Complexes of thiazoles. Part I. Complexes of benzothiazole with cobalt(II), nickel(II), copper(II), and zinc(II) halides, thiocyanates, and perchlorates

Abstract

Complexes of benzothiazole (BT) have been prepared and studied by magnetic and spectroscopic techniques. Tetrahedral complexes, M(BT)₂X₂, which have been well characterised, are formed with ZnX₂(X = Cl, Br) and CoX₂(X = Cl, Br, I, NCS). Tetrahedral Ni(BT)₂I₂ has also been formed, but the following nickel complexes have an octahedral or distorted octahedral stereochemistry: Ni(BT)₄Br₂, Ni(BT)₂X₂(X = Cl, Br), Ni(BT)Br₂. The Ni(BT)₂X₂ species involve halogen-bridged polymeric structures with benzothiazole molecules above and below the plane, while in Ni(BT)Br₂ the planes of nickel atoms and bridging bromine atoms are connected by bridging benzothiazole molecules. It is suggested that bridging benzothazole is also present in [Cu₂(BT)₆](ClO₄)₄. Tetragonal polymeric copper(II) complexes, Cu(BT)₂X₂, with bridging X (Cl, Br) and 1 : 1 complexes, Cu(BT)X₂, which it is suggested are dimeric, four-co-ordinate, with bridging X, are also reported. A number of other 1 : 2 species with CuBr₂ are reported, together with some octahedral perchlorates and perchlorato-complexes of Ni(II) and Co(II). It appears that benzothiazole co-ordinates through the nitrogen heteroatom in these complexes (except when acting as a bridging ligand, when both heteroatoms are involved).