The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(40), P. 16879 - 16891
Published: Oct. 1, 2024
Language: Английский
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
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
1
Journal of Computational Chemistry, Journal Year: 2025, Volume and Issue: 46(8)
Published: March 26, 2025
Computational investigations of Inverted Singlet-Triplet (INVEST) emitters often rely on ADC(2) and TD-DFT excitation energies (EEs) obtained with the vertical approximation. Here, we first considered several cyclazine derivatives examine sensitivity EEs (VEEs) as well singlet-triplet gaps, ΔES1T1 to level at which ground state (S0) structure was optimized. For cyclazine, VEEs gaps from or are spread over a narrow range (< 0.064 eV) whether S0 is optimized various DFT, CCSD, RI-MP2 methods. However, for asymmetric cyclazines, depending protocol optimizing structures, not only substantially wider (up 0.75 but so 0.30 eV), leading cases where, different one obtains positive significantly negative gaps. We relate this behavior introduction significant asymmetry bond-length variations in derivatives, formed by ligand functionalization modification core. On more note, adiabatic (AEEs) display lower (7-30× less) geometry optimization protocols than their analogs. Crucially, M06-HF functional 100% non-local exchange provides closest available CCSD(T) data. show that effect exists also other frameworks (e.g., azulene, pentaazaphenalene, non-alternant polycyclic hydrocarbons) have been INVEST property, broader up 1.19 eV 0.62 eV. emitters, it therefore extremely important judiciously choose computational geometries, computing
Language: Английский
Citations
1
The Journal of Physical Chemistry Letters, Journal Year: 2025, Volume and Issue: unknown, P. 5213 - 5220
Published: May 19, 2025
Molecular engineering of organic emitter molecules with inverted singlet-triplet energy gaps (INVEST) has emerged as a powerful approach for enhancing fluorescence efficiency through triplet harvesting. In these unique materials, the first excited singlet state (S1) lies below lowest (T1), enabling efficient reverse intersystem crossing. Previous computational studies have focused on accurately calculating gap and establishing qualitative structure-property relationships. Here, we present quantitative relationships that link molecular structure to S1-T1 gap, ΔEST, by introducing benchmark set 15 heptazine-based INVEST (HEPTA-INVEST15). We identify strong linear correlation (R2 > 0.94) between ΔEST both degree intramolecular charge transfer deviation from single-excitation character, quantified %R1 values transition density matrix norms. These trends persist across our expanded 44 mono-, di-, tri-substituted heptazines (HEPTA-INVEST44), underscoring generality findings. Notably, strongly electron-donating groups, such -NH2, minimize magnitude in mono-substituted yet produce most negative certain derivatives, result arising competing resonance effects excited-state aromaticity. Although shows no clear Hammett parameters, results reveal physically meaningful, computable descriptors offer mechanistic foundation future data-driven design emitters. findings pave way machine-learning approaches connect without requiring high-level calculations.
Language: Английский
Citations
0
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
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
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
The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown
Published: Oct. 17, 2024
Language: Английский
Citations
1
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
The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(40), P. 16879 - 16891
Published: Oct. 1, 2024
Language: Английский
Citations
0