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).