Calculating equilibrium constants from spectral data: Reliability of the Benesi-Hildebrand method and its modifications
✍ Scribed by Otto Exner
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 798 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0169-7439
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✦ Synopsis
Equations for statistical evaluation of complex formation in solution were revised and a simple modification of the correct least-squares procedure was advanced. The main difference against the previous treatment is in the uncertainty of the estimated parameters: the equilibrium constant K and extinction coefficient of the complex E. This uncertainty is always greater, often by an order of magnitude, than that given in the literature using various methods and programs. On a couple of examples, the new method was compared with the previous ones, also with most commonly used procedure of Benesi-Hildebrand. According to the quality of data, particularly the concentration range and the number of measurements, one can distinguish cases when Benesi-Hildebrand method yields reasonable results and when it is unreliable: in no case it gives any idea about the uncertainty. Many K values determined in this way should be better removed from the literature. 0 1997 Elsevier Science B.V.