CHARGE AND ENERGY TRANSFER IN BINAPHTHALENE MOLECULE WITH TWO SPIROPYRAN UNITS USED FOR CHIRAL MOLECULAR SWITCHES AND LOGIC GATES

2006 ◽  
Vol 05 (02) ◽  
pp. 163-174 ◽  
Author(s):  
MENGTAO SUN ◽  
FENGCAI MA
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Absorption Spectra ◽  
Transition Density ◽  
Logic Gates ◽  
Molecular Switches ◽  
Transition Dipole Moment ◽  
Real Space ◽  
Transition Dipole ◽  
Contour Plots

A new binaphthalene molecule with two spiropyran units used for chiral molecular switches and logic gates was synthesized and characterized.12 In this paper, charge and energy transfer in binaphthalene molecule with two spiropyran units are theoretically investigated with quantum chemistry method, as well as 2D and 3D real space analysis methods, since molecule construction with photoinduced electron transfer or charge transfer is one of the most frequently used pathways for building useful sensors and molecular machines. The orientation and strength of transition dipole moment in absorption spectra are obtained by 3D transition density. The orientation and results of intramolecular charge transfer on the excitation are obtained with 3D charge difference densities. The electron-hole coherence and excitation delocalization in absorption spectra are investigated with 2D contour plots of transition density matrix. Overall, the computed results remain in good agreement with the relevant experimental data, and the theoretical results reveal the relationship between the function of sensor and the excited state properties of the structure and transformation of the compound, upon addition of acid and base in absorption spectra.

THEORETICAL STUDY ON PHOTOINDUCED INTRAMOLECULAR CHARGE TRANSFER IN A NOVEL ORGANIC SENSITIZER C201

2011 ◽  
Vol 10 (05) ◽  
pp. 641-649 ◽  
Author(s):  
FENGJIE ZHOU ◽  
YAPING ZHANG ◽  
SHUO CAO ◽  
YONG DING ◽  
SHASHA LIU
Keyword(s):  
Charge Transfer ◽  
Molecular Orbital ◽  
Density Functional ◽  
Intramolecular Charge Transfer ◽  
Transition Density ◽  
Dft Method ◽  
Transition Dipole Moment ◽  
Transition Dipole ◽  
Level Densities ◽  
Charge Difference Density

A new organic dye (C201) composed of triarylamine unit as electron donor and anchoring unit as electron acceptor, was theoretically investigated by quantum chemical methods. We optimized the geometry of C201 with density functional theory (DFT) at B3LYP/6-311G (d) level. Densities of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), as well as the energies are listed. The excited states of the dye molecules C201 were calculated by time dependent-DFT (TD-DFT) method. Two main visible bands at 572 nm and 407 nm were mainly attributed to the electronic transition from HOMO→LUMO and HOMO-1→LUMO, respectively. 3D cube representations including transition density (TD) and charge difference density (CDD) directly visualized the character of intramolecular charge transfer of C201. The orientation and strength of transition dipole moment were showed visually using TD. Furthermore, we illustrate the orientation and results of the intramolecular charge transfer by CDD.

scholarly journals Probing intramolecular vibronic coupling through vibronic-state imaging

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fan-Fang Kong ◽  
Xiao-Jun Tian ◽  
Yang Zhang ◽  
Yun-Jie Yu ◽  
Shi-Hao Jing ◽  
...  
Keyword(s):  
Single Molecule ◽  
Molecular Spectroscopy ◽  
Transition Density ◽  
Real Space ◽  
Vibronic Coupling ◽  
Vibronic State ◽  
Dipole Orientation ◽  
Transition Dipole ◽  
Franck Condon ◽  
Strong Dynamic

AbstractVibronic coupling is a central issue in molecular spectroscopy. Here we investigate vibronic coupling within a single pentacene molecule in real space by imaging the spatial distribution of single-molecule electroluminescence via highly localized excitation of tunneling electrons in a controlled plasmonic junction. The observed two-spot orientation for certain vibronic-state imaging is found to be evidently different from the purely electronic 0–0 transition, rotated by 90°, which reflects the change in the transition dipole orientation from along the molecular short axis to the long axis. Such a change reveals the occurrence of strong vibronic coupling associated with a large Herzberg–Teller contribution, going beyond the conventional Franck–Condon picture. The emergence of large vibration-induced transition charges oscillating along the long axis is found to originate from the strong dynamic perturbation of the anti-symmetric vibration on those carbon atoms with large transition density populations during electronic transitions.

