Towards new cesium containing manganese vanadates via a precursor method

Two new cesium containing manganese vanadates are synthesized by a facile method. The known compound K2Mn(VO3)4 (1), synthesized via a milder method than the previous hydrothermal reaction, was firstly used as a precursor to prepare two new manganese vanadates, namely CsMn(VO3)3·H2O (2) and Cs4.34Mn1.83(VO3)8·2.965H2O (3) in concentrated Cs+ aqueous solutions at 80 °C. Compound 2 features a three-dimensional (3D) microporous framework constructed from serrated (VO3)n chains interconnected by Mn2+ ions. The Cs+ ions and the lattice water molecules are located in the channels of the structure along the a-axis. In compound 3, the sinusoidal (VO3)n chains are linked by Mn2+ ions into V–O–Mn double chains, which are further weaved by {Mn4O8} units to form a 3D microporous network with channels occupied by disordered Cs+ ions. Compounds 2 and 3 are the first Cs–Mn–V–O examples with a 3D microporous framework. Thermal stabilities of compounds 2 and 3 were investigated by thermogravimetric (TG) analysis. This work provides an effective synthetic method for preparing alkali-metal containing heterometallic vanadates with new composition and structures.