(C7H3NO4)2Sb2F2·2H2O: a pyridine-based compound shows large optical anisotropy

Abstract

A new organic–inorganic hybrid compound, (C₇H₃NO₄)₂Sb₂F₂·2H₂O, was synthesized. It has two-dimensional [C₁₄H₁₀F₂N₂O₁₀Sb₂]_∞ parallel layers, which are further optimally aligned by the π–π conjugation mode. Remarkably, this compound exhibits a large birefringence (0.40@550 nm), surpassing those of most of the other pyridine-derived birefringent materials reported so far.