Abstract
Heterolytic and homolytic C-D bond dissociation energies of three NADH models: BNAH-4,4-d2, HEH-4,4-d2 and Acrd2 in acetonitrile were first estimated by using an efficient method. The results showed that the heterolytic C-D bond dissociation energies are 65.2, 70.2, and 81.9 kcal/mol and the homolytic C-D bond dissociation energies are 72.66, 70.69, and 74.95 kcal/mol for BNAH-4,4-d2, HEH-4,4-d2, and AcrD2, respectively. According to the bond dissociation energy differences of isotope isomers, an interesting conclusion can be made that the primary kinetic isotope effects are dependent not only on the zero-point energy difference of the isotope isomers, but also on the types of C-D bond dissociations, and the C-D bond homolytic dissociations should have much larger primary kinetic isotope effects (26.9–28.8) than the corresponding C-D bond heterolytic dissociations (3.9–5.4).
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Cao, C., Tan, Y. & Zhu, XQ. Heterolytic and homolytic C-D bond dissociation energies of NADH models in acetonitrile and primary isotopic effects on hydride versus hydrogen atom transfer reactions. Sci. China Chem. 55, 2054–2056 (2012). https://doi.org/10.1007/s11426-012-4679-6
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DOI: https://doi.org/10.1007/s11426-012-4679-6