Analysis of the main structural trends for biscyclometalated dinuclear rhodium compounds with nitrogen donor axial ligands

The crystal structures for a new series of dinuclear rhodium(II) compounds with two cyclometalated aryl phosphines [(C6H4)P(C6H5)2 or [(p-FC6H3)P(p-FC6H4)2], two bridging acetate groups and two nitrogen donor molecules in the axial positions (py, 3-COCH3py, 4-COCH3py or NH2Ph) have been determined by X-ray diffraction. The main structural trends, bond lengths, bond angles and torsion angles have been analyzed, and have also been compared with the structural parameters of analogous complexes previously described in the literature. The thermodynamics for the coordination of two axial ligands in biscyclometalated dinuclear rhodium compounds with structural parameters have also been studied and compared.