THE INFRARED REFRACTIVE-INDEXES OF CHBR3, CCL4 AND CS2

Spectrally resolved data for the real part, n(lambda), of the complex refractive index, n = n + ik, of bromoform (tribromomethane, CHBr3) at room temperature (298 K) in the wavelength range 1-13 mum are present ed. The measurements were made using the near-normal reflectance techn ique. The accuracy of the method was confirmed by comparing measured v alues of n(lambda) of water with available data in the literature. For bromoform, n(lambda) is found to decrease gradually from 1.58 to 1.51 over this wavelength range, except in the region of anomalous dispers ion near absorption bands at 3.3 and 8.7 mum. A complete infrared wind ow for extinction measurements on suspended particulates can be obtain ed using CCl4 in the spectral range 1-6 mum, CHBr3 in the ranges 6.0-7 .4 mum and 11-13 mum, and CS2 in the range 7.4-11.0 mum. The data for n(lambda) of CCl4 in the range 1-9 mum, and those for CS2 in the range 7.4-11.0 mum, obtained from reflectance measurements, compare favorab ly with data available in the literature.