Molecular vibrations of irregular chains. I. Analysis of infrared spectra and structures of polymethylene chains consisting of CH2, CHD,and CD2 groups

Various samples of irregularly deuterated polyethylene were prepared and their infrared spectra were studied. The results support the previously proposed view that poly-trans-CHD?CHD or -cis-CHD?CHD obtained with Al(i-Bu)₃–TiCl₄ is an irregularly deuterated chain consisting of the CH₂, CHD, and CD₂ groups. A simplified calculation of the CHD scissors and CDH rocking vibration frequencies has been made for various model chains. The assignments of the CDH rocking vibration bands in the region of 700–500 cm.^?1 have been given on this basis.