Interstate Crossing-Induced Chemiexcitation Mechanism as the Basis for Imidazopyrazinone Bioluminescence

• Tipo: Artigo em Revista Científica Internacional
• Data: 2016

Autores

da Silva, LP (Autor) FCUP; Magalhaes, CM (Autor) Outra; Joaquim C G E Esteves da Silva (Autor) FCUP

Revista

Título: ChemistrySelect

Vol. 1

Páginas: 3343-3356

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 21 Citações

Scopus - 25 Citações

Outras Informações

ID Authenticus: P-00M-ND4

DOI: 10.1002/slct.201600688

Abstract (EN): Imidazopyrazinone dioxetanone is a central molecule in bioluminescence, as it is the scaffold responsible for light emission in many marine species. Herein, we have theoretically studied the thermolysis of its neutral and anionic forms. Our results allowed us to explain imidazopyrazinone bioluminescence with the Interstate Crossing-Induced Chemiexcitation (ICIC) mechanism, and explain why neutral forms emit light efficiently to the contrary of anionic ones. Both forms decompose via a step-wise-biradical pathway, but the biradical is formed either via an electron transfer (anion) or due to homolytic bond cleavage (neutral species). Absence of electron transfer leads to an entropic trap, a flat region where infinite possibilities for chemiexcitation exist. However, the resulting products can be in either triplet or singlet excited states. The triplet to singlet ratio is determined by the electron spin density distribution, which controls the rates of intersystem crossing.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 14