000190023 001__ 190023
000190023 005__ 20181203023314.0
000190023 0247_ $$2doi$$a10.1039/c3cp53698j
000190023 02470 $$2ISI$$a000327667500022
000190023 037__ $$aARTICLE
000190023 245__ $$aKinetic isotope effect in malonaldehyde determined from path integral Monte Carlo simulations
000190023 269__ $$a2014
000190023 260__ $$bRoyal Society of Chemistry$$c2014
000190023 336__ $$aJournal Articles
000190023 520__ $$aThe primary H/D kinetic isotope effect on the intramolecular proton transfer in malonaldehyde is determined from quantum instanton path integral Monte Carlo simulations on a fully dimensional and validated potential energy surface for temperatures between 250 and 1500 K. Our calculations, based on thermodynamic integration with respect to the mass of the transferring particle are significantly accelerated by the direct evaluation of the kinetic isotope effect instead of computing it as a ratio of two rate constants. At room temperature, the KIE from the present simulations is 5$\pm$4. The KIE is found to vary considerably as a function of temperature and the low-T behaviour is dominated by the fact that the free energy derivative in the reactant state increases more rapidly than at the transition state. Detailed analysis of the various contributions to the quantum rate constant together with estimates for rates from conventional transition state theory and from periodic orbit theory suggest that the KIE in malonaldehyde is dominated by zero point energy effects and that tunneling plays a minor role at room temperature
000190023 700__ $$aHuang, Jing
000190023 700__ $$0243870$$g187560$$aBuchowiecki, Marcin
000190023 700__ $$aNagy, Tibor
000190023 700__ $$g181577$$aVanicek, Jiri$$0240352
000190023 700__ $$aMeuwly, Markus
000190023 773__ $$j16$$tPhysical Chemistry Chemical Physics$$k1$$q204-211
000190023 909C0 $$xU11812$$0252116$$pLCPT
000190023 909CO $$pSB$$particle$$ooai:infoscience.tind.io:190023
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000190023 917Z8 $$x148230
000190023 917Z8 $$x221270
000190023 937__ $$aEPFL-ARTICLE-190023
000190023 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000190023 980__ $$aARTICLE