K(MoO₂)₄O₃(AsO₄)

Abstract

A new compound with a non-centrosymmetric structure, potassium tetra-kis-[dioxomolybdenum(IV)] arsenate trioxide, K(MoO2)4O3(AsO4), has been synthesized by a solid-state reaction. The [(MoO2)4O3(AsO4)](+) three-dimensional framework consists of single arsenate AsO4 tetra-hedra, MoO6 octa-hedra, MoO5 bipyramids and bi-octa-hedral units of edge-sharing Mo2O10 octa-hedra. The [Mo2O8]∞ octa-hedral chains running along the a-axis direction are connected through their corners to the AsO4 tetra-hedra, MoO6 octa-hedra and MoO5 bipyramids, so as to form large tunnels propagating along the a axis in which the K(+) cations are located. This structure is compared with compounds containing M 2O10 (M = Mo, V, Fe) dimers and with those containing M 2O8 (M = V) chains.