PREPARATION AND SPECTRAL STUDIES OF DINUCLEAR MIXED-LIGAND COPPER(I) COMPLEXES - THE CRYSTAL-STRUCTURE OF BIS[MU-S(PYRIDINE-2-THIONE)(TMTP)COPPER(I) BROMIDE

[Cu(tmtp)Br]n (tmtp = tri-m-tolylphosphine) reacts with heterocyclic t hiones (L) [L = pyridine-2-thione (py2SH), 1,3-thiazolidine-2-thione ( tzdtH), benz-1,3-imidazoline-2-thione (bzimtH2), benz-1,3-thiazoline-2 -thione (bztzdtH), imidazoline-2-thione (imtH), benz-1,3-oxazoline-2-t hione (bzoxtH2), 5-nitrobenz-1,3-imidazoline-2-thione (nbzimtH2), and 5-methyl-benz-1,3-imidazoline-2-thione (mebzimtH2)] to give binuclear complexes of the general formula [Cu(tmtp)(L)Br]2. These complexes hav e been characterized by various spectroscopic methods. The crystal str ucture of the pyridine-2-thione complex has been determined by single- crystal X-ray diffraction methods. The molecule contains a planar Cu2S 2 moiety with Cu-S bond lengths of 2.3348(9) and 2.4879(7) angstrom. T he Cu-Br and Cu-P distances are 2.4929(1) and 2.2525(4) angstrom, resp ectively, whereas the Cu...Cu separation is 2.6906(1) angstrom.