Theoretical investigation on degradation of CH[triple bond, length as m-dash]CCH 2 OH by NO 3 radicals in the atmosphere

A detailed computational investigation is executed on the reaction between NO and CH[triple bond, length as m-dash]CCH OH at the CCSD(T)/cc-pVTZ//B3LYP/6-311++G(d,p) level. Addition/elimination and H-abstraction mechanisms are found for the NO + CH[triple bond, length as m-dash]CCH OH reaction, and they could compete with each other. The most feasible addition/elimination pathway through a series of central-C addition, 1,4-H migration to generate intermediates IM1 (CHCONO CH OH) and IM3 (CH CONO CH O), and then IM3 directly decompose into product P2 (CH CONO CHO + H). The dominant H-abstraction pathway is abstracting the H atom of the -CH - group to generate h-P1 (CHCCHOH + HNO ). RRKM-TST theory was used to compute the kinetics and product branching ratios of the NO + CH[triple bond, length as m-dash]CCH OH reaction at 200-3000 K. The rate constants at 298 K are consistent with the experimental values. The lifetime of CH[triple bond, length as m-dash]CCH OH is estimated to be 59.72 days at 298 K. The implicit solvent model was used to examine the solvent effect on the total reaction. Based on the quantitative structure-activity relationship (QSAR) model, the toxicity during the degradation process is increased towards fish, and decreased towards daphnia and green algae.