Rb3BaTeB7O15: a novel [B7O16] fundamental building block in a new telluroborate with [TeO3] polyhedra

Abstract

A new telluroborate Rb₃BaTeB₇O₁₅, with a new type of fundamental building block, namely [B₇O₁₆] units, has been synthesized by the high-temperature flux method, and it crystallizes in the monoclinic space group P2₁/n (no. 11) with a three dimensional network. To the best of our knowledge, Rb₃BaTeB₇O₁₅ is the first telluroborate that is constructed only by using [TeO₃] polyhedra. Meanwhile, the stereochemical activity of the [TeO₃] polyhedra was demonstrated by employing theoretical calculations. The UV-vis-NIR diffuse reflectance spectrum, thermal gravimetric results, differential scanning calorimetry curves and infrared spectrum of Rb₃BaTeB₇O₁₅ were characterized and analyzed. In addition, the electronic structures and birefringence were discussed by using the first-principles calculations.