Study on reaction mechanism of nitrogen dioxide detection by diazotization coupling reaction

The detection of nitrogen dioxide in air is based on the principle that nitrite diazotization and coupling reaction produce azo compounds. The reaction mechanism is explored by using the method of quantum chemistry. The reaction path is searched by using density functional theory at the level of B3LYP/6-311++G(D,P) The geometric configuration optimization, frequency calculation and thermodynamic function calculation of the transition state and product were carried out, the single point energy and zero correction energy were obtained, the potential energy profile of the reaction was constructed, the activation energy of the reaction was calculated, the TDDFT calculation of the product was carried out, and the UV-vis Spectrum was obtained.