Synthesis and characterization of (H2dab)2Cu8Ge4S14·2H2O: An expanded framework based on icosahedral Cu8S12 cluster

► A new 3-D framework copper-thiogermanate was prepared under solvothermal condition. ► The framework is built up from icosahedral Cu8S12 clusters linked by GeS4 and dimeric Ge2S6 units. ► The result provides a new strategy to expand octahedral SBUs-based framework. ► Compound 1 is a semiconductor with the band gap of 2.5 eV.