Brian D. Wladkowski

The proton‐transfer surface of CH3OHF−

Diverse aspects of the potential surface for the proton‐transfer reaction CH3OH+F−→CH3O−+HF have been investigated by means of high‐level ab initio electronic structure methods based on single‐reference wave functions, namely, Mo/ller–Plesset perturbation theory from second through fourth order (MP2–MP4), the configuration interaction and coupled‐cluster singles and doubles methods (CISD and CCSD), and CCSD theory augmented by a perturbative correction for connected triple excitations [CCSD(T)]. The one‐particle Gaussian basis sets for (C,O,F;H) ranged in quality from [4s2p1d;2s1p] to [14s9p6d4f;9s6p4d], including as many as 482 atomic orbitals for the CH3OHF− system. The ion–molecule complex on the proton‐transfer surface is a tight, hydrogen‐bonded structure of CH3OH⋅F− character, exhibiting a nearly linear ‐OHF− framework, an elongated O–H distance of 1.07(1) A, and a small interfragment separation, r(H–F)=1.32(1) A. Improved structural data for F−⋅H2O are obtained for calibration purposes. A large flu...