Theoretical simulation of vibrationally resolved electronic spectra of combustion intermediates including temperature effect

Abstract

It is difficult to diagnose qualitatively the radicals and ions produced by high temperature combustion of hydrocarbon fuel. An effective way is to simulate their fine electronic spectra. In this work, a method of spectral calculation considering temperature effect is proposed to simulate the vibrationally resolved electronic spectra of the typical intermediates NH* and NO+ produced by hydrocarbon fuel combustion. The results show that only the theoretical spectra simulated at high temperature are consistent with the experimental ones, indicating that temperature has an important influence on the fine electronic spectra of combustion intermediates. The vibrationally resolved electronic spectra of CH2*, CH3*, C2H* and C2H3* radicals, which are important intermediates of combustion core mechanism, are predicted by this method, and their main vibrational peaks are assigned in detail. We hope that the predicted electronic spectra can be confirmed in future experiments, which will provide a reliable theoretical basis for establishing correct combustion reaction mechanism.