Effect of ferrocene moieties on the copper‐based atom transfer radical polymerization of methyl methacrylate

The atom transfer radical polymerization (ATRP) of methyl methacrylate catalyzed by copper–tripodal complexes with ferrocene moieties (CuX/TRENFcImine, where X is Br or Cl, and TRENFcImine is tris‐[2‐(ferrocenylmethyleneimino)ethyl]amine) was investigated to understand the effect of redox active moieties on the performance of ATRP catalysts. The CuBr/TRENFcImine system was highly active, with 82% conversion in 2 h. However, the polymerization became slower at higher molar ratios of monomer to catalyst. The polydispersity index was broad, and the initiation efficiency was relatively low. On the basis of the conformational analysis, the highly active and less controlled polymerization was probably caused by the electronic effect rather than the steric effect on the ferrocene moieties, which led to the higher and lower values in the activation and deactivation steps, respectively. The polydispersity index was improved by the addition of CuBr₂, but this led to slower rates of polymerization. The effect of halide groups on ATRP caused a faster rate in the CuBr/TRENFcImine polymerization system than in the CuCl/TRENFcImine system. The higher molar ratio of monomer to catalyst had no significant effect on the CuCl/TRENFcImine system. Nonetheless, the trace of water in the CuCl₂·2H₂O system accelerated the rate of propagation, which led to a higher molecular weight. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of ferrocene substituents and ferricinium additive on the properties of polyaniline derivatives and catalytic activities of palladium‐doped poly(m‐ferrocenylaniline)‐catalyzed Suzuki–Miyaura cross‐coupling reactions

Poly(aniline‐co‐m‐ferrocenylaniline) and ferricinium‐doped poly(aniline‐co‐m‐ferrocenylaniline) were synthesized by a conventional chemical oxidative polymerization, then characterized by spectroscopic techniques and quantitative analyzes. Increasing of the percentages of m‐ferrocenylaniline in the copolymers resulted to a blue shift of UV–Vis absorption spectra. Broader EPR spectra indicated the loss of conjugation and crystallinity of copolymers. ¹H NMR spectra confirmed the presence of ferrocene moieties and ferricinium in the polymers. The CV measurements showed that the electron withdrawing power of ferrocene moieties could lead to the decreasing of electron delocalization on the polymer main chain. The VSM results showed that as‐prepared copolymers were soft magnetic materials with very low magnetization. Pd‐doped poly(m‐ferrocenylaniline) as catalysts were utilized in the Suzuki–Miyaura cross‐coupling reactions to improve the catalytic activities. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1489–1497, 2013     

Tripodal “click” ligands for copper‐catalyzed ATRP

A series of tris(R‐methyltriazolylmethyl)amines [R = C₆H₅ ( 1 ), 4‐FC₆H₄ ( 2 ), 4‐MeOC₆H₄ ( 3 ), Fc ( 4 )] were prepared and used as ligands for catalytic ATRP of methyl methacrylate (MMA). Despite a lower activity, the CuBr/ 4 catalyst promoted relatively well controlled polymerization compared to CuBr/ 1 , as evidenced by narrower polydispersity indices. Meanwhile, no polymerization activity was observed with CuBr/ 2 and CuBr/ 3 under the catalytic conditions investigated. The CV measurements of CuBr₂ complexes supported 1 and 4 in DMSO showed E_1/2 values of –0.206 and –0.224 V, respectively, confirming the more electron‐rich nature of CuBr/ 4 . Although both CuBr/ 1 and CuBr/ 4 catalysts were only partially soluble in several organic solvents used, kinetic studies revealed a pseudo first order linear plot of ln[M]₀/[M]_t versus time. Addition of CuBr₂ into the polymerization systems led to a decrease in polymer polydispersities and the observed rate constants (k_obs). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013