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Manganese(II) and (III) complexes of potentially bidentate and tridentate Schiff base ligands have been prepared. The ligands were prepared from substituted salicylaldehyde or pyridine-2-carboxaldehyde and amines with hydrocarbon or alkylpyridyl substituents. The electrochemistry and the oxygenation kinetics of these and similar tetradentate, pentadentate, and hexadentate complexes have been studied. The electrochemistry of the majority of the complexes involves the Mn(III)/Mn(II) couple. However, varying the solvent shows that electron transfer is often accompanied by slow changes in the number of solvent molecules coordinated to the metal or changes in the actual denticity of the ligand. Activation energies and entropies for the reactions with 0₂ show that a large number of parameters influence the rate of reaction. Primary among these is competition between 0₂, solvent molecules, and donor atoms from the ligands for coordination sites on the metal. However, the reactions were all (with one exception) found to be first order in both complex and 0₂, implying that the slow step is formation of a Mn(III)-superoxo complex. The exception was with complexes of the tetradentate Mn(SALC_n) type, where a simple rate law could not be fitted. This was explained by either steric hindrance or polymerization of the complex due to the flexibility imparted by the long polymethylene chain in the tetradentate ligand. / Ph. D.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 1975 / Vita. / Includes bibliographical references. / Ph. D. / Ph. D. Massachusetts Institute of Technology, Department of Materials Science and Engineering

Call number: LD2668 .T4 1985 J665 / Master of Science

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

The organic linker 1,2,4,5-benzenetetracarboxylic acid (BTC) has been widely used in the construction of lanthanide metal-organic frameworks (MOFs) due the high symmetry and versatile nature of its structure. Under identical hydrothermal reaction conditions, it was discovered that lanthanide BTC MOFs will form one of four unique structures based on its location in the series (La-Sm, Eu-Tb, Dy-Tm, Yb-Lu). This is uncommon in LOF materials, as in many cases the same compound can be produced for all of the lanthanides or two different structures may be observed for the first and second half of the series. Descriptions and comparisons of these structures as discussed herein, noticeably the decrease in coordination number and the lanthanide-oxygen bond lengths as the lanthanide atomic number increases. This thesis also attempts to use these compounds to catalyze a model mixed-aldol reaction. Two closely related BTC compounds from yttrium and uranium are also presented. The structure of the yttrium BTC MOFs was identical to that of the Eu, Gd and Tb compounds. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection