SYNTHESIS, PHOTOPHYSICS, AND TRANSIENT ABSORPTION SPECTROSCOPIC STUDIES OF LUMINESCENT COPPER(I) CHALCOGENIDE COMPLEXES - CRYSTAL-STRUCTUREOF [CU-4(MU-DTPM)(4)(MU(4)-S)](PF6)(2) (DTPM EQUALS BIS[BIS(4-METHYLPHENYL)PHOSPHINO]METHANE)

A luminescent copper(I) sulfide cluster [Cu-4(mu-dtpm)(4)(mu(4)-S)](PF 6)(2) (3) {dtpm = bis[bis(4-methylphenyl)-phosphino]methane} has been synthesized and characterized by X-ray crystallography. Its photophysi cal and electrochemical properties have also been studied. The long-li ved photoluminescence of 3 is assigned to originate from an excited st ate with a parentage of large ligand-to-metal charge-transfer LMCT [(S 2-) --> Cu-4] character, with mixing of metal-centered MC [(ds/dp) Cu( I)(4)] state, The phosphorescent state of 3, as well as those of its a nalogues [Cu-4(mu-dppm)(4)(mu(4)-S)](PF6)(2) (1) and [Cu-4(mu-dppm)(4) (mu(4)-Se)](PF6)(2) (2), have been found to undergo facile electron-tr ansfer reactions with different pyridinium accepters, which have been investigated with nanosecond transient absorption spectroscopy. Crysta l data for 3: a = 37.38(1) Angstrom, b = 15.905(7) Angstrom, c = 27.76 1(5) Angstrom, beta = 128.69(1)degrees, V = 12881(6) Angstrom(3), Z = 4.