Calculations on the electronic structure and nonlinear second-order susceptibilities of fulleropyrrolidine–tetrathiafulvalene(C60PY–TTF) based on donor–bridge–acceptor dyads

2001 ◽  
Vol 79 (9) ◽  
pp. 1366-1375
Author(s):  
Wei Fu ◽  
Hong-Xing Zhang ◽  
Ji-Kang Feng ◽  
Wei Li
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Electronic Spectra ◽  
Electronic Structures ◽  
Second Order ◽  
Enhancing Effect ◽  
Charge Transfer Interaction ◽  
Indo Calculations ◽  
Equilibrium Geometries

The semiempirical INDO calculations were carried out to investigate the charge-transfer interaction and to evaluate the second-order nonlinear susceptibilities for a series of fulleropyrrolidine–tetrathiafulvalene(C60PY–TTF) dyads, C60PY, and C60PY-(CH=CH)n-TTF (n = 0–6). The equilibrium geometries, electronic structures, and UV–vis spectra of these C60PY–TTFs D–B–A dyads were determined by using ZINDO methods. On the basis of electronic spectra, we calculated the β for the dyads using the ZINDO-SOS expression, and found that these dyads have relatively large β. The calculated values of β are 48.78, 62.34, 97.90, 123.24, 183.78, 189.43, 193.45, 195.82 × 10–30 esu for C60PY and C60PY-(CH=CH)n-TTF (n = 0–6), respectively, which shows the enhancing effect when TTF is introduced. The β significantly increases as n increases from 0–3; and it tends to be saturated in the end.Key words: ZINDO-SOS, CI, structure, spectra, C60PY–TTF.

Article

1998 ◽  
Vol 76 (3) ◽  
pp. 307-312
Author(s):  
A Wallace Cordes ◽  
Robert C Haddon ◽  
Robin G Hicks ◽  
Richard T Oakley ◽  
Kristen E Vajda
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Magnetic Susceptibility ◽  
Electronic Structure ◽  
Charge Transfer ◽  
Electronic Structures ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Diamagnetic State

Electroreduction of the 2,5-thiophene-bridged bis(1,2,3,5-diselenadiazolylium) salt [T-2,5-Se][SbF6]2 in acetonitrile, at a Pt wire and in the presence of iodine, affords a highly conductive ( sigma = 102 S cm-1 at 293 K) 1:1 charge-transfer (CT) salt [T-2,5-Se][I], the crystal structure of which has been determined by single-crystal X-ray diffraction. The crystals belong to the orthorhombic space group Fm2m, a = 3.544(2), b = 10.9808(16), c = 31.464(5) Å , V = 1224.5(7) Å 3. The structure consists of perfectly superimposed pi -stacks of molecular units bridged by columns of disordered iodines. This packing motif is similar to that of the related 1,3-benzene-bridged derivative [1,3-Se][I], but the lateral intermolecular Se···Se interactions linking adjacent pi -stacks are considerably shorter, indicative of a more isotropic electronic structure for [T-2,5-Se][I]. Magnetic susceptibility measurements on [T-2,5-Se][I] nonetheless indicate a phase transition to a diamagnetic state near 200 K, behaviour similar to that observed for [1,3-Se][I]. The electronic structures and transport properties of the two compounds are discussed in the light of extended Hückel band-structure calculations.Key words: diselenadiazolyl, diradical, charge-transfer salt, magnetic susceptibility, crystal structure.

INTERACTION OF BERYLLIUM WITH ACCEPTOR HYDROCARBONS: ELECTRONIC STRUCTURE AND SECOND HYPERPOLARIZABILITY

2013 ◽  
Vol 12 (06) ◽  
pp. 1350046 ◽  
Author(s):  
KAUSHIK HATUA ◽  
PRASANTA K. NANDI
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Computational Cost ◽  
Longitudinal Component ◽  
Basis Set ◽  
Thermally Stable ◽  
Second Hyperpolarizability ◽  
Charge Delocalization ◽  
Charge Transfer Interaction

Some selected acceptor-Be hydrocarbon complexes have been considered for evaluation of second hyperpolarizability at different DFT functional. All the complexes have been found thermally stable and there is a significant increase of second hyperpolarizability compared to the ligands. Second hyperpolarizability has been explained in terms of charge transfer interaction. Co-operative interaction is required for maximization of second hyperpolarizability. Localized charge transfer in the vicinity of metal alone cannot increase second hyperpolarizability while charge delocalization over entire molecule is mandatory. Substitution by more electropositive metals e.g. Mg , Ca have greater enhancement in longitudinal component of γ. Basis set 6-311++G** is reasonable with respect to computational cost at aug-cc-pVnZ's (n = D, T, Q) for evaluation of second hyperpolarizability for the present complexes.

