The inelastic neutron scattering spectra of diphosgene and triphosgene

Phosgene is one of the most important C1 synthons in chemical industry. In a research laboratory, phosgene is often substituted by trichloromethyl chloroformate (diphosgene) or bis(trichloromethyl) carbonate (triphosgene), which react similarly to phosgene and are much easier to handle. Crystal structures of both compounds have been reported, however, as far as we are aware, no solid-state vibrational spectroscopy studies are documented. In view of their synthetic importance and as possible contaminants in the industrially important phosgene, we propose to carry out a comprehensive study of the vibrational spectra. The INS spectrum is essential in this regard, as it provides access to all the modes, in particular the low energy modes below 400 cm-1 that are difficult to access with conventional vibrational spectroscopy.