General Considerations for the Use of Ionic Liquids in Hydroformylation

ILs also present good and tunable solubility with olefins. As described above for organic/water biphasic hydroformylation systems, the partial solubility of olefins in the phase containing the catalyst is essential to obtain a viable biphasic process. 

IL is first introduced into the reactor, followed by n-heptanal. 

The magnetic stirring bar is run for 15 min and stopped for another period of 15 min before the observation of miscibility. 

Another important parameter which must be considered in the case of hydro-formylation, is the solubility of gaseous substrates (CO and H2) in the phase containing the catalyst. Measurements of Henry s constants for CO and H2 in common ionic liquids indicate a very poor solubility of these gases [20], For the correct design of the reactor and process scheme, this point has to be seriously considered as it can yield to mass-transport limitation. 

As a consequence of classical homogeneous hydroformylation systems, the study of this reaction in ILs has essentially been developed around rhodium as catalyst. Only a few exceptions deal with the use of other metals such as platinum, cobalt, or ruthenium. 

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