THE WATER-METHANOL COMPLEXES - MATRIX INDUCED STRUCTURAL CONVERSION OF THE 1-1 SPECIES

The infrared spectrum of the CH3OH:H2O heterodimer trapped in solid ar gon has been identified from experiments at low concentration in both dopants and by exploring a large domain of the CH3OH/H2O molar ratio. The touchstone for the identification of its structure is the frequenc y of the nu(CO) mode, measured at about 1031 cm-1, which implies a rol e of proton acceptor for the methanol subunit. Ab initio calculations at the MP2 level and also using the DFT technique provide convincing s upport for the existence of the CH3HO...HOH form. This conclusion agre es with that drawn in the gas phase but is opposite to that reached in nitrogen matrix in which a sole CH3OH...OH2 structure has been identi fied.