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| DC Field | Value | Language |
|---|---|---|
| dc.contributor.author | Rounaghi, G | - |
| dc.contributor.author | Milani-Nejad, F. | - |
| dc.contributor.author | Taheri, K | - |
| dc.date.accessioned | 2013-01-18T17:04:36Z | - |
| dc.date.available | 2013-01-18T17:04:36Z | - |
| dc.date.issued | 1999-06 | - |
| dc.identifier.uri | http://hdl.handle.net/123456789/15768 | - |
| dc.description | 568-574 | en_US |
| dc.description.abstract | The formation constant of 1:1 complexes of 18-crown-6 (18C6) with potassium ion in dimethylformamide (DMF)-methanol (MeOH), DMF-nitrobenzene (NB), DMF- benzonitrile (BN) binary solvents and dibenzo-24-crown-8 (DB24C8) with potassium ion in DMF-MeOH binary mixtures have been determined conductometrically at different temperatures. The values of thermodynamic parameters (∆ H°C and (∆ S°C) for complexion reactions have been determined from temperature dependence of formation constants. In all cases, the complexes are enthalpy stabilized but with very few exceptions entropy destabilized and the results show that both parameters are very sensitive to solvent composition. The origins of the enthalpies and entropies of the complexation are discussed in terms of the solvent composition and the structural features of the ligand. The stability of complexes is strongly affected by the nature of solvent and solvent composition. The stability constants of complexes increase with increase in the concentration of solvent with lower donocity (smaller Gutman Donor Number) in binary mixtures. In addition, it has been found that the variation of stability constant (log K°f) of 18C6- K+ complex versus the solvent composition is linear in DMF-BN and DMF-NB binary mixtures, but a nonlinear behaviour is observed for 18C6-K+ and of DB24C6-K+ complexes in DMF-MeOH binary systems. | en_US |
| dc.language.iso | en_US | en_US |
| dc.publisher | NISCAIR-CSIR, India | en_US |
| dc.rights |  CC Attribution-Noncommercial-No Derivative Works 2.5 India | en_US |
| dc.source | IJC-A Vol.38A(06) [June 1999] | en_US |
| dc.title | Thermodynamic studies of the complexation of 18-crown-6 and dibenzo-24- crown-8 with potassium ion in mixed non-aqueous solvents | en_US |
| dc.type | Article | en_US |
| Appears in Collections: | IJC-A Vol.38A(06) [June 1999] | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| IJCA 38A(6) 568-574.pdf | 1.3 MB | Adobe PDF | View/Open |
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