Residue infrared spectrum obtained after HC₅N photolysis experiment (top) and C₄N₂ photolysis experiment (bottom) at room temperature. Complementarity of the photopolymer functional groups is evident in this figure: HC₅N polymer is dominated by NH and CH functional groups because of the presence of hydrogen, whereas the C₄N₂ polymer is dominated by CC functional groups. Also shown in the figure are the IR spectra of C₄N₂ polymer made with 266 nm laser irradiation at JPL and the spectra of Titan measured by the Cassini VIMS and CIRS instruments.