Kinetics and Mechanism of Anation of Hydroxopentaaquochromium(III) Ion by DL-Methionine in Water-Ethanol Medium
| Main Authors: | H. G. MITRA MUSTOFY, G. S. DE |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 1986
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/6275995 |
Daftar Isi:
- Department of Chemistry, University of Burdwan, Burdwan-713 104 Manuscript received 24 March 2986, revised 26 June 1986, accepted 13 November 1986 The kinetics of substitution of aquo-ligands of hydroxopentaaquochromium(III) ion by DL-methionine in water—ethanol medium has been studied spectrophotometriÂcally. The rate law involving the ion-pair formation has been established as \({d[Cr(H_2O)OH)(Methio)_2] \over dt}\)=\({k_aK_E[Cr(H_2O)_5(OH)_{total}^{2+}[Methio.II] \over 1+K_E[Methio.H]}\) where, ka is the anation rate constant, KE is the ion-pair equilibrium constant and \([Cr(H_2O)_5(OH)]_{total}^{2+}\) is the concentration of the total amount of unreacted substrate and [Methio. H] is the concentration of zwitterionic methionine. The reaction rate is higher compared to the rates of water-exchange and other anation reactions of hydroxopentaaquocbromium(III) ion. Activation parameters have been calculated and compared with other substitution reactions of the same complex. Mechanism involving the prior formation of ion-pair followed by associative interchange (Ia) has been suggested.