中文摘要：

运用HF/3-21G方法和密度泛函理论（DFT）的B3LYP/6-31G^＊方法,对羰基硼化合物（BCO）n（n=1～12）的各种可能结构进行了优化,对在B3LYP/6-31G^＊水平上得到的几何构型、电子态、结合能、振动频率、核独立化学位移（NICS）、能量二次差分和热力学性质进行了理论研究,得到了（BCO）n（n=1～12）结构的稳定性信息.十二种基态结构都是端配位（μ1-CO）,（BCO）n（n=1～3,5,6）的基态是线型或平面结构,（BCO）n（n=4,7～12）的基态是笼状结构;B-C平均键能呈现奇偶交替现象,偶数的结构比奇数稳定;能量二次差分得到同样的结论;羰基的振动频率与实验值非常吻合;热力学性质的研究对实验具有重要的指导意义.

英文摘要：

The structures of the （BCO）n（n=1-12） compounds were studied by HF（Hartree-Fock）/3-21G and B3LYP of density functional theory （DFT） with a basis set of 6-31G^＊. By discussing the geometries, electron structures, vibrational frequencies, B-C average bonding energies, nucleus independent chemical shifts （NICS）, and energy secondary differences of the most stable structures at the B3LYP/6-31G^＊ level the stability information of the （BCO）, （n=1-12） compounds was obtained. The carbonyls of ground state of the （BCO）n（n=1-12） are μ1-CO. The most stable structures are linear or planar for the compounds （BCO）n（n=1 -3, 5, 6）, and polyhedron cages for （BCO）n（n=4, 7-12）. Analyses of the B-C average binding energies and energy secondary differences of the most stable structures at the B3LYP/6-31G^＊ level provides theoretic interpretation for experiment results.