%0 Journal Article %A Feng, Xiaojing %A Maurya, Devendra S. %A Bensabeh, Nabil %A Moreno, Adrian %A Oh, Takahiro %A Luo, Yuqing %A Lejnieks, Ja̅nis %A Galià, Marina %A Miura, Yoshiko %A Monteiro, Michael J. %A Lligadas, Gerard %A Percec, Virgil %D 2019 %T Replacing Cu(II)Br2 with Me6‑TREN in Biphasic Cu(0)/TREN Catalyzed SET-LRP Reveals the Mixed-Ligand Effect %U https://acs.figshare.com/articles/journal_contribution/Replacing_Cu_II_Br_sub_2_sub_with_Me_sub_6_sub_TREN_in_Biphasic_Cu_0_TREN_Catalyzed_SET-LRP_Reveals_the_Mixed-Ligand_Effect/9971375 %R 10.1021/acs.biomac.9b01282.s001 %2 https://acs.figshare.com/ndownloader/files/17970437 %K monomer conversion %K TREN %K mixed-ligand system %K DMF %K mixed-ligand effect %K MALDI-TOF %K Mixed-Ligand Effect %K chain end analysis studies %K MA %K SET-LRP %K Statistical analysis %K methyl acrylate %K weight control %K H 2 O %K electron transfer-living %K NMR %K Cu %K dipolar aprotic solvents NMP %K tris %K control experiments %X The mixed-ligand system consisting of tris­(2-aminoethyl)­amine (TREN) and tris­(2-dimethylaminoethyl)­amine (Me6-TREN) during the Cu(0) wire-catalyzed single electron transfer-living radical polymerization (SET-LRP) of methyl acrylate (MA) in “programmed” biphasic mixtures of the dipolar aprotic solvents NMP, DMF, and DMAc with H2O is reported. Kinetic and chain end analysis studies by NMR and MALDI-TOF before and after thio-bromo “click” reaction demonstrated that Me6-TREN complements and makes the less expensive TREN a very efficient ligand in the absence of externally added Cu­(II)­Br2. Statistical analysis of the kinetic data together with control experiments demonstrated that this mixed-ligand effect enhanced the apparent rate constant of propagation, monomer conversion, and molecular weight control. The most efficient effect was observed at a 1/1 molar ratio between these two ligands, suggesting that in addition to a fast exchange between the two ligands, a new single dynamic ligand generated by hydrogen bonding may be responsible for the mixed ligand observed. %I ACS Publications