Amino derivatives of symmetric 1,3,5-triphenylbenzene. Nature of the polar singlet excited state.

Verbeek, G.; Depaemelaere, S.; Auweraer, Mark Van der; Schryver, F. C. De; Vaes, A.; Terrell, D.; Meutter, S. De

doi:10.1016/0301-0104(93)85017-3

Cited by 50 publications

(44 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The steep PES for the ground state could be due to steric hindrance. In contrast to what was observed earlier for molecules with a strongly dipolar excited state, 43 the values of the Stokes shift estimated from the fwhmabs and fwhmem are overestimated and the deviation becomes stronger for broader bands. Especially when the bands of the BODIPY derivatives get broader, fwhmabs and fwhmem are no longer uniquely determined by low frequency (torsional) vibrations but also envelope the 0-1 high frequency vibronic band.…”

Section: Spectroscopic and Photophysical Propertiescontrasting

confidence: 52%

“…If only low frequency molecular vibrations (hvib < kT) contribute to  and fwhmem or fwhmabs, the relation between both properties is given by eqn (1): [41][42][43] (fwhm) 2 = 16 (ln 2) ER kT (1) where ER is the excess energy with which a vertical transition from the minimum of the ground state reaches the excited state potential energy surface (PES) upon absorption of a photon (and analogously for emission). Hence the Stokes shift  is 2ER.…”

Section: Spectroscopic and Photophysical Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Effect of the substitution position (2, 3 or 8) on the spectroscopic and photophysical properties of BODIPY dyes with a phenyl, styryl or phenylethynyl group

et al. 2016

View full text Add to dashboard Cite

Noël (2016) Effect of the substitution position (2, 3 or 8) on the spectroscopic and photophysical properties of BODIPY dyes with a phenyl, styryl or phenylethynyl group. RSC Advances, 6 . pp. 102899-102913. ISSN 2046-2069 Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/37842/1/Ph%20Ethyn%20Styryl%20BODIPYs%20-%20Accepted%20Manuscript.pdf Copyright and reuse:The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the University of Nottingham End User licence and may be reused according to the conditions of the licence. For more details see: http://eprints.nottingham.ac.uk/end_user_agreement.pdf A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham. ABSTRACT. A very active branch of organic chemistry is putting great effort in tailoring fluorescent dyes for a myriad of applications, from technological to bioanalytical and biomedical applications. Among the major families of fluorophores, those derived from 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY dyes) are undergoing a recent boost thanks to the simplicity and robustness of the chemistry involved. The BODIPY core can be modified with numerous side groups, the 8-position being a modification place with important effects on the spectroscopic and photophysical properties of the resulting dyes. Likewise, previous work has shown that the addition of groups attached at the 3-and 2-positions can result in dyes with very different properties. Herein, we generalize the effect of the substituent side groups by studying nine BODIPY dyes substituted with a phenyl, styryl or phenylethynyl moiety at the 2-, 3-or 8-position of the BODIPY scaffold. Within the class of phenyl-or phenylethynyl-substituted dyes, substitution at the 2-position always leads to dyes with the broadest bandwidths and the largest Stokes shifts. We investigate the solvent effect on the spectroscopic properties of the dyes, using four empirical solvent scales (dipolarity, polarizability, acidity and basicity: Catalán, J. Phys. Chem., 2009, 113, 5951). These analyses identify solvent dipolarity and polarizability as critical parameters accounting for the observed solvent-dependent shifts of the absorption and emission maxima. Finally, time-dependent density functional theory calculations provide insights into the structural and energetic issues concerning the spectroscopic properties of these fluorophores.KEYWORDS: Fluorescent dyes, solvent effect, Catalán solvent scales, quantum chemical calculations TOCUnderstanding the spectroscopic properties of BODIPY dyes for a rationale design of tailored fluorescent ...

show abstract

Section: Spectroscopic and Photophysical Propertiescontrasting

confidence: 52%

Section: Spectroscopic and Photophysical Propertiesmentioning

confidence: 99%

Effect of the substitution position (2, 3 or 8) on the spectroscopic and photophysical properties of BODIPY dyes with a phenyl, styryl or phenylethynyl group

et al. 2016

View full text Add to dashboard Cite

show abstract

“…This suggests that the existence of a considerable dipole moment in the excited state in contrast to the ground state has only a quadrupolar or octupolar moment. [13][14][15][16][17][18][19][20][21][22][23][24] Moreover, the relative intensity of the S 1 ← S 0 and S 2 ← S 0 bands in the one-and two-photon absorption spectra of these molecules points to symmetric ground and Franck-Condon excited states. 20,[25][26][27] These two apparently contradictory observations have been reconciled by invoking a break-up of the symmetry in the excited state a) Authors to whom correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 89%

