VUV spectroscopy of formamide ices

Vacuum UltraViolet (VUV) spectra of formamide ice have been studied using synchrotron radiation. VUV spectra of formamide ice recorded at 30 K revealed two photoabsorption bands, historically labelled V1 and Q in gas phase VUV spectra. However, in contrast to such gas phase spectra the Q band was found to be more intense than the V1 band in the ice spectra. At higher temperatures changes observed in the spectra have been ascribed to the rearrangement of formamide dimers within the ice. At 160 K a phase change from amorphous to crystalline ice was also observed, at higher temperatures (200 K) there is some evidence of possible polymerization within the ice.