Models for copper proteins. Copper(I) and (II) complexes of a novel binucleating tetraamino-tetrathioether ligand

The novel binucleating ligand, 6,6 prime-methylene-bis(5 prime-amino-3 prime,4 prime-benzo-2 prime-thiapentyl)-1,11-diamino-2,3:9,10-dibenzo-4,8-dithiaundecane (H4L) was prepared and reacted with copper(II) salts in dry MeOH to yield mixtures of copper(I) and copper(II) complexes with Cl- and ClO-4 counter ions. The amine functions on the ligand release protons to form copper(I) complexes: (Cu2L)X2, where X=Cl−, ClO4-. The complexes were oxidized to (Cu2L)X4 with H2O2 in DMF; Cu(NO3)2 gave a different complex, [Cu2(H4L)(NO3)2](NO3)2, as regards proton releasing ability, coordination and oxidation number. Evidence for the structures of this new tetraamino-tetrathioether ligand and its copper complexes is provided by 1H-, 13C-n.m.r., mass, u.v.–vis., i.r. spectra, elemental analyses, molar conductivities and magnetic moments. This revised version was published online in June 2006 with corrections to the Cover Date.