Abstract
Chloride ions are efficient catalysts for the synthesis of phosgene from carbon monoxide and elemental chlorine at room temperature and atmospheric pressure. Control experiments rule out a radical mechanism and highlight the role of triethylmethylammonium trichloride, [NEt(3)Me][Cl(3)], as active species. In the catalytic reaction, commercially available [NEt(3)Me]Cl reacts with Cl(2) to form [NEt(3)Me][Cl(3)], enabling the insertion of CO into an activated Cl─Cl bond with a calculated energy barrier of 56.9 to 77.6 kJ mol(−1). As [NEt(3)Me]Cl is also a useful chlorine storage medium, it could serve as a catalyst for phosgene production and as chlorine storage in a combined industrial process.