Synthesis and Photophysical Properties of Au(III)-Ag(I) Aggregates

Abstract

Cyclometalated gold(III) complexes of the type (CNC)AuX [HCNCH = 2,6-bis(4-ButC6H4)pyrazine; 2,6-bis(4-ButC6H4)pyridine, or 2,6-bis(4-ButC6H4)4-Butpyridine; X = CN, CH(COMe)2, or CH(CN)2] have been used as building blocks for the construction of the first family of AuIII/AgI aggregates. The crystal structures of these aggregates reveal the formation of complex architectures in which the Ag+ cations are stabilized by the basic centers present on each of the Au precursors. The photophysical properties of these aggregates are reported. Compared to mononuclear pincer complexes, a general red-shift and an increase in the emission intensity are observed. In agreement with DFT calculations, the lowest energy absorption and the emission are assigned to 1IL(CNC) and 3IL(CNC) transitions dominated by the HOMO and the LUMO orbitals.