Date of Award
Doctor of Philosophy (PhD)
A family of new chiral C2 symmetric amido-oxazolinate ligands with three different linkers has been synthesized and the respective bimetallic zinc complexes were generated with two equiv. of Zn[N(SiMe3)2]2, a while bischelating zinc complex was synthesized with one equiv. Zn[N(SiMe3)2]2. The bimetallic catalyst with m-phenylenediamine linker afforded poly(cyclohexene carbonate) (PCHC) formation with 78% carbonate linkages, while the catalyst with 1,8-diaminoanthracene linker generated isotactic PCHC with 86% m-centered tetrads.
A monometallic version of the amido-oxazolinate zinc complexes were also used to catalyze ring-opening copolymerization (ROCOP) of styrene oxide (SO) or cyclohexene oxide (CHO) with different anhydrides. Type of substituents on the ligand frame work was observed to influence the catalytic activity of the reaction. These complexes were observed to be viable initiators for ROCOP of epoxides and anhydrides.
A manganese(V) salen complex was used as an effective pre-catalyst in hydrosilylation of aldehydes and ketones, dehydrogenative coupling of hydroxyl groups with hydrosilanes, condensation of diols and dicarbonyls with hydrosilanes to synthesize poly(silylethers). The catalyst was active in all cases and a range of functional groups, such as chloro, nitro, methoxy, carbonyl, and carbon-carbon multiple bonds were tolerated in these reactions. Mechanistic studies suggest that the reaction likely proceeds through a reduced manganese(III) hydride species that undergoes electrophilic attack by the substrates.
In addition, inexpensive, easy-to-make, readily available metal complexes were used for the epoxidation of sucrose soyate (SS) using environment benign, non-toxic oxidants like H2O2, and molecular oxygen. Methyltrioxorhenium (MTO) was proved to be an effective biphasic catalyst to afford 100% epoxide content with complete conversion using H2O2 and 2-methyl THF. Further details regarding the activity of iron, manganese, and molybdenum complexes were also discussed.
Chidara, Vamshi Krishna, "Synthesis And Exploration Of Catalytic Activity Of Amidooxazolinate Zinc Complexes And A Manganese Salen Complex" (2016). Theses and Dissertations. 2003.