<mods:mods xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-7.xsd"><mods:titleInfo><mods:title>Exogenous Ligand Assisted Rare-earth Complexes: Catalyst Design, Applications in Ring-Opening Polymerization and Reaction Kinetics</mods:title></mods:titleInfo><mods:typeOfResource authority="primo">dissertations</mods:typeOfResource><mods:name type="personal"><mods:namePart>Dong, Xiang</mods:namePart><mods:role><mods:roleTerm type="text">creator</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Robinson, Jerome</mods:namePart><mods:role><mods:roleTerm type="text">Advisor</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Chen, Ou</mods:namePart><mods:role><mods:roleTerm type="text">Reader</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Zimmt, Matthew</mods:namePart><mods:role><mods:roleTerm type="text">Reader</mods:roleTerm></mods:role></mods:name><mods:name type="corporate"><mods:namePart>Brown University. Department of Chemistry</mods:namePart><mods:role><mods:roleTerm type="text">sponsor</mods:roleTerm></mods:role></mods:name><mods:originInfo><mods:copyrightDate>2022</mods:copyrightDate></mods:originInfo><mods:physicalDescription><mods:extent>xvi, 199 p.</mods:extent><mods:digitalOrigin>born digital</mods:digitalOrigin></mods:physicalDescription><mods:note type="thesis">Thesis (Ph. D.)--Brown University, 2022</mods:note><mods:genre authority="aat">theses</mods:genre><mods:abstract>Complexes of rare-earth elements (REs, Sc, Y, La-Lu) are among the most successful catalysts for ring-opening polymerization (ROP) of lactones. However, there are gaps in synthesizing the polymers with both high efficiency and good steric selectivity. Our studies provided a novel way of constructing RE catalyst and tuning its catalytic performance by introducing exogenous ligands [phosphine oxides or lutidine-oxides (LO)]. We applied this catalytic system on the ROP of rac-β-butyrolactone (rac-BBL), which usually displays relatively low reactivity among lactone monomers and challenges in polymerization with high iso-tacticity (Pm ≥ 0.80) and got unprecedent success in both high reactivity (TOF up to 1,900 /h) and good iso-selectivity (Pm up to 0.82). Furthermore, the critical side reaction were systematically examined that significantly affected distribution of molecular weights of macromolecular product and reaction rate. In the study of raction kinetics, a method of track evolution of active catalytic species was developed and applied to quantatively determine kinetic parameters of the primary propagation and the coupling side reaction. These results may direct further developments of this exogenous ligand assisted RE catalytic system.</mods:abstract><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/01909666"><mods:topic>Homogeneous catalysis</mods:topic></mods:subject><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/00853025"><mods:topic>Chemical kinetics</mods:topic></mods:subject><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/00853488"><mods:topic>Chemistry, Inorganic</mods:topic></mods:subject><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/01790205"><mods:topic>Polymer chemistry</mods:topic></mods:subject><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/01090143"><mods:topic>Rare earth metals</mods:topic></mods:subject><mods:language><mods:languageTerm authority="iso639-2b">English</mods:languageTerm></mods:language><mods:recordInfo><mods:recordContentSource authority="marcorg">RPB</mods:recordContentSource><mods:recordCreationDate encoding="iso8601">20221018</mods:recordCreationDate></mods:recordInfo></mods:mods>