Preparation and characterization of some ruthenium(II) porphyrins containing tertiary phosphine axial ligands, including the crystal structure of (octaethylporphinato)bis(triphenylphosphine)ruthenium(II)

Abstract

The ruthenium(II) porphyrin complex Ru(OEP)(PPh 3 ) 2 (OEP = the dianion of octaethylporphyrin) has been prepared from Ru(OEP)(CO)EtOH, and the X-ray crystal structure determined; as expected, the six-coordinate ruthenium is situated in the porphyrin plane and has two axial phosphine ligands. Synthesized also from the carbonyl(ethanol) precursors were the corresponding tris(p-methoxyphenyl)phosphine complex, and the Ru(TPP)L 2 (TPP = the dianion of tetraphenylporphyrin, L = PPh 3 , P(p-CH 3 OC 6 H 4 ) 3 , P″Bu 3 ) and Ru(TPP)(CO)PPh 3 complexes. Optical and 1 H nmr data are presented for the complexes in solution. In some cases dissociation of a phosphine ligand to generate five-coordinate species occurs and this has been studied quantitatively in toluene at 20 °C for the Ru(OEP)L 2 and Ru(TPP)L 2 systems.