It is arguably the case that the majority of acid-base proton transfer (PT) reactions important in chemistry and biochemistry occur in the ground electronic state. Nonetheless, ultrafast spectroscopy--- with its defined origin of time--- offers the most detailed experimental characterization of the analogous reactions of photo-acids in the excited electronic state, especially when infrared (IR) vibrational spectroscopic probing is also performed. We aim to assist the comprehension of and predictions for such experiments (as well as for the reactions of their ground electronic state cousins) by constructing a theory described in the abstract title. The theory differs considerably from prior efforts in focusing on hydrogen (H)-bond complexes (schematically AH�B), surrounded by a solvent which is out of equilibrium with respect to e.g. the proton motion and during the vibrational transition, attention to electronic structure aspects---including charge transfer, whose characters differ in ground and excited electronic states---via a Valence Bond description, and quantization of the proton's (and the H-bond coordinate's) nuclear motion. Several important distinctions are also made: between IR red-shift contributions due to H-bond formation in the complex and due to the electrical interactions with the surrounding solvent, and between the red-shift variations with solvent dielectric properties for non-polar and polar solvents.  Connections are made with related experimental results.

Theory of proton vibrational stretch frequencies in solution phase acid-base hydrogen-bonded complexes in ground and excited electronic states

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.