Organically Templated Vanadyl Selenites with Layered Structures

Two layered vanadyl selenites with the compositions, [DABCOH2]0.5[(VIVO)(HSeO3)(SeO3)].H2O,I, and [enH2][(VivO)2-(VVO)O2(SeO3)3]-.1.25H2O, II, have been prepared by the reaction of NaVO3 with SeO2 or H2SeO4 under hydrothermal conditions in the presence of organic amines. Crystal data: I, orthorhombic, space group Pbcn (No. 60), a = 6.3152(3) A, b = 18.1918(8) A, c = 17.7172(8) A, V = 2035.4(2) A3, Z = 8, R1 (all data) = 0.0368; II, triclinic, space group P1 (No.2), a = 6.3406(2) A, b = 10.2085(3) A, c = 13.2551(10) A, alpha = 101.238(2) degrees, beta = 96.503(2) degrees, gamma = 104.332(2) degrees, V = 803.47(4) A3, Z = 2, R1 (all data) = 0.0814. While I contains the ladder motif, commonly found in open-framework metal phosphates, II is formed by a secondary building unit composed of a V4O18 cluster along with SeO3 and VO5 groups. The study demonstrates that the selenite unit can be fruitfully exploited to design interesting open-framework structures.