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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Thermodynamics of the partition of oxine and its Ni(II) and Fe(III) chelates

Lipschitz, Irving January 1965 (has links)
The effects of temperature on the first and second acid dissociation constants of 8-hydroquinoline (oxine) have been measured and the following thermodynamic values assigned to solutions of 0.1M strength. For the process, H₂Ox⁺ ⇋ H⁺ + HOx at 25°C., pK₁ = 5.103, ΔH = 5.7 kcal/mole, and ΔS° = -4 e.u. For the second acid dissociation constant, HOx ⇋ H⁺ + Ox⁻ at 25°C., pK₂ = 9.76, ΔH = 6.3 kcal/mole, and ΔS° = -23 e.u. The values for the second acid dissociation constant agree with those previously published. The values for the first dissociation constant have not been previously determined but are consistent with the result expected for reactions of this charge and chemical type. The partition of 8-hydroxyquinoline was determined as a function of temperature for the following systems: water-benzene, water-nitrobenzene, water-toluene, and water-chloroform. The pertinent thermodynamic values for the partitions are as follows: a. Water-benzene: log P = 2.44; ΔH = -2.0 kcal/mole; ΔS° = 4.5 e.u. b. Water-nitrobenzene: log P = 2.67; ΔH = -1.7 kcal/mole; ΔS° = 6.6 e.u. c. Water-toluene: log P = 2.33; ΔH = -1.3 kcal/mole; ΔS° = 6.2 e.u. d. Water-chloroform log P = 2.703 ΔH = -2.5 kcal/mole; ΔS° = 3.9 e.u. The values obtained for the water-chloroform system agree well with tho literature and serve as a check on the rest of the data. The effect of temperature on the overall extraction constant of nickel oxinate and ferric oxinate was measured for the system water-chloroform. The thermodynamic values found for the process Me⁺ⁿ + nHOx ⇌ MeOx<sub>n</sub> + nH⁺ are the following at 25°C. and an ionic strength of 0.1M: a. Nickel oxinate log Kₑ = -2.73; ΔH = -40.4 kcal/mole; ΔS° = -148 e.u. b. Ferric oxinate log Kₑ = -3.97; ΔH = -14.1 kcal/mole; ΔS° = -29 e.u. The effect of ionic strength on the partition of S-hydroxyquinoline between water and benzene was determined for four different uni-univalent salts: potassium chloride, sodium chloride, potassium nitrate and sodium perchlorate. The “salting out” of oxine observed is typical of non-electrolytes. / Doctor of Philosophy

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