Tris(2-pyridyl)phosphine complexes of ruthenium(II) and rhodium(I). Hydroformylation of hex-1-ene by rhodium complexes

Complexes of ruthenium(II) and rhodium(I) containing tris(2-pyridyl)phosphine [P(py)3] are described, examples being RuHCl[P(py)3]3 and RhCl[P(py)3]2. In certain cases, as in these, the nitrogen atom of one of the 2-pyridyl groups can act as a donor to give a P,N chelate ligand. In the presence of an excess of P(py)3, and at low CO + H2(1 : 1) pressures, the complex RhH(CO)(PPh3)[P(py)3]2 acts as a catalyst for the selective hydroformylation of hex-1-ene to n-heptanal.