A New Method for Incorporating Thiolate Donors into a Metal Coordination Sphere. Synthesis and Crystal Structures of the First Nickel Complexes of an N₃S Ligand

Abstract

A new method for the synthesis of metal complexes with thiolate coordination is described which eliminates the need for protection/deprotection of the thiol. The reaction in methanol of 2,2‘-dithiodibenzaldehyde with nickel(II) complexes containing coordinated primary amines results in the concomitant Schiff-base condensation and cleavage of the disulfide bond to form a chelating amine/thiolate ligand. This method is used to synthesize nickel(II) complexes with varying N/S donor sets, including the first structurally characterized nickel complexes of tetradentate N3S ligands. [Ni(C11H16N3S)]BPh4 crystallizes in monoclinic P21 (a = 9.128(2) Å, b = 15.219(5) Å, c = 10.317(4) Å, β = 110.23(2)°, Z = 2); [Ni(C14H22N3S)]BPh4 crystallizes in orthorhombic P212121 (a = 9.894(2) Å, b = 16.687(4) Å, c = 21.807(7) Å, Z = 4).