Zinc thiolate complexes with chelating nitrogen ligands

Article abstract of DOI:10.1016/S0020-1693(98)00215-1

The thiolates SPh^-, SCH₂Ph^- and SCH₂CH₂Ph^- were combined with polydentate nitrogen donor ligands in monomeric zinc complexes. N-substituted bis(benzimidazolylmethyl)sulfides (R-BIMS) yielded the complexes (R-BIMS)Zn(SR)₂ (1-3) in which the central thioether sulfur does not coordinate. This holds also for the o-hydroxymethyl-thiophenolate complex (4). 2,9-Dimethylphenanthroline (neocuproin, NEO) produced compounds (NEO)Zn(SR)₂ (5). Bis(dimethylpyrazolyl-N-ethyl)amine (PEA) led to (PEA)Zn(SPh)₂ (6) in which only one pyrazole nitrogen and the central amine nitrogen are coordinated. 2-Mercaptomethylpyridine (HMMP) formed the bis-ligand complex (MMP)₂Zn (7). Six structure determinations have shown that all complexes are characterized by a tetrahedral ZnN₂S₂ coordination, irrespective of the ring size (5,6, 8) which is thereby enforced on the chelate ligand, even at the expense of unused ligand donor atoms.