Document Type
Dissertation
Date of Award
2024
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
First Advisor
James D JH Hoefelmeyer
Abstract
This dissertation describes two distinct projects: 1) hollow Mn3O4 nanoparticles for selective oxidation of alkenes with O2, and 2) investigation of chloro[2-(mesityl(quinoline-8-yl-κN)boryl]-3,5-dimethyl-phenyl}methyl-κC)palladium(II) for activation of C-F bonds in aryl fluorides. Hollow Mn3O4 nanoparticles were synthesized from the galvanic reaction between Cu2+ and MnO nanocrystals. The hollow Mn3O4 particles were characterized with transmission electron microscopy and powder X-ray diffraction. The particles have diameter of 31 nm and a hollow cavity of 16 nm. We investigated the role of the hollow Mn3O4 nanoparticles in the selective oxidation of organic substrates with molecular oxygen. The results indicate that the hollow Mn3O4 nanoparticles catalyze the oxidation of cyclohexene in the presence of O2 and found major oxidation products, namely cyclohexene-oxide, 2-cyclohexene-1-o1, and 2-cyclohexene-1-one, 7-oxabicyclo [4.1.0]-heptan-2-one. However, other substrates (toluene, stilbene, styrene, 1-octanol) did not undergo oxidation under similar reaction conditions. The observations of allylic and olefinic oxidations suggested a possible reaction mechanism based on known pathways: allylic oxidation proceed through a radical pathway in which reactive oxygen species attack the allylic C-H bond and epoxidation occurs by the direct oxidation of cyclohexene on the olefinic C=C bond. Hollow Mn3O4 catalysts exhibit higher conversion for cyclohexene oxidation through allylic oxidation particularly 2-cylohexne-1-one (45%) as the main product under 60°C for 8 h in acetonitrile. Reactivity of chloro[2-(mesityl(quinoline-8-yl-κN)boryl]-3,5-dimethyl-phenyl}methyl-κC)palladium(II) toward aryl fluorides was investigated. Hydrodefluorination of arylfluorides and Suzuki type cross-coupling of arylfluorides with phenylboronic acid were investigated. Hydrodefluorination was found only with extremely electron-poor arenes, hexafluorobenzene or p-nitrofluorobenzene. No cross-coupling of arylfluorides with phenylboronic acid was observed. As an offshoot to this study, we report a series of coordination complexes featuring bidentate κN,κI-8-iodoquinoline with metals (M = Cu+, Cu2+, Ag+, Pd2+ and Hg2+) and a Cu2+ complex with 6,6′-dibromo-2,2′-dipyridyl.
Subject Categories
Chemistry
Keywords
Materials Chemistry
Number of Pages
137
Publisher
University of South Dakota
Recommended Citation
Kumar Nandy, Pranab, "Activation of molecular oxygen for the selective oxidation of alkenes catalyzed by hollow Mn3O4 nanoparticles" (2024). Dissertations and Theses. 260.
https://red.library.usd.edu/diss-thesis/260