Spectroscopy of the transition state : hydrogen abstraction reactions of fluorine
The reactions F + CH30H HF + CH30, F + C2HSOH HF + C2HS0, and F + OH HF + O(3P,'D) are studied by photoelectron spectroscopy of the negative ions CH30HF, C2HSOHF, and OHF. In each case, photodetachment accc%cE the transition-state region for direct hydrogen abstraction. The photoelectron spectra exhibit resolved vibrational structure which is sensitive to details of the potential surface in the transition-state region. To aid in the interpretation of the spectra, ab initio equilibrium structures, harmonic frequencies, and hydrogen bond dissociation energies are calculated for the ions C H 3 0 H F and O H F . The anharmonic hydroxyl hydrogen stretching potential is also calculated for the two ions. Using the calculated ion properties and the fitted ab initio reaction surfaces of Sloan et al. ( J . Chem. Phys. 1981, 75, 1190), a two-dimensional dynamical simulation of the photoelectron spectrum of O H F is presented and modifications to the reaction surfaces are discussed. The spectra of the alcohol complexes are discussed in light of this simulation, and the role of the "bath" degrees of freedom in these spectra is considered.