Crystal structure of vanadium(III) tris(metaphosphate)

Vanadium(III) tris(metaphosphate), V(PO 3 ) 3 , crystallizes in the monoclinic space group Ic with lattice parameters a = 10.615(2), b = 19.095(4), c = 9.432(1) Å, β = 97.94(1)° with Z = 12. The equivalent parameters in the standard space group Cc are a = 13.189(1), b = 19.095(4), c = 9.432(1) Å, and β = 127.15(1)°. The structure was refined by full-matrix least-squares to an R = 0.091 (R ω = 0.065) utilizing 2467 reflections with the atomic positions and their isotropic vibration amplitudes as parameters. The structure consists of infinite chains of PO 4 tetrahedra sharing corners with each other and bridged by VO 6 octahedra. All oxygen atoms are shared between just two cations. The average [Formula: see text] bond is 1.581 Å while the average of those shared with vanadium is 1.483 Å. The VO 6 group is moderately distorted, with differences of less than 0.06 Å between the longest and shortest V—O bond lengths in any of the three distinct VO 6 groups. The average V—O bond lengths for the three VO 6 groups are 1.995, 1.991, and 1.987 Å. A marked superlattice effect based on a cell with b/3 is noted.