GAUCHE EFFECT AND PM3 CALCULATION OF OPEN-CHAIN POLYPHOSPHORUS HYDRIDES

摘要

The geometries and the energies of conformers of PnHn + 2 (n = 2-9) have been studied with PM3 method. To test the quality of the semiempirical results, ab initio calculations have been carried out on P3H5. All results of P2H4 and P3H5 with PM3 are consistent with the experimental and ab initio data. According to the analysis of P3H5 and P4H6 results, it is concluded that gauche interaction between adjacent lone electron pairs and gauche interaction between polar P-H bond with adjacent polar P-P bond are important for predicting the stable conformer of open-chain phosphoanes. The calculations of PnHn + 2 (n > 4) give further support to this conclusion. (C) 1996 John Wiley & Sons, Inc. [References: 14]