First-Principles Calculations of Excited-State Decay Rate Constants in Organic Fluorophores

do Casal, Mariana T.; Veys, Koen; Bousquet, Manon H. E.; Escudero, Daniel; Jacquemin, Denis

doi:10.1021/acs.jpca.3c06191

Cited by 20 publications

(16 citation statements)

References 150 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was reported that for relatively bright transitions ( k r > 10 7 s −1 ), the HT effects have a small impact (<10%) on the radiative rate and can essentially be neglected for bright fluorophores ( k r > 10 8 s −1 ). 53,66 To calculate the ISC rates, two different ISC channels S 1 → T 1 and S 1 → T 2 were taken into account (Fig. 5).…”

Section: Resultsmentioning

confidence: 99%

“…In cases where the SOC is extremely low, the vibrationally induced SOCs and/or spin-vibronic SOCs 68 could contribute significantly. 53,69 Therefore, the HT-like vibrational SOCs were included in the ISC rate calculations for the transitions with small SOCs (<5 cm −1 ).…”

Section: Resultsmentioning

confidence: 99%

“…In addition, molecules with flexible groups, such as methyl groups, are more prone to anharmonic motions. 53 Moreover, when the energy gap between electronic states is large, the highly excited vibrational states are likely to deviate from harmonic oscillator eigenfunctions. Therefore, it is important to systematically investigate the reliability of the harmonic approximation in these substituted derivatives.…”

Section: Resultsmentioning

confidence: 99%

“…k isc for an S i → T f transition is given by 53 where Ĥ SO is the spin–orbit coupling (SOC) operator.…”

Section: Theoretical Methods and Computational Detailsmentioning

confidence: 99%

“…k r and k ic rates were calculated using the MOMAP program, 58–60 while the k isc rate was computed using the ORCA 4.2.1 program. 61,62 The Herzberg Teller (HT)-like vibrational SOC 53 was included, and the obtained rate of k isc was the summation of three spin substate contributions. The electron transition characteristics were analyzed using the Multiwfn program.…”

Section: Theoretical Methods and Computational Detailsmentioning

confidence: 99%

See 4 more Smart Citations

Excellent ratiometric two-photon fluorescent probes for hydrogen sulfide detection based on the fluorescence resonance energy transfer mechanism

Ma,

Geng,

Cheng

et al. 2024

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…k isc for an S i → T f transition is given by 53 where Ĥ SO is the spin–orbit coupling (SOC) operator.…”

Section: Theoretical Methods and Computational Detailsmentioning

confidence: 99%

Section: Theoretical Methods and Computational Detailsmentioning

confidence: 99%

See 3 more Smart Citations

Excellent ratiometric two-photon fluorescent probes for hydrogen sulfide detection based on the fluorescence resonance energy transfer mechanism

Ma,

Geng,

Cheng

et al. 2024

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

The Photophysics of Naphthalimide‐Phenoselenazine Electron Donor‐Acceptor Dyads: Revisiting the Heavy‐Atom Effect in Thermally Activated Delayed Fluorescence

Pei,

Sukhanov,

Chen

et al. 2024

Chemistry A European J

View full text Add to dashboard Cite

We prepared thermally activated delayed fluorescence (TADF) emitter dyads, NI‐PTZ, NI‐PTZ‐2Br and NI‐PSeZ, with naphthalimide (NI) as electron acceptor and 10H‐phenothiazine (PTZ) or 10H‐phenoselenazine (PSeZ) as electron donor to study the heavy‐atom effect on the intersystem crossing (ISC) and reverse ISC (rISC) in the TADF emitters. The delayed fluorescence lifetimes of the dyads containing heavy atoms ( =5.9 μs for NI‐PSeZ and =16.5 μs for NI‐PTZ‐2Br, respectively) are longer than the heavy atom‐free counterpart NI‐PTZ ( =2.0 μs). Nanosecond transient absorption (ns‐TA) spectral study and the time‐resolved electron paramagnetic resonance (TREPR) spectra show the presence of both 3LE and 3CS states. These findings represent solid experimental evidences for the spin‐vibronic coupling mechanism of TADF. Moreover, the ns‐TA spectra show that the heavy atoms don't have a significant effect since the lifetime of the triplet transient species (1.3 μs for NI‐PTZ) is not shortened in their presence (4.5 μs for NI‐PSeZ and 5.3 μs for NI‐PTZ‐2Br). These results show that the previously claimed heavy‐atom effect on rISC and TADF is not a universal principle. The femtosecond transient absorption (fs‐TA) spectra of the compounds indicate the occurrence of fast charge separation within 1–2 ps, and the charge recombination is slow (>4 ns)

show abstract

Thiocarbonyl‐Bridged N‐Heterotriangulenes for Energy Efficient Triplet Photosensitization: A Theoretical Perspective

Manna

2024

ChemPhysChem

View full text Add to dashboard Cite

Rigid metal‐free organic molecules are of high demand for various triplet harvesting applications. Inefficient intersystem crossing (ISC) due to large singlet‐triplet gap ([[EQUATION]]) and small spin‐orbit coupling (SOC) between lowest excited singlet and triplet in these molecules often limits their efficiency. We computationally investigate excited‐state electronic structures, fluorescence and ISC rates in several thiiocarbonyl‐bridged N‐heterotriangulene ([[EQUATION]]S‐HTG) with systematically increased S‐content ([[EQUATION]]0‐3). All [[EQUATION]]S‐HTGs are dynamically stable and also thermodynamically feasible to synthesize. Relative energies of several low‐lying singlets ([[EQUATION]]) and triplets ([[EQUATION]]), and their excitation nature ([[EQUATION]] or [[EQUATION]]) and SOC for these [[EQUATION]]S‐HTGs in dichloromethane are determined implementing time‐dependent optimally‐tuned range‐separated hybrid. Low‐energy optical peak displays gradual red‐shift with increasing S‐content due to relatively smaller electronic gap resulted from greater degree of orbital delocalization. Significantly large SOC due to different orbital‐symmetry and heavy‐atom effect produces remarkably high ISC rates ([[EQUATION]] ~1012 s‐1) for enthalpically favoured [[EQUATION]]([[EQUATION]]) channel in these [[EQUATION]]S‐HTGs, which outcompete radiative fluorescence rates (~108 s‐1) even directly from higher lying optically bright [[EQUATION]] singlets (anti‐Kasha’s emission). Importantly, high energy triplet excitons of ~1.7 eV resulting from such significantly large ISC rates from non‐fluorescent [[EQUATION]] make these thionated molecules ideal candidates for energy efficient triplet harvest including triplet‐photosensitization.

show abstract

First-Principles Calculations of Excited-State Decay Rate Constants in Organic Fluorophores

Cited by 20 publications

References 150 publications

Excellent ratiometric two-photon fluorescent probes for hydrogen sulfide detection based on the fluorescence resonance energy transfer mechanism

Excellent ratiometric two-photon fluorescent probes for hydrogen sulfide detection based on the fluorescence resonance energy transfer mechanism

The Photophysics of Naphthalimide‐Phenoselenazine Electron Donor‐Acceptor Dyads: Revisiting the Heavy‐Atom Effect in Thermally Activated Delayed Fluorescence

Thiocarbonyl‐Bridged N‐Heterotriangulenes for Energy Efficient Triplet Photosensitization: A Theoretical Perspective

Contact Info

Product

Resources

About