Excited-State Hund’s Rule Violations in Bridged [10]- and [14]Annulene Perimeters DOI
J. Terence Blaskovits, Clémence Corminbœuf, Marc H. Garner

et al.

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 21, 2024

Molecules with Hund's rule violations between low-lying singlet and triplet states may enable a new generation of fluorescent emitters. However, only few classes molecules are known this property at the current time. Here, we use high-throughput screening algorithm FORMED database to uncover class compounds where first excited state violates rule. We examine bridged [10]- [14]annulene perimeters saturated bridges, relate them conjugated polycyclic systems violations. Despite structural similarities related nonalternant hydrocarbons, mechanism is different in these annulene perimeters. two molecular orbital configurations contribute each state. Consequently, violation can be unambiguously assigned based on symmetry lowest states. With several examples synthetically realistic molecules, [14]annulenes thus provides link alternant (azaphenalene) violating These design principles open avenues for identification types order photophysically relevant inverted.

Language: Английский

Benchmark computations of nearly degenerate singlet and triplet states of N-heterocyclic chromophores. II. Density-based methods DOI
Shamik Chanda, Subhasish Saha, Sangita Sen

et al.

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(2)

Published: Jan. 8, 2025

In this paper, we demonstrate the performance of several density-based methods in predicting inversion S1 and T1 states a few N-heterocyclic triangulene based fused ring molecules (popularly known as INVEST molecules) with an eye to identify well performing but cost-effective preliminary screening method. Both conventional linear-response time-dependent density functional theory (LR-TDDFT) ΔSCF (namely maximum overlap method, square-gradient minimization restricted open-shell Kohn–Sham) are considered for excited state computations using exchange–correlation (XC) functionals from different rungs Jacob’s ladder. A well-justified systematism is observed when compared against fully internally contracted multireference configuration interaction singles doubles and/or equation motion coupled-cluster (EOM-CCSD), most important feature being capture spin-polarization presence correlation. set least mean absolute error proposed both approaches, LR-TDDFT ΔSCF, which can be more alternatives on synthesizable larger derivatives templates studied here. We have our findings extensive studies three cyclazine-based molecular templates, additional six related templates. Previous benchmark subsets were conducted domain-based local pair natural orbital-similarity transformed EOM-CCSD (STEOM-CCSD), resulted inadequate evaluation due deficiencies theory. The role exact-exchange, spin-contamination, context DFT comes forefront supports numerical XC these applications. Suitable connections drawn two exciton models, minimal physics governing interactions molecules.

Language: Английский

Citations

1
The Role of Theoretical Calculations for INVEST Systems: Complementarity Between Theory and Experiments and Rationalization of the Results DOI Creative Commons
Á. J. Pérez‐Jiménez, Yoann Olivier, J. C. Sancho-Garcı́a

et al.

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: March 5, 2025

Abstract Here, the key role played by theoretical calculations for molecules presenting an inverted singlet‐triplet excited state (e.g. S 1 and T ) energy difference, or Δ E ST < 0, whose interest has steadily raised in recent years fostered experimental advances showing negative values a collection of real‐world systems is reviewed. The evolution computational efforts from pioneering on reduced set prototypical covered, to high‐throughput virtual screenings thousands identify new molecular scaffolds tune properties other than excitation energies, describe necessary benchmarking methods done parallel along years. Overall, complementarity prompted discovery more displaying 0 values, basic design principles are rationalized thus reviewed here too, while allowing at same time find which offer reasonable trade‐off between accuracy cost.

Language: Английский

Citations

0
Singlet–Triplet Inversion in Triangular Boron Carbon Nitrides DOI
Matteo Bedogni, Francesco Di Maiolo

Journal of Chemical Theory and Computation, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 12, 2024

The discovery of singlet-triplet (ST) inversion in some π-conjugated triangle-shaped boron carbon nitrides is a remarkable breakthrough that defies Hund's first rule. Deeply rooted strong electron-electron interactions, ST has garnered significant interest due to its potential revolutionize triplet harvesting organic LEDs. Using the well-established Pariser-Parr-Pople model for correlated electrons systems, we employ combination CISDT and restricted active space configuration interaction calculations investigate photophysics several triangular nitrides. Our findings reveal these systems primarily driven by network alternating electron-donor electron-acceptor groups molecular rim, rather than structure itself.

Language: Английский

Citations

3
Turning on Organic Radical Emitters DOI Creative Commons

Matteo Dubbini,

Federico Bonvini,

Francesco Di Maiolo

et al.

Published: July 2, 2024

Radical emitters have attracted considerable interest because of their potential to surpass the limitations singlet due spin statistics, thereby revolutionizing organic LEDs. Utilizing well-known Pariser-Parr-Pople (PPP) model for correlated electrons in π-conjugated systems, we perform extended CISDT (XCISDT) calculations explore photophysics various phenalenyl radicals differently decorated with nitrogen atoms. By introducing PPP particle-hole difference operator and connecting it DFT calculations, offer a new tool predicting highly emissive using ground state quantum chemistry methods.

