Semiempirical study of low molecular weight polymers of 3-phenyl-1-ureidonitrile

Conformational searching and semiempirical (AM1) structure optimizations have been carried out on low degree polymers of 3-phenyl-1-ureidonitrile (PUN), a system of interest for its potential application in thin-film ultra-high-density data storage. The predicted structural properties and vibrational frequencies are in good agreement with experimental data. Most notably, a downshift in this C-N stretching frequency upon polymerization and the absence of a peak near 2200 cm−1 in both the experimental and theoretical IR spectra, support the proposal that PUN film polymerizes by opening of the CN bond.