Zeolite analogues based on oxysulfidometalate supertetrahedral clusters via coulombic interactions

Abstract

Four zeolite-like crystalline salts, T3-MEP and T4-MTN/DIA/LON (where MEP, MTN, DIA and LON are the topological codes), have been fabricated. They are self-assemblies of anionic supertetrahedral clusters of T3-[Sn₁₀O₄S₂₀]⁸⁻/T4-[Sn₄In₁₂Zn₄O₄S₃₁]¹⁰⁻ and protonated amines by electrostatic interactions. Among them with zeotype assignment, T3-MEP has the cubic unit-cell parameter a = 50.58 Å whereas T4-MTN features cubic system axial-lengths reaching 80.44 Å. All of them present excellent proton-conductivity, e.g., T3-MEP exhibits over 10⁻³ S cm⁻¹ under 50 °C and 98% relative humidity.