LUMINESCENCE STUDIES OF GOLD(I) THIOLATE COMPLEXES

A series of monomeric gold(I) complexes containing phosphine and thiol ate ligands have been synthesized. The two phosphines used were triphe nylphosphine and the 1,3,5-triaza-7-phosphaadamantanetriylphosphine (T PA). Substituted benzenethiolate ligands were used with the substituen t in either the ortho, meta or para position. All of the compounds syn thesized luminesce at 77 K in the solid state, where the excitation is assigned to a ligand to metal charge transfer (LMCT) transition from the sulfur of the thiolate ligand to the gold center. The large Stokes shifts and long lifetimes measured imply that the emission is phospho rescence. The position of the emission maxima can be affected by both the substituents on the thiolate ligand and the presence of gold-gold interactions between neighboring molecules in the solid state. Four of these compounds have been structurally characterized. Compound 3 crys tallizes in the triclinic space group P (l) over bar (No. 2) with cell constants a = 8.641(2) Angstrom, b = 11.423(2) Angstrom, c = 12.118(2 ) Angstrom, alpha = 103.36(3)degrees, beta = 99.34(3)degrees, gamma = 105.95(3)degrees, and Z = 2. Refinement of 2861 reflections and 253 pa rameters yields R = 0.0275 and R(w) = 0.0669. Compound 4 crystallizes in the orthorhombic space group P2(1)2(1)2(1) (No. 18) with cell const ants a = 6.3100(10) Angstrom, b = 12.127(3) Angstrom, c 18.193(3) Angs trom, and Z = 4. Refinement of 1231 reflections and 163 parameters yie lds R = 0.0292 and R(w) = 0.0360. Compound 5 crystallizes in the monoc linic space group P2(1)/n (No. 13) with cell constants a = 12.252(3) A ngstrom, b = 17.002(6) Angstrom, c = 22.845(4) Angstrom, beta = 91.25( 2)degrees and Z = 12. Refinement of 5534 reflections and 541 parameter s yields R = 0.0698 and R(w) = 0.0786. Compound 10 crystallizes in the monoclinic space group C2/c (No. 15) with cell constants a = 17.542(5 ) Angstrom, b = 18.831(6) Angstrom, c = 11.647(4) Angstrom, beta = 119 .52(2)degrees, and Z = 8, Refinement of 2207 reflections and 181 param eters yields R = 0.0327 and R(w) = 0.0441.