C_(20)分子与C_(20)^-、C_(20)^(2-)离子的特性分析与比较

The analysis and compare of the characters between C_(20) molecule,C_(20)^- and C_(20)^(2-) ion

应用密度范函理论(DTF)的B3LYP方法,在6-31G*基组水平上对C_1对称C_(20)富勒烯分子及C_(20)^-、C_(20)^(2-)离子进行了几何结构的全局优化、频率以及自然键轨道分析计算(NBO),然后对三者的几何构型、稳定性、振动光谱等做了分析和比较.研究表明:离子的键长普遍比分子的键长长,C_(20)^-离子的稳定性最高.C_(20)^(2-)离子的红外峰值较大,C_(20)^-离子的拉曼光谱峰值较大,振动光谱可以用来作为区分三者的手段.

The geometric configurations, vibration frequencies and NBO of fullerene C20 , C20（1-） and C20（2-） with CI symmetry were calculated with a B3LYP method under 6-31G＊ level. Then the results were analyzed and compared. The calculations show that the band length of C20（1-） and C20（2-） are much longer than that of the C20 . The C20（1-） ion is most stable. The C20（2-） ion has the highest infrared spectrum peak and the C20（1-） ion has the highest Raman spectrum peak. The vibration spectrums can be used for distinguish the C20,C20（1-） and C20（2-）.