Crystal and Molecular Structure of Dihydroxo (5,10,15,20-tetraphenylporphinato) phosphorus(V) Hydroxyde Dihydrate

The structure of dihydroxo(5,10,15,20-tetraphenylporphinato)phosphorus(V) hydroxide dihydrate, (C4H3,,02P+)(OH-).2H20, has been determined from three-dimensional diffractometer data. It crystallizes in the monoclinic space group P2,/c with a = 14.636 (4) A, b = 13.953 (3) A, c = 17.592 (4) A, /3 = 90.21 (2)", and Z = 4. The structure was solved by heavy-atom methods and refined by full-matrix least-squares methods to yield a final R factor of 0.090. This is the first reported structural analysis of a "metalloporphyrin" where the central ion is a nonmetal. The coordination geometry is distorted octahedral with the phosphorus atom displaced 0.09 8, from the mean plane of the pyrrole nitrogen atoms. The P-N bond lengths range from 1.87 (1) to 1.92 (1) 8,. The two P-O distances are 1.644 (8) and 1.545 (8) 8,. The porphyrin ring shows marked S4 deviations from planarity. There is extensive hydrogen bonding between the axial hydroxyl groups, the hydroxide counterion and the waters of hydration forming quasi-linear hydrogen-bonded polymers.