ORCID Identifier(s)

0000-0001-5739-2111

Graduation Semester and Year

2020

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Chemistry

Department

Chemistry and Biochemistry

First Advisor

Rasika Dias

Abstract

Trinuclear copper pyrazolate complexes (copper trimers) function as excellent precursors to synthesize multinuclear complexes of copper. Using highly fluorinated pyrazolates as supporting ligands, we have successfully synthesized and isolated several unique complexes of copper with alkene (e.g., ethylene), alkynes (e.g., 3-hexyne, butyne, acetylene, etc.) and carbon monoxide from the copper trimers. Synthetic details, solid-state structures, and physico-chemical properties of a series of multinuclear complexes have been studied. Chapter 2 of this research work focuses on the olefin/paraffin separation technology. For this we have succesfully synthesized a novel, highly fluorinated copper pyrazolate complex, that undergoes remarkable structural rearrangement forming a dinuclear species, [(3,4,5-(CF3)3Pz)Cu(H2C=CH2)]2, when exposed to ethylene. We have discussed in detail the benefit of this transformation, and how it can be efficiently used for separation of olefins from a mixture of gases. Chapter 3 covers the synthesis, study of photophysical properties and computational analysis of di- and tetranuclear complexes of copper with internal alkynes. This class of molecules show interesting photoluminescence at different temperatures, and in different solvents. Copper trimer also acts as a powerful catalyst for alkyne transformations as evident from its ability to catalyze the alkyne C(sp)–H bond for carboxylation with CO2, azide-alkyne cycloaddition and hydrothiolation. The reaction intermediates for these catalytic reactions were isolated and investigated in chapter 3. Chapter 4 describes the carbonyl chemistry of multinuclear copper pyrazolates and the effects of additional donors such as chloride, bromide, and [3,5-(CF3)2Pz]− ions on the stability of the resulting copper(I) carbonyl adducts. Accordingly, {[3,5-(CF3)2Pz]Cu(CO)}2, {[4-Cl-3,5-(CF3)2Pz]Cu(CO)}2, {[3,4,5-(CF3)3Pz]Cu(CO)}2, [NEt4][{[3,5-(CF3)2Pz]Cu(CO)}4(μ4-Br)], [NEt4]{[3,5-(CF3)2Pz]3Cu2(CO)2}, [NEt4][{[4-Cl-3,5-(CF3)2Pz]Cu(CO)}4(μ4-Br)], [NEt4][{[4-Cl-3,5-(CF3)2Pz]Cu(CO)}4(μ4-Cl)] and [{[4-Cl-3,5-(CF3)2Pz]Cu(CO)}2(μ2-CH3CN)] were synthesized and characterized. Theoretical calculations were also performed to study the bonding energy of the synthesized complexes.

Keywords

Coordination Chemistry, Ligands, Pyrazole, Copper, Copper-pyrazolates, Synthesis, Olefin/Paraffin separation, Ethylene, Acetylene, Alkynes, Carbon monoxide, Catalysis, Luminescence, Structure and Bonding, Chemisorption, Adsorption Isotherms, Enthalpy, Variable Temperature NMR

Disciplines

Chemistry | Physical Sciences and Mathematics

Comments

Degree granted by The University of Texas at Arlington

Included in

Chemistry Commons

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