Density functional calculation of phenoxyl radical and phenolate anion: an examination of the performance of DFT methods

Density functional theory calculations using several popular exchange and correlation functionals and two popular basis sets, 6-31 G* and 6-311 + +G(2d,p), were carried out on phenoxyl radical and phenolate anion. The radical structure is predicted satisfactorily by all functionals and both basis sets, but the mode composition and 17O isotope shift of ν5 are predicted satisfactorily only by local spin density approximation. All the functionals predict an unexpectedly short CO distance (≈ 1.26 Å) of the anion and a CO stretching frequency over 100 cm−1 higher than experimental result.