New nonsymmetric P(OH)3 species. Comparison with the C3 isomer and themochemistry at the DFT, MP2, and CCSD(T) levels of theory.
Two new less-symmetric P(OH)3 isomers that are more stable than the C3 structure are found at the density functional theory (B3PW91, B3LYP), MP2, and CCSD(T) levels with the large aug-cc-pvdz/pvtz basis sets. The C1 and C3 structures are qualitatively different from those found for the As(OH)3 molecule. An additional lower lying P(OH)3 structure with Cs symmetry has been obtained. With the largest basis set the Cs isomer is predicted to be the most stable. However, the inclusion of zero-point-energy corrections induces an inversion between the Cs and C1 isomers, with the latter becoming the lowest energy structure at the highest correlated level. Increasing inclusion of electronic correlation effects reduces the energy difference between the C1 and Cs structures while the C1-C3 energy difference and C1-Cs interconversion barrier become larger. In all cases, energy differences and barrier heights are around 1 kcal/mol.
Maron
L
L
Laboratoire de Physique Quantique, IRSAMC, Université Paul Sabatier, 118, Route de Narbonne Toulouse 31062 Cedex, France.
Ramírez-Solís
A
A