The favorable routes for the hydrolysis of CHOO with (HO) (n = 1-4) investigated by global minimum searching combined with quantum chemical methods.

The hydrolysis reaction of CHOO with water and water clusters is believed to be a dominant sink for the CHOO intermediate in the atmosphere. However, the favorable route for the hydrolysis of CHOO with water clusters is still unclear. Here global minimum searching using the Tsinghua Global Minimum program has been introduced to find the most stable geometry of the CHOO(HO) (n = 1-4) complex firstly. Then, based on these stable complexes, favorable hydrolysis of CHOO with (HO) (n = 1-4) has been investigated using the quantum chemical method of CCSD(T)-F12a/cc-pVDZ-F12//B3LYP/6-311+G(2d,2p) and canonical variational transition state theory with small curvature tunneling. The calculated results have revealed that, although the contribution of CHOO + (HO) is the most obvious in the hydrolysis of CHOO with (HO) (n = 1-4), the hydrolysis of CHOO with (HO) is not negligible in atmospheric gas-phase chemistry as its rate is close to the rate of the CHOO + HO reaction. The calculated results also show that, in a clean atmosphere, the CHOO + (HO) (n = 1-2) reaction competes well with the CHOO + SO reaction at 298 K when the concentrations of (HO) (n = 1-2) range from 20% relative humidity (RH) to 100% RH, and SO is 2.46 × 10 molecules per cm. Meanwhile, when the RH is higher than 40%, it is a new prediction that the CHOO + (HO) reaction can also compete well with the CHOO + SO reaction at 298 K. Besides, Born-Oppenheimer molecular dynamics simulation results show that all the favorable channels of the CHOO + (HO) (n = 1-3) reaction cannot react on a time scale of 100 ps in the NVT simulation. However, the NVE simulation results show that the CHOO + (HO) reaction can be finished well at 8.5 ps, indicating that the gas phase reaction of CHOO + (HO) is not negligible in the atmosphere. Overall, the present results have provided a definitive example of how the favorable hydrolysis of important atmospheric species with (HO) (n = 1-4) takes place, which will stimulate one to consider the favorable hydrolysis of water and water clusters with other Criegee intermediates and other important atmospheric species.