N. Tyagi, P. Mathur / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 96 (2012) 759–767
767
of the formation of 2,3-diaminophenazine. The initial rate of reac-
tion decreases and the kinetic data is shown in Tables 4a and 4b
Fig. 11a and b. The order of quenching of the initial rate of reaction
is: acetate ion < azide ion < citrate ion. This order is same for both
of the catalysts. A experiment was conducted to ascertain whether
ꢅ In the reaction the H
2 2
O is consumed so the rate of reaction is
increased as the concentration of H
optimum value.
2 2
O is increased, up to an
addition of different anions to the catalyst [Fe(L)Cl
3
] or [Fe(L)(-
Acknowledgement
NO ] in the absence of the substrate show any changes in the
3 3
)
UV–VIS spectra. It is found that addition of the anion acetate, azide
and citrate cause a shift in the UV band by 5–7 nm, suggesting that
binding of these anions occurs at the iron(III) centre. In the case of
the azide anion, addition causes a new shoulder to appear at
Financial support of the Council of Scientific and Industrial Re-
search (01(2218)08/EMRII) and University of Delhi is gratefully
acknowledged. The authors are grateful to Ravinder Kumar(UGC-
JRF) for helping in preparing the revised manuscript.
4
25 nm confirming the above.
.6. Role of H
The effect of varying the concentration of H
Appendix A. Supplementary data
4
2 2
O
2 2
O on the initial
rate of reaction was also studied. For this the concentration of cat-
alyst (0.15 mM) and o-phenylenediamine (1.5 mM) was kept con-
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[