NEW POLYMORPHS OF RU(III)P3O9 - CYCLOHEXAPHOSPHATE RU2P6O18 AND METAPHOSPHATE RU(PO3)(3) WITH A NOVEL STRUCTURE

Two new polymorphs of ruthenium phosphate with RuP3O9 composition were prepared and their crystal structures were determined by single-crystal X-ray diffraction. They are cyclo-hexaphosphate Ru2P6O18 and metaphosphate Ru(PO3)(3). Ru2P6O18 crystallizes in the monoclinic space group P2(1)/c with a = 6.292(2) Angstrom, b = 15.276(2) Angstrom, c = 8.365(2) Angstrom, beta = 106.54(2)degrees, V = 770.6(3) Angstrom(3), Z = 2, R = 0.043, R(W) = 0.035. The structure contains cyclo-hexaphosphate rings stacking obliquely along the [100] direction and is isotypic with B-form cyclo-phosphates. Ru(PO3)(3) has a novel structure and crystallizes in the triclinic space group P (1) over bar with a = 6.957(1) Angstrom, b = 10.324(2) Angstrom, c = 5.030(1) Angstrom, alpha = 92.45(2) Angstrom, beta = 92.31(2)degrees, gamma = 98.61(1)degrees, V = 356.5(1) Angstrom(3), Z = 2, R = 0.030, R(W) = 0.027. It is built up of a network of infinite [PO3-](infinity) chains and RuO6 octahedra. The configuration of the metaphosphate chains is different from that in the C-form Ru(PO3)(3). While the chains in the C-form consisting of PO3-O-PO3 units are condensed in nearly staggered configurations, the units in the new phosphate are eclipsed. (C) 1995 Academic Press, Inc.