The first examples of thiogermanate anion [GeS3(SH)]3− as a bridging ligand to a lanthanide complex

Abstract

Two new lanthanoid thiogermanates [Ln(dien)₂(μ–η¹,η²-GeS₃(SH))]_n {Ln = La(1), Nd(2); dien = diethylenetriamine} were solvothermally synthesized and structurally characterized. Both 1 and 2 represent the first examples of the soft Lewis basic [GeS₃(SH)]³⁻ anions as tridentate bridging ligand to hard Lewis acidic Ln³⁺ ions. Both 1 and 2 exhibit semiconducting properties with absorption band edges of 2.11 eV for 1 and 2.28 eV for 2. The DFT study of 1 indicates a direct band gap with an electronic transfer excitation of S 3p to both Ge 4s and La 5d orbital electrons.