Carbon monoxide, reaction with chlorine

An enormous e-f-fort has been made on -finding new, phosgene—free routes to isocyanates. Phosgene, produced by reaction o-f carbon monoxide with chlorine, is an energy-intensive material, very poisonous and corrosive since it is a hydrolyzable chlorine derivative. One such process involves reductive carbonyl at i on o-f the nitro compounds by reaction with carbon monoxide 2,3,53 ... 

The second example also involves catalysts development. The goal of this project, headed by Leo E. Manzer and Walter Cicha at the DuPont Central Research Station, was charged with developing a new highly selective catalyst for the manufacture of phosgene while reducing the amount of the undesired by-product, carbon tetrachloride. As a result of basic studies by the DuPont catalysts research team, it was recognized that carbon tetrachloride formation arose from chlorination of the carbon catalyst that is used in the commercial process to promote the reaction of carbon monoxide and chlorine. 

A 3.00-liter reaction vessel is filled with carbon monoxide gas, CO, and chlorine gas, Cl2. The mixture is heated to 670 K and allowed to reach equilibrium according to the balanced equation shown below ... 

Dichlorotetracarbonyldirhodium has been obtained by the action of carbon monoxide at high temperature and pressure on a mixture of anhydrous rhodium(III) chloride and finely divided copper powder and by reaction of rhodium(III) chloride 3-hydrate with carbon monoxide saturated with methanol at moderate temperatures and atmospheric pressure. The preparation described here is a modification of the latter method, without use of methanol. This procedure is considerably simpler than the recently described preparation which involves adsorption of rhodium chloride on silica gel, chlorination, and subsequent carbonylation. ... 

Derivation Reaction of carbon monoxide with gaseous chlorine, producing phosgene (COCl,), which is then treated with anhydrous ethanol, giving ethyl chlorocarbonate and splitting off hydrogen chloride. 

This scheme will be applied to phosgene (bp 7.56°C.),1 a reagent that is made by the reaction of carbon monoxide with chlorine (2.1) over activated carbon at elevated temperatures.2... 

Phosgene is manufactured by the reaction of excess chlorine with carbon monoxide in the presence of activated charcoal, at a temperature of about 50°C ... 

Phosgene is a toxic gas prepared by the reaction of carbon monoxide with chlorine ... 

Electrolytic chlorine from a steel bottle contains small amounts of oxygen, chlorine oxides, nitrogen, carbon monoxide, carbon dioxide, hydrogen chloride, chlorinated hydrocarbons, and moisture. For complete purification, chlorine washed with concentrated sulfuric acid is condensed into a receiver (preferably calibrated) cooled in ether/carbon dioxide, and a regular stream of chlorine is produced by placing the receiver in a bath of ice and water. A safety flask should be placed between the reaction flask and the chlorine supply. Chlorine bombs cool very considerably if chlorine is removed in a rapid stream they should, if that happens, never be warmed above 30°C (vapor pressure of Cl2 at 0° 3.76 atm, at +10° 5.14, at +20° 6.86, at +30° 8.97, and +40° 11.52 atm). 

Carbon monoxide is purified and used as a feedstock for several primary petrochemicals The largest quantity is used for carbonylation of methanol to produce acetic acid. Acetic acid is used in the production of vinyl acetate, acetic anhydride and cellulose acetates. Phosgene, formed by the reaction of carbon monoxide with chlorine, is reacted with amines to form polyurethane intermediates. Phosgene is also reacted with bisphenol A to form polycarbonate resins, used for engineering plastics. 

The reactions of chlorine gas with either dry sulfur dioxide, or with carbon monoxide are remarkably slow. In both cases reaction only occurs at high temperature, and by a complex process involving free chlorine atoms (Bamford and Tipper 22)). Simple concerted mechanisms can be imagined in both cases. 

---