DIMETHYLTHALLIUM(III) AND METHYLMERCURY(II) DERIVATIVES OF PYRIDINE-2-CARBALDEHYDE THIOSEMICARBAZONE - SYNTHESIS AND STRUCTURE

The reaction of dimethylthallium(III) hydroxide and methylmercury(II) chloride with pyridine-2-carbaldehyde thiosemicarbazone (HL) and its sodium salt, respectively, afforded [TlMe2(L)] and [HgMe(L)]. The thallium complex crystallizes in the triclinic space group P1BAR (no.2) with a = 11.005(2), b= 12.153(2), c= 10.822(1) angstrom, alpha = 110.18(1), beta = 99.79(1), gamma = 70.39(1)-degrees, and Z=4 (R=0.031, R' = 0.035). The unit cell has two independent molecules in each asymmetric unit, both containing an N,N',S-tridentate ligand but with significant differences in bond distances and angles. The H-1 NMR spectrum of [TlMe2(L)] in CDCl3, indicates that the bonding scheme observed in the solid state is retained in solution. Infrared data for [HgMe(L)] in the solid state suggest that the metal is N(hydrazinic), S-co-ordinated; in solution in chloroform, [HgMe(L)] consists of a mixture of (E) and (Z) isomers.