First Advisor
Theresa McCormick
Date of Award
Spring 6-13-2025
Document Type
Thesis
Degree Name
Bachelor of Science (B.S.) in Biochemistry and University Honors
Department
Chemistry
Language
English
Subjects
Photochemistry, Organo Metallic Chemistry, Synthesis, Novel Dye, Characterization, Tellurium
Abstract
Renewable energy, such as solar fuel, is a focus in chemistry due to a need to limit greenhouse gas emissions. Visible light absorbing organic dyes are key to realizing solar energy goals, because they facilitate the conversion of solar energy to high energy chemical bonds. A challenge to this is capturing the full solar spectrum. To capture as much sunlight as possible a dye must have a smaller excitation energy (red-shifted) to capture more radiation from the sun. This project studied how modifications to tellurium containing rhodamine dyes can better capture the visible light spectrum of the sun. Additionally, modifications to the core structure of the dye allows for better understanding of the effect of electron withdrawing groups on photophysical characteristics of this dye class. We synthesized Tellurorhodamine Thiophene-Carboxy (Te-TC) and characterized it using 1H-NMR, 13C-NMR, UV-Vis and Mass Spectroscopy. UV-Vis spectroscopy found peak absorption 611 nm, far red-shifted compared to mesityl substituted dye. However, irradiation in MeOH found that the compound adopts a spiro-lactone form, Te-TC-SL, causing a loss of aromaticity and color. This was supported by analysis of both the 1H-NMR and 13C-NMRs through the observation of extra peaks in both spectra. Creation of Te-TC-SL prevents oxidation to a Te(IV) structure that is observed for other dyes of this class and prevents it from working as an oxidation catalyst. Future work aims to alter the carboxylic acid to prevent spiro-lactone formation to allow us to study the oxidation chemistry of electron withdrawing substituents on tellurorhodamine dyes.
Recommended Citation
McWilliams, Timothy RT Jr., "Synthesis and Characterization of a Novel Tellurorhodamine Dye" (2025). University Honors Theses. Paper 1734.