Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes

Detalhes bibliográficos
Ano de defesa: 2024
Autor(a) principal: Melo, Diêgo Ulysses de
Orientador(a): Bartoloni, Fernando Heering
Banca de defesa: Não Informado pela instituição
Tipo de documento: Tese
Tipo de acesso: Acesso aberto
Idioma: eng
Instituição de defesa: Universidade Federal do ABC
Programa de Pós-Graduação: Programa de Pós-Graduação em Ciência e Tecnologia/Química
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Link de acesso: http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=128673&midiaext=82016
Resumo: Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior
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spelling info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisCombined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes2024-11-14Bartoloni, Fernando HeeringMelo, Diêgo Ulysses deUniversidade Federal do ABCPrograma de Pós-Graduação em Ciência e Tecnologia/QuímicaUFABCengCINÉTICAPERTEORIA DO FUNCIONAL DA DENSIDADEINTERMEDIFOTOQUKINETICSCYCLIC PEROXIDEHIGH-ENERGY INTERMEDIATEPHOTOCHEMISTRYDENSITY FUNCTIONAL THEORYPROGRAMA DE PCoordenação de Aperfeiçoamento de Pessoal de Nivel SuperiorChemical processes and reactions are often characterized by the macroscopic changes and effects they produce. Chemiluminescence (CL) is typically described as the cold light emitted from specific exothermic reactions, while bioluminescence (BL) refers to these phenomena occurring within living organisms. By applying scientific tools and methodologies, researchers can provide a molecular interpretation of these processes, describing mechanistic pathways, transition state structures, and thermodynamic changes, among others. In this work, we first provide a brief introduction to basic concepts in the relationship between light and matter in Chapter 1. We then present our findings on the molecular interpretation of two CL systems, combining experimental and theoretical data. Chapter 2 investigates the CL reaction of eight different 2-(4-hydroxyphenyl)-4,5-dihydrothiazole-4-carboxylate esters in the presence of na organic superbase and oxygen, employing both kinetic and computational analyses. These esters are structural analogs of the luciferin substrate involved in the efficient firefly BL. Kinetic data from CL emission and light absorption assays were analyzed through linear free energy relationships (LFER), yielding a Hammett reaction constant of ?? = +1.62 ± 0.09 and a Brønsted constant of ?????? = -0.39 ± 0.04. These LFER findings, along with activation parameters derived from Arrhenius plots, suggest that the high-energy intermediate (HEI) 1,2-dioxetanone is generated via a concerted mechanism during the rate-determining step. Additionally, density functional theory (DFT) calculations indicate a late transition state for HEI formation, with the reaction pathway characterized by geometric parameters, Wiberg bond indices from natural bond order analysis, and atomic charges obtained from electrostatic potential evaluations. Chapter 3 then discusses the effect of the position of the -O? group in the chemiexcitation efficiency of three isomeric silylperoxides derived from lophines. The experimentally determined singlet excited state formation quantum yield (???) of the ortho-O? derivative is 100 and 10 times higher than ??? for the meta- and para- ones. By using DFT and time-dependent DFT calculations to address spin states, intrinsic reaction coordinates, and changes in electrostatic charges, for ground and excited states (singlet and triplet), we propose late electron transfer chemiexcitation (LETC) as a novel CL mechanism to rationalize these ??? values. LETC involves the intramolecular electron transfer from the imidazolyl anion moiety to the biradical species initially generated from the homolytic O-O bond cleavage of the 1,2-dioxetane HEI. When the -O? group of the imidazolyl anion is at the ortho position, a field effect pumps LETC, increasing the generation of singlet states and adequately explaining the observed ??? values. Therefore, our combined experimental-theoretical approach to describe CL systems provides significant molecular insights into the findings presented in this work, advancing the current understanding of CL and BL systems.http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=128673&midiaext=82016application/pdfreponame:Repositório Institucional da UFABCinstname:Universidade Federal do ABC (UFABC)instacron:UFABCinfo:eu-repo/semantics/openAccess2026-01-15T22:16:18Zoai:BDTD:128673Repositório InstitucionalPUBhttp://www.biblioteca.ufabc.edu.br/oai/oai.phpopendoar:2025-11-07T10:08:54Repositório Institucional da UFABC - Universidade Federal do ABC (UFABC)false
dc.title.pt.fl_str_mv Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
title Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
spellingShingle Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
Melo, Diêgo Ulysses de
title_short Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
title_full Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
title_fullStr Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
title_full_unstemmed Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
title_sort Combined experimental-theoretical approach for the elucidation of mechanisms in chemiluminescence : 1,2-dioxetanone formation with luciferin-like analogs and intramolecular electron transfer during chemiexcitation with in situ generated 1,2-dioxetanes
author Melo, Diêgo Ulysses de
author_facet Melo, Diêgo Ulysses de
author_role author
dc.contributor.advisor1.fl_str_mv Bartoloni, Fernando Heering
dc.contributor.author.fl_str_mv Melo, Diêgo Ulysses de
contributor_str_mv Bartoloni, Fernando Heering
description Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior
publishDate 2024
dc.date.issued.fl_str_mv 2024-11-14
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=128673&midiaext=82016
url http://biblioteca.ufabc.edu.br/index.php?codigo_sophia=128673&midiaext=82016
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universidade Federal do ABC
dc.publisher.program.fl_str_mv Programa de Pós-Graduação em Ciência e Tecnologia/Química
dc.publisher.initials.fl_str_mv UFABC
publisher.none.fl_str_mv Universidade Federal do ABC
dc.source.none.fl_str_mv reponame:Repositório Institucional da UFABC
instname:Universidade Federal do ABC (UFABC)
instacron:UFABC
instname_str Universidade Federal do ABC (UFABC)
instacron_str UFABC
institution UFABC
reponame_str Repositório Institucional da UFABC
collection Repositório Institucional da UFABC
repository.name.fl_str_mv Repositório Institucional da UFABC - Universidade Federal do ABC (UFABC)
repository.mail.fl_str_mv
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