Author

Sy-Wen Wong

Publication Date

1983

Document Type

Dissertation/Thesis

First Advisor

Schilt, Alfred Ayars, 1927-

Degree Name

M.S. (Master of Science)

Department

Department of Chemistry

LCSH

Organonitrogen compounds||Organoiron compounds||Complex compounds

Abstract

The acid dissociations constants of 2,4,6-tris(2-pyridyl)- 1,3,5-triazine, TPTZ, and 2,6-bis(2-pyridyl)-pyridine, terpy, were reevaluated using successive approximations to match calculated with experimental curves of absorbance vs. pH. The results are pKa₁=2.10 and pKa₂=3.40 for TPTZ, and pKa₁=3.60 and pKa₂=4.62 for terpy. The formation constants of the bis-complexes of TPTZ with iron(II) and of terpy with iron(II) were redetermined based on the above pKa's. The results are log K[sub f]=11.00 with a standard derivation of 0.04 for Fe(TPTZ)₂⁺² and log K[sub f]=21.00 with a standard derivation of 0.24 for Fe(terpy)₂⁺². For the ternary complex, Fe(TPTZ)(terpy)⁺², four different approaches were explored to determine the equilibrium constants, but only one proved successful. A value of 0.394 with a standard derivation of 0.06 was obtained for the mixing constant, K[sub M], determined photometrically by the method of continuous variations applied to mixtures of the binary complexes. The other ternary constants, K[sub f] K(+B-A)₁₁, K(+A-B)₁₁, and K[sub S], were calculated from K[sub M] and the formation constants of the binary complexes. The results indicate that formation of the mixed ligand complex involves a small loss in stabilization energy, due perhaps to some interaction between the dissimilar ligands or to a loss in solvation energy.

Comments

Bibliography: pages 57-58.

Extent

viii, 58 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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