Luminescence and charge transfer. Part 4. ‘On–off’ fluorescent PET (photoinduced electron transfer) sensors with pyridine receptors: 1,3-diaryl-5-pyridyl-4,5-dihydropyrazoles
- 1 January 1995
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 2
- No. 4,p. 685-690
- https://doi.org/10.1039/p29950000685
Abstract
1,3-Diaryl-5-pyridyl-4,5-dihydropyrazoles, some of which have been previously synthesized for use as optical brighteners, satisfy the design criteria for fluorescent PET pH sensors by a proton-induced ‘switching off’ of fluorescence. In practice, they are the first family of ‘on–off’ fluorescent PET pH sensors whose signals cover most of the visible spectrum. They also show significant absorptiometric pH sensing action due to the coupling of the protonatable pyridine with the ICT (internal charge transfer) excited state of the 1,3-diaryl-4,5-dihydropyrazole. Experimentally identical pKa values arise from the fluorimetric and absorptiometric pH dependences. The examination of 2-, 3- and 4-pyridyl regioisomers shows understandable differences in pKa and maximum fluorescene quantum yield [φF(base)] values, but show no significant variations in fluorescence switching factors (FE).Keywords
This publication has 48 references indexed in Scilit:
- Luminescent pH sensors based on p-tert-butylcalix[4]arene-linked ruthenium(II) trisbipyridyl complexesJournal of the Chemical Society, Chemical Communications, 1994
- The effect of pH on the luminescence quenching of tris(2,2′-bipyridine) ruthenium (II) by phenolic compoundsJournal of Photochemistry and Photobiology A: Chemistry, 1993
- Fluorescent Photoinduced Electron-Transfer SensorsPublished by American Chemical Society (ACS) ,1993
- Fluorescent PET (photoinduced electron transfer) sensorsPublished by Springer Nature ,1993
- Luminescence and charge transfer. Part 3. The use of chromophores with ICT (internal charge transfer) excited states in the construction of fluorescent PET (photoinduced electron transfer) pH sensors and related absorption pH sensors with aminoalkyl side chainsJournal of the Chemical Society, Perkin Transactions 2, 1993
- Excited state electron transfer reactions of tris(4,4′-dialkyl-2,2′-bipyridine)ruthenium(II) complexes with phenolate ions: structural and solvent effectsJournal of Photochemistry and Photobiology A: Chemistry, 1992
- Photoinduced electron transfer in supramolecular systems for artificial photosynthesisChemical Reviews, 1992
- Luminescence and charge transfer. Part 2. Aminomethyl anthracene derivatives as fluorescent PET (photoinduced electron transfer) sensors for protonsJournal of the Chemical Society, Perkin Transactions 2, 1992
- Molecular fluorescent signalling with ‘fluor–spacer–receptor’ systems: approaches to sensing and switching devices via supramolecular photophysicsChemical Society Reviews, 1992
- Fundamental concepts of photoinduced electron transferPublished by Springer Nature ,1990