The results of our earlier studies of reflection and absorption in various spectral regions are reviewed and then used to provide values of the complex index of refraction ?=n+ik of water at 27¿C in the spectral range 5000-10 cm-1, corresponding to wavelengths in the range 2 μm to 1 mm. Values of n, k, and the Lambert absorption coefficient α, which are presented graphically and in tabular form, should prove useful in studies of the scattering of infrared radiation by water droplets in the atmosphere and in studies of radiative heat balance at water surfaces.