INFRARED-ABSORPTION INTENSITIES OF ALLENE

The infrared absorption intensities of the fundamental bands of CH 2 = C = CH2 and CD2 = C = CD2 were measured in the gas phase. The Coriolis interaction between v7 and v10, bands of CD2 = C = CD, was analyzed to obtain information about the signs of (∂p/∂Qi). The perturbation was found to be positive. Utilizing the obtained data, the correct sign combination was determined. The polar tensors and the atomic effective charges as well as the local intensity parameters have been obtained using the determined sign combination of (∂p/∂Qi). The results were discussed in connection with the empirical rules for the signs of CH bond stretching and bending motions. Predictions of this rule were found to be well satisfied in this molecule. © 1979 American Institute of Physics.