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) Å, b = 18.1918(8) Å, c = 17.7172(8) Å, V = 2035.4(2) Å3, Z = 8, R1(all data) = 0.0368; II, triclinic,
space group P1̄ (No.2), a = 6.3406(2) Å, b = 10.2085(3) Å, c = 13.2551(10) Å, α = 101.238(2)°, β = 96.503(2)°,
γ = 104.332(2)°, V = 803.47(4) Å3, 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.