| Two types of chelating agents were prepared: 5-carbonyl-8-hydroxyquinoline N-oxides and spin-labeled 8-hydroxyquinolines. The formyl, acetyl, and benzoyl N-oxide derivatives were compared to the corresponding 8-hydroxyquinoline derivatives. Two spin-labeled reagents were prepared: compound A, 2-(8-hydroxyquinol-5-yl-N-oxide)-4,4,5,5-tetramethylimidazoline 3-oxide 1-oxyl, and compound B, the corresponding 8-hydroxyquinoline derivative. Two other compounds were prepared and isolated: ;All chelating agents were tested for chelating ability with eight metal ions: Cu(II), Ni(II), Mn(II), Co(II), Pb(II), Zn(II), Fe(III), and Al(III). Two testing procedures were used. The pH range was 6-8.;The carbonyl derivatives were studied by IR, UV, NMR, and TLC. The differences observed between the 5-carbonyl-8-hydroxyquinoline N-oxides and the corresponding 8-hydroxyquinoline derivatives were primarily the result of hydrogen bonding. In the N-oxides, a strong intra-molecular chelation-type hydrogen bond is formed between the phenolic hydrogen and the N-oxide oxygen. Both intra- and inter-molecular hydrogen bonds are formed in the 8-hydroxyquinolines. In addition, evidence was observed for possible hydrogen bond formation between the carbonyl oxygen and the peri hydrogen. The spectra--NMR, UV, and IR--of 8-hydroxyquinoline, 8-hydroxyquinoline N-oxide, and their carbonyl derivatives are shown in the thesis.;The radicals were studied by IR, UV-VIS, ESR, and TLC. Separation and purification of the radicals were done by chromatographic methods. Flash chromatography employing silica gel and eluant mixtures of methanol and chloroform was used to isolate and purify compound A. However, the characteristic tailing of 8-hydroxyquinoline compounds on silica gel hindered the separation, and compound B was not isolated. In the chelation testing, both compounds A and B reacted with Cu(II) and Fe(III). The reaction products were not isolated. Linear absorbance-concentration curves were observed in both ESR and UV-VIS. The isolated dihydroxylamine radical precursors were studied by IR and NMR. Spectra for IR, NMR, ESR, and UV-VIS are shown in the thesis. |
