The measurement and application of absolute intensities in the IR spectra of liquids

This thesis presents the work done to measure absolute intensities in the IR spectra of liquid samples by transmission and attenuated total reflection (ATR) methods, and to apply the intensities to investigate the hydrogen bonding interaction in water solutions. The intensities are measured by the infrared optical constant, k and n, spectra, and the n spectrum is usually calculated from the k spectrum through the Kramers-Kronig (KK) transform. This work presents an approach for colorless liquids to obtain the contribution from electronic absorption to improve the n value calculated. Results for ten common liquids are presented.;Transmission method was used to measure liquid dichloromethane to obtain optical constant and molar absorption coefficient spectra between 6500 and 800 cm;ATR is another method to measure IR spectra. A modified KK transform from reflectance to the phase shift with non constant phase correction was developed to improve the non iterative procedure of refining ATR spectra. This transform gives errors less than 0.1% for the value of the k spectrum recovered from the simulated spectra. The ATR method was used to measure the spectra of water and water-acetonitrile mixtures. The reproducibility of the ATR spectra for water has been improved. The precision of the k spectrum is now 0.3% for the area in the region 4000-2660 cm...