The Experimental Determination of the Intensities of Infra-Red Absorption Bands II. Measurements on Ethylene and Nitrous Oxide

Abstract

The absolute intensities of the chief infra‐red absorption bands of ethylene and nitrous oxide have been determined experimentally to be (in cycles per centimeter at N.T.P.): Ethylene Nitrous oxide 950 cm −1 band : 1540×10 10 590 cm −1 band : 120×10 10 1444 cm −1 band : 210×10 10 1285 cm −1 band :1150×10 10 3050 cm −1 band : 840×10 10 2224 cm −1 band :5600×10 10 From these intensities it is possible to calculate the dipole moments, μ, of bonds between vibrating atoms and also the rates of change of dipole moment with inter‐nuclear distances, ∂μ/∂r. The values of μ obtained are all of the order of magnitude of 0.5×10−18 c.g.s. unit, while values of ∂μ/∂r are of the order of 1×10−10 c.g.s. unit. The results are in agreement with available data on infra‐red dispersion and on atomic polarization within the limits of experimental error, which are estimated to be approximately ±10 percent.