Hydrothermal Syntheses and Structures of Three-Dimensional Oxo-fluorovanadium Phosphates: [H2N(C2H4)2NH2]0.5[(VO)4V(HPO4)2(PO4)2F2(H2O)4] · 2H2O and K2[(VO)3(PO4)2F2(H2O)] · H2O

Abstract

The hydrothermal reactions of FPO3H2with vanadium oxides result in the incorporation of fluoride into V–P–O frameworks as a consequence of metal-mediated hydrolysis of the fluorophosphoric acid to produce F−and PO3−4. By exploiting this convenient source of F−, two 3-dimensional oxo-fluorovanadium phosphate phases were isolated, [H2N(C2H4)2NH2]0.5[(VO)4V(HOP4)2(PO4)2F2(H2O)4) · 2H2O (1 · 2H2O) and K2[(VO)3(PO4)2F2(H2O)] · H2O (2 · H2O). Both anionic frameworks contain (VIVO)–F−-phosphate layers, with confacial bioctahedral {(VIVO)2FO6} units as the fundamental motif. In the case of 1, the layers are linked through {VIIIO6} octahedra, while for 2 the interlayer connectivity is provided by edge-sharing {(VIVO)2F2O6} units. Crystal data are 1 · 2H2O, CH10FN0.5O13P2V2.5, monoclinicC2/m,a= 18.425(4) Å,c= 8.954(2) Å, β = 93.69(2)0,V= 1221.1(4) Å3,Z= 4,Dcalc= 2.423 g cm−3; 2 · H2O, H4F2K2O13P2V3, triclinicP1,a= 7.298(1) Å,b= 8.929(2) Å,c = 10.090(2) Å, α = 104.50(2)0, β = 100.39(2)0, δ = 92.13(2)0,V= 623.8(3) Å3,Z= 2,Dcalc= 2.891 g cm−3.