Probing the Vibrations of Shared, OH+O‐Bound Protons in the Gas Phase

Spectral signature of a proton bridge? Gas-phase infrared spectra are reported in the range of 500–1800 cm−1 for three species with short, strong hydrogen bonds, namely the proton-bound dimers of dimethyl ether (shown in the picture) and diethyl ether, and protonated 1,1′-oxybis[2-methoxyethane] (diglyme). The spectra are all quite similar, and furthermore they also strongly resemble the spectrum of the proton-bound water dimer (H5O2+), suggesting that there may be a conserved “spectral signature” for a proton bound between two oxygen atoms.