Na-呋喃荷移络合物弱相互作用的密度泛函理论研究

在B3LYP/6-311+C*水平上,对Na-呋喃体系可能存在的弱相互作用复合物进行了全自由度能量梯度优化,发现了Na-呋喃体系存在两个能量极小结构A、B,其中,结构A是Na原子的3s1电子直接和呋喃杂环体系中的所有重原子的共轭大π体系相互偶合,形成一个具有C8对称性的金属有机复合物;而结构B为Na原子的3s1电子主要通过杂原子O和杂环上原有的五中心六电子大π体系形成一个新的平面六中心七电子大π体系,具有C2v对称性.结构B较结构A稳定3.40kJ/mol.结构A中的Na-O键长为0.38 nm,∠COC为106.9°,由于金属Na对呋喃杂环的作用使整个分子平面变形,C1、C2、C3、C4在同一个平面内,而O5则稍微翘离平面且O5原子距离由Cl、C2、C3、C4组成的平面的垂直距离约为0.035 nm.结构B中Na-O键长为0.26 nm,∠COC为106.8°,金属Na原子和杂环中所有的原子在同一个平面内.并在MP2和B3LYP水平下,用6-311+G*基组精确计算了最稳定结构B的结合能为ΔE=4.5～5.1 kJ/mol.

Theoretical Study on the Weak-interaction of Na-Furan Charge Transfer Complex with Density Functional Theory

The SO2absorption spectrum is recorded using Xe lamp source under atmospheric conditions at ambient temperatures. The SO2concentration is retrieved to study the relation between SO2concentration and time. In this experiment, effects of temperature and the buffer gas N2are also considered. It is demonstrated that the concentration of SO2decreases in a linear relation to the time and the period of illumination may have effects on the rate of decrease. These results are applicable to SO2pollution monitoring in the atmosphere using high resolution spectrometer and differential absorption lidar.