자료유형  

 학위논문

Control Number  

0017162157

International Standard Book Number  

9798384024958

Dewey Decimal Classification Number  

540

Main Entry-Personal Name  

Furigay, Maxwell Hyland.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Pennsylvania., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

290 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-02, Section: B.

General Note  

Advisor: Schelter, Eric J.;Dmochowski, Ivan J.

Dissertation Note  

Thesis (Ph.D.)--University of Pennsylvania, 2024.

Summary, Etc.  

요약Metal-ligand cooperativity provides avenues for altering the electronic structure, reactivity, and spectroscopic properties of metal cations. In the context of separations chemistry, metal-ligand cooperativity may allow for differential reactivity and separation of otherwise similarly behaving metal cations, such as niobium (Nb) and tantalum (Ta). Niobium and tantalum are always found together in their naturally-occurring ores and require separation before use. Current industrial processes use hydrofluoric acid (HF) in the solvent extraction separation process, a hazardous and toxic reagent. Through tailored ligand design and characterization of novel, isostructural Nb/Ta coordination complexes, new methodologies for greener, fluoride-free Nb/Ta separations are expected. In Chapter 2, a set of [Na(CH3CN)3(Et2O)][MV (BINOLate)3] (M = Nb, Ta; BINOL = (S)-(−)-1,1'-bis-(2-naphthol)) aryloxide-complexes are described. Through selective reduction of the [NbV (BINOLate)3]- species, the first redox-based, molecular Nb/Ta separations strategy is reported. In Chapter 3, amidophenoxide-type Nb/Ta coordination complexes in two oxidation states, [Na(DME)3][(MVClamp)] and MVClamp (DME = dimethoxyethane; M = Nb, Ta; Clamp = tris-(2-(3',5'-di-tert-butyl-2'-oxyphenyl)amidophenyl)amine), are described. Their characterization revealed differences in metal-ligand covalency and associated properties, such as redox and photo-excited-state lifetimes. In Chapter 4, two strategies for Nb/Ta pentachloride differentiation are described. An electrochemical separation strategy employs the mild reductant, ferrocene, to selectively reduce monomeric NbVCl5(CH3CN)in acetonitrile, representing an improvement on the separation described in Chapter 2. A photochemical separation strategy comprises selective excitation of the putative, dimeric species: NbV2Cl10 in toluene, allowing for subsequent selective precipitation of a photoreduced "NbIVCl4" product, representing the first reported light-driven Nb/Ta separation strategy. From the perspective of electronic structure studies, metal-ligand cooperativity also allows for significantly altered ground-state electronic properties of metal cations by mechanisms such as σ-donation from a ligand or π-backbonding to a metal cation. In the context of monovalent silver (Ag+), coordination of the metal center with alkynes allows for metal-ligand covalency and observable π-backbonding to the alkyne moiety. In Chapter 5, the synthesis of a novel tris-alkyne ligand, tris-(2-(trimethylsilyl)ethynyl-4-tert-butyl-benzyl)amine, and associated Ag+ chelating tris-alkyne complex, [Ag-tris-(2-(trimethylsilyl)ethynyl-4-tert-butylbenzyl)amine][PF6], are presented, and the ground state electronic properties and luminescent properties of the complex are described.

Subject Added Entry-Topical Term  

Chemistry.

Subject Added Entry-Topical Term  

Physical chemistry.

Subject Added Entry-Topical Term  

Materials science.

Subject Added Entry-Topical Term  

Organic chemistry.

Index Term-Uncontrolled  

Metal-ligand cooperativity

Index Term-Uncontrolled  

Niobium

Index Term-Uncontrolled  

Tantalum

Index Term-Uncontrolled  

Silver

Index Term-Uncontrolled  

Hydrofluoric acid

Added Entry-Corporate Name  

University of Pennsylvania Chemistry

Host Item Entry  

Dissertations Abstracts International. 86-02B.

Electronic Location and Access  

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Control Number  

joongbu:658553