Electronic coupling in inter- and intramolecular donor-acceptor systems as revealed by their solvent-dependent charge-transfer fluorescence

1995 ◽  
Vol 114 (11-12) ◽  
pp. 443-448 ◽  
Author(s):  
J. W. Verhoeven ◽  
T. Scherer ◽  
B. Wegewijs ◽  
R. M. Hermant ◽  
J. Jortner ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electronic Coupling ◽  
Donor Acceptor

Electronic Coupling and Spin–Orbit Charge-Transfer Intersystem Crossing in Phenothiazine–Perylene Compact Electron Donor/Acceptor Dyads

2019 ◽  
Vol 123 (12) ◽  
pp. 7010-7024 ◽  
Author(s):  
Muhammad Imran ◽  
Andrey A. Sukhanov ◽  
Zhijia Wang ◽  
Ahmet Karatay ◽  
Jianzhang Zhao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electron Donor ◽  
Electronic Coupling ◽  
Intersystem Crossing ◽  
Spin Orbit ◽  
Donor Acceptor

scholarly journals Shallow distance-dependent triplet energy migration mediated by endothermic charge-transfer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Runchen Lai ◽  
Yangyi Liu ◽  
Xiao Luo ◽  
Lan Chen ◽  
Yaoyao Han ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Semiconductor Nanocrystals ◽  
Electronic Coupling ◽  
Alternative Mechanism ◽  
Acceptor Pair ◽  
Triplet Energy ◽  
Distance Dependence ◽  
Donor Acceptor ◽  
Triplet Energy Transfer

AbstractConventional wisdom posits that spin-triplet energy transfer (TET) is only operative over short distances because Dexter-type electronic coupling for TET rapidly decreases with increasing donor acceptor separation. While coherent mechanisms such as super-exchange can enhance the magnitude of electronic coupling, they are equally attenuated with distance. Here, we report endothermic charge-transfer-mediated TET as an alternative mechanism featuring shallow distance-dependence and experimentally demonstrated it using a linked nanocrystal-polyacene donor acceptor pair. Donor-acceptor electronic coupling is quantitatively controlled through wavefunction leakage out of the core/shell semiconductor nanocrystals, while the charge/energy transfer driving force is conserved. Attenuation of the TET rate as a function of shell thickness clearly follows the trend of hole probability density on nanocrystal surfaces rather than the product of electron and hole densities, consistent with endothermic hole-transfer-mediated TET. The shallow distance-dependence afforded by this mechanism enables efficient TET across distances well beyond the nominal range of Dexter or super-exchange paradigms.

scholarly journals Interplay of Direct and Indirect Charge Transfer Pathways in Donor-Bridge-Acceptor Systems

2019 ◽  
Author(s):  
Junjie Liu ◽  
Dvira Segal
Keyword(s):  
Charge Transfer ◽  
Quantum Interference ◽  
Transport Processes ◽  
Electronic Coupling ◽  
Transfer Processes ◽  
Quantum Interference Effect ◽  
Donor Acceptor ◽  
Charge Transfer Dynamics ◽  
Reduced Density ◽  
Coherent Part

Charge transfer in donor-bridge-acceptor (DBA) structures typically takes place through the combination of donor-bridge and bridge-acceptor overlap integrals forming an effective, indirect electronic coupling between the donor (D) and acceptor (A) moieties. Here, we examine the effects of an additional direct DA electronic coupling on charge transfer processes in DBA systems with local interaction to thermal baths. First, using the exact Nakajima-Zwanzig master equation (NZME) for the reduced density matrix, we rigorously define probability currents as the coherent part of the NZME, thereby allowing us to quantify the contribution of the different electronic pathways (direct and indirect) to the charge transfer dynamics. Focusing on two minimal DBA systems of three sites (V and L models), and adopting well-developed methods, we find that the interplay between different transfer pathways can be assessed by the McConnell formula in the weak systembath coupling regime. We then demonstrate that the combination of indirect and direct donor-acceptor coupling either enhances or leads to a destructive quantum interference effect on charge transport processes, depending on the energy landscape of the DBA system.<br>

scholarly journals Role of intramolecular hydrogen bonds in promoting electron flow through amino acid and oligopeptide conjugates

2021 ◽  
Vol 118 (11) ◽  
pp. e2026462118
Author(s):  
Rafał Orłowski ◽  
John A. Clark ◽  
James B. Derr ◽  
Eli M. Espinoza ◽  
Maximilian F. Mayther ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Hydrogen Bonds ◽  
Electron Flow ◽  
Intramolecular Hydrogen Bonding ◽  
Electronic Coupling ◽  
Molecular Architecture ◽  
Energy Flows ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Intramolecular Hydrogen

Elucidating the factors that control charge transfer rates in relatively flexible conjugates is of importance for understanding energy flows in biology as well as assisting the design and construction of electronic devices. Here, we report ultrafast electron transfer (ET) and hole transfer (HT) between a corrole (Cor) donor linked to a perylene-diimide (PDI) acceptor by a tetrameric alanine (Ala)4. Selective photoexcitation of the donor and acceptor triggers subpicosecond and picosecond ET and HT. Replacement of the (Ala)4 linker with either a single alanine or phenylalanine does not substantially affect the ET and HT kinetics. We infer that electronic coupling in these reactions is not mediated by tetrapeptide backbone nor by direct donor–acceptor interactions. Employing a combination of NMR, circular dichroism, and computational studies, we show that intramolecular hydrogen bonding brings the donor and the acceptor into proximity in a “scorpion-shaped” molecular architecture, thereby accounting for the unusually high ET and HT rates. Photoinduced charge transfer relies on a (Cor)NH…O=C–NH…O=C(PDI) electronic-coupling pathway involving two pivotal hydrogen bonds and a central amide group as a mediator. Our work provides guidelines for construction of effective donor–acceptor assemblies linked by long flexible bridges as well as insights into structural motifs for mediating ET and HT in proteins.

scholarly journals Interplay of Direct and Indirect Charge Transfer Pathways in Donor-Bridge-Acceptor Systems

2019 ◽  
Author(s):  
Junjie Liu ◽  
Dvira Segal
Keyword(s):  
Charge Transfer ◽  
Quantum Interference ◽  
Transport Processes ◽  
Electronic Coupling ◽  
Transfer Processes ◽  
Quantum Interference Effect ◽  
Donor Acceptor ◽  
Charge Transfer Dynamics ◽  
Reduced Density ◽  
Coherent Part

Charge transfer in donor-bridge-acceptor (DBA) structures typically takes place through the combination of donor-bridge and bridge-acceptor overlap integrals forming an effective, indirect electronic coupling between the donor (D) and acceptor (A) moieties. Here, we examine the effects of an additional direct DA electronic coupling on charge transfer processes in DBA systems with local interaction to thermal baths. First, using the exact Nakajima-Zwanzig master equation (NZME) for the reduced density matrix, we rigorously define probability currents as the coherent part of the NZME, thereby allowing us to quantify the contribution of the different electronic pathways (direct and indirect) to the charge transfer dynamics. Focusing on two minimal DBA systems of three sites (V and L models), and adopting well-developed methods, we find that the interplay between different transfer pathways can be assessed by the McConnell formula in the weak systembath coupling regime. We then demonstrate that the combination of indirect and direct donor-acceptor coupling either enhances or leads to a destructive quantum interference effect on charge transport processes, depending on the energy landscape of the DBA system.<br>

scholarly journals Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Theoretical Investigations ◽  
Donor Acceptor ◽  
And Control ◽  
Two Temperature

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.

Sign in / Sign up

Export Citation Format

Share Document