Octahedral-tetrahedral framework solids of the vanadium phosphate system. Hydrothermal syntheses and crystal structures of the vanadium(III) phosphate Cs[VIII2(PO4)(HPO4)2(H2O)2] and of the mixed-valence species K[(VIVO)VIII(HPO4)3(H2O)2

Abstract

The cesium vanadium phosphate Cs[V III 2 (PO 4 )(HPO 4 ) 2 (H 2 O) 2 ] (1) and the potassium vanadium phosphate K[(V IV O)V III (HPO 4 ) 3 (H 2 O) 2 ] (2) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray methods. Green phosphate 1 is monoclinic, space group P2 1 /a, with a=10.004(1) A, b=17.812(3) A, c=6.370(2) A, β=97.02(2) o , and Z=4, while green phosphate 2 is monoclinic, space group P2 1 /n, with a=6.399(3) A, b=10.275(2) A, c=17.810(2) A, β=96.12(2) o , and Z=4