Two wide‐band‐capturing donor‐acceptor conjugates featuring bis‐styrylBODIPY and perylenediimide (PDI) have been newly synthesized, and the occurrence of ultrafast excitation transfer from the1PDI* to BODIPY, and a subsequent electron transfer from the1BODIPY* to PDI have been demonstrated. Optical absorption studies revealed panchromatic light capture but offered no evidence of ground‐state interactions between the donor and acceptor entities. Steady‐state fluorescence and excitation spectral recordings provided evidence of singlet‐singlet energy transfer in these dyads, and quenched fluorescence of bis‐styrylBODIPY emission in the dyads suggested additional photo‐events. The facile oxidation of bis‐styrylBODIPY and facile reduction of PDI, establishing their relative roles of electron donor and acceptor, were borne out by electrochemical studies. The electrostatic potential surfaces of the S1and S2states, derived from time‐dependent DFT calculations, supported excited charge transfer in these dyads. Spectro‐electrochemical studies on one‐electron‐oxidized and one‐electron‐reduced dyads and the monomeric precursor compounds were also performed in a thin‐layer optical cell under corresponding applied potentials. From this study, both bis‐styrylBODIPY⋅
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The fluorescence, phosphorescence, and photochemical properties of di‐ and triaryl‐substituted‐1,2,3‐triazoles are reported in this work. The ease of synthesis of regioisomers of substituted triazoles enables a systematic study on the correlation between regiochemistry and excited state properties, which include the solvent dependence of fluorescence, energy gap between singlet and triplet emitters, and propensity to photon‐triggered transformations. The triazoles that carry electron (e)‐donor and e‐acceptor aryl substituents show high fluorescence quantum yields in weakly polar solvents and exhibit solvent‐dependent fluorescence. The luminescence properties of these compounds in glass matrices at 77 K are characterized. The thermal and photo‐stability, two parameters that are crucial to their potential utilities in optical devices, of these compounds are determined. The position of the e‐donor substituent has a significant impact on the fluorescence emission energy and solvent sensitivity, singlet‐triplet energy gap, and photochemical reactivity and stability. The experimental observations on the structural correlation with the photophysical and photochemical properties are explained by quantum chemical calculations. This study provides a rationale on the placement of substituent on a donor‐acceptor type fluorophore to maneuver a range of photo‐related properties.
more » « less- Award ID(s):
- 1955262
- NSF-PAR ID:
- 10434532
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemPhysChem
- Volume:
- 24
- Issue:
- 18
- ISSN:
- 1439-4235
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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