ZINC-COMPLEXES OF S,N LIGANDS DERIVED FROM THIAZOLINES

Three different thiazoline derivatives or their tautomeric mercaptoethylamine derivatives were used for the preparation of zinc complexes containing S,N ligands. 2-(2-pyridyl)-3-(2-pyridylmethyl)-1,3-thiazolidine (PPMT) could not be opened reductively but acted as a tridentate nitrogen ligand in (PPMT)ZnX(2) (1a, b, X= Br, NO3). The thiazolidine tautomer N-(2-mercaptoethyl)salicylideneimine (MESIH(2)) yielded polymeric (MESI)Zn (2) and, after oxidation, monomeric (MESI)(2)Zn (3) containing a disulfide unit. The 2-aryl-benzo-1,3-thiazoline tautomers N-(2-mercaptophenyl)-p-fluorobenzylideneimine (MPFBH) and N-(2-mercaptophenyl)-p-methoxybenzylideneimine (MPMBH) underwent reaction with diethyl zinc resulting in the unstable L . Zn-Et complexes 4a and b, which are probably dimeric and the stable 2:1 complex (MPFB)(2)Zn (5). The structures of 3 and 5 were determined and were found to exhibit distorted tetrahedral ZnN2O2 and ZnN2S2 coordinations, respectively.