02326nas a2200241   4500008004100000022001400041245018300055210006900238260007300307300001200380490000800392520131100400653001801711653002901729653005701758653003301815653002301848100002301871700001701894700001901911700002801930856012601958       2005                        eng d  a1381-116900aBis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II) anchored onto chloromethylated polystyrene for the biomimetic oxidative coupling of 2-aminophenol to 2-aminophenoxazine-3-one0 aBis2alphahydroxyethylbenzimidazolatocopperII anchored onto chlor  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a132-1380 v2363 a<p>2-(alpha-Hydroxyethyl)benzimidazole (Hhebmz) has been covalently anchored to chloromethylated polystyrene cross-linked with 5% divinylbenzene. This polymer-anchored chelating resin reacts with cupric acetate in presence of Hhebmz to give polymer-anchored copper(II) complex PS-[Cu(hebmz)(2)]. Elemental analyses, FT-IR, electronic, scanning electron micrographs (SEM) and TGA-DTA pattern have been used to characterize the complex. Oxidative coupling of 2-aminophenol (OAP) to 2-aminophenoxazine-3-one (APX) catalyzed by PS-[Cu(hebmz)(2)] in presence of air at 70 degrees C in DMF gave 62% substrate conversion over a period of 8 h. Kinetics of the above reaction indicated that the rate of oxidative coupling of OAP has a first order dependence with respect to substrate, catalyst and air pressure (dissolved O-2) concentrations in the range of conditions evaluated. Based on these observations, a plausible mechanism for the above reaction has been proposed. From, the study on the effect of temperature on the rates of oxidative coupling, an activation energy 34.2 kcal/degree mole was evaluated from Arrhenius plot of -ln rate versus 1/T. Enthalpy, entropy and free energy were calculated using standard thermodynamic equations for the above reaction. (c) 2005 Elsevier B.V. All rights reserved.</p>10a2-aminophenol10a2-aminophenoxazine-3-one10abis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II)10achloromethylated polystyrene10aoxidative coupling1 aMaurya, Mannar, R.1 aSikarwar, S.1 aJoseph, Trissa1 aHalligudi, Shivappa, B.  uhttps://library.ncl.res.in/content/bis2-alpha-hydroxyethylbenzimidazolatocopperii-anchored-chloromethylated-polystyrene-1