A Thermodynamic Study of Some Tetracyclines and Their Complexes with lndium(Ill) in Aqueous Medium
| Main Authors: | N. P. SACHAN, K. M. SUYAN, C. P. S. CHANDEL, C. M. GUPTA |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 1983
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/6348855 |
Daftar Isi:
- Thermodynamic parameters of protonated tetracycline, oxytetracycline, chlorotetracycline and dimethylchlorotetracycline and their complexes with In(III) were determined. The changes in ∆H° and ∆S° have indicated that (a) the nature of linkage of the dissociating proton of the tricarbonylmethane system must be somewhat different from that of the phenol-β-diketone system and of the dimethylammonium cation, in solution and (b) the contact of the phenolic oxygen at C11 with metal ion is electrostatic in nature and the ketonic oxygen at Ci, is attached to the metal ion with covalent forces. The reversible half-wave potential of simple In(III) ion, which can not be measured directly owing to the irreversible nature of the reduction, was calculated as —500.2\(±\)0.2, —491.7\(±\)0.2 and —483.4\(±\)0.3 mV vs SCE at 20, 30 and 40°, respectively.