Y. M. Baron, C. Tubaro, A. Biffis, M. Basata, C. Graiff, A. Poater, L. Cavallo, N. Armaroli, G. Accorsi
Inorg. Chem., 51, 1778-1784, (2012)
Dinuclear N-heterocyclic dicarbene gold(I) complexes of general formula [Au2(RIm-Y-ImR)2](PF6)2 (R = Me, Cy; Y = (CH2)1–4, o-xylylene, m-xylylene) have been synthesized and screened for their luminescence properties. All the complexes are weakly emissive in solution whereas in the solid state some of them show significant luminescence intensities. In particular, crystals or powders of the complex with R = Me, Y = (CH2)3 exhibit an intense blue emission (λmax = 450 nm) with a high quantum yield (Φem = 0.96). The X-ray crystal structure of this complex is characterized by a rather short intramolecular Au···Au distance (3.272 Ǻ). Time dependent density functional theory (TDDFT) calculations have been used to calculate the UV/vis properties of the ground state as well as of the first excited state of the complex, the latter featuring a significantly shorter Au···Au distance.