Carbon monoxide, replacement

Hemoglobin (Hb) binds to both oxygen and carbon monoxide. When tiie carbon monoxide replaces the oxygen in an organism, the following reaction occurs ... 

Carbon monoxide poisoning results when carbon monoxide replaces oxygen bound to hemoglobin. The oxygenated form of hemoglobin, Hb 02 carries 02 to the lungs. 

Potts, Ehrlinger, and Nichols573 treated the mesoionic 1,3-thiazine betaine (92) with DMAD and obtained the thiophene 94 (28% yield), which was also synthesized from 97 and DMAD. Some 96 (R = 4-MeOC6H4) was also formed through rearrangement of the starting material. Product 94 could arise from 93 by loss of phenyl isocyanate or from 95 by loss of carbon monoxide. Replacement of the p-methoxy-... 

At low temperatures, carbon monoxide replaces all three allyl groups in triallylchromium to give Cr(CO)j (138). The reaction also affords the compound (77-C3H5)jCrCO, which the authors failed to isolate but confirmed by mass spectra. In the same manner, CO replaces one allyl group in tris(77-allyl)iron to give (VI) (139). 

The action in the human organism is well understood the carbon monoxide replaces the oxygen on attaching itself to the normal haemoglobin. Thus it inhibits the normal respiratory function of the haemoglobin which is to transport the oxygen contained in the air to the body tissues. 

Carbon Monoxide Replacement in Mononuclear Metal Carbonyls... 

Mixed Ligand Carbonyls.—General. Solvent and structural effects on reactivities of metal carbonyl halides towards carbon monoxide replacement have been probed for manganese, iron, and ruthenium compounds. The compounds were MnX(CO>5, where X == Br or I, RuX(CO)2(/i -C6H6), where X = Cl or Br, and FeX(CO)2(/i -C3H5), where X = Br or I. The displacing nucleophiles were triphenylphosphine or triphenyl phosphite the solvents were n-octane, xylene, di-n-butyl ether, or nitrobenzene. Kinetic parameters for some of these reactions, with some earlier values for related systems for comparison, are listed in Table 1. The main conclusion... 

Carbon monoxide replaces oxygen in oxygenated hemoglobin according to the reaction ... 

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