Study on the structure and intra- and intermolecular hydrogen bonding of 2-methoxyphenol · (H2O)n (n=1,2)

Clusters of 2-methoxyphenol (2MP) with one and two water molecules have been studied using R2PI and IR/R2PI. Under microhydration the intramolecular hydrogen bond between the OH and OCH3 groups is destroyed. One water molecule is inserted between both substituents forming a cyclic structure with 2MP. The OH stretching band of 2MP is red shifted by 122 cm−1 relative to the monomer. Two water molecules form a dimer bridge with less strained H-bonds. The two H-bonded OH stretches of the water dimer exhibit red shifts of 205 and 230 cm−1. The larger red shifts result from stronger H-bonds, as compared to similar clusters with phenol. The experimental data are supported by the calculations.