ZINC THIOLATE COMPLEXES WITH CHELATING NITROGEN LIGANDS

The thiolates SPh-, SCH2Ph- and SCH2CH2Ph- were combined with polydent ate nitrogen donor ligands in monomeric zinc complexes. N-substituted bis(benzimidazolylmethyl)sulfides (R-BIMS) yielded the complexes (R-BI MS)Zn(SR)(2) (1-3) in which the central thioether sulfur does not coor dinate. This holds also for the o-hydroxymethyl-thiophenolate complex (4). 2,9-Dimethylphenanthroline (neocuproin, NEO) produced compounds ( NEO)Zn(SR)(2) (5). Bis(dimethylpyrazolyI-N-ethyl)amine (PEA) led to (P EA)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)(2)Zn (7). Six structure determinations h ave shown that all complexes are characterized by a tetrahedral ZnN2S2 coordination, irrespective of the ring size (5, 6, 8) which is thereb y enforced on the chelate ligand, even at the expense of unused ligand donor atoms. (C) 1998 Elsevier Science S.A. All rights reserved.