An ab initio MO study on the structures and electronic states of hydrogen-bonded O3- HF and SO2-HF complexes.
An ab initio MO study on the structures and electronic states of hydrogen-bonded O3- HF and SO2-HF complexes.
复制标题
对氢键 O3-HF 和 SO2-HF 配合物的结构和电子态进行从头开始 MO 研究。
DOI：
10.1021/ic000880i
复制
发表时间：
2001
影响因子：
4.6
通讯作者：
T. Iyama
中科院分区：
文献类型：
--
作者：
H. Tachikawa;S. Abe;T. Iyama
用从头算方法对碱式氟化氢(HF)络合物(BASE=O_3和SO_2)进行了分子轨道计算，以阐明其结构和能级。从头计算一直进行到QCISD(T)/6-311++G(d，p)理论水平。在这两种配合物中，氢键结构均以稳定的形式存在，氢键结构中的氢原子指向碱中的一个氧原子。计算结果表明，两种配合物中均存在顺式和反式异构体。对SO2-HF络合物的所有计算表明，顺式比反式更稳定。另一方面，在O_3-Hf络合物中，稳定结构随从头算理论能级的变化而变化，顺式和反式的能量接近。从最复杂的计算(QCISD(T)/6-311++G(d，p)//QCISD/6-311+G(D)水平)预测，顺式SO2-HF、反式SO2-HF、顺式O3-HF和反式O3-HF的络合生成能分别为6.1、5.7、3.4和3.6kcal/mol，说明HF与SO2的结合能大于与O3的结合能。顺O_3-HF和顺SO_2-HF络合物的简谐振动频率的计算结果与Andrews等人的实验值符合得很好。计算得到的顺式SO2-HF的旋转常数与实验结果吻合较好。
Ab initio molecular orbital (MO) calculations have been carried out for base-hydrogen fluoride (HF) complexes (base = O3 and SO2) in order to elucidate the structures and energetics of the complexes. The ab initio calculations were performed up to the QCISD(T)/6-311++G(d,p) level of theory. In both complexes, hydrogen-bonded structures where the hydrogen of HF orients toward one of the oxygen atoms of bases were obtained as stable forms. The calculations showed that cis and trans isomers exist in both complexes. All calculations for the SO2-HF complex indicated that the cis form is more stable in energy than the trans form. On the other hand, in O3-HF complexes, the stable structures are changed by the ab initio levels of theory used, and the energies of the cis and trans forms are close to each other. From the most sophisticated calculations (QCISD(T)/6-311++G(d,p)//QCISD/6-311+G(d) level), it was predicted that the complex formation energies for cis SO2-HF, trans SO2-HF, cis O3-HF, and trans O3-HF are 6.1, 5.7, 3.4, and 3.6 kcal/mol, respectively, indicating that the binding energy of HF to SO2 is larger than that of O3. The harmonic vibrational frequencies calculated for cis O3-HF and cis SO2-HF complexes were in good agreement with the experimental values measured by Andrews et al. Also, the calculated rotation constants for cis SO2-HF agreed with the experiment.