortho rhombic (space group P2(1)2(1)2(1)) with a = 7.257(1), b = 14.559(2), c = 15.214(2)Angstrom, Z = 4 and R = 0.0455. The ligand in this latter is tetradentate, coordinating through the S and N(3) atoms of the thi osemicarbazone moiety, the oxygen atom of the CH3CO group and the pyri dine nitrogen in the equatorial plane of a distorted pentagonal bipyra mid whose fifth equatorial position is occupied by one of the chloride ions and whose apical positions are occupied by the other chloride an d the water molecule. The IR spectra suggest a dimeric solid state str ucture with hexacoordinated Cd atoms for [CdL1] and monomeric with hep tacoordinated Cd atoms for [CdCl2(H2L1)]. All the complexes were also studied in solution by H-1, C-13, and Cd-113 NMR spectroscopy.