Theoretical study of the gas-phase reaction of hydrogen isocyanate with water

Transition states for the two probable pathways for the gas-phase hydrolysis of hydrogen isocyanate have been determined using the MINDO /3 method. Activation barriers obtained showed that the one-step mechanism is preferred to the two-step mechanism involving an intermediate. It was shown that the reaction of polymeric water has lower activation barrier than the reaction of monomeric water. Energy and charge decomposition analysis showed that in the former less energy is required in the deformation of molecules for the transition state (TS ) formation due to the cyclic flow of electronic charges in the TS .