Quantum-chemical investigation of tautomerism of hydrophosphoryl compounds

The tautomerization energies for the reaction R₂P(O)H R₂P-OH, where R= OH, OCH₃, OC₂H₅, CH₃, and CF₃, have been calculated by the CNDO/2 method with optimization of the exponents of the Slater 3d AO's according to the criterion of a minimum total energy for the molecule. The results are in qualitative agreement with the experimental data. The MNDO and CNDO/2 calculations with the use of a standard sp basis predict greater stability for the structures with a three-coordinate phosphorus atom, in contradiction to experiment.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 4, pp. 486–490, July–August, 1989.In conclusion, we express our thanks to V. L. Foss for showing an interest in this work and for some valuable discussions.