The  kinetics  of  reduction of tris(1,10erthophenantiroline)iron(III) ion by  two different  reductants  hexacyanoferrate(II) ion and    bis(s-cyclopentadienyl)iron(II) has been spectrophotometrically investigated in studies   median.   Measurements were  recorded  under pseudo-first  order  condition. The  rate  of  electron  transfer between  tris(1,10-orthophenan- throline)iron(III) and each reductants was measured. The rate laws are suggested to be,  rate = k1 [Fe(C5N5)2]       [Fe(o-phen)3]3+ /1 + K[H+] and rate =  k [Fe(C5H5)2] [Fe(o-phen)3]3+ for the reduction   of  tris(1,10-orthophenanthroline)iron(III) ion with hexacyano-ferrate(II) ion and bis(scyclopentadienyl)iron(II) respectively, showing first order  with  respect to  each of  the reactants in the  both cases. It was  found that the rate of reaction with hexacyanoferrate(II) is faster than that of bis(p-syclopentadienyl)iron(II) having the second order rate constant values of 8.33 x 107M-1s-1 and 5 x 106 M-1s-1 respectively.


I I NAQVI ,M A FARRUKH ,