P5H6^＋和P5Me6^＋全反式构象的理论研究  

Theoretical study on all trans conformations for P_5H_6^+ and P_5Me_6^+

作　　者：蒲志凤[1] 李前树[1,2] 

机构地区：[1]北京理工大学化学物理研究所,北京100081 [2]华南师范大学量子化学计算中心,广东广州510631

出　　处：《分子科学学报》2008年第6期427-429,共3页Journal of Molecular Science

基　　金：111计划项目(B07012)

摘　　要：用HF和MP2两种从头算方法结合cc-pVDZ和cc-pVTZ两种基组对P5H6+及其甲基取代物P5Me6+的反式构象进行理论计算,各限制优化出11个反式构象.进而分别得到其构象势能面曲线,P5H6+势能面曲线是单调平滑的,其上只有一个稳定点(3T4)和一个过渡态(4T3),说明3T4构象是势能面上的全局最小点.而P5Me6+势能面曲线与P5H6+大致相同,不同的是在势能面曲线中还存在另一个稳定点,在HF或MP2用cc-pVDZ基组时为2E(φ=216°),在HF/cc-pVTZ时为2T1(φ=198°),并且,3T4和2E的能量非常接近.最后将这两势能面与四氢呋喃进行了比较.The all-trans conformations on the full pseudorotational cycle for the eyclotetraphosphinophosphonium cation （P5H6^＋ ） and its methyl-substituted derivative （P5Me6^＋ ） were located systematically on their potential energy surfaces. The potential energy for the pseudorotational circuit of P5H6^＋ is smooth and monotonic with only one minimum （^3T4） and one maximum （^4T3）,but the analogous P5Me6^＋ circuit has two minima. The P5H6^＋ and P5Me6^＋ potential surfaces appear to be qualitatively very different from that for the well investigated tetrahydrofuran. Since the 3T^4 form of P5H6^＋ avoids unfavorable eclipsing PH-PH and lone pair-lone interactions, it is the global minimum among all possible P5H6^＋ eonfigurations and conformations.

关 键 词：构象 势能面 从头算理论方法 全局最小点 

分 类 号：O614[理学—无机化学]