REACTIVITY, ABSORPTION AND EMISSION OF DIMETHYLGERMYLENE PHOTO-GENERATED FROM DODECAMETHYLCYCLOHEXAGERMANE

The UV photolysis of dodecamethylcyclohexagermane (1) in cyclohexane at room temperature proceeds readily with loss of dimethylgermylene species to give two of the lower homologs, decamethylcyclopentagermane (2) and octamethylcyclotetragermane (3). The photochemically generated dimethylgermylene species reacts with 2,3-dimethylbuta-1,3-diene or CCl4 to give 1,1,3,4-tetramethyl-1-germacyclopent-3-ene or trichloromethyldimethylchlorogermane, respectively. The transient absorption of 1 in cyclohexane at 450 nm obtained by laser flash-photolysis is due to dimethylgermylene. The reaction rates of dimethylgermylene with some substances are examined. In 3-methylpentane glass dimethylgermylene shows an absorption band at 430 nm and a fluorescence peak at 650 nm. The photo-generated germylene appears to be the singlet ground state.