scholarly journals Dipole moments of conjugated donor–acceptor substituted systems: calculations vs. experiments

RSC Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 934-945
Author(s):  
Vladimir Lokshin ◽  
Mark Sigalov ◽  
Nina Larina ◽  
Vladimir Khodorkovsky
Keyword(s):  
Organic Molecules ◽  
Dipole Moments ◽  
High Accuracy ◽  
Conjugated Organic Molecules ◽  
B3lyp Functional ◽  
Donor Acceptor

B3LYP functional can reproduce the experimental dipole moments of conjugated organic molecules with high accuracy.

Synthesis and Optical Properties of Donor-Accepter Organic Conjugated Molecules Composed of Fluorene and Phenothiazine

2014 ◽  
Vol 1061-1062 ◽  
pp. 296-300
Author(s):  
Ze Biao Tang ◽  
Xiao Xia Sun ◽  
Pei Lin Zhang
Keyword(s):  
Optical Properties ◽  
Fluorescence Spectra ◽  
Organic Molecules ◽  
Green Light ◽  
Organic Light Emitting Diodes ◽  
Conjugated Molecules ◽  
Strong Emission ◽  
Light Emitting ◽  
Conjugated Organic Molecules ◽  
Donor Acceptor

Novel donor-acceptor conjugated organic molecules composed of central fluorene and phenothiazine units and aldehyde terminal groups have been designed and constructed via the Vilsmeier-Haack reaction. Optical properties of the resulting molecules were examined by UV-vis and fluorescence spectroscopies. The fluorescence spectra of the molecules in the solid state show strong emission peaks in the violet, blue, cyan and green light regions. Thus, the molecules are expected to be promising light-emitting materials for organic light-emitting diodes applications.

scholarly journals Charge transport parameters for carbon based nanohoops and donor–acceptor derivatives

2019 ◽  
Vol 21 (4) ◽  
pp. 2057-2068 ◽  
Author(s):  
Sofia Canola ◽  
Christina Graham ◽  
Ángel José Pérez-Jiménez ◽  
Juan-Carlos Sancho-García ◽  
Fabrizia Negri
Keyword(s):  
Charge Transport ◽  
Crystalline Structure ◽  
Organic Molecules ◽  
Transport Parameters ◽  
Conjugated Organic Molecules ◽  
Donor Acceptor ◽  
Reorganization Energies ◽  
Carbon Based

The effect of donor–acceptor (D–A) moieties on magnitudes such as reorganization energies and electronic couplings in cycloparaphenylene (CPP) carbon based nanohoops (i.e. conjugated organic molecules with cyclic topology) is highlighted via model computations and analysis of the available crystalline structure of N,N-dimethylaza[8]CPP.

Theoretical study on naphthyl-phenylacetylenes for second-order nonlinear optical applications

1997 ◽  
Vol 75 (7) ◽  
pp. 1041-1046 ◽  
Author(s):  
B.V.V.S.N. Prabhakara Rao ◽  
D.C. Dube ◽  
D.P. Tewari ◽  
S.C. Mathur ◽  
M. Banerjee
Keyword(s):  
Ground State ◽  
Nonlinear Optical ◽  
Organic Molecules ◽  
Theoretical Study ◽  
Dipole Moments ◽  
Second Order ◽  
Donor Acceptor ◽  
Optical Applications ◽  
Nonlinear Optical Applications ◽  
Ground State Dipole Moments

The ground state dipole moments (μg), excited state dipole moments (μe), linear polarizabilities (α), first hyperpolarizabilities (β), and absorption maxima [Formula: see text] of a new series of 6,4′-disubstituted 2-naphthylphenylacetylenes have been calculated using the finite field – MNDO (Modified Neglect of Diatomic Overlap) technique and studied for second-order nonlinear optical (NLO) applications. Among all the molecules studied here, the strongest and the weakest electron donor/acceptor pairs [N(CH3)2/NO2] and [CH3/CN] exhibit the largest and the smallest βμ (projection of β on the axis of the μ) of 46.3 × 10−30 esu and 10.2 × 10−30 esu, respectively. The coefficients of the power law that describes the dependence of α and β on the number of conjugated bonds (n) were calculated for [NH2/NO2]n=1–5 and [NH2/CN]n=1–5 molecules. For β, exponents of 0.36 and 0.31 were obtained for [NH2/NO2]n=1–5 and [NH2/CN]n=1–5 molecules, respectively, and for α, an exponent of 0.37 was obtained for both series of molecules. A comparison is made between naphthylphenylacetylenes and diphenylacetylenes on the basis of their hyperpolarizabilities. Keywords: nonlinear optics, organic molecules, hyperpolarizabilities.

scholarly journals An investigation of the interrelationships between linear and nonlinear polarizabilities and bond-length alternation in conjugated organic molecules

1993 ◽  
Vol 90 (23) ◽  
pp. 11297-11301 ◽  
Author(s):  
C B Gorman ◽  
S R Marder
Keyword(s):  
Bond Length ◽  
Organic Molecules ◽  
Computational Method ◽  
Bond Length Alternation ◽  
Conjugated Molecules ◽  
Conjugated Organic Molecules ◽  
Alpha Beta ◽  
Relationship Of ◽  
The Relationship ◽  
Observable Parameter

A computational method was devised to explore the relationship of charge separation, geometry, molecular dipole moment (mu), polarizability (alpha), and hyperpolariz-abilities (beta, gamma) in conjugated organic molecules. We show that bond-length alternation (the average difference in length between single and double bonds in the molecule) is a key structurally observable parameter that can be correlated with hyperpolarizabilities and is thus relevant to the optimization of molecules and materials. By using this method, the relationship of bond-length alternation, mu, alpha, beta, and gamma for linear conjugated molecules is illustrated, and those molecules with maximized alpha, beta, and gamma are described.

