Search

Matrix isolation infrared spectroscopy has been combined with MP2/aug‘-cc-pVDZ calculations to characterize the 1:1 hydrogen-bonded complexes between H2O2 and the hydrogen halides HF, HCl, and HBr. The infrared spectra of the these complexes are characterized by an intense, red-shifted H−X stretching band, as well as slight perturbations to several of the HOOH vibrational bands. For the HF complex, the intermolecular librational modes were also observed. The ab initio calculations identified two equilibrium structures on each surface, one an open structure, and the other cyclic. These two structures have similar binding energies. However, only the open structure appears to be present in argon and nitrogen matrices. This open structure is preferentially stabilized by interaction of its larger dipole moment with the matrix medium.

Matrix isolation infrared spectroscopy has been combined with MP2/6-31+G(d,p) and MP2/aug‘-cc-pVTZ calculations to characterize the 1:1 hydrogen-bonded complexes between H2O2 and bases containing phosphorus and sulfur as electron pair donor atoms. Most obvious from the spectra of the complexes HOOH:PH3, HOOH:P(CH3)3, HOOH:SH2, and HOOH:S(CH3)2 and their deuterated analogues is the shift to lower frequency of the hydrogen-bonded O−H or O−D stretching bands (νs) relative to isolated H2O2 and D2O2. The experimental shifts are in good agreement with the computed shifts. Shifted modes of both H2O2 and base subunits have been observed, along with the band for the intermolecular librational mode of each complex. Comparisons are made between the structures and spectral properties of these complexes and related complexes formed between H2O2 and corresponding N and O bases.

Matrix isolation infrared spectroscopy has been combined with MP2/6-31+G(d,p) calculations to characterize the 1:1 hydrogen-bonded complexes between H2O2 and the bases NH3 and N(CH3)3. Most obvious from the spectra of these complexes and their deuterated analogues is the shift to lower frequency of the hydrogen-bonded O−H or O−D stretching bands relative to the isolated monomers. The experimental shifts are in good agreement with the computed shifts. Perturbation of the O−O−H bending mode was also observed, along with shifts of certain vibrational modes of the base subunits in the complexes. Surprisingly, the experimental intensities of the product bands are low when compared to other hydrogen-bonded systems and to the computed intensities.