Potential energy surfaces for all-trans P5H6 and P5Me6 may be less complicated than anticipated

作者：Li, Qian Shu^*; Pu, Zhifeng; Xie, Yaoming; Schleyer, Paul von Rague; Schaefer, Henry F

来源：Journal of the American Chemical Society, 2008, 130(29): 9380-9385.

DOI：10.1021/ja800177p

• Global minima
• Lone pair
• Potential surfaces
• Pseudorotation
• Tetra-hydrofuran
• Trans conformations

Burford and co-workers recently (2007) investigated the synthesis, structure, and pseudorotation of a family of cyclotetraphosphinophosphonium ions comprehensively. We now report theoretical computations through the CCSD(T) level to study the conformations of the parent model rings, P5H6 and P5Me6 . The all-trans conformations on the full pseudorotational cycle for the cyclotetraphosphinophosphonium cation (P5H6 ) and for 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 (T-3(4)) and one maximum (T-4(3)), 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 T-3(4) form Of P5H6 avoids unfavorable eclipsing PH-PH and lone pair-lone pair interactions, it is the global minimum among all possible P5H6 configurations and conformations.

• 出版日期2008-7-23
• 单位华南师范大学; 北京理工大学