On the splitting of ν(OH) k = 0 phonons and band-width in hydrogen bonded organic solids: α-naphthol

α-naphthol crystallizes with the same type of hydrogen bonded chain like planar zig-zag structure as other XH…X systems (X = F, Cl, Br, and sometimes O). The intramolecular k = 0 splitting for ν(OH) motions of α-naphthol has been clearly observed in the infrared spectrum with polarized light on iso-oriented small single crystals. It is found that the observed intramolecular ν(XH) splitting or the corresponding f_XH/XH nearest neighbour quadratic force constants across the hydrogen bond can be correlated with the electronegativity of the X atom.