Wan, Li-Min, Li, Hong-Xi, Zhao, Wei, Ding, Hong-Ye, Fang, Yang-Yang, Ni, Pei-Hong, and Lang, Jian-Ping
In the presence of excess NaOH, reaction of Cu(OAc)2·H2O with equimolar ammonium calix[4]arene [H4L]I4 ( 1, H4L = [5,11,17,23-tetrakis(trimethylammonium)-25,26,27,28-tetrahydroxycalix[4]arene]) resulted in the formation of a mononuclear cationic Cu(II) complex [Cu(II)L(H2O)]I2 ( 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 L4− 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 O2 as oxidizing agent in water under mild conditions. The selective polymerization produced poly(2,6-dimethyl-1,4-phenylene 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. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]