125. The infrared absorption spectra of some chloroformates and carbonates. The structure of “di- and tri-phosgene”

Bis(trichloromethyl)carbonate (BTC, Triphosgene): A Safer Alternative to Phosgene?

“…Hales was first to draw attention to the inappropriate term “triphosgene” because the compound is not derived from carbonyl chloride (structure A ) . The two trichloromethoxy groups of BTC (structure B ) are almost electronically equivalent to the chlorine atoms in phosgene, which explains these compounds’ similar nucleophilic reactivity patterns.…”

“…The structure of BTC was predicted by Hales et al on the basis of IR spectra, with special reference to CO and C–O stretching vibrations . The importance of this work resides in the first confirmation of a planar structure for BTC before X-ray data were available .…”

Phosgenation Reagents

“…To identify the gases produced from the decomposition of triphosgene, an experiment was performed on a thermogravimetric analyzer interfaced to a Fourier transform infrared spectrometer (TGA-FTIR) [16]. At lower temperatures, such as during its distillation under reduced pressure, triphosgene decomposes into phosgene and diphosgene, but when mixed with powdered activated carbon (or with Lewis acids [57]) and heated to the melting temperature, rapid decomposition to phosgene occurs [59]. [69,80,81].…”

“…The thermal decomposition of a series of compounds containing the trichloromethyl group, generating two or three moles of phosgene per mole of starting material, has been reported[55,57,59,62].…”

35Cl Nuclear Quadrupole Resonance of Alkyl Chloroformates, Alkyl Acid Chlorides, and Carbamyl Chlorides

“…od proved by i.r. measurements on similar compounds in CCl,, and there is no evidence for such structures in the solid state (14). Dipole moments have favored the R to be cis to C1 in RXCOCl(15) and electron diffraction (1) has shown cis for the methyl chloroformate only.…”