Photolysis of 2- and 4-cyanophenyl azides in solid N-2 matrices at 12-20 K yielded anisotropic samples with linearly dichroic infrared spectra. An attempt was made to use the observed dichrosim, largely qualitatively, to correlate the directions of C drop N bonds with other bond directions in the molecules, thus developing a method of conformational analysis for matrix-isolated molecules. By this means, improved estimates for the directions of the transition moments of the azide stretches and the photo-active electronic absorptions were derived, and 2-cyanophenyl azide was shown, with a high degree of probability, to exist mainly as the anti conformer. Overlap of product and starting material v(CN) bands, however, proved to be a serious disadvantage of this approach. (C) 1997 Elsevier Science B.V.
