Quantum dynamics of the Walden inversion reaction Cl+CH3Cl->ClCH3+Cl

DAVID C. CLARY; JULIANA PALMA

JOURNAL OF CHEMICAL PHYSICS

Año: 1997 vol. 106 p. 575 - 583

0021-9606

Quantum scattering calculations on the SN2 reaction Cl21CH3Cl!ClCH31Cl2 are reported. Therotating bond approximation ~RBA! has been adapted so that three degrees of freedom including theC–Cl stretching vibration and the CH3 umbrella mode are treated explicitly. The calculations havebeen done with minor modifications of a potential due to Vande Linde and Hase. It is found thatinitial excitation of the C–Cl vibration has a large effect on the reaction probabilities, whileexcitation of the CH3 umbrella vibration is less significant. The reaction is dominated by scatteringresonances with lifetimes ranging from 0.1 to 10 ps. It is found that the length of the C–Cl bond atthe transition state of the reaction has a particularly pronounced effect on the reaction probabilities.The magnitude of the quantum reaction probabilities compares quite well with those calculatedusing the quasiclassical trajectory method.