Synthesis, X-ray crystal structure, DFT calculations, spectroscopic characterization and redox behaviour of a rhodium(III) complex of an anthracene–pyridylhydrazone ligand

A pyridylhydrazone incorporating an anthracene moiety, designated as HLAnc, has been synthesized in order to examine its coordination behaviour towards rhodium(III). The complex [RhLAnc(PPh3)2Cl2], incorporating a four-membered metallacycle, has been isolated and authenticated by a single-crystal X-ray diffraction study. The complex shows interesting redox and optoelectronic properties, and to better understand these, theoretical investigations have been performed using density functional theory (DFT) and time-dependent DFT. The visible excitation for the complex arises from primarily mixed singlet-manifold 1ILCT and 1LLCT transitions.