Sarkar Saptarshi, Mallick Subhasish, Kumar Pradeep, Bandyopadhyay Biman
Department of Chemistry, Malaviya National Institute of Technology Jaipur, J. L. N. Marg, Jaipur - 302017, India.
Phys Chem Chem Phys. 2017 Oct 18;19(40):27848-27858. doi: 10.1039/c7cp05475k.
A comprehensive investigation of the roles of acidic, neutral and basic catalysts in isomerization of methoxy radical in the troposphere has been carried out by quantum chemical calculations at the MP2 and CCSD(T) levels of theory. The effect of basic catalysts, namely ammonia and an ammonia-water complex, on the isomerization process has been studied for the very first time. In terms of rate coefficients ammonia was found to be a better catalyst than a water monomer whereas the ammonia-water complex was found to be more efficient over a water dimer but marginally less efficient than formic acid. Based on the effective rate constants under various tropospheric conditions, it was found that at 0 km altitude water dimers and ammonia-water complexes could compete with acid catalysts but at higher altitudes the acid catalysts would dominate their neutral and basic counterparts by a long distance.
通过在MP2和CCSD(T)理论水平上进行量子化学计算，对对流层中酸性、中性和碱性催化剂在甲氧基自由基异构化中的作用进行了全面研究。首次研究了碱性催化剂，即氨和氨 - 水络合物对异构化过程的影响。就速率系数而言，发现氨是比水单体更好的催化剂，而氨 - 水络合物比水二聚体更有效，但比甲酸略低。根据各种对流层条件下的有效速率常数，发现在0公里高度处，水二聚体和氨 - 水络合物可以与酸催化剂竞争，但在更高海拔处，酸催化剂将在很长距离上主导其对应的中性和碱性催化剂。
