Structural and spectroscopic study of Mg13.4(OH)6(HVO4)2(H0.2VO4)6

Single-crystals of the polar compound magnesium hydrogen vanadate(V), Mg13.4(OH)6(HVO4)2(H0.2VO4)6,were synthesized hydrothermally. It represents the first hydrogen vanadate(V) among inorganic compounds.Its structure was determined by single-crystal X-ray diffraction [space group P63mc, a = 12.9096(2), c =5.0755(1) A, V = 732.55(2) A3, Z = 1]. The crystal structure of Mg13.4(OH)6(HVO4)2(H0.2VO4)6 consists ofwell separated, vacancy-interrupted chains of face sharing Mg2O6 octahedra, with short Mg2-Mg2distances of 2.537(1) A, embedded in a porous magnesium vanadate 3D framework having the topology ofthe zeolite cancrinite. All three hydrogen positions in the structure were confirmed by FTIR spectroscopy.