Thorium-ligand bond disruption enthalpies (D(Th-R)) have been determined in the series of complexes Cp3ThR, where Cp = η5-C5Hg5 and R = an alkyl group. Thermochemical data were obtained by anaerobic batch-titration solution calorimetry from enthalpies of solution of the Cp3ThR complexes in toluene followed by enthalpies of alcoholysis with CF3CH2OH. D(Th-R)gas, values obtained (2σ) were as follows: CH2Si(CH3)3, 86.1 (3.6) kcal/mol; CH3, 82.7 (1.1) kcal/mol; CH2C(CH3)3, 77.9 (3.0) kcal/mol; CH2C6H5, 77.9 (2.2) kcal/mol; CH(CH3)2, 77.3 (2.7) kcal/mol. These disruption enthalpies parallel but are significantly larger than those for the identical R functionalities in the Cp'2ThR2 series, Cp' = η5-(CH3)5C5.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry