Simulation of vibrationally resolved electronic spectra of combustion intermediates at high temperature

Abstract Because of high temperature, the experimental diagnosis for the combustion intermediates of hydrocarbon fuel is still a great challenge. In this letter, we propose a method to detect qualitatively the combustion intermediates by introducing temperature into the expression of vibrationally resolved electronic spectrum, which is based on the relationship between molecular structure and its spectrum. Using this method, the fine electronic spectra of CO+ and N2+ molecules are simulated, and the results reproduce their experimental ones very well, indicating the reliability of this method. Further, the electronic spectra of combustion intermediates C2N, NO2, OOH and HCO are predicted and the main vibrational bands are assigned. This work provides theoretical guidance for the qualitative detection of hydrocarbon fuel combustion intermediates under high temperature.