Matrix Isolation and ab Initio Study of the Hydrogen-Bonded Complex between H₂O₂ and (CH₃)₂O

Abstract

Matrix isolation infrared spectroscopy has been combined with MP2/6-31+G(d,p) calculations to characterize the 1:1 hydrogen-bonded complex between H 2 O 2 and (CH 3 ) 2 O. The O−H stretching mode was observed to red shift 234 cm -1 upon hydrogen bond formation, while a 45 cm -1 blue shift was noted for the O−O−H bending mode of the H 2 O 2 subunit in the complex. These values compare well to the computed shifts of −293 and +20 cm -1, respectively. The perturbations to the vibrational modes of the two subunits in the HOOH:O(CH 3 ) 2 complex are substantially larger than the perturbations reported previously for the analogous HOH:O(CH 3 ) 2 complex, suggesting that H 2 O 2 is a better proton donor for hydrogen bonding than H 2 O. In contrast, band shifts in HOOH:O(CH 3 ) 2 are much less than observed for FH:O(CH 3 ) 2 and ClH:O(CH 3 ) 2 .