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Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.19 [2012] >
IJCT Vol.19(4) [July 2012] >
| Title: | Silver(I)-catalysed abstraction of coordinated cyanide in hexacyanoferrate(II) by D-penicillamine in aqueous medium |
| Authors: | Naik, R M
Tiwari, R K
Yadav, S B S
Kumar, B
Asthana, A |
| Keywords: | D-penicillamine
Hexacyanoferrate(II)
Kinetics
Spectrophotometry |
| Issue Date: | Jul-2012 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | The kinetics and mechanism of Ag(I)-catalyzed exchange
of coordinated cyanide in hexacyanoferrate(II) by
D-penicillamine (D-PA) have been monitored by
following the appearance of blue colored complex [Fe(CN)5(D-PA)]3-at
423 nm, corresponding to metal to ligand charge transfer
(MLCT) transition. The effect of pH, ionic strength, catalyst
concentration and concentration of hexacyanoferrate(II) and D-penicillamine on
the rate of reaction has also studied and explained. The findings indicate
first order dependence each in [Fe(CN)6]4- and [D-PA].
The composition of the complex formed has been established to be 1:1 by mole
ratio and slope ratio method. The kinetic observations suggest that the
substitution follows an interchange dissociative (Id) mechanism
which proceeds via formation of
a solvent bound intermediate. The activation parameters ΔH# and ΔS#
have also been calculated and provided in support of the proposed
mechanistic scheme. It is observed first time that
the drug D-penicillamine used acts as a potential ligand and it can replace the
coordinated cyanide in hexacyanoferrate(II). |
| Page(s): | 250-256 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-0991 (Online); 0971-457X (Print) |
| Source: | IJCT Vol.19(4) [July 2012]
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