Murray State Theses and Dissertations

Abstract

Mechanochemical synthesis is a rapidly developing, more environmentally friendly alternative to traditional solution based syntheses. Mechanochemical methods often result in higher overall yields, minimize undesirable side reactions, and present cleaner more concise methods for compound preparation. This work will address the syntheses of three dialkyl 2,2′-bipyridyl-4,4′-dicarboxylate complexes of palladium(II) iodide and the kinetics of these reactions. Then, this work will address the improved synthesis and purification of 1,3-dimethyl-1H-benzimidazolium iodide and the synthesis of diiodo-bis(1,3-dimethyl benzimidazol-2-ylidene) palladium(II).

The successful synthesis of dialkyl 2,2′-bipyridyl-4,4′-dicarboxylate complexes of palladium(II) iodide was carried out under solvent free ball milling conditions and the kinetic analysis was carried out utilizing 1H NMR spectroscopy. The kinetics of these reactions were analysed by comparison to several mathematical models. These reactions were found to fit the nonlinear form of the Johnson-Mehl-Avrami-Yerofeev-Kolmogrov (JMAYK) equation and demonstrated pre-existing nucleation sites and discernible dimensionality of crystal growthThe JMAYK model gave coefficients of determination between 0.9702-0.9880, 0.9681-0.9811, and 0.9739-0.9825 for diiodo di-2-decyl 2,2′-bipyridyl-4,4′-dicarboxyl palladium(II) , diiodo di-2-hexadecyl 2,2′-bipyridyl-4,4′-dicarboxyl palladium(II), and diiodo dihexadecyl 2,2′-bipyridyl-4,4′-dicarboxyl palladium(II) respectively.

Finally, the mechanochemical synthesis of diiodo-bis(1,3-dimethyl benzimidazol-2-ylidene) palladium(II) began to be analysed under similar ball milling conditions as the bipyridyl complexes. This synthesis began with synthesis and purification of the ligand precursor, 1,3-dimethyl-1H-benzimidazolium iodide. It was found that given the correct reaction conditions, this material could be synthesized at room temperature without mechanical energy input and via ball milling reactions.

Year manuscript completed

2017

Year degree awarded

2017

Author's Keywords

mechanochemistry, ball milling, solid state kinetics

Degree Awarded

Master of Science

Department

Chemistry

College/School

Jesse D. Jones College of Science, Engineering and Technology

Thesis Advisor

Rachel J. Allenbaugh

Committee Member

Harry Fannin

Committee Member

Kevin Miller

Committee Member

Rachel Whittaker

Document Type

Thesis

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