Open-framework cobalt (II) phosphates with sodalite-related architectures

Three new framework cobalt (II) phosphates have been synthesized hydrothermally in the presence of piperazine as a structure-directing agent. Crystal data: compound I, [C4N2H12][Co(HPO4)(2)], monoclinic space group = P2(1)/n (no. 14), a = 8.5521 (10) Angstrom, b = 13.5791(15) Angstrom, c = 10.0405(11) Angstrom beta = 96.855 (2)degrees, V = 1157.7 (2) Angstrom(3), Z = 4, M = 339.04, D, 1.945 g cm(-3), MoKalpha, lambda = 0.71073 Angstrom, R-1 (F-0) = 0.053; compound II, [C4N2H11] [Co-2(PO4)(H2PO4)(2)] monoclinic space group = C2/c (no. 15), a = 13.444(5) Angstrom, b = 12.874(5) Angstrom, c = 8.224(2), beta = 94.64(2)degrees, V = 1418.8 (2) Angstrom(3), Z = 8, M = 494.96, D-c = 2.317 g cm(-3), MoKalpha, lambda = 0.71073 Angstrom, R-1(F-0) = 0.047; compound III, [C4N2H12](2)[Co-4(HPO4)(6)], monoclinic space group = P2(1)/c (no. 14) a = 12.8780(13) Angstrom, b = 26.671(3) Angstrom, c = 8.2592(8) Angstrom, beta = 96.931(2)degrees, V = 2816.0(5) Angstrom(3), Z = 4, M = 987.90, D-c = 2.330 g cm(-3), MoKalpha, lambda = 0.71073 Angstrom, R-1 (F-0) = 0.048. The structure of I consists of one-dimensional chains built up of corner-shared four rings (Co2P2) which are key structural units that form the sodalite cage. Compounds II and III have interrupted sodalite-type structures resulting from the removal of Co2+ atoms from sites related by two-fold axes passing through the four rings of the normal sodalite cage structure. The modes of the interruptions in II and III differ in relation to the structure of a regular sodalite cage. (C) 2002 Elsevier Science (USA).