STRUCTURES OF CDSRP2O7 AND CDBAP2O7

(I) CdSrP2O7, M(r) = 374.0, monoclinic, P2(1)/n, a = 5.414 (1), b = 8.615 (3), c = 12.878 (5) angstrom, beta = 90.01 (3)degrees, V = 600.6 (4) angstrom 3, Z = 4, D(m) = 4.10 (5), D(x) = 4.135 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 126.6 cm-1, F(000) = 688, T = 298 K, R = 6.0% for 942 observed reflections. (II) CdBaP2O7, M(r) = 423.7, triclinic, P1BAR, a = 5.641 (1), b = 7.038 (2), c = 7.624 (2) angstrom, alpha = 78.55 (2), beta = 89.83 (2), gamma = 86.79 (2)degrees, V = 296.2 (2) angstrom 3, Z = 2, D(m) = 4.68 (5), D(x) = 4.750 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 107.1 cm-1, F(000) = 380, T = 298 K, R = 6.0% for 1217 observed reflections. The single-crystal structures of two mixed alkaline earth/transition metal diphosphates show them to exist in the solid state as dichromates with Cd in a distorted octahedral environment and the alkaline earth atoms, Sr and Ba, respectively eight and nine coordinate.