Oxidative polymerization of 2,6‐dimethylphenol to form poly(2,6‐dimethyl‐1,4‐phenylene oxide) in water through one water‐soluble copper(II) complex of a zwitterionic calix[4]arene

Abstract

In the presence of excess NaOH, reaction of Cu(OAc) 2 ÁH 2 O with equimolar ammonium calix[4]arene [H 4 L]I 4 (1, H 4 L ¼ [5,11,17,23-tetrakis(trimethylammonium)-25,26,27,28tetrahydroxycalix[4]arene]) resulted in the formation of a mononuclear cationic Cu(II) complex [Cu(II)L(H 2 O)]I 2 (2) in 43% yield. Complex 2 was characterized by elemental analysis, infrared (IR), and single crystal X-ray diffraction. The Cu(II) atom in 2 is coordinated by four oxygen atoms of one L 4À ligand and one O atom from one water molecule, forming a square pyramidal geometry. Complex 2 exhibited high catalytic activity in the oxidative polymerization of 2,6-dimethylphenol using O 2 as oxidizing agent in water under mild conditions. The selective polymerization produced poly(2,6-dimethyl-1,4phenylene oxide) in high yields with almost no diphenoquinone. The influence of the polymerization temperature, the time interval, the molar ratio of 2,6-dimethylphenol/2, the concentrations of sodium hydroxide, and sodium n-dodecyl sulfate were examined. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: [4864][4865][4866][4867][4868][4869][4870] 2012

Construction of Four Copper Coordination Polymers Derived from a Tetra-Pyridyl-Functionalized Calix[4]arene: Synthesis, Structural Diversity, and Catalytic Applications in the A3 (Aldehyde, Alkyne, and Amine) Coupling Reaction

“…As a consequence, by tethering particular transition metals on such a structure, the as-synthesized coordination polymers would be potential catalysts. The calix[4]­arene platform provides a peculiar arrangement for the binding/catalytic site in a complementary array to recognize/transform a potential substrate, which would be favorable for the design of versatile catalysts. , Furthermore, owing to the presence of the well-defined cavity near the catalytic center, we envisioned that the calix[4]­arene-based coordination polymers could give high selectivity for the catalytic reaction. , …”

“…The calix [4]arene platform provides a peculiar arrangement for the binding/catalytic site in a complementary array to recognize/transform a potential substrate, which would be favorable for the design of versatile catalysts. 31,32 Furthermore, owing to the presence of the well-defined cavity near the catalytic center, we envisioned that the calix [4] coordination polymers could give high selectivity for the catalytic reaction. 33,34 Nowadays, it is widely acknowledged that microwave irradiation has great advantages over traditional heating because of its shorter reaction time, higher product yield, and lower energy consumption.…”

Immobilized Horseradish Peroxidase (I-HRP) as Biocatalyst for Oxidative Polymerization of 2,6-Dimethylphenol

“…PPO is an important engineering thermoplastic material with outstanding characteristics such as high melting point and good toughness over a wide temperature range and also with self-extinguishing and electrically insulating properties . Many researchers have developed novel catalysts for PPO synthesis via oxidative polymerization. − The use of natural enzymes as catalysts is highly desirable and provides a green methodology for PPO synthesis. − …”

Poly(N-4-vinylbenzyl-1,4,7-triazacyclononane) Copper Complex Grafted Solid Catalyst for Oxidative Polymerization of 2,6-Dimethylphenol

“…The yield and molecular weight of the obtained PPO were 16% and M w = 5100, M w /M n = 1.6, respectively. The molecular weight of the polymer was comparable to the other PPO obtained in water or biphasic solvent system, however, the yield of the polymerization was lower than the other route due to the nature of the heterogeneous conditions with the solid catalyst [12,23]. The obtained PPO was evaluated by thermogravimetric analysis at a heating rate of 10˝C/min under a nitrogen atmosphere to measure the 10% thermal degradation temperature.…”