Excited‐State Pathways of Four‐Coordinate N, C‐Chelate Organoboron Dyes. Issue 1 (8th December 2017)

• Record Type: Journal Article
• Authors: Boscá, Francisco; Cuquerella, M. Consuelo; Pais, Vânia F.; Ros, Abel; Pischel, Uwe
• Is Part Of: ChemPhotoChem. Volume 2:Issue 1(2018)
• Page Start: 34
• Page End: 41
• Publication Date: 2017-12-08
• Subjects: charge transfer -- fluorescence -- organoboron dyes -- photophysics -- singlet oxygen; Photochemistry -- Periodicals; Periodicals; Electronic journals; 541.35
• DOI: 10.1002/cptc.201700176
• Languages: English
• ISSNs: 2367-0932

Abstract

Abstract: The excited‐state behavior of four‐coordinate N, C‐chelate organoboron dyes, based on arylisoquinoline ligands with varying degree of charge‐transfer character, was characterized. Data related to excited triplet state formation, oxygen quenching, and singlet‐oxygen formation were obtained. The results jointly rationalize the previously observed high photostability of the dyes in air‐equilibrated media. Furthermore, femtosecond transient absorption experiments enabled the spectroscopic visualization of the excited intramolecular charge transfer (ICT) state that gives rise to the fluorescence of the dyes. Abstract : Quo vadis? The excited‐state trajectory of organoboron fluorophores with aryl‐isoquinoline ligands was characterized by fluorescence measurements and laser flash photolysis. This study provided information about excited triplet states, the role of charge‐transfer states and exciplexes as well as the generation of singlet oxygen. The results corroborate the recently proposed application of the dyes as photostable fluorophores in bioimaging.