Germa-closo-dodecaborate reacts with the elements sulfur, selenium and tellurium to give well defined products: [S–GeB₁₁H₁₁]²⁻, [Se–GeB₁₁H₁₁]²⁻ and [Te–GeB₁₁H₁₁]²⁻. The chalcogen adducts were characterized by single crystal structure analysis, NMR and IR spectroscopy. By using quantum chemical methods the nature of the germanium chalcogen bond was studied. Furthermore the first transition metal complexes of [S–GeB₁₁H₁₁]²⁻ and [S–SnB₁₁H₁₁]²⁻ with Pd and Pt were synthesized and characterized, showing that the dianionic chalcogen adducts can be used as new ligands in transition metal chemistry.