Ab initiostudy of the phenolhyphen;water cation radical

摘要

The phenolhyphen;water cation radical has been investigated byabinitiotheory using the spinhyphen;restricted openhyphen;shell Hartreendash;Fock and spinhyphen;restricted openhyphen;shell secondhyphen;order Moslash;llerndash;Plesset theories with 3hyphen;21Gast;(O) and 6hyphen;31Gast; basis sets. The full geometrical optimization was performed for several hydrogenhyphen;bonded structures and one hemibonded structure. Clearly, the most stable structure has been found forCssymmetry with the linear hydrogen bond between the proton of the OH group of the phenol cation radical and the oxygen of the water, and the water hydrogens pointing away from the phenyl ring. For this structure harmonic (and for some intermolecular modes anharmonic) vibrational frequencies have been computed for various isotopic complexes. The computed shifts of phenolhyphen;localized intramolecular modes on complexation and on deuteration as well as the calculated intermolecular frequencies of the different isotopic complexes allow for an assignment of vibrational frequencies observed in the experimental zerohyphen;kinetichyphen;energy (ZEKE) photoelectron spectra. Five out of a possible six intermolecular vibrations and several intramolecular modes have been assigned, including the 18bvibration which shows a strong blue shift in frequency upon complexation. Structure and properties of the phenolhyphen;water cation radical are compared with those of the corresponding neutral complex.