ENERGY TRANSFER IN THE PERIDININ CHLOROPHYLL a PROTEIN OF AMPHIDINIUM CARTERAE STUDIED BY POLARIZED ABSORPTION MEASUREMENTS

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3849-3852 ◽  
Author(s):  
STEFANIA. S. LAMPOURA ◽  
B. P. KRUEGER ◽  
I. H. M. VAN STOKKUM ◽  
J. M. SALVERDA ◽  
C. C. GRADINARU ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Chlorophyll A ◽  
Internal Conversion ◽  
Transient Absorption ◽  
Global Analysis ◽  
Transition Dipole Moment ◽  
Transition Dipole ◽  
Amphidinium Carterae ◽  
Light Harvesting Complex ◽  
Chl A

In this work we report the results of ultrafast transient absorption studies which examined energy transfer between carotenoids and chlorophylls in Peridinin-Chlorophyll-a-Protein (PCP) light harvesting complex from the dinoflagellate Amphidinium carterae. Global analysis of the isotropic decay reveals that the peridinin lifetime in PCP is 2.3±0.2 ps. This time constant is the peridinin- Chl a energy transfer, which is essentially entirely mediated by coupling of the peridinin S 1 and Chl a Q y transitions. Based on this lifetime we estimated an energy transfer timescale of ~2.4 ps and a peridinin- Chl a coupling of 46 cm -1. The magnitude of this coupling suggests a peridinin S 1 transition dipole moment of ~3 D . Global analysis of the depolarization measurements, shows, a small decrease in the depolarization from the initial 0.4 value to 0.36±0.03. This decrease occurs on the same timescale as the S2→S1 internal conversion, suggesting that either the S 1 transition dipole is oriented ~15° away from the S 2 transition dipole, or, that a small amount of peridinin S 2-peridinin S 2 energy transfer occurs in competition with internal conversion, or some combination of the two.

scholarly journals Charge Transfer Excitation and Asymmetric Energy Transfer at the Interface of Pentacene-Perfluoropentacene Heterostacks

2020 ◽  
Author(s):  
Anna-Katharina Hansmann ◽  
Robin C. Döring ◽  
Andre Rinn ◽  
Steffen M. Giesen ◽  
Melanie Fey ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Absorption Spectra ◽  
Molecular Alignment ◽  
Cryogenic Temperatures ◽  
Photoluminescence Excitation ◽  
Donor Acceptor ◽  
Charge Transfer Excitation ◽  
The One

The formation pathways of CT-excitons at the model crystalline donor-acceptor interface of pentacene-perfluoropentacene (PEN-PFP) is studied by a combination of advanced experimental and theoretical techniques. More specifically, we compare the one-photon photoluminescence excitation (PLE) and absorption spectra of three different PEN-PFP heterostructures with different molecular alignment at the interface at cryogenic temperatures. <br><div></div>

scholarly journals Polarization angle dependence of stark absorption spectra of spirilloxanthin bound to the reconstituted LH1 complexes using LH1-subunits isolated from the purple photosynthetic bacterium Rhodospirillum rubrum.

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Tomoko Horibe ◽  
Katsunori Nakagawa ◽  
Toshiyuki Kusumoto ◽  
Ritsuko Fujii ◽  
Richard J Cogdell ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Absorption Spectra ◽  
Rhodospirillum Rubrum ◽  
Photosynthetic Bacterium ◽  
Transition Dipole Moment ◽  
Polarization Angle ◽  
Transition Dipole ◽  
Angle Dependence ◽  
Induced Dipole ◽  
Purple Photosynthetic Bacterium

Reconstituted LH1 complexes were prepared using the LH1 subunit-type complexes, isolated from the purple photosynthetic bacterium Rhodospirillum (Rs.) rubrum, and purified all-trans spirilloxanthin. Stark absorption spectra of spirilloxanthin bound to both the native and reconstituted LH1 complexes were compared in different polarization angles (χ) against the external electric field. From the polarization angle dependence of the Stark absorption spectra, two angles were determined in reference to the direction of transition dipole moment (m) of spirilloxanthin: one is the change in polarizability upon photoexcitation (Δα), θ(Δα) and the other is the change in static dipole moment upon photoexcitation (Δμ), θ(Δμ). Despite the symmetric molecular structure of all-trans spirilloxanthin, its Stark absorption spectra show pronounced values of Δμ. This large Δμ values essentially caused by the effect of induced dipole moment through Δα both in the cases for native and reconstituted LH1 complexes. However, slightly different values of θ(Δα) and θ(Δμ) observed for the native LH1 complex suggest that spirilloxanthin is asymmetrically distorted when bound to the native LH1 complex and gives rise to intrinsic Δμ value.

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