Influence of conjugation length on ultrafast electronic tunneling in organic semiconductor thin films

2018 ◽  
Vol 20 (38) ◽  
pp. 25085-25095 ◽  
Author(s):  
Vincent V. Duong ◽  
Alexander L. Ayzner
Keyword(s):  
Molecular Electronics ◽  
Organic Molecules ◽  
Electron Delocalization ◽  
Conjugation Length ◽  
Conjugated Organic Molecules ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Semiconductor Thin Films ◽  
Electronic Tunneling ◽  
Rate Limiting

Electron delocalization in conjugated organic molecules is a rate-limiting step in maximizing the photo conversion efficiency of next generation photovoltaics and molecular electronics.

Chemical sensors based on π-conjugated organic molecules and gold nanoparticles

2009 ◽  
Vol 52 (6) ◽  
pp. 715-730 ◽  
Author(s):  
MingJian Yuan ◽  
YongJun Li ◽  
HuiBiao Liu ◽  
YuLiang Li
Keyword(s):  
Gold Nanoparticles ◽  
Chemical Sensors ◽  
Organic Molecules ◽  
Conjugated Organic Molecules

Dipole moments induced in larger molecule. Long-chain aliphatic esters

1982 ◽  
Vol 47 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Otto Exner ◽  
Ayfer Bapçum
Keyword(s):  
Benzene Solution ◽  
Dipole Moments ◽  
Straight Chain ◽  
Basic Assumptions ◽  
Donor Acceptor ◽  
Eyring Theory ◽  
Aliphatic Esters ◽  
Long Chain

Dipole moments of straight-chain aliphatic esters Ia-Ic and IIa-IIf were measured in benzene solution. The observed trends are poorly reproduced by the classical Smith-Eyring theory; the reason may be partly the unknown conformation, partly even donor-acceptor complexes with the solvent. No deviations were observed with the highest members of the series, attributable to violation of some basic assumptions of the theory of dielectrics.

scholarly journals The Surface Properties of Calcite: An Adsorption Model with Orbital Control

2001 ◽  
Vol 19 (3) ◽  
pp. 237-244 ◽  
Author(s):  
Nikolai V. Nikolenko
Keyword(s):  
Surface Properties ◽  
Organic Compounds ◽  
Electron Donor ◽  
Organic Molecules ◽  
Orbital Interaction ◽  
Adsorption Model ◽  
Acceptor Interaction ◽  
Donor Acceptor ◽  
Correlation Parameters ◽  
Adsorptive Properties

The energies of unoccupied and occupied orbitals were used as the correlation parameters between the electronic and adsorptive properties of organic molecules. A model describing the chemisorption of organic compounds on CaCO3 involving two types of interaction, i.e. two-electron, donor–acceptor interaction HOMO(adsorbent) → LUMO(adsorbate) and four-electron, three-orbital interaction HOMO(adsorbent) → {LUMO(adsorbate) + HOMO(adsorbate)}, was proposed. It was concluded that strengthening of the bond involved in chemisorption occurred if the energies of the occupied orbitals associated with the adsorbate and adsorbent were concurrent.

scholarly journals Phosphorene–Fullerene Nanostructures: A First-Principles Study

2021 ◽  
Author(s):  
Diego Cortes-Arriagada ◽  
Daniela E. Ortega
Keyword(s):  
Active Sites ◽  
Short Range ◽  
Density Functional ◽  
Dipole Moments ◽  
Molecular Size ◽  
Bandgap Engineering ◽  
Donor Acceptor ◽  
The Stability ◽  
Strong Repulsion ◽  
Intermolecular Distances

Hybrid materials formed by carbon fullerenes and layered materials have emerged due to their advantages for several technological applications, and phosphorene arises as a promising two-dimensional semiconductor for C60 adsorption. However, the properties of phosphorenefullerene hybrids remain mainly unexplored. In this work, we employed density functional theory to obtain structures, adsorption energies, electronic/optical properties, binding (AIM, NBO), and energy decomposition analyses (ALMO-EDA) of nanostructures formed by phosphorene and fullerenes (C24 to C70). We find fullerenes form covalent and non-covalent complexes with phosphorene depending on the molecular size, showing remarkable stability even in solution. Two classes of covalent complexes arise by cycloaddition-like reactions: the first class, where short-range effects (charge-transfer and polarization) determines the stability; and the second one, where short-range effects decay to avoid steric repulsion, and balanced longrange forces (electrostatics and dispersion) favors the stability. Otherwise, high-size fullerenes (C50 to C70) only form non-covalent complexes due to strong repulsion at shorter intermolecular distances and lack of dissociation barriers. In terms of electronic properties, fullerenes act as mild p-dopants for phosphorene, increasing its polar character and ability to acquire induced dipole moments (polarizability). Also, small energy-bandgap fullerenes (<0.8 eV) largely increase the phosphorene metallic character. We also note fullerenes retain their donor/acceptor properties upon adsorption, acting as active sites for orbital-controlled interactions and maximizing the phosphorene light absorbance at the UV-Vis region. Finally, we strongly believe our study will inspire future experimental/theoretical studies focused on phosphorene-fullerene uses for storage, anode materials, sensing, phosphorene bandgap engineering, and optoelectronics.<br>

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