Results 1 to 10 of about 3,640 (114)

Aromaticity of aza aromatic molecules: prediction from Hückel theory with modified parameters [PDF]

open access: yesQuímica Nova, 2023
Hückel theory is a simple and powerful method for predicting the molecular orbital and the energy of conjugated molecules. However, the presence of nitrogen atoms in aza aromatic molecules alters the Coulomb and resonance integrals owing to the ...
Inge M. Sutjahja   +3 more
doaj   +1 more source

The McClelland approximation and the distribution of π-electron molecular orbital energy levels [PDF]

open access: yesJournal of the Serbian Chemical Society, 2007
The total π-electron energy E of a conjugated hydrocarbon with n carbon atoms and m carbon–carbon bonds can be approximately calculated by means of the McClelland formula E = g SQRT(2mr), where g is an empirical fitting constant, g ≈ 0.9.
IVAN GUTMAN
doaj   +3 more sources

Topology and stability of conjugated hydrