Photophysical properties of novel [1,2,3]triazolo[4,5-d] pyridazine derivatives

Krisztina Nagy, L. Biczók, A. Demeter, Péter Kövér, Z. Riedl

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Photostability, fluorescence properties and triplet yield of [1,2,3]triazolo[4,5-d]pyridazine derivatives have been studied in various solvents. The energy of the lowest singlet excited state significantly decreases in the series of 1, 2, and 3, and the latter compound emits negligible fluorescence. All substances are photochemically very stable. No photodecomposition occurs from singlet excited state and the triplet molecules do not react with alcohol showing that the lowest triplet state has ππ* character. Internal conversion is found to be the dominant singlet excited state depopulating process. The short fluorescence lifetime of 2 is attributed to the particularly rapid non-radiative transition to the ground state. Both 1 and 2 readily form hydrogen-bonded complex with hexafluoroisopropanol. Light absorption does not enhance the hydrogen bonding power, therefore; no fluorescence quenching but fluorescence yield enhancement is observed.

Original languageEnglish
Pages (from-to)83-88
Number of pages6
JournalJournal of Photochemistry and Photobiology A: Chemistry
Volume153
Issue number1-3
DOIs
Publication statusPublished - Nov 1 2002

Fingerprint

Fluorescence
Derivatives
fluorescence
Excited states
excitation
photodecomposition
internal conversion
hydrogen
Electron transitions
electromagnetic absorption
Light absorption
Ground state
atomic energy levels
Hydrogen
Quenching
Hydrogen bonds
alcohols
Alcohols
quenching
pyridazine

Keywords

  • Fluorescence
  • Hydrogen bonding
  • Internal conversion
  • Intersystem crossing

ASJC Scopus subject areas

  • Bioengineering
  • Physical and Theoretical Chemistry

Cite this

Photophysical properties of novel [1,2,3]triazolo[4,5-d] pyridazine derivatives. / Nagy, Krisztina; Biczók, L.; Demeter, A.; Kövér, Péter; Riedl, Z.

In: Journal of Photochemistry and Photobiology A: Chemistry, Vol. 153, No. 1-3, 01.11.2002, p. 83-88.

Research output: Contribution to journalArticle

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AU - Riedl, Z.

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AB - Photostability, fluorescence properties and triplet yield of [1,2,3]triazolo[4,5-d]pyridazine derivatives have been studied in various solvents. The energy of the lowest singlet excited state significantly decreases in the series of 1, 2, and 3, and the latter compound emits negligible fluorescence. All substances are photochemically very stable. No photodecomposition occurs from singlet excited state and the triplet molecules do not react with alcohol showing that the lowest triplet state has ππ* character. Internal conversion is found to be the dominant singlet excited state depopulating process. The short fluorescence lifetime of 2 is attributed to the particularly rapid non-radiative transition to the ground state. Both 1 and 2 readily form hydrogen-bonded complex with hexafluoroisopropanol. Light absorption does not enhance the hydrogen bonding power, therefore; no fluorescence quenching but fluorescence yield enhancement is observed.

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