【摘要】 使用密度泛函理论B3LYP方法和6-31G(d,p)、6-31+G(d,p)、6-311G(d,p)及6-311+G(d,p)基组,分别对2-C5H10+和1-C5H10+的各种构象进行了几何构型优化,并用B3LYP/6-311G(d,p)进行了频率分析计算.计算预言1-C5H10+具有非平面构型,与以往报导的从头算计算结论相反.在两个自由基阳离子的各种构象的B3LYP几何构型上,进行了B3LYP和UMP2(full)方法的超精细偶合常数计算,得到了比以往更好的结果.更多还原

【Abstract】 The density function theory(DFT) B3LYP study on the and radical cations has been carried out. The molecular geometries for various conformations of the two cations were optimized at the B3LYP/6 31G(d,p), B3LYP/6 31+G(d,p), B3LYP/6 311G(d,p), and B3LYP/6 311+G(d,p) levels,and the frequency analysis calculations were performed at the B3LYP/6 311G(d,p) level. The ion was predicted to have a nonplanar structure, which is in contrast to the previous conclusions based on ab initio calculations. Based on the B3LYP/6 311G(d,p) geometries, the proton isotropic hyperfine coupling constants( HFCCs) were calculated at the B3LYP/6 311G(d,p) and MP2(full)/6 311G(d,p) levels. The calculated HFCCs resultsare in good agreement with experiment and more accurate than the previous theoretical results.更多还原