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.

Quantum yield in blue-emitting anthracene derivatives: vibronic coupling density and transition dipole moment density

2014 ◽  
Vol 16 (27) ◽  
pp. 14244-14256 ◽  
Author(s):  
Motoyuki Uejima ◽  
Tohru Sato ◽  
Daisuke Yokoyama ◽  
Kazuyoshi Tanaka ◽  
Jong-Wook Park
Keyword(s):  
Dipole Moment ◽  
Quantum Yield ◽  
Transition Dipole Moment ◽  
Vibronic Coupling ◽  
Transition Dipole ◽  
Anthracene Derivatives ◽  
Vibronic Couplings ◽  
Franck Condon

Diagonal vibronic couplings in the Franck–Condon S1 state cause torsional distortion, which gives rise to enhancement of fluorescence with a large transition dipole moment.

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.

scholarly journals Theoretical study of the electric and the magnetic dipole in UV-Vis and ECD of fluralaner: the folded conformation and the extended conformation

2021 ◽  
Author(s):  
kamal ziadi
Keyword(s):  
Theoretical Study ◽  
Transition Density ◽  
Real Space ◽  
Photon Absorption ◽  
Transition Dipole ◽  
Extended Conformation ◽  
Difference Density ◽  
Charge Difference Density ◽  
Via Hole ◽  
Transition Density Matrix

Abstract In our contribution, we have carried out a theoretical study of the transition characteristics of one-photon absorption (OPA) spectra of the folded conformation and the extended conformation of fluralaner. The electronic transitions in OPA are visualized with charge difference density (CDD) and transition density matrix (TDM) to explain the charge transfer via hole-electron distribution. We also analyze the transition dipole electric/ magnetic moment by using the isosurface (real space) and TDM diagram in order to determine the portions of molecules which have the most contribution in ECD 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.

Real-Space Imaging of a Single-Molecule Monoradical Reaction

2020 ◽  
Vol 142 (31) ◽  
pp. 13550-13557 ◽  
Author(s):  
Shaotang Song ◽  
Na Guo ◽  
Xinzhe Li ◽  
Guangwu Li ◽  
Yohei Haketa ◽  
...  
Keyword(s):  
Single Molecule ◽  
Real Space

Ab Initio Calculations of Vibrational Energy Levels and Transition Dipole Moments of CO2 Molecules

2008 ◽  
Author(s):  
Zhi Liang ◽  
Hai-Lung Tsai
Keyword(s):  
Ab Initio ◽  
Vibrational Energy ◽  
Molecular Spectroscopy ◽  
Dipole Moments ◽  
Energy Levels ◽  
Wave Functions ◽  
Molecular Vibration ◽  
Transition Dipole ◽  
Transition Dipole Moments ◽  
Vibrational Energy Levels

Ab initio MD simulation of laser-matter interactions is a hot area in the study of the mechanisms of photo-dissociation, photo-ionization and laser induced chemical reactions. The major problems in the study of laser-molecule interactions are to determine the energies and wave functions of molecular vibration states and the molecular transition dipole moments. An efficient method is presented to calculate the intramolecular potential energies and electrical dipole moments of CO2 molecules at the electronic ground state by solving the Kohn-Sham (KS) equation for a total of 101,992 nuclear configurations. The Projector-Augmented Wave (PAW) exchange-correlation potential functionals and Plane Wave (PW) basis functions were used in solving the KS equation. The calculated intra-molecular potential function was then included in the pure vibrational Schro¨dinger equation to determine the vibrational energy eigen values and eigen functions. The vibrational wave functions combined with the calculated dipole moment function were used to determine the transition dipole moments. The calculated results have a good agreement with experimental values. These results can be further used to determinations of molecular spectroscopy and laser absorption coefficients.

Transition Dipole Orientation of Linear Polyenes:  Semiempirical Models and Extrapolation to the Infinite Chain Limit

1999 ◽  
Vol 103 (14) ◽  
pp. 2251-2255 ◽  
Author(s):  
Robert R. Birge ◽  
Marek Z. Zgierski ◽  
Luis Serrano-Andres ◽  
Bruce S. Hudson
Keyword(s):  
Infinite Chain ◽  
Dipole Orientation ◽  
Transition Dipole ◽  
Linear Polyenes ◽  
Semiempirical Models

scholarly journals Single-Molecule van der Waals Compass

2020 ◽  
Author(s):  
Xiao Chen ◽  
Boyuan Shen ◽  
Huiqiu Wang ◽  
Hao Xiong ◽  
Weizhong Qian ◽  
...  
Keyword(s):  
Single Molecule ◽  
Potential Field ◽  
Van Der Waals ◽  
Real Space ◽  
Channel Structure ◽  
Transmission Electron ◽  
Imaging Results ◽  
Scanning Transmission ◽  
Para Xylene ◽  
Temporal Dimensions

Abstract Imaging the single molecules is always challenging under the diverse microscopes, but highly demanded for investigating the intermolecular interactions at the molecular level1-6. The van der Waals (vdW) interactions at sub-nanometer scale will deeply influence various molecular behaviors under the confinement conditions7-11. Here, inspired by the traditional compass12, we introduce a classical strategy using a vertical para-xylene (PX) molecule as a rotating pointer to detect the vdW potential field in a MFI straight channel. Based on the integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM)13-17, we achieve the real-space imaging of single PX molecule pointer in each channel with a certain orientation. The solid relation between the pointer orientation and atomic channel structure in this vdW compass is established by combining the calculations and imaging results. Thus, these PX orientations help us identify the varied vdW potential field related to the channel geometry both in the spatial and temporal dimensions. This work not only provides a visible and sensitive pointer to investigate the host-guest vdW interactions in porous materials at the molecular level, but also promotes the further imaging and study of other single-molecule behaviors by the iDPC-STEM.

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