A simple model of solvent-induced symmetry-breaking charge transfer in excited quadrupolar molecules

Ivanov

Dereka

Vauthey

2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

A simple model has been developed to describe the symmetry-breaking of the electronic distribution of A-D-A type molecules in the excited state, where D is an electron donor and A and A are identical acceptors. The origin of this process is usually associated with the interaction between the molecule and the solvent polarization that stabilizes an asymmetric and dipolar state, with a larger charge transfer on one side than on the other. An additional symmetry-breaking mechanism involving the direct Coulomb interaction of the charges on the acceptors is proposed. At the same time, the electronic coupling between the two degenerate states, which correspond to the transferred charge being localised either on A or A, favours a quadrupolar excited state with equal amount of charge-transfer on both sides. Because of these counteracting effects, symmetry breaking is only feasible when the electronic coupling remains below a threshold value, which depends on the solvation energy and the Coulomb repulsion energy between the charges located on A and A. This model allows reproducing the solvent polarity dependence of the symmetry-breaking reported recently using time-resolved infrared spectroscopy.

show abstract

“…However for many of these chromophores, experimental data suggest the existence of polar excited states. For example, strong fluorescence solvatochromism has been observed for quadrupolar and/or octupolar systems, 10,13,17,18,36,42,48,49 revealing the existence of highly J. AM.…”

Section: Introductionmentioning

confidence: 99%

“…A large body of experimental data is available for many families of quadrupolar 5,7,[9][10][11]13,18,[33][34][35][36] and octupolar chromophores 15,17,18,34,[37][38][39][40][41][42][43][44][45] as well as for branched and dendritic systems. 16,40,43,44,46,47 Due to their highly symmetric structure, all these systems have no permanent dipole moment and of course vertical (unrelaxed) states are non-dipolar as well.…”

Section: Introductionmentioning

confidence: 99%

Charge Instability in Quadrupolar Chromophores: Symmetry Breaking and Solvatochromism

et al. 2006

View full text Add to dashboard Cite

We present a joint theoretical and experimental work aimed to understand the spectroscopic behavior of multipolar dyes of interest for nonlinear optics (NLO) applications. In particular, we focus on the occurrence of broken-symmetry states in quadrupolar organic dyes and their spectroscopic consequences. To gain a unified description, we have developed a model based on a few-state description of the charge-transfer processes characterizing the low-energy physics of these systems. The model takes into account the coupling between electrons and slow degrees of freedom, namely, molecular vibrations and polar solvation coordinates. We predict the occurrence of symmetry breaking in either the ground or first excited state. In this respect, quadrupolar chromophores are classified in three different classes, with distinctively different spectroscopic behavior. Cases of true and false symmetry breaking are discriminated and discussed by making resort to nonadiabatic calculations. The theoretical model is applied to three representative quadrupolar chromophores: their qualitatively different solvatochromic properties are connected to the presence or absence of broken-symmetry states and related to two-photon absorption (TPA) cross-sections. The proposed approach provides useful guidelines for the synthesis of dyes for TPA application and represents a general and unifying reference frame to understand energy-transfer processes in multipolar molecular systems, offering important clues to understand basic properties of materials of interest for NLO and energy-harvesting applications.

show abstract

Amino derivatives of symmetric 1,3,5-triphenylbenzene. Nature of the polar singlet excited state.

Cited by 50 publications

References 52 publications

Effect of the substitution position (2, 3 or 8) on the spectroscopic and photophysical properties of BODIPY dyes with a phenyl, styryl or phenylethynyl group

Effect of the substitution position (2, 3 or 8) on the spectroscopic and photophysical properties of BODIPY dyes with a phenyl, styryl or phenylethynyl group

A simple model of solvent-induced symmetry-breaking charge transfer in excited quadrupolar molecules

Charge Instability in Quadrupolar Chromophores: Symmetry Breaking and Solvatochromism

Contact Info

Product

Resources

About