Kinetics of copper(II) catalyzed oxidation of iodide by iron(III) orthophenanthroline complex in aqueous solution.
Orthophenanthroline (OPT) forms stable complex with Iron(II) at pH 3.5. In presence of Ce(IV) it forms a metal-ligand complex in which Fe is in the form of Fe(+++) for short period when mixed in mole ratio of 1:3 (Iron: OPT). This complex is stable for not more than 30 minutes. At the end, this complex reduces itself back to iron(II)orthophenanthroline [Fe(OPT)3](+2) complex. In present work, this property of iron(III) complex was used to oxidize I(-1) to I2. Analysis of [Fe(OPT)3](+2) was carried out at 510 nm to monitor the reduction of [Fe(OPT)3](+3) complex. Copper was used as a catalyst during the described reaction to convert back [Fe(OPT)3](+2). The reaction increased with increase in copper concentration. The conversion of [Fe(OPT)3](+3) to [Fe(OPT)3](+2) followed first order kinetics.
Ishrat
Qurat Ul Ain
QU
Department of Chemistry, University of Karachi, Karachi-75270.
Iftikhar
Abid
A
D002384:Catalysis; D003300:Copper / Q000494:pharmacology*; D007454:Iodides / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D010618:Phenanthrolines / Q000737:chemistry*; D012996:Solutions
D007454:Iodides; D010618:Phenanthrolines; D012996:Solutions; D003300:Copper; D007501:Iron; C025205:1,10-phenanthroline