Infrared spectrum of solid isocyanic acid (HNCO): vibrational assignments and integrated band intensities.

Infrared spectra of thin films of solid HNCO condensed from the gas phase are characterized in terms of their vibrational frequencies, mode assignments, and integrated band intensities at low temperatures ( approximately 20-145 K). Isocyanic acid is shown to react with water (H2O) and ammonia (NH3) even at low temperatures; consequently, it may be an important species in the chemistry of interstellar ices and comets.