The Near Infra-Red Absorption Spectrum of Methyl Iodide

The infra-red absorption spectrum of methyl iodide vapor has been reexamined under improved conditions at 3.3, 6.9, 8, and 11.3 microns with the result that each region reveals new detail. Near 3.36 microns some regular structure of mean separation 4.8 cm−1 overlaps the parallel band. The Q branches of the 6.9 mu band show a definite fine structure. The Q branch of the 8 mu band converges toward lower frequencies. In the 11.3 mu band the lines composing the Q branches converge toward higher frequencies.