New Tripodal N3S Ligands and Some Zinc Complexes Thereof

Attachment of 2-pyridylmethyl units to cysteine amide and 2-mercaptobenzylamine leads to the new tripodal N3S Ligands N-alpha-(4-methylbenzoyl)-L-cysteine-bis(2-pyridylmethyl)amide (CBPA-H) and 2-mercaptobenzyl-bis(2-pyridylmethyl)amine (MBPA-H). Their treatment with zinc halides yields the neutral complexes L . ZnHal (Hal = Cl, Br, I). With zinc perchlorate MBPA forms the ionic compound [L . Zn] ClO4, presumed to be a thiolate bridged dimer. Structure determinations of MBPA . ZnHal (Hal = Cl, Br) have confirmed the tripodal nature of the ligand in the trigonal-bipyramidal complexes.