Some Aspects of the Structural and Coordination Chemistry of the 2,2′-Biphosphole

The 2,2′-biphosphole which presents axial chirality generated by the biphosphole framework and central chiralities due to the phosphorus atoms leads to the existence of six stereoisomers corresponding to three pairs of enantiomers which have been fully characterised by X-ray diffraction studies. Among these three diastereoisomers, one has a favourable configuration for chelating metals. The synthesis and structure of numerous transition metal complexes are reported. Their X-ray analysis proved that in each complex the 2,2′-biphosphole ligands have the expected configuration.