Synthesis of oligomeric and polymeric Rh(I) halocarbonyl diphosphine compounds

In the last years, we pursued the synthesis of coordination polymers starting from the Rh(I) halocarbonyl [RhCl2(CO)2]- and different diphosphine ligands reporting some successful example of 1D polymeric structures.1,2 Significant results obtained with diphosphines of general formula PPh2(CH2)nPPh2 (n=5-12) are here summarized. Generally, the formation of coordination rings is observed and sometimes this is the only species isolated; interestingly, rings with n=6 and 8, subsequently evolve to the corresponding polymers, probably through a reaction of ring-opening polymerization.