Synthesis and Photophysical Properties of T-Shaped Coinage-Metal Complexes

The photophysical properties of a series of T-shaped coinage d(10) metal complexes, supported by a bis(mesoionic carbene)carbazolide (CNC) pincer ligand, are explored. The series includes a rare new example of a tridentate T-shaped Ag-I complex. Post-complexation modification of the Au-I complex provides access to a linear cationic Au-I complex following ligand alkylation, or the first example of a cationic square planar Au-III-F complex from electrophilic attack on the metal centre. Emissions ranging from blue (Cu-I) to orange (Ag-I) are obtained, with variable contributions of thermally-dependent fluorescence and phosphorescence to the observed photoluminescence. Green emissions are observed for all three gold complexes (neutral T-shaped Au-I, cationic linear Au-I and square planar cationic Au-III). The higher quantum yield and longer decay lifetime of the linear gold(I) complex are indicative of increased phosphorescence contribution.