Synthesis and crystal structure of Zn 2VO(PO 4) 2, a vanadyl(IV) orthophosphate containing a dimer of edge-sharing ZnO 5 square pyramids
Reactions in the ZnOVO 2P 2O 5 system afford the new phase Zn 2VO(PO 4) 2, the structure of which was determined by the single-crystal X-ray diffraction method ( I4 cm, a = 8.9227(13), c = 9.039(3) Å, Z = 4, R = 0.026 for 228 unique reflections). The structure consists of infinite chains of corner-sharing VO 6 octahedra along the c-axis and finite chains of edge-sharing ZnO 5 and PO 4 polyhedra parallel to the <110> directions. The VO 6 octahedra are distorted such that alternately long and short VO bonds along the axis of the infinite chain are formed. The Zn 2+ ions exhibit a square pyramidal coordination.