Is the H2OCl+ ion a viable intermediate for the hydrolysis of ClONO2 on ice surfaces?

The involvement of the H2OCl+ ion in the ClONO2 hydrolysis on an ice surfac e is shown to be unlikely via quantum chemical calculations and comparative analysis of infrared spectra of low temperature mixtures of H2O with HNO3, N2O5 or ClONO2. For the ClONO2 hydrolysis on ice, the reaction path involv ing H2OCl+ is estimated to be similar to 10- 14 kcal/mol higher in energy t han the one involving H3O+ via proton transfer in the ice lattice. An analy sis of literature infrared spectra, complemented by quantum chemical calcul ations of the vibrational frequencies of the relevant species, indicates th at the spectral feature previously assigned to H2OCl+ should instead be ass igned to molecular HNO3.