Atom transfer radical polymerization understanding

Abstract During the past decade, atom transfer radical polymerization (ATRP) has had a tremendous impact on the synthesis of macromolecules with well-defined compositions, architectures, and functionalities. Structural features of copper and copper(II) complexes with bidentate, tridentate, tetradentate, and multidentate nitrogen-based ligands commonly utilized in ATRP are reviewed and discussed. Additionally, recent advances in mechanistic understanding of copper-mediated ATRP are outlined. 

Keywords Atom transfer radical polymerization, ATRP, Copper complexes, Mechanistic understanding, Structures... 

Zhang H, Marin V, Fijten MWM, Schubert US (2004) High-throughput experimentation in atom-transfer radical polymerization a general approach toward a directed design and understanding of optimal catalytic systems. J Polym Sci Part A Polym Chem 42 1876-1885... 

Tang W, Kwak Y, Braunecker W et al. (2008) Understanding atom transfer radical polymerization effect of ligand and initiator structures on the equilibrium constants. J Am Chem Soc 130 10702-10713... 

Atom transfer radical polymerization (ATRP) was selected as an exemplary CRP technique to systematically study the kinetics and gelation behavior during the concurrent copolymerization of monovinyl monomers and divinyl cross-linkers (Scheme 2). The effect of different parameters on the experimental gelation was studied, including the initial molar ratio of cross-linker to initiator, the concentrations of reagents, the reactivity of vinyl groups present in the cross-linker, the efficiency of initiation, and the polydispersity of primary chains. Experimental gel points based on the conversions of monomer and/or cross-linker at the moment of gelation, were determined and compared with each other in order to understand the influence of each parameter on the experimental gel points. 

SCHEME 2.26 Influence of initiators on values for polymerizations using tris(2-pryidyhnethyl)amine (TPMA) as ligand in conjunction with Cu(I)X. Reprinted (adapted) with permission from Tang W, Kwak Y, Braunecker WA, Tsarevsky NV, Coote ML, Matyjaszewski K. Understanding atom transfer radical polymerization effect of ligand and initiator structures on the equilibrium constants. J Am Chem Soc 2008 130 10702-10713. 2008 American Chemical Society. 

---