Influence of substituents on the anharmonicity of nus(OH) vibration in phenol derivatives explored by experimental and theoretical approach

Very good reproducibility of the first five vibrational transitions of phenol in the gas phase by the MP2/ 6-31G potential for O-H bond stretching was found. The vibrational levels were calculated by a program for variational solving of the time-independent Schr?dinger equation in one dimension. Relative intensities of particular transitions were determined on the basis of the function of the dipole moment. The substituent effects on the nu(s)(OH) transitions and on the intensity of these transitions, as well as on the structure of eleven phenols, was analyzed as a function of the pK(a) values.