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Reaction Rates as a Function of Scale within Ionic Liquids: Microscale in Droplet Microreactors versus Macroscale Reactions in the Case of the Grieco Three‐Component Condensation Reaction
Author(s) -
Dubois Philippe,
Marchand Gilles,
Gmouh Said,
Vaultier Michel
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200700331
Subject(s) - microreactor , microscale chemistry , ionic liquid , condensation , microfluidics , chemistry , reaction rate , chemical engineering , ionic bonding , micromixing , electrowetting , damköhler numbers , mixing (physics) , thermodynamics , materials science , nanotechnology , organic chemistry , catalysis , ion , electrode , physics , mathematics education , mathematics , quantum mechanics , engineering , combustion
Task‐specific ionic liquids (TSILs) and more specifically binary task‐specific ionic liquids (BTSILs), a unique subclass, have been shown to be excellent supports for solution‐phase chemistry. The negligible volatility of ionic liquids enables their use as stable droplet microreactors in atmospheric environments without oil protection or confinement. These droplets can be moved, merged and mixed by electrowetting on a chip. Solution‐phase synthesis can be performed on these open digital microfluidic labs‐on‐a‐chip as illustrated by a study of the Grieco three‐component reaction in [tmba][NTf 2 ]‐droplet (tmba= N ‐trimethyl‐ N ‐butylammonium NTf 2 =bis(trifluoromethylsulfonyl)imide) microreactors. A detailed study of matrices and scale effects on conversion and kinetic rates of this three‐component condensation is presented in this paper. Reactions have been shown to be slower in droplets than in batches in the absence of additional mixing. Also, a significant influence of the ionic‐liquid matrix has been observed. Finally, an increase of droplet's temperature resulted in a kinetics enhancement so as to reach macroscale reaction rates, probably because of a much better mixing of reaction's components involving a Marangoni's effect.