SYNTHESIS, STRUCTURE AND SPECTRAL PROPERTIES OF [(HGPH)(2)TBSME] - A DINUCLEAR 2-S-METHYLTHIOBARBITURATE OF PHENYLMERCURY(II) EXHIBITING LINKAGE ISOMERISM

The reaction of 2-S-methylthiobarbituric acid (H(2)TbSMe) with phenylm ercury(II) acetate in ethanol afforded the title complex, which crysta llizes in the space group P2(1)/c (No. 14). The asymmetric unit consis ts of two independent [(HgPh)(2)TbSMe] molecules: in molecule 1, the t wo organometallic moieties are bound primarily to the nitrogen atoms o f the ligand ring (N(1) and N(3)); in molecule 2, one phenylmercury(lI ) is N(1)-bound but the other is bound to the exocyclic oxygen contigu ous to N(3). Hence molecules 1 and 2 are linkage isomers. Several weak intra- and intermolecular interactions are also observed. In DMSO sol ution, H-1, C-13 and Hg-199 NMR measurements suggest fast exchange of phenylmercury(II) between N- and O-coordination, with prevalence of th e former.