Syntheses, crystal structures and characterizations of new vanadium arsenites and arsenates

Systematic explorations in vanadium arsenites and arsenates led to the isolation four new compounds, namely, α-(VIVO)3(AsIIIO3)2 (1), β-(VIVO)3(AsIIIO3)2 (2), (VIVO)[VIVO(H2O)]2(AsVO4)2 (3), VIIIVIVO2(AsVO4) (4). Compounds 1, 2 and 4 were synthesized by standard solid-state reactions, and compound 3 is a vanadium arsenate dihydrate synthesized through hydrothermal reactions. Compounds 1 and 2 are isomers, and they represent the first examples of ternary inorganic vanadium(IV) arsenites. Single crystal X-ray diffraction analysis indicated that the four compounds display four different structural types. Magnetic property measurements for compound 1 indicated that it exhibits ferromagnetism with the Curie temperature Tc=65 K. Thermal stability and optical properties for compounds 1 and 3 were also investigated.