Non-radiative decay paths in rhodamines: new theoretical insights

Savarese, Marika; Raucci, Umberto; Adamo, Carlo; Netti, Paolo A.; Ciofini, Ilaria; Rega, Nadia

doi:10.1039/c4cp02622e

Cited by 44 publications

(74 citation statements)

References 48 publications

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“…The computed S 1 states of RDs by TDDFT with GH GGA and meta‐GGA functionals are in the ππ* state and correspond to pure transitions from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO). This result is in accordance with those of previous theoretical studies . Figure shows the computed HOMO and LUMO of Rhod101 by TD‐B3LYP as an example, and both the HOMO and LUMO are localized on xanthene moiety.…”

Section: Resultssupporting

confidence: 92%

“…Designing and development of new RDs are still in progress despite the fact that many chemically modified RDs are commercially available . Previous theoretical studies found that the lowest excitation energies of RDs are overestimated systematically at approximately 0.4 eV by TDDFT approximations . Savarese et al also reported that the TD‐B3LYP‐D/6‐31 + G(d,p)/CPCM calculated the lowest excitation energy of rhodamine 110 (R110) in aqueous solution (~2.63 eV) and reproduces the experimental data (2.49 eV) .…”

Section: Introductionmentioning

confidence: 63%

“…In addition, the TD‐BP86 computed S 2 state of 5Rox is a mixed LE and CT state involving the CT from xanthene moiety to benzene moiety. However, the S 1 state of RDs should be a locally excited (LE) ππ* state, as demonstrated by previous studies . Therefore, as shown in Table and Supporting Information Table S1, the corresponding S 2 or S 3 states are listed to compare the experimental data.…”

Section: Resultsmentioning

confidence: 99%

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Why the lowest electronic excitations of rhodamines are overestimated by time‐dependent density functional theory

Zhou

2018

Int J of Quantum Chemistry

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Rhodamines are widely used as laser dyes and fluorescent probes due to their excellent photophysical and photochemical properties. Previous theoretical studies have shown that the lowest excitation energies of rhodamines are overestimated systematically by time‐dependent density functional theory (TDDFT). In this study, we first perform a TDDFT benchmark study with 21 exchange‐correlation functionals (XCFs) on a series of rhodamines and assess the performance of different types of functional in predicting the lowest excitation energies of rhodamines. Statistical results reveal that the fraction of Hartree–Fock exchange (HFX) included in the XCF is a key parameter. Pure functionals without HFX offer the best performance, with the mean absolute error (MAE) of approximately 0.1 eV. However, they provide a wrong order of the lowest nπ* and ππ* states and suffer from charge‐transfer contamination problem for rhodamine dyes (RDs) in zwitterionic form. Among the other tested functionals, popular global hybrid functional B3LYP delivers the smallest MAE of 0.36 eV. We then perform calculations with second‐order algebraic diagrammatic construction and extended multiconfiguration quasi‐degenerate perturbation theory at second‐order of PT expansion methods. Remarkably accurate results are obtained. We confirm that the reason for the overestimation of the lowest excitation energies of RDs by TDDFT method should be similar to that of cyanine dyes, and that double excitations contribute to this systematic deviation.

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Section: Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 63%

Section: Resultsmentioning

confidence: 99%

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Why the lowest electronic excitations of rhodamines are overestimated by time‐dependent density functional theory

Zhou

2018

Int J of Quantum Chemistry

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“…The electron density redistribution upon the excitation along The Journal of Physical Chemistry B Article the IRC path can be analyzed and described through densitybased indexes such as the D CT one, as also demonstrated in previous works. 6,41,42 In Figure 4 D CT values calculated along the IRC path are reported. The transition state region of the ESPT reaction represents the maximal charge separation Figures 2 and 4, it is clear that the highest energy arrangement of the reaction (namely the TS) corresponds to the configurational space characterized by the maximum D CT , and therefore by the highest charge transfer degree.…”

Section: Resultsmentioning

confidence: 99%

Intrinsic and Dynamical Reaction Pathways of an Excited State Proton Transfer

Raucci¹,

Savarese

Adamo

et al. 2015

J. Phys. Chem. B

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The detailed knowledge of excited state proton transfer mechanisms in complex environments is of paramount importance in chemistry. However, the definition of an effective reaction coordinate and the understanding of the driving force of the reaction can be difficult from both the experimental and the theoretical points of view. Here we analyzed by theoretical approaches the mechanism and the driving forces of the excited state proton transfer reaction occurring between the 7-hydroxy-4-(trifluoromethyl)coumarin photoacid and the 1-methylimidazole base molecules in toluene solution. In particular, we compared the intrinsic and the dynamical reaction pathways, obtained by integrating the reaction coordinate, and by performing ab initio simulations of molecular dynamics, respectively. Time-dependent density functional theory and polarizable solvation continuum models were adopted to define the excited state potential energy surface. Results were analyzed by means of the D(CT) electronic density based index. Our findings suggest that the reaction coordinate is mainly composed of several intra- and intermolecular modes of the reactants. An analysis of both the intrinsic coordinate and the dynamical results shows that the charge transfer induced by electronic excitation of the coumarin molecule is the main proton transfer driving force. With regards to the methodological validation, the combination of ab initio molecular dynamics with time-dependent density functional theory appears to be feasible and reliable to study excited state proton transfer reactions in the condensed phase.

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“…Not surprisingly, these methodologies have been extensively applied to study ESPT reactions . Moreover, the same approach can be applied, with due care, to the analysis of nonradiative events …”

Section: Introductionmentioning

confidence: 99%

Computational Insights into Excited‐State Proton‐Transfer Reactions in Azo and Azomethine Dyes

et al. 2015

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State of the art density functional theory approaches are employed to provide an accurate description of the photophysical properties of azodyes and Schiff bases displaying intramolecular hydrogen-bonding features. These compounds exist as tautomeric mixtures at the ground state and, in the case of Schiff bases, an excited-state intramolecular proton transfer (ESIPT) occurs upon excitation. The experimentally observed photophysical properties are discussed here in light of the theoretical findings. To rationalize the different experimentally observed radiative behavior of the azo and azomethine structures, a nonradiative decay pathway that is possibly active in such systems is determined. The characterization of this deactivation path, tested for two related compounds exhibiting different fluorescence quantum yields, enables us to disentangle the different and contrasting effects governing the excited-state behavior of these molecular systems.

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Non-radiative decay paths in rhodamines: new theoretical insights

Cited by 44 publications

References 48 publications

Why the lowest electronic excitations of rhodamines are overestimated by time‐dependent density functional theory

Why the lowest electronic excitations of rhodamines are overestimated by time‐dependent density functional theory

Intrinsic and Dynamical Reaction Pathways of an Excited State Proton Transfer

Computational Insights into Excited‐State Proton‐Transfer Reactions in Azo and Azomethine Dyes

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