富勒醇C_(60)(OH)_8的结构和UV谱的理论研究

Theoretical study on the structures and spectra of C_(60_(OH)_8.

用 INDO系列方法研究 C60 (OH) 88种异构体的结构和光谱 ,探讨羟基不同加成位置对异构体稳定性的影响 ,表明 8个羟基以 1,2 -加成方式加在 C60 的五元环与六元环相邻棱上所得的异构体最稳定 ,其生成热比次稳定异构体低 2 5 e V,故实验室合成的 C60 (OH) 8主要以这种构型存在。以优化构型为基础 ,计算了 8种异构体的 UV谱 ,对电子跃迁进行理论指认 ,讨论产物 UV谱带红移的原因 ,对反应机理进行探讨 ,并对 C60 R8(R=F,OH,Cl)的某些性质进行了对比。

The structures and spectra on eight isomers of C\-\{60\}(OH)\-8 were studied by INDO methods. The stability and symmetry of C\-\{60\}(OH)\-8 isomers were shown to be affected by different additive positions of hydroxyl groups. In the most stable isomer, all the hydroxyl groups locate on 1,2\|additive positions and its heat of formation is at least 25 eV lower than that of other isomers. So this isomer might be the main one in C\-\{60\}(OH)\-8 synthesized in the experiment. Based on the optimized geometries, the electronic spectra were calculated and electronic transition was assigned theoretically. Meanwhile the reason of red the shift for various UV absorptions of the isomer was compared with those of C\-\{60\}, the reaction mechanism was discussed, and nature of various C\-\{60\}R\-8 isomers was compared(where R=F, OH, and Cl).