Qin Xiao-Fang, Wu Hai-Shun, Jiao Haijun
State Key Laboratory of Coal Conversion, Institute of Coal chemistry, Chinese Academy of Sciences, Taiyuan, People's Republic of China.
J Mol Model. 2007 Aug;13(8):927-35. doi: 10.1007/s00894-007-0210-y. Epub 2007 Jun 5.
Structures and stabilities of tricarbonyl closo-boranes cation, BnHn-3(CO)3+ (n = 5-12), isolobal with cationic closo-carboranes C3Bn-3Hn+, have been investigated at the B3LYP/6-311+G** level of theory. The most stable positional isomers of individual cluster are in agreement with those of closo-C3Bn-3Hn+ clusters except for n = 8 and 10. Energetic analysis identifies closo-B6H3(CO)3+, closo-B10H7(CO)3+ and closo-B12H9(CO)3+ as the most stable cages. It is also found that closo-BnHn-3(CO)3+ is much less strained than closo-C3Bn-3Hn+. The negative nucleus independent chemical shifts (NICS) at the cage center reveal three-dimensional aromaticity of the closo-BnHn-3(CO)3+ cages. The CO stretching frequencies have been computed in advance to aid experimental study.
已在B3LYP/6-311+G**理论水平上研究了与阳离子封闭型碳硼烷C3Bn-3Hn+等瓣的三羰基封闭型硼烷阳离子BnHn-3(CO)3+（n = 5-12）的结构和稳定性。除了n = 8和10之外，单个簇的最稳定位置异构体与封闭型C3Bn-3Hn+簇的异构体一致。能量分析确定封闭型B6H3(CO)3+、封闭型B10H7(CO)3+和封闭型B12H9(CO)3+为最稳定的笼状结构。还发现封闭型BnHn-3(CO)3+的张力比封闭型C3Bn-3Hn+小得多。笼状结构中心的负核独立化学位移（NICS）揭示了封闭型BnHn-3(CO)3+笼状结构的三维芳香性。已预先计算了CO伸缩频率以辅助实验研究。
