Zinc complexes of the N,N,S ligand (mercaptophenyl)(picolyl)amine

The zinc complex chemistry of the tridentate thiol ligand N ‐ (2‐mercaptophenyl)(2‐picolyl)amine ( MPPAH ) differs considerably from that of the aliphatic analogue N ‐(2‐mercaptoethyl)(2‐picolyl)amine reported previously. This is due to the lower basicity and hence bridging tendency of its aromatic thiolate function. With zinc salts of oxo anions the 1:1 complexes ( MPPA )ZnX ( 1a–c : X = ONO 2 , OAc, OBz) are formed which according to spectroscopic data are monomeric while the halide ( MPPA )ZnBr ( 2 ) seems to be polymeric. In the absence of coordinating anions the monomeric 2:1 complex ( MPPA ) 2 Zn ( 3 ) results which according to a crystal structure determination contains tetrahedral zinc coordinated by one MPPA ligand in a tridentate fashion while the other is only monodentate and sulfur‐bound. A similar N 2 S 2 coordination can be deduced for the 1:1:1 complex ( MPPA )Zn(STrt) ( 4 ) resulting from ZnEt 2 , MPPAH and triphenylmethanethiol.