摘要
由激光产生的磷原子团簇正离子的质谱图中呈现很强的 P5+和 P5- 谱峰。使用分子图形学方法设计出 9种可能的同分异构体 ,对其中性及正负离子分子进行了分子力学、PM3半经验量子化学和 ADF密度泛函优化。在磷原子团簇模型中 ,磷原子采用 2、3或 4配位方式成键。从各异构体成键能量的比较可得知 ,最稳定的 P5+构型是四方锥的结构 ,最稳定的 P5-构型是平面五边形的结构 ,而最稳定的 P5构型是在最稳定的 P4的增加一个
In the study of cationic phosphorus clusters produced in direct laser vaporization, it has been observed that P 5 + and P 5 - show the higher intensity in the mass spectrum. We acquired nine P 5 +, P 5 - and P 5 isomers with molecular graphics and then carried out the optimizations with molecular mechanics, PM3 semi empirical and ADF density functional calculations. In these isomers, the phosphorus atoms could be in two fold, three fold, four fold. According to bonding energies, the most stable P 5 + has the square pyramidal structure. The planar pentagon configuration of P 5 - has the lowest bonding energy. P 5 derived from the most stable P 4 by adding a twofold phosphorus atom has the most stable structure.
基金
国家自然科学基金! (2 95 73117)
关键词
磷原子团簇
同分异构体
P5
分子力学
密度泛涵
phosphorus clusters, isomers, P 5, molecular mechanics, density functional
