Studies On The Excited States Of Ionized Cyclopentanone

It is important to know the structure, stability and vibrational spectra of excited state of ionized molecule in order to comprehend the multiphoton ionization/dissociation processes of molecules in ultrashort pulse laser field. Our theoretical study aims to analyze ionization and dissociation mechanism of cyclopentanone in the excited states and gives out a result with proved and directed significance for the corresponding experiments.Using the CIS(Configuration Interaction with Single Substitute) method, and 3-21G* basis set, we calculated the frequency of excited state of cyclopentanone ion molecule. We have investigated the different vibration patterns of C-C bond and C-H bond under different excited states with imaginary frequency. Five dissociation channels have been obtained. Generally, the possible dissociation fragments in the excited state are C3H3O+,,C2H2O+,CO+ etc. Every possible sort of stable structure and vibrational frequency of various fragments are calculated through the method of B3LYP/6-31+G (d, p). The dissociation channels of ionized cyclopentanone in the excited states are given as follows:...