New CpCrCl2(PR3) complexes: Physical properties and reduction chemistry

Article abstract of DOI:10.1016/S0277-5387(97)00496-8

Compounds CpCrCl₂L (L = PMe₂Ph, 1; PMePh₂, 2; PPh₃, 3) have been prepared. Their magnetic moment is in accord with the presence of three unpaired electron and a variable temperature ¹H NMR investigation of 1 shows Curie-Weiss behavior. The ¹H NMR, EPR and UV-visible spectra are in agreement with those of other previously reported compounds of the same family. An electrochemical investigation shows the accessibility of an irreversible reduction process. A parallel sodium reduction investigation of complexes CpCrCl₂L (L = PMe₃ and η¹-dppe) suggests that the reduction process is followed by immediate chloride loss, and then by a ligand redistribution process to afford chromocene and unstable inorganic phosphine complexes of Cr(II).