Electronic structures and spectroscopic regularities of phenylene-modified SWCNTs

2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Xinwei Huang ◽  
Zhengyuan Tu ◽  
Zipeng Ma ◽  
Shi Wu
Keyword(s):  
Electronic Spectra ◽  
Electronic Structures ◽  
Density Functional ◽  
Chemical Shifts ◽  
Single Wall Carbon Nanotubes ◽  
Functional Theory ◽  
Energy Gaps ◽  
The Density Functional Theory ◽  
Equilibrium Geometries ◽  
Pristine Swcnts

AbstractThe equilibrium geometries and electronic structures for a series of single-wall carbon nanotubes (SWCNTs) modified with phenylene were studied using the density functional theory (DFT) at the B3LYP/6-31G(d) level. Of the four configurations of the phenylene-modified SWCNTs, the v-configuration in which the bond is perpendicular to the main axis of the SWCNT is the most thermodynamically stable. The increase in radii of the modified SWCNTs generally leads to a decrease in the energy gaps. The first absorptions in the electronic spectra of the modified SWCNTs compared with those in the electronic spectra of pristine SWCNTs are basically red-shifted. The chemical shifts of bridged carbon atoms connected with phenylene in the v-configuration are shifted downfield relative to those of the pristine SWCNTs. The aromaticity of the rings in SWCNTs is improved owing to the addition of phenylene.

Fluorescence Quenching of Aminodiphenylamines with Chloromethanes

2002 ◽  
Vol 67 (8) ◽  
pp. 1154-1164 ◽  
Author(s):  
Nachiappan Radha ◽  
Meenakshisundaram Swaminathan
Keyword(s):  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Ground State ◽  
Rate Constants ◽  
Quenching Mechanism ◽  
Quenching Rate ◽  
Charge Transfer Interaction ◽  
Electronically Excited ◽  
A Charge

The fluorescence quenching of 2-aminodiphenylamine (2ADPA), 4-aminodiphenylamine (4ADPA) and 4,4'-diaminodiphenylamine (DADPA) with tetrachloromethane, chloroform and dichloromethane have been studied in hexane, dioxane, acetonitrile and methanol as solvents. The quenching rate constants for the process have also been obtained by measuring the lifetimes of the fluorophores. The quenching was found to be dynamic in all cases. For 2ADPA and 4ADPA, the quenching rate constants of CCl4 and CHCl3 depend on the viscosity, whereas in the case of CH2Cl2, kq depends on polarity. The quenching rate constants for DADPA with CCl4 are viscosity-dependent but the quenching with CHCl3 and CH2Cl2 depends on the polarity of the solvents. From the results, the quenching mechanism is explained by the formation of a non-emissive complex involving a charge-transfer interaction between the electronically excited fluorophores and ground-state chloromethanes.

scholarly journals Electronic Structure of n-Cycloparaphenylenes Directly Observed by Photoemission Spectroscopy

2021 ◽  
Author(s):  
Kaname Kanai ◽  
Takuya Inoue ◽  
Takaya Furuichi ◽  
Kaito Shinoda ◽  
Takashi Iwahashi ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electronic Structures ◽  
Photoemission Spectroscopy ◽  
Cyclic Structure ◽  
Visible Absorption ◽  
X Ray ◽  
Inverse Photoemission

A series of n-cycloparaphenylenes ([n]CPP) were studied by ultraviolet photoemission, inverse photoemission, ultraviolet-visible absorption, and X-ray photoemission spectroscopy to detect their unique electronic structures. [n]CPP has a cyclic structure in...

scholarly journals Understanding contact electrification at liquid–solid interfaces from surface electronic structure

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mingzi Sun ◽  
Qiuyang Lu ◽  
Zhong Lin Wang ◽  
Bolong Huang
Keyword(s):  
Charge Transfer ◽  
Electronic Structures ◽  
Electrochemical Cell ◽  
Cell Model ◽  
Electrostatic Charge ◽  
Direct Visualization ◽  
Solid Interface ◽  
Surface Electronic Structure ◽  
Contact Electrification ◽  
Triboelectric Nanogenerators

AbstractThe charge transfer phenomenon of contact electrification even exists in the liquid–solid interface by a tiny droplet on the solid surface. In this work, we have investigated the contact electrification mechanism at the liquid–solid interface from the electronic structures at the atomic level. The electronic structures display stronger modulations by the outmost shell charge transfer via surface electrostatic charge perturbation than the inter-bonding-orbital charge transfer at the liquid–solid interface, supporting more factors being involved in charge transfer via contact electrification. Meanwhile, we introduce the electrochemical cell model to quantify the charge transfer based on the pinning factor to linearly correlate the charge transfer and the electronic structures. The pinning factor exhibits a more direct visualization of the charge transfer at the liquid–solid interface. This work supplies critical guidance for describing, quantifying, and modulating the contact electrification induced charge transfer systems in triboelectric nanogenerators in future works.

Sign in / Sign up

Export Citation Format

Share Document