A lanthanide–tellurium heterometal encapsulated sandwich-type heteropolyoxoniobate with a 3D pcu-type hydrogen-bonded network

Abstract

A rare sandwich-type heteropolyoxoniobate cluster, [Eu(H₂O)₃Te₆Nb₁₈O₆₄(OH)₄]¹⁵⁻ {EuTe₆Nb₁₈}, has been isolated by simultaneously incorporating a lanthanide cation and tellurite anions into polyoxoniobate. The {EuTe₆Nb₁₈} cluster represents the first example of lanthanide-incorporated telluroniobate with unprecedented Eu–Te heterometal cations in the sandwiched sites. The N–H⋯O hydrogen bonds link the copper–amine complexes and {EuTe₆Nb₁₈} polyoxoanions into a 3D supramolecular framework 1 with pcu topology. Furthermore, compound 1 exhibits moderate proton conduction and water vapor adsorption properties.