Isomeric Tetradentate Ligand-Containing Cyclometalated Gold(III) Complexes

A simple one-pot two bond-forming reaction for the rapid
construction
of cyclometalated gold­(III) complexes with fully π-conjugated
tetradentate ligand is reported. The coupling of the bifunctional
gold­(III) precursor with the bifunctional aromatic compound has led
to the formation of two regioisomers with either C- or N-coordination. Through monitoring by high-throughput
high performance liquid chromatography, the regioselectivity of the
reaction has been effectively tuned toward the formation of a single
isomer, allowing easy separation of the metal complexes. The structures
of the complexes have been determined by X-ray crystallography, and
the photophysical, electrochemical, and electroluminescence (EL) studies
have been carried out. Computational study has been performed to provide
insights into the nature of the excited states. Isomeric effect has
been shown to have a significant influence on the EL behavior of the
organic light-emitting devices.