A series of pentanary inorganic supramolecular sulfides (A3X)[MB12(MS4)3] (A = K, Cs; X = Cl, Br, I; M = Ga, In, Gd) featuring B12S12 clusters

Abstract

A series of new pentanary inorganic supramolecular sulfides (A₃X)[MB₁₂(MS₄)₃] (A = K, Cs; X = Cl, Br, I; M = Ga, In, Gd) have been synthesized using high-temperature solid-state reactions. They crystallize in the noncentrosymmetric hexagonal space group P6₃22. Their structures feature a MS₄ tetrahedra saturated B₁₂ icosahedron, and the latter is also alternately connected with a MS₆ octahedron via face sharing to form a chain. [(A₃X)²⁺]_n polycationic chains fill in the 1D channels of the 3D open-framework {[MB₁₂(MS₄)₃]²⁻}_n. A discussion about their structural chemistry is also presented. Their second-order nonlinear optical (NLO) properties are calculated using Material Studio software, and the results show that this series of thioborates show tunable NLO properties.