Closer to the "ideal recoverable catalyst" for atom transfer radical polymerization using a molecular non-fluorous thermomorphic system.
The tetramine ligand 1 hexasubstituted by very long alkyl chains (C18H37) exhibits an exceptionally large temperature-dependent solubility in 1,4-dioxane, its solubility increasing ca. approximately 104-fold between 23 and 50 degrees C. The preformed copper(I) complex CuBr/1 was shown to catalyze the atom transfer radical polymerization of methyl methacrylate with good control of the molar masses and polydispersities. Due to the thermoresponsive character of CuBr/1 polymerizations were carried out in homogeneous conditions while lowering the temperature to 10 degrees C led to the precipitation of the catalyst. Catalyst recovery was achieved with high yield ( approximately 95%) by a simple filtration under noninert atmosphere. Very low residual copper contamination ( approximately 200 ppm) was measured in the final polymer. The catalyst was recycled two times without significant loss of activity.
Barré
Guillaume
G
Laboratoire de Chimie Organique et Organométallique (UMR-CNRS 5802), Université Bordeaux 1, 351 cours de la Libération, 33405 Talence Cedex, France.
Taton
Daniel
D
Lastécouères
Dominique
D
Vincent
Jean-Marc
JM