The Copper Catalyst in Atom Transfer Radical Polymerizations: Structural Observations

Electrospray ionization mass spectrometric study of CuI and CuII bipyridine complexes employed in atom transfer radical polymerization

“…6,7 Recently, we were able to characterize the Cu I Br/2dNbpy system in non-polar solvents by EXAFS (extended x-ray absorption fine structure). 17 The results are consistent with the mass spectra reported in this paper. The Cu-N bond length in the cation was found to range from 2.000 to 2.030Å, and the average bond length of Cu-Br in anion was determined to range from 2.250 to 2.290Å.…”

Effect of ligand on the synthesis of star polymers by resorcinarene‐based ATRP initiators

“…An ideal catalyst should provide an appropriate rate of activation and fast deactivation 43. Bulky ligands, for instance 2,2′‐bipyridine and its derivatives, reduce the accessibility of the transition metal by halogen, decreasing the rate of activation 42, 44. Electronic interactions of the ligand with the transition metal affect the rates of both activation and deactivation of the radicals, and thereby the controllability of the polymerization.…”

“…Electronic interactions of the ligand with the transition metal affect the rates of both activation and deactivation of the radicals, and thereby the controllability of the polymerization. The ligand used in our previous study was indeed 2,2′‐bipyridine, which tends to form large 2:1 complexes with Cu 44. By replacing the bipyridyl with smaller multidentate amines forming 1:1 complexes, we would reduce the steric hindrance and increase the rate of polymerization, since the Cu‐amine complexes have lower redox potentials than the Cu‐bipyridyl complex 33…”

Facile atom transfer radical homo and block copolymerization of higher alkyl methacrylates at ambient temperature using CuCl/PMDETA/quaternaryammonium halide catalyst system

“…This study thus shows that the CuCl/PMDETA/AQCl works well for the ambient temperature ATRP of higher alkyl methacrylates as it does for the lower members of the homologous alkyl methacrylate series [13]. Regarding the role of AQCl in increasing the solubility of the catalyst, it was suggested from phenomenological consideration in our earlier work [13] that more than one halide ion gets involved as ligands in the formation of the catalyst complex which in the absence of the extra halide ions has the composition [Cu(PMDETA)X] [27]. The resultant new complex would require PMDETA to act either as a bidentate or as a monodentate ligand due to the maximum co-ordination number of Cu C being 4.…”