C_（60）CH_2结构和电子光谱的理论研究

A Theoretical Study of the Structure and Electronic spectra of C_(60)CH_2

用ＩＮＤＯ系列方法研究Ｃ_（６０）ＣＨ_２的两种结构：ＣＨ_２加在两个六元环之间的键上为Ｃ_（２ｖ）构型；ＣＨ_２加在一个五元环和一个六元环之间的键上为Ｃ_ｓ构型．计算表明，从总能量和ＬＵＭＯ－ＨＯＭＯ能级差看，Ｇ_（６０）ＣＨ_２的稳定结构应是Ｃ_（２ｖ）构型；该Ｃ_（２ｖ）异构体有类环丙烷结构（Ｃ_（１５）─Ｃ_（３０））桥键键长为０．１５５６ｎｍ，键序等于０．８６６３），其电子光谱计算结果与实验值符合较好．

The INDO series methods are used to study the two structures of C_(60)CH_2:one is of C_2v geometry with a bridging CH_2 across the bond between two fused six-membered rings in C_60;another is C_s geometry with a bridging CH_2 across the bond shared by a five-and a six-membered rings. From the calculated results,including total energy,LUMO-HOMO energy gap,the most stable isomer of C_(60)CH_2 should be tlie C_2v geornetry. Our calculations also find that this C_2v isomer has a cyclopropane-like structure(bridging C_15─C_30 bond length is 0.1556 nm, the bond-order is equal to 0.8663).The calculated result of electronic spectrum of the C_2v geomety is in good accordance with experimental result.