Elucidating the chemiexcitation of dioxetanones by replacing the peroxide bond with S-S, N-N and C-C bonds

• Type: Article in International Scientific Journal
• Date: 2021-09-07

Authors

Magalhaes, CM (Author) FCUP; Gonzalez Berdullas, P (Author) Other; Joaquim C G E Esteves da Silva (Author) FCUP; da Silva, LP (Author) FCUP

Journal

Title: New Journal of Chemistry

Vol. 45

ISSN: 1144-0546

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Associated Projects

ChemiTumorTher - Quimioluminescência Marinha como uma Terapia Anticancro de Amplo Espectro com uma Selectividade e Actividade Tumoral Melhorada

Other information

Authenticus ID: P-00V-B85

DOI: 10.1039/d1nj03440e

Abstract (EN): Dioxetanone is one of the prototypical cyclic peroxide intermediates in several chemiluminescent and bioluminescent systems, in which thermolysis reactions allow efficient singlet chemiexcitation. While the chemiexcitation mechanism of dioxetanone and peroxide intermediates is still far from understood, the presence of a peroxide bond that undergoes bond breaking has been found to be a constant. Here we have addressed the following questions: can other non-peroxide bonds lead to chemiexcitation and, if not, can the differences between dioxetanone and non-peroxide derivatives help to elucidate their chemiexcitation mechanism? To this end, we have used a reliable TD-DFT approach to model the thermolysis and chemiexcitation of a model dioxetanone and its three other non-peroxide derivatives. The results showed that only the dioxetanone molecule could lead to chemiluminescence as it is the only one for which thermolysis is energetically favorable and provides a pathway for singlet chemiexcitation. Finally, the chemiexcitation of the model dioxetanone is explained by its access, during thermolysis, to a biradical region where the ground and excited states are degenerate. This occurs due to an increased interaction between the reaction fragments, which extends the biradical regions and delays the rupture of the peroxide ring.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10