The synthetic cobalt vanadium selenite, Co₂V₂Se₂O₁₁

Abstract

The crystal structure of dicobalt(II) divanadium(V) disel­enium(IV) undeca­oxide, Co2V2Se2O11, exhibits a three-dimensional framework, the building units being distorted CoO6 octa­hedra and VO5 square pyramids arranged so as to form alternate chains along [010]. The framework has channels along [100] and [010] in which the two Ψ-SeO3 E (site symmetries m; E being the 4s 2 lone electron pair of SeIV) tetra­hedra reside and connect to the other building blocks. The structure contains corner- and edge-sharing CoO6 octa­hedra, corner- and edge-sharing VO5 square pyramids and edge-sharing Ψ-SeO3 E tetra­hedra. Co2V2Se2O11 is the first oxide containing all the cations CoII, VV and SeIV.

α-ScVSe2O8, β-ScVSe2O8, and ScVTe2O8: New Quaternary Mixed Metal Oxides Composed of Only Second-Order Jahn–Teller Distortive Cations

“…With these ideas in mind, we investigated the Sc 3+ –V 5+ –Q 4+ (Q = Se or Te)–oxide system. Thus far, several quaternary vanadium selenite/tellurite materials containing alkali metals, alkaline-earth metals, and transition metals have been reported. A few stoichiometrically similar phases, M 3+ VQ 2 O 8 (M = Bi, Eu, Gd, Tb, and In), also have been discovered, where InVSe 2 O 8 crystallizes in NCS framework structures with SHG efficiency of 30 times that of α-SiO 2 .…”