scholarly journals Controlling through-space and through-bond intramolecular charge transfer in bridged D-D’-A TADF Emitters

2021 ◽  
Author(s):  
Hector Gerardo Miranda-Salinas ◽  
Andrew P Monkman ◽  
Chih-Hao Chang ◽  
Hao-Che Kao ◽  
Dian Luo ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Acceptor Molecules

Donor-Donor’-Acceptor molecules where the Donor’ bridges the Donor and Acceptor have different possible interaction pathways for charge transfer. Here we study a series of Donor-Donor’-Acceptor molecules, having the same Acceptor...

Photoinduced intramolecular charge-transfer state in thiophene-π-conjugated donor–acceptor molecules

2008 ◽  
Vol 876 (1-3) ◽  
pp. 102-109 ◽  
Author(s):  
Ruikui Chen ◽  
Guangjiu Zhao ◽  
Xichuan Yang ◽  
Xiao Jiang ◽  
Jifeng Liu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Charge Transfer State ◽  
Donor Acceptor ◽  
Transfer State ◽  
Acceptor Molecules

Intramolecular charge transfer in donor-acceptor molecules

1990 ◽  
Vol 94 (10) ◽  
pp. 3894-3902 ◽  
Author(s):  
A. Slama-Schwok ◽  
M. Blanchard-Desce ◽  
J. M. Lehn
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Donor Acceptor ◽  
Acceptor Molecules

scholarly journals A general design approach toward covalent organic frameworks for highly efficient electrochemiluminescence

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ya-Jie Li ◽  
Wei-Rong Cui ◽  
Qiao-Qiao Jiang ◽  
Qiong Wu ◽  
Ru-Ping Liang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
High Speed ◽  
Intramolecular Charge Transfer ◽  
High Sensitivity ◽  
Covalent Organic Frameworks ◽  
Transport Networks ◽  
Promising Direction ◽  
Highly Efficient ◽  
Donor And Acceptor ◽  
Donor Acceptor

AbstractElectrochemiluminescence (ECL) plays a key role in analysis and sensing because of its high sensitivity and low background. Its wide applications are however limited by a lack of highly tunable ECL luminophores. Here we develop a scalable method to design ECL emitters of covalent organic frameworks (COFs) in aqueous medium by simultaneously restricting the donor and acceptor to the COFs’ tight electron configurations and constructing high-speed charge transport networks through olefin linkages. This design allows efficient intramolecular charge transfer for strong ECL, and no exogenous poisonous co-reactants are needed. Olefin-linked donor-acceptor conjugated COFs, systematically synthesized by combining non-ECL active monomers with C2v or C3v symmetry, exhibit strong ECL signals, which can be boosted by increasing the chain length and conjugation of monomers. The present concept demonstrates that the highly efficient COF-based ECL luminophores can be precisely designed, providing a promising direction toward COF-based ECL phosphors.

scholarly journals Predicting Excitation Energies of Twisted Intramolecular Charge-Transfer States with Time-Dependent Density Functional Theory: Comparison with Experimental Measurements in the Gas-Phase and Solvents Ranging from Hexanes to Acetonitrile

2020 ◽  
Author(s):  
James Shee ◽  
Martin Head-Gordon
Keyword(s):  
Charge Transfer ◽  
Gas Phase ◽  
Excited States ◽  
Linear Response ◽  
Density Functional ◽  
Intramolecular Charge Transfer ◽  
Experimental Measurements ◽  
Excitation Energies ◽  
Donor And Acceptor ◽  
Donor Acceptor

Electronically-excited states characterized by intramolecular charge-transfer play an essential role in many biological processes and optical devices. The ability to make quantitative ab initio predictions of the relative energetics involved is a challenging yet desirable goal, especially for large molecules in solution. In this work we present a data set of 61 experimental measurements of absorption and emission processes, both in the gas phase and solvents representing a broad range of polarities, which involve intramolecular charge-transfer mediated by a non-zero, “twisted” dihedral angle between one or more donor and acceptor subunits. Among a variety of density functionals investigated within the framework of linear-response theory, the “optimally tuned” LRC-ωPBE functional, which utilizes a system-specific yet non-empirical procedure to specify the range-separation parameter, emerges as the preferred choice. For the entire set of excitation energies, involving changes in dipole moment ranging from 4 to >20 Debye, the mean signed and absolute errors are 0.02 and 0.18 eV, respectively (compared, e.g., to -0.30 and 0.30 for PBE0, 0.44 and 0.47 for LRC-ωPBEh, 0.83 and 0.83 for ωB97X-V). The performance of polarizable continuum solvation models for these charge-transfer excited states is closely examined, and clear trends emerge when measurements corresponding to the four small DMABN-like molecules and a charged species are excluded. We make the case that the large errors found only for small molecules in the gas phase and weak solvents cannot be expected to improve via the optimal tuning procedure, which enforces a condition that is exact only in the wellseparated donor-acceptor limit, and present empirical evidence implicating the outsized importance for small donor-acceptor systems of relaxation effects that cannot be accounted for by linear-response TDDFT within the adiabatic approximation. Finally, we demonstrate the utility of the optimally tuned density functional approach by targeting the charge-transfer states of a large biomimetic model system for light-harvesting structures in Photosystem II.

