Infrared photoconversion between two forms of the CH 3OH:HI one-to-one complex trapped in a nitrogen matrix

The infrared-induced photoconversion between two forms of the CH ₃OH:HI complex trapped in solid N ₂ has been studied. The hydrogen-bonded form (C) is converted into a non-hydrogen-bonded form (U) upon excitations of the OH, HI and possibly, CH stretching modes. The C←U back-conversion has been observed upon excitation of the CO stretching mode of U by the P(36) emission line of a cw low power CO ₂ laser and the quantum yield of conversion has been deduced from kinetic measurements. In contrast no spectral change was detected upone excitation of the CO stretching mode of C by P(38).