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 HL Anc , has been synthesized in order to examine its coordination behaviour towards rhodium(III). The complex [RhL Anc (PPh 3 ) 2 Cl 2 ], 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 1 ILCT and 1 LLCT transitions.