A TWO-FORM DESCRIPTION OF PUSH-PULL MOLECULES: CORRELATIONS BETWEEN STRUCTURE, INTRAMOLECULAR CHARGE TRANSFER AND (HYPER) POLARIZABILITIES

1996 ◽  
Vol 05 (04) ◽  
pp. 757-765 ◽  
Author(s):  
M. BARZOUKAS ◽  
A. FORT ◽  
M. BLANCHARD-DESCE
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Intramolecular Charge Transfer ◽  
Ground States ◽  
Solvent Polarity ◽  
Reaction Field ◽  
Donor Acceptor ◽  
Semi Empirical ◽  
Relevant Factors ◽  
Acceptor Molecules

We present a quantum two-form two-state description of donor-acceptor molecules. We single out relevant factors that are characteristic of the molecule and its environment. In addition, we define a parameter which rules the geometry of both ground and excited states. Also, this parameter is proportional to the change in dipole between excited and ground states. We show that correlations between (hyper)polarizabilities and this parameter reproduce remarkably well semi-empirical predictions. We extend this model in order to account for the solvent reaction field. This model helps in the understanding of the dependencies of (hyper)polarizabilities on solvent polarity.

scholarly journals Predicting Excitation Energies of Twisted Intramolecular Charge-Transfer States with Time-Dependent Density Functional Theory: Comparison with Experimental Measurements in the Gas-Phase and Solvents Ranging from Hexanes to Acetonitrile

2020 ◽  
Author(s):  
James Shee ◽  
Martin Head-Gordon
Keyword(s):  
Charge Transfer ◽  
Gas Phase ◽  
Excited States ◽  
Linear Response ◽  
Density Functional ◽  
Intramolecular Charge Transfer ◽  
Experimental Measurements ◽  
Excitation Energies ◽  
Donor And Acceptor ◽  
Donor Acceptor

Electronically-excited states characterized by intramolecular charge-transfer play an essential role in many biological processes and optical devices. The ability to make quantitative ab initio predictions of the relative energetics involved is a challenging yet desirable goal, especially for large molecules in solution. In this work we present a data set of 61 experimental measurements of absorption and emission processes, both in the gas phase and solvents representing a broad range of polarities, which involve intramolecular charge-transfer mediated by a non-zero, “twisted” dihedral angle between one or more donor and acceptor subunits. Among a variety of density functionals investigated within the framework of linear-response theory, the “optimally tuned” LRC-ωPBE functional, which utilizes a system-specific yet non-empirical procedure to specify the range-separation parameter, emerges as the preferred choice. For the entire set of excitation energies, involving changes in dipole moment ranging from 4 to >20 Debye, the mean signed and absolute errors are 0.02 and 0.18 eV, respectively (compared, e.g., to -0.30 and 0.30 for PBE0, 0.44 and 0.47 for LRC-ωPBEh, 0.83 and 0.83 for ωB97X-V). The performance of polarizable continuum solvation models for these charge-transfer excited states is closely examined, and clear trends emerge when measurements corresponding to the four small DMABN-like molecules and a charged species are excluded. We make the case that the large errors found only for small molecules in the gas phase and weak solvents cannot be expected to improve via the optimal tuning procedure, which enforces a condition that is exact only in the wellseparated donor-acceptor limit, and present empirical evidence implicating the outsized importance for small donor-acceptor systems of relaxation effects that cannot be accounted for by linear-response TDDFT within the adiabatic approximation. Finally, we demonstrate the utility of the optimally tuned density functional approach by targeting the charge-transfer states of a large biomimetic model system for light-harvesting structures in Photosystem II.

Energy and charge transfer by donor–acceptor pairs confined in a metal–organic framework: a spectroscopic and computational investigation

2014 ◽  
Vol 2 (10) ◽  
pp. 3389-3398 ◽  
Author(s):  
Kirsty Leong ◽  
Michael E. Foster ◽  
Bryan M. Wong ◽  
Erik D. Spoerke ◽  
Dara Van Gough ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Energy Harvesting ◽  
Metal Organic Framework ◽  
Phase Segregation ◽  
Computational Investigation ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Metal Organic ◽  
Organic Framework ◽  
Acceptor Molecules

A metal–organic framework serves as a multifunctional host for donor and acceptor molecules, enabling energy harvesting and transfer without phase segregation.

scholarly journals Single-Component Organic Solar Cells Based on Intramolecular Charge Transfer Photoabsorption

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1200
Author(s):  
Ken-ichi Nakayama ◽  
Tatsuya Okura ◽  
Yuki Okuda ◽  
Jun Matsui ◽  
Akito Masuhara ◽  
...  
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
Organic Solar Cells ◽  
Intramolecular Charge Transfer ◽  
Internal Quantum Efficiency ◽  
Single Component ◽  
Chemical Calculation ◽  
Key Factor ◽  
Donor Acceptor ◽  
Acceptor Molecules

Conjugated donor–acceptor molecules with intramolecular charge transfer absorption are employed for single-component organic solar cells. Among the five types of donor–acceptor molecules, the strong push–pull structure of DTDCPB resulted in solar cells with high JSC, an internal quantum efficiency exceeding 20%, and high VOC exceeding 1 V with little photon energy loss around 0.7 eV. The exciton binding energy (EBE), which is a key factor in enhancing the photocurrent in the single-component device, was determined by quantum chemical calculation. The relationship between the photoexcited state and the device performance suggests that the strong internal charge transfer is effective for reducing the EBE. Furthermore, molecular packing in the film is shown to influence photogeneration in the film bulk.

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