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在B3LYP/6-311G(d)和QCISD(t)/6-311+G(2df)(单点)水平下计算得到了[Si,N,N,P]体系势能面上的一些驻点,研究了异构体之间的异构化过程,并讨论了该体系异构体的结构与稳定性。结果表明在[Si,N,N,P]体系中的11个异构体中只有含有Si-P交叉成键的类蝶型四元环异构体SiNPN(E_1,~2A″)是稳定的,其他异构体由于易于重排或是解离,稳定性较低。研究同时给出了E1的电子与几何结构、振动频率及指认、偶极矩和转动常数等相关数据。分析结果表明通过中问体E3(SiNPN)的反应SiN(~2∏)+PN(~1∑)→E1是由SiN(~2∏)和PN(~1∑)碎片产生E1的最有利途径,因此E1可成为星际观测的目标,G2级别下此反应的反应焓变为215.25kJ/mol(298.15K),而异构体E1在298.15K下的标准生成焓为457.99kJ/mol。
Some stationary sites on the potential energy surface of [Si, N, N, P] system were calculated at B3LYP / 6-311G (d) and QCISD (t) / 6-311 + G (2df) The isomerization process of isomers was studied, and the structure and stability of the isomers were also discussed. The results showed that only the four-membered ring-shaped isomers SiNPN (E_1, ~ 2A ") containing Si-P crossbonded among the 11 isomers in the [Si, N, N, P] , Other isomers due to easy rearrangement or dissociation, the stability is low.At the same time give the electronic and geometric structure of E1, vibration frequency and identification, dipole moment and rotation constant and other related data.The analysis results show that by The reaction of SiN (~ 2Π) + PN (~ 1Σ) → E1 is the most favorable way to generate E1 from SiN (~ 2Π) and PN (~ 1Σ) fragments. The target of interstellar observation was 215.25kJ / mol (298.15K) for the G2 level and 457.99kJ / mol for the isomer E1 at 298.15K.