T. Pandiyan et al., COPPER(II)-THIOLATE COMPLEXES WITH NOVEL TRIPODAL-LIKE AND TETRAPODAL-LIKE BENZIMIDAZOLES, Transition metal chemistry, 20(5), 1995, pp. 440-444
The tripodal copper(II) thiolate complexes Cu(L1)(Cl). 2H(2)O and Cu(L
1)(mim)(Cl) [H(L1) = -(2-mercaptoethyl)-N,N-bis(pyrid-2'-ylmethyl)amin
e and mim = N-methylimidazole] have been isolated. Both contain monome
ric copper(II) and display two ligand field bands and axial cryogenic
e.p.r. spectra, suggesting a square-based geometry. A copper(II) thiol
ate complex Cu(L2)(ClI). H2O [H(L2) = -tris(benzimidazol-2'-ylmethyl)-
1,2-ethanediamine] with a CuN5S chromophore has been also isolated. It
exhibits only one ligand field band and an axial cryogenic e.p.r. spe
ctrum, consistent with a distorted tetragonal coordination geometry. A
ll the thiolates display intense S- --> Cu-II charge transfer bands in
the u.v. region, suggesting equatorial thiolate coordination. All of
the complexes exhibit irreversible electrochemical behaviour.