Synthesis, X-Ray Crystallography, Characterization And Luminescence Studies Of Selected Tertiary Phosphine Gold (I) Complexes

The structures, and spectroscopic properties of a series of three new monocoordinated, four new bis-, tris-, and tetrakis-phosphine gold(I) complexes are reported. Six different monodentate tertiary phosphine ligands including tris(3,5-dimethylphenyl)phosphine,tris(2,6-dimethoxyphenyl)phosphine, tris(pentafluorophenyl)phosphine, tris(4-methoxyphenyl)phosphine, tert-butyldiphenyl phosphine, and tris(4-fluorophenyl)phosphine are used in this study. Three of the complexes have been studied with single crystal X-ray crystallographic techniques and the structural information was collaborated with Raman, and 31P-NMR studies. The crystal structure of the complexes reveal the geometry and coordination of the ligands to the gold(I) atom as well as to Cl- within the crystal lattice. Detail luminescence, 1H-NMR, UV-Vis and FTIR spectroscopic studies were also performed. The photo-luminescence of the complexes compared with that of the ligand show ligand centered emission perturbed by the metal coordination. Theoretical DFT studies conducted on these complexes support the experimental studies and the assignment of the electronic transitions. Comparison of the electronic absorption behaviors also show a hyperchromic shift as the number of chromophores added to the gold (I) center increases and the molar extinction coefficient values of the ligands and the complexes determined are in excess of 104 M-1 cm-1. Nuclear site analysis was used extensively for elucidating the number of IR and Raman bands that are possible for these complexes. A correlation between the structural and the vibrational data was established