Infrared Absorption Spectra of the CO2/H2O Complex in a Cryogenic Nitrogen Matrix-Detection of a New Bending Frequency

Infrared absorption spectra have been measured for the mixture of CO2 and H2O in a cryogenic nitrogen matrix. The 1:1 CO2/H2O complex has been observed. Each structure of this complex should have two bending frequencies corresponding to the CO2 fundamental bending mode (nu(2)). In this work, three bending frequencies corresponding to the CO2 fundamental bending mode (nu(2)) have been detected; one of them at 660.3 cm(-1) is reported here for the first time. This finding helps confirm the existence of two structures for this complex. A new feature attributed to a CO2 and H2O complex is observed at 3604.4 cm(-1) and is tentatively assigned to the CO2/H2O complex band corresponding to the CO2 combination mode (v(3) + 2 nu(2)). In addition, a band that belongs to a CO2 and H2O complex is detected at 3623.8 cm(-1) for the first time and is tentatively assigned to the (CO2)(2)/H2O complex band corresponding to the symmetric stretching mode (nu(1)) of H2O.