Date of Award

12-1-2022

Language

English

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College/School/Department

Department of Chemistry

Content Description

1 online resource (vi, 30 pages) : illustrations (some color)

Dissertation/Thesis Chair

Jeremy I. Feldblyum

Committee Members

Michael T. Yeung

Keywords

alkahest, amine, ethylenediamine, mercaptoethanol, thiol, Amine oxidase, Ethylenediamine, Mercaptoethylguanidine, Thiols, Thin films, Solvents

Subject Categories

Chemistry | Materials Science and Engineering

Abstract

Since its introduction, the amine-thiol cosolvent system has been successfully utilized for the deposition of various thin-film devices, but its mechanism of action is still uncertain. Herein, we have attempted to dissect some of the chemical characteristics of amine-thiol cosolvents, with a special interest taken towards a mixture of ethylenediamine (en) and mercaptoethanol (ME). Conductivity was measured for multiple amine-thiol combinations at different ratios to determine extent of ionization in solution, with en-ME having one of the highest solution conductivities. Exposing the solution to air for several days was found to decrease the conductivity of en-ME, indicating the formation of disulfides that cannot participate in ionization with amine. Thiols in these cosolvents appear to be especially vulnerable to aerobic oxidation due to the presence of basic amines. Transition metals can act as catalysts in this system, and their dissolution further increases rate of oxidation. Metal-alkahest complexes may participate in a metal-to-ligand charge transfer with dioxygen, which is reversed upon the consumption of dioxygen by thiol. The distinct chromatic behavior observed in solutions of Mn, Fe, and Co dissolved in en-ME gives further credence to this theory

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