As mentioned above, it has been shown that the presence of solvents of varying polarity has a significant influence on the stability of the phosphinylidene tautomers as well as on the activation barriers and reaction energies of its tautomerization. For multidimensional tunneling computations, the use of explicit solvent in the reaction is alas computationally intractable. To study the solvent effect on the tunneling rates, we computed the rate constants using an implicit polarizable continuum model, which can at least mimic the role of the electrostatic effect on the tunneling rates. We studied the reaction with the highest kappa factor, i.e., 1H,H and along with two other systems 5Me,Me and 5CF3,CF3 in three different solvents, namely toluene (e = 2.4), THF (e = 7.4) and water (e = 78.4). 5Me,Me and 5CF3,CF3 were selected for the sake of comparing the nature of electron-donating and -withdrawing groups on the tunneling rates in solvent media.