Na₂MoO₂As₂O₇

Abstract

Disodium molybdenum dioxide diarsenate, Na2MoO2As2O7, has been synthesized by a solid-state reaction. The structure is built up from MoAs2O12 linear units sharing corners to form a three-dimensional framework containing tunnels running along the a-axis direction in which the Na(+) cations are located. In this framework, the As(V) atoms are tetra-hedrally coordinated and form an As2O7 group. The Mo(VI) atom is displaced from the center of an octa-hedron of O atoms. Two Na(+) cations are disordered about inversion centres. Structural relationships between different compounds: A2MoO2As2O7 (A = K, Rb), AMOP2O7 (A = Na, K, Rb; M = Mo, Nb) and MoP2O7 are discussed.