HYDROTHERMAL SYNTHESIS AND CRYSTAL-STRUCTURES OF 2 COPPER VANADIUM PHOSPHATES - CU-0.5[VOPO4]CENTER-DOT-2H(2)O AND CU-0.5(OH)(0.5)[VOPO4]CENTER-DOT-2H(2)O

Two layered copper vanadium phosphates, Cu-0.5[OPO4] . 2H(2)O (1) and Cu-0.5(OH)(0.5)[VOPO4] . 2H(2)O (2), have been synthesized hydrothermally and their structures determined by single-crystal X ray crystallography. Phosphate 1 is monoclinic, space group P2(1)/m, a = 6.614 (2) Angstrom, b = 8.930 (2) Angstrom, c = 9.071 (2) Angstrom, beta = 103.79 (2)degrees, Z = 4, V = 520.3 (3) Angstrom(3). Refinement with 750 observed reflections for which I greater than or equal to 3 sigma(I) gave R (R(w)) = 0.051 (0.058). The structure has hydrated Cu2+ ions bonded to layers composed of distorted VO6 octahedra and PO4 tetrahedra. Each Cu2+ ion is bonded to only one layer and possesses a nearly square planar geometry but with two very long axial bonds. This results in a very distorted octahedral configuration composed of two phosphate oxygens, three water molecules, and one vanadyl oxygen. Phosphate 2 is triclinic, space group P (1) over bar, a = 7.0124 (8) Angstrom, b = 12.6474 (9) Angstrom, c = 6.3022 (6) Angstrom, alpha = 90.079 (8)degrees, beta = 96.076 (9)degrees, gamma = 74.002 (7)degrees, Z = 2, V = 534.05 (9) Angstrom(3). Refinement using 2311 observed reflections with I greater than or equal to 3 sigma(I) gave R (R(w)) = 0.035 (0.043). The structure consists of VOPO4 layers somewhat similar to those of 1, but with the layers bridged together through Cu dimers of Cu-2(OH)(2)(H2O)(4). Each Cu2+ ion is in a distorted square planar configuration. (C) 1995 Academic Press, Inc.