LUMINESCENCE STUDIES OF GOLD(I) THIOLATE COMPLEXES

A series of monomeric gold(I) complexes containing phosphine and thiolate ligands have been synthesized. The two phosphines used were triphenylphosphine and the 1,3,5-triaza-7-phosphaadamantanetriylphosphine (TPA). Substituted benzenethiolate ligands were used with the substituent in either the ortho, meta or para position. All of the compounds synthesized 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 phosphorescence. 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 crystallizes 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 parameters 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 constants a = 6.3100(10) Angstrom, b = 12.127(3) Angstrom, c 18.193(3) Angstrom, and Z = 4. Refinement of 1231 reflections and 163 parameters yields R = 0.0292 and R(w) = 0.0360. Compound 5 crystallizes in the monoclinic space group P2(1)/n (No. 13) with cell constants a = 12.252(3) Angstrom, b = 17.002(6) Angstrom, c = 22.845(4) Angstrom, beta = 91.25(2)degrees and Z = 12. Refinement of 5534 reflections and 541 parameters 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 parameters yields R = 0.0327 and R(w) = 0.0441.