S. Coussan et al., INFRARED PHOTOISOMERIZATION OF THE METHANOL CYCLIC TRIMER TRAPPED IN A NITROGEN MATRIX, Chemical physics letters, 217(1-2), 1994, pp. 123-130
Condensation of nitrogen/methanol mixtures at 15 K revealed broad 3450
and 3284 cm(-1) absorptions assignable to (CH3OH)(n) aggregates, n gr
eater than or equal to 3. The 3450 cm(-1) band is infrared photosensit
ive and progressively disappears upon irradiation in the beam of the s
pectrometer, with appearance of three main V-OH bands at 3661.9, 3433.
3 and 3389.2 cm(-1) growing at the same rate. Mixed CH3OH/CH3OD sample
s revealed several mixed isotopic satellites of these three bands in b
oth v(OH) and Y-OD regions, which allows us to conclude that the stabl
e cyclic trimer responsible for the 3450 cm(-1) absorption is converte
d upon OH (OD) vibrational excitation into an open chain trimer consis
ting of three non-equivalent subunits. This conclusion agrees with com
plementary observations in the v(co) region.