A new tridentate N2Sthiolate ligand, PATH, has been prepared and includes a sterically hindered aliphatic thiolate donor as a cysteine mimic. PATH was em ployed in the synthesis of the monomeric complexes [(PATH)(MBr)-Br-II] and [(PATH)(MNCS)-N-II] (M = Zn, Co), which have been characterized by X-ray diffraction. These complexes are close structural analogues of the His(2)Cys site found in peptide deformylase.