No abstract

A series of [Cu(NN')]2(OTf)2 complexes containing pyridine-triazole ligands [OTf = OSO2CF3; NN' = NN'Ph (1), NN'hex (2), NN'py (3)] with different substituents at the triazole N4 position or 2,2'-bipyridine (bpy; 4) have been synthesized. Crystal structures of 1 and 3 reveal a trans-isomer with strong preference for regular-type triazole coordination (for 3) whereas the Cu-bipyridine complex 4 is more stable in a cis-form. Cyclic voltammetry of 1-4 suggest that the electron-donating strength follows the trend: bpy > NN'py > NN'hex ~ NN'Ph. The catalyst systems consisting of 5 mol% CuOTf2/NN'/TEMPO (TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxy) in the presence of 2x2.0 cm 2 Cu 0 sheets as a reducing agent and 10 mol% N-methylimidazole (NMI) exhibit good activities for aerobic oxidation of benzyl alcohol to benzaldehyde. Catalytic studies have shown that the activities were higher with more electron-rich N-based ligands. Furthermore, oxidation of aliphatic alcohols such as 1-hexanol and 2-methyl-1-pentanol using the Cu catalyst system with the NN'py ligand at room temperature afforded the corresponding aldehydes in >99% and 46% yields, respectively after 24 h.

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

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 CuBr 2 , 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 CuCl 2 Á2H 2 O system accelerated the rate of propagation, which led to a higher molecular weight.