Controlled radical polymerization catalyzed by copper(I)-sparteine complexes

Stereospecific Living Radical Polymerization: Dual Control of Chain Length and Tacticity for Precision Polymer Synthesis

“…No 1 H NMR spectral changes were observed for the polystyrene obtained with CuBr/sparteine (Cu-2) although the tacticity was not measured. 100 Another paper on copper ATRP of MMA with chiral ligands was reported using quadridentate ligands (Cu-3) coupled with CuBr, in which the tacticity (mm/mr/rr ) 2.7/33.9/63.5) was almost the same as that obtained with a similar but achiral quadridentate ligand (mm/mr/rr ) 2.6/34.0/63.5) and was consistent with the Bernoullian statistics. 101 For possible tacticity control by coordination of the metal catalyst to monomer, a halfsandwich molybdenum catalyst (Mo-1) with a chiral ligand was thus synthesized and used for ATRP of MMA.…”

“…Analogous to the chiral catalysts or initiators in coordination or anionic stereospecific living polymerizations, 431 one of the apparently promising strategies might be to use chiral living catalysts [99][100][101][102][103][104] or regulating agents, [80][81][82][83][84] which would induce controlled/living radical propagation as well as stereospecific chain growth via a possible interaction with the propagating radical species. However, as described above for several attempts, no tacticity control was achieved by this approach most probably because the chiral counterparts might be located too far away from the monomer addition reaction site as well as because of the difficulty in controlling tacticity by enantioselective insertion.…”

Surface-initiated atom transfer radical polymerization of methyl methacrylate on magnetite nanoparticles

“…Sp is a ligand coordinating with Cu, providing a homogeneous ATRP system for MMA [38]. After polymerization, a small amount of the sample solution filtered through a 0.2 mm pore-size filter was subjected to the gel permeation chromatographic (GPC) measurement.…”

Reactions of polystyrene radicals in a monomer-free atom transfer radical polymerization system

“…A styrene solution of 1-phenylethyl bromide (80 mM), Cu(I)Br (80 mM), and sparteine [13] (160 mM) in a glass tube was degassed and heated at 110 o C for 45 min. After purification [11], PS-Br was isolated with M n = 1500 and M w /M n = 1.09.…”