Jiao Yuge, Dibble Theodore S
Department of Chemistry, College of Environmental Science and Forestry, State University of New York , Syracuse, New York 13210, United States.
J Phys Chem A. 2015 Oct 22;119(42):10502-10. doi: 10.1021/acs.jpca.5b04889. Epub 2015 Oct 7.
Quantum chemical calculations have been carried out to investigate the structures, vibrational frequencies, and thermochemistry of the products of BrHg(•) reactions with atmospherically abundant radicals Y(•) (Y = NO2, HO2, ClO, BrO, or IO). The coupled cluster method with single and double excitations (CCSD), combined with relativistic effective core potentials, is used to determine the equilibrium geometries and harmonic vibrational frequencies of BrHgY species. The BrHg-Y bond energies are refined using CCSD with a noniterative estimate of the triple excitations (CCSD(T)) combined with core-valence correlation consistent basis sets. We also assess the performances of various DFT methods for calculating molecular structures and vibrational frequencies of BrHgY species. We attempted to estimate spin-orbit coupling effects on bond energies computed by comparing results from standard and two-component spin-orbit density functional theory (DFT) but obtained unphysical results. The results of the present work will provide guidance for future studies of the halogen-initiated chemistry of mercury.
已进行量子化学计算，以研究BrHg(•)与大气中含量丰富的自由基Y(•)（Y = NO2、HO2、ClO、BrO或IO）反应产物的结构、振动频率和热化学性质。采用含单双激发的耦合簇方法（CCSD）并结合相对论有效核势，来确定BrHgY物种的平衡几何结构和谐波振动频率。使用CCSD并结合非迭代三重激发估计（CCSD(T)）以及核价相关一致基组，对BrHg - Y键能进行优化。我们还评估了各种密度泛函理论（DFT）方法在计算BrHgY物种分子结构和振动频率方面的性能。我们试图通过比较标准和二分量自旋轨道密度泛函理论（DFT）的结果来估计自旋轨道耦合对计算出的键能的影响，但得到了不符合实际的结果。本工作的结果将为未来汞的卤素引发化学研究提供指导。
