Kinetics and mechanism of the thermal decomposition of 1,1-dimethylgermetane

Article abstract of DOI:10.1021/om00046a031

The gas-phase unimolecular decomposition of 1,1-dimethylgermetane has been investigated over the temperature range 683.9-751.2 K at pressures of ca. 15 Torr. Four products, cyclopropane, propene, ethene, and 1,1,2,2-tetramethylgermacyclopentane, are formed. Arrhenius parameters for the primary decomposition channels to (1) 1,1-dimethylgermene and ethene and (2) dimethylgermylene, cyclopropane, and propene are reported: (1) log k₁/s^-1 = 14.7 ± 0.4 - 63.1 ± 1.2 kcal mol^-1/RT ln 10; (2) log k₂/s^-1 = 14.1 ± 0.3 - 60.7 ± 0.8 kcal mol^-1/RT ln 10. (Matrix Presented) The surprisingly high activation energy for the 2 + 2 cycloreversion is interpreted in terms of a strong Ge-C bond dissociation enthalpy and/or reduced ring strain in the germetane.