The highly preorganized ligands 8-(2-Pyridyl) Quinoline, 2,2'-dipyridyl amine and 1,10-phenanthroline-2, 9-dicarboxylic acid, and their complexing properties with metal ions
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- Charles Richard Gaver (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
- Advisor
- Robert Hancock
Abstract: Highly preorganized ligands are those that are constrained as the free ligands to
be in the conformation required to complex the target metal ion. Such ligands have been
shown to form more stable complexes, and display higher metal ion selectivity than less
preorganized analogs. These ligands have become of particular interest in a variety of
different areas, including biomedical, environmental, nuclear and industrial applications.
The preorganized ligands 8-(2-pyridyl)Quinoline (8PQ), 2,2’-dipyridyl amine (DIPY),
and 1,10-phenanthroline-2, 9-dicarboxylic acid (PDA) and their complexing properties
with metal ions are explored in this project.
The interest in 8PQ and DIPY is that they form six-membered chelate rings on
complex-formation. Following rules on ligand design1 , ligands that form six-membered
chelate rings should show selectivity for smaller metal ions as compared to analogs such
as 2,2’-bipyridyl that form five-membered chelate rings.Thus, 8PQ and DIPY can be compared in this regard to BIPY, which forms a fivemembered
chelate ring. Titration experiments were carried out on aqueous solutions of
these ligands and metal ions in order to determine their formation constants. UV-Vis
spectrophotometry was used to monitor the equilibria involved in the formation of metalligand
complexes. The log K1 values for the formation of metal-ligand complexes were
determined from UV absorbance data as a function of pH, and are reported in 0.1 M
NaClO4 at 25.0ºC. Formation constants (log K1, in parentheses) for 8PQ with Cd(II)
(2.19), Ca(II) (0), Cu(I) (4.66), Cu(II) (4.37), Ni(II) (3.3), and Zn(II) (3.48); DIPY with
Al(III) (0), Cd(II) (2.67), Co(II) (4.36), Cu(II) (7.34), Ga(III) (0), Ni(II) (6.15), and
Zn(II) (3.52); and PDA with In(III) (19.78) and UO2
2+ (19.78) are reported. The results
are discussed in terms of the role of chelate ring geometry in controlling metal ion
selectivity.
The highly preorganized ligands 8-(2-Pyridyl) Quinoline, 2,2'-dipyridyl amine and 1,10-phenanthroline-2, 9-dicarboxylic acid, and their complexing properties with metal ions
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Created on 1/1/2009
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment of the Requirements for the Degree of Master of Science
- Language: English
- Date: 2009
- Keywords
- Chemistry Organic, Ligands (Biochemistry), Ligands--Synthesis
- Subjects
- Chemistry, Organic
- Ligands (Biochemistry)
- Ligands -- Synthesis