Article ID Journal Published Year Pages File Type
9575314 Chemical Physics 2005 7 Pages PDF
Abstract
To estimate the kinetic isotope effect (KIE) for hydrogen (or deuterium) abstraction from H(D)OR (R = H, CH3, and CN) by an OH radical, we have considered the geometrical isotope effect (GIE) induced by the difference of the protonic and deuteronic wavefunctions using the multi-component MO method. The difference by the GIE of hydrogen bond was about 0.005 Å. The ratio (kaH/kaD) of the rate constant of the reaction for R = H, HO + HOR → HOH + OR and HO + DOR → HOD + OR, is estimated as 4.4 by our calculation, which is reasonable agreement with experimental result of 6.0 ± 2.0. We have found that the difference of the nuclear wavefunction of the proton and deuteron affects the changes of geometry and electronic charge density, which plays an important role to theoretically determine the effective potential energy surfaces and the corresponding KIE between H and D compounds.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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