Quantum dynamics of the trimethylene biradical Stereomutation of cyclopropane and unimolecular decay

摘要: A reduced-dimensionality three degrees-of-freedom quantum dynamics calculation of the stereomutation cyclopropane has been performed. In one set calculations, wavepackets are initiated centered around stationary points on conrotatory, disrotatory and single rotation (cis/trans conversion) pathways. The ratio trans to cis isomer formed, Rtc, is shown be highly dependent location, average energy initial wavepacket as well orientation terminal methylene torsions. a second ‘highly excited cyclopropane’, in four possible isomeric configurations, designated configuration for purposes analysis. Here also, Rtc depends torsional orientation. Analysis density time constants formation product indicate that contributing mechanisms range from direct, concerted conrotatorymotion more statistical behavior. ‘Boltzmann’ at 695 K theratio ‘double’ ‘single’ rotations, k12/k1, results k12/k1=2Rtc=2.2. Wavepacket orient preferentially along conrotatory pathways rather than higher rotation(cis/trans pathway.