Complex refractive indices in the infrared for ZnCl2 in water

Near-normal incidence reflectance spectra relative to water were measured throughout the 270?ν?5000 cm−1 spectral region for 20.3%, 29.4%, and 40.2% aqueous solutions of ZnCl2. Spectral values of the complex refractive index N (ν) =n (ν)+ik (ν) of the ZnCl2 solutions were computed by use of subtractive Kramers–Kronig techniques. Values of N (ν) were obtained in a form suitable for future computations of Mie scattering in a cloud composed of aqueous ZnCl2 droplets. The spectra were further analyzed to determine the central frequencies, half-widths, and strengths of infrared bands due to the fundamental intra- and intermolecular vibrational modes of liquid water.