Carbonylation iridium-platinum based

Carbonyl complexes of rhodium, ruthenium, osmium, iridium, and platinum, in the presence of H2O and a weak base (e.g., trimethylamine), act as catalysts for the conversion of propene to a mixture of butanol and methylpropanal with the exception of the platinum system, these catalysts are considerably more active than Fe(CO)s as reported by Reppe. Under the same conditions, but in the absence of olefin, the carbonyls act as catalysts for the conversion of CO and H2O to CO2 and H2. The metal carbonyls, together with Fe(CO)s, in the presence of H2O, CO, and a weak base such as McsN, serve as catalysts for the conversion of nitrobenzene, dinitrobenzene, and 2,4- and 2,6-di-nitrotoluene to the corresponding aminobenzene derivatives. 

Among the complexes studied, the rathenium carbonyls were found to be significantly more active than their iridium, osmium, and platinum analogs. The activity reached for triruthenium dodecacarbonyl [Ru3(CO)j2] is stiU one of the highest ever reported in homogeneous WGS. Based on infrared studies of the less reactive iron carbonyl systems, they postulated a mechanism for the WGS reaction that involves addition of a hydroxide anion as the rate-determining step (RDS), as depicted in Figure 16.3. 

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