NICKEL (2) AND COBALT (2) COMPLEXES OF A NEW SEXADENTATE MACROCYCLE

Nickel(II) and cobalt(II) complexes of the new macrocyclic sexadentate ligand, 12,13,26,27-tetra-hydrotetrabenzo[e,i,o,s][l,4,11,14,7,18]tetrathiadiazacycloeicosine (MAC) of the types [M(MAC)]X2 (M = Ni, × = ClO4, I; M = Co, × = ClO4) have been prepared. The complexes were initially prepared by reaction in situ of a solution of the appropriate metal salt with solutions of 1,2-bis(2-aminophenylthio)ethane and 1,4-bis(2-formylphenyl)-1,4-dithiabutane. Both nickel complexes are high spin, whereas the cobalt complex is low spin. For comparison, the high-spin nickel perchlorate complex of the related open-chain sexadentate, N,Nʹ-[ethylenebis(thio-o-phenylenemethylidyne)]bis[2-(methylthio)aniline], has also been prepared. Physical measurements indicate that in all the complexes the ligands are acting as sexadentate chelating agents. © 1969, American Chemical Society. All rights reserved.