Acceptor properties and conformation isomerism in CH2CH-PX2 (X = F or Cl) compounds

Abstract

Ab initio calculations of CH2CH-PF2 and CH2CH-PCl2 were performed to investigate their conformational isomerism. It has been shown that both compounds have two conformers: the cis and the eclipsed. The concept of group orbital interactions was used to analyse the electronic structure and geometry of these molecules. The most stable conformer of CH2CH-PX2 has a cis orientation of the phosphorus lone pair and the CH2CH group due to the alkene-PX2 hyperconjugation. From PMO and Mulliken population analysis, the PX2 fragment acts as a π acceptor. © 1990.