Ab initio studies on hydrogen-transfer tunneling for Cl + HCl abstraction hydrogen reaction

✍ Scribed by Yuxiang Bu; Zhaohua Cao; Xinyu Song

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 798 KB
• Volume: 57
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1996)57:1<95::aid-qua11>3.0.co;2-7

✦ Synopsis

This article presents a treatment scheme of the tunneling of hydrogen between two molecular centers ((3.'. Cl). The purpose is to calculate the tunneling probabilities of hydrogen atom transfer from the initial (the proceeding complex) to the final-state energy minima (the succeeding complex) in two anharmonic vibrational states (0 + 0 and 1 + 1) in terms of the time-dependent perturbation theory expression and to see whether spectroscopic signatures of tunneling persist in the form of splittings of the vibrational modes. The analysis uses the realistic potential energy function calculated at the 11~/6-31 + G* * self-consistent-field basis-set level for the interaction between transferred hydrogen and its molecular skeleton (Cl... H ... Cl). This potential energy surface is calibrated by comparing its properties with those from S~-POLCI and the LEPS potentialenergy surfaces. The anharmonic vibrational state is characterized by the corrected vibrational energy levels and a set of linear combination coefficients obtained via perturbation theory. The tunneling probabilities for two transitions (0 + 0 and 1 + 1) were calculated and compared with those from Gamow's equation. Applicability of the time-dependent perturbation theory expression and Gamow's equation to the [Cl-H ... CI] system is discussed. The vibrational splitting energies are obtained, and a spectroscopic signature caused by tunneling is expected and should be observable. 0 1996 John Wiley &