Crossed Molecular Beam Study on the Reaction Dynamics of Fluorine Molecule with Propene

• Main Authors: Jing-Wen Fang, 方靜雯
• Other Authors: Yuan-Tseh Lee
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/69491314414815875048

碩士 === 國立臺灣大學 === 化學研究所 === 96 === The reaction of F2 + C3H6 was investigated using crossed molecular beam technique for a wide range of collision energy. The F + C3H6F was observed to be the only primary product channel; the HF + C3H5F product channel was searched but not found. The relative reaction cross section was measured as a function of collision energy; the reaction threshold was determined to be 2.4 ± 0.3 kcal/mol. Time-of-flight spectra and angular distributions of the products were measured and analyzed. The center-of-mass frame angular distribution displayed strongly backward, indicating that the reaction time scale is much shorter than one rotational period of the collision complex. All experimental results support a rebound reaction mechanism, which agrees with the structure of the calculated transition state. The transition state geometry suggests an early barrier; such dynamics is consistent with the small kinetic energy release of the products observed in the experiment. Compared with the F2 + C2H4 reaction, both the experimental and computational results in the present reaction give the same trend that the methyl-substitution effect in propene reduced the reaction threshold by about 3 kcal/mol.