Language: Английский

Citations

1
Singlet-Triplet Inversion in Triangular Boron Carbon Nitrides DOI Creative Commons
Matteo Bedogni, Francesco Di Maiolo

Published: Aug. 12, 2024

The discovery of singlet-triplet (ST) inversion in some π-conjugated triangle-shaped boron carbon nitrides is a remarkable breakthrough that defies Hund’s first rule. Deeply rooted strong electron-electron interactions, ST has garnered significant interest due to its potential revolutionize triplet harvesting organic LEDs. Using the well-established Pariser-Parr-Pople model for correlated electrons systems, we employ combination CISDT and RASCI calculations investigate photophysics several triangular nitrides. Our findings reveal these systems primarily driven by network alternating electron- donor electron-acceptor groups molecular rim, rather than structure itself.

Language: Английский

Citations

1
Turning on Organic Radical Emitters DOI

Matteo Dubbini,

Federico Bonvini,

Lorenzo Savi

et al.

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 17, 2024

Language: Английский

Citations

0
Multiscale Modeling of Charge Transport in Organic Semiconductors: Assessing the Validity of the Harmonic Approximation for Low-Frequency Vibrations DOI
Daniele Padula, Leonardo Barneschi, Alessandro Landi

et al.

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 16, 2024

In recent years, the importance of intrinsic disorder in organic semiconductors has gained increasing attention as a factor limiting transport properties these substrates. particular, presence low-frequency phonon modes modulating questions adoption harmonic approximation theoretical descriptions such modes, since large displacements from equilibrium positions are expected. Herein, we have analyzed process several using combination molecular dynamics simulations based on quantum mechanically derived force fields, together with transferable and differentiable deep learning models, trained density functional theory calculations, able to predict transfer integrals their gradients for different substrates, providing ingredients be used within kinetic Monte Carlo prediction charge mobility. obtained fluctuations species crystals approximation, both adopting DFT model, which was also anharmonic strategies exploiting dynamics. Although comparison among approaches evaluate integral difficult interpret, incorporated calculation mobility, compare experiments. Mobilities computed described foundations were consistent agreement experimental literature data, highlighting that, although involved modulation properties, is still appropriate.

Language: Английский

Citations

0
Singlet-Triplet Inversion in Triangular Boron Carbon Nitrides DOI Creative Commons
Matteo Bedogni, Francesco Di Maiolo

Published: June 3, 2024

The discovery of singlet-triplet (ST) inversion in some π-conjugated triangle-shaped boron carbon nitrides is a remarkable breakthrough that defies Hund’s first rule. Deeply rooted strong electron-electron interactions, ST has garnered significant interest due to its potential revolutionize triplet harvesting organic LEDs. Using the well-established Pariser-Parr-Pople model for correlated electrons systems, we employ combination CISDT and RASCI calculations investigate photophysics several triangular nitrides. Our findings reveal these systems primarily driven by network alternating electron- donor electron-acceptor groups molecular rim, rather than structure itself.

Language: Английский

Citations

0
Excited-state Hund’s Rule Violations in Bridged [10]- and [14]Annulene Perimeters DOI Creative Commons
J. Terence Blaskovits, Clémence Corminbœuf, Marc H. Garner

et al.

Published: June 17, 2024

Molecules with Hund’s rule violations between low-lying singlet and triplet states may enable a new generation of fluorescent emitters. However, only few classes molecules are known this property at the current time. Here, we use high-throughput screening algorithm FORMED database to uncover class compounds where first excited state violates rule. We examine bridged [10]- [14]annulene perimeters saturated bridges, relate them conjugated polycyclic systems violations. Despite structural similarities related non-alternant hydrocarbons, mechanism is different in these annulene perimeters. two molecular orbital configurations contribute each state. Consequently, violation can be unambiguously assigned based on symmetry lowest states. With several examples synthetically realistic molecules, [14]annulenes thus provides link alternant (azaphenalene) violating rule, open avenues for design inverted singlet-triplet gaps.

Language: Английский

Citations

0
Excited-State Hund’s Rule Violations in Bridged [10]- and [14]Annulene Perimeters DOI
J. Terence Blaskovits, Clémence Corminbœuf, Marc H. Garner

et al.

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 21, 2024

Molecules with Hund's rule violations between low-lying singlet and triplet states may enable a new generation of fluorescent emitters. However, only few classes molecules are known this property at the current time. Here, we use high-throughput screening algorithm FORMED database to uncover class compounds where first excited state violates rule. We examine bridged [10]- [14]annulene perimeters saturated bridges, relate them conjugated polycyclic systems violations. Despite structural similarities related nonalternant hydrocarbons, mechanism is different in these annulene perimeters. two molecular orbital configurations contribute each state. Consequently, violation can be unambiguously assigned based on symmetry lowest states. With several examples synthetically realistic molecules, [14]annulenes thus provides link alternant (azaphenalene) violating These design principles open avenues for identification types order photophysically relevant inverted.

Language: Английский

Citations

0