Routine method for the determination of the optical constants of liquids

A modification of the Kramera-Kronig method is used to obtain the spectra of the absorption and refraction indices, k and n, of benzene, chloroform and carbon tetrachloride from their infrared attenuated total-internal-reflectance spectra. The existing software of the Fourier-transform infrared spectrometer is applied for the calculation. For medium-strength bands with k between 0.004 and 0.3, agreement with earlier values is within a few percent, whereas for strong bands, the present k values are about 20% lower.