Luminescent Di- and Tetranuclear Gold Complexes of Bis(diphenylphosphinyl)-Functionalized Dipyrido-Annulated N-Heterocyclic Carbene.

Phosphine-functionalized N-heterocyclic carbene (NHC) ligands are known to complex group 11 metal centers to form multinuclear complexes with photoluminescence properties. This study reports a structurally rigid ortho-substituted dipyrido-annulated NHC with T-shape coordination geometry and its di- and tetranuclear gold(I) complexes. The free ligand as well as all metal complexes are found luminescent at room temperature and phosphorescent at 77 K. Although metal d10-d10 interactions are evident based on their solid-state structures, their effect on the photoemission is limited, most likely due to the weak coordination of the ligand to the metal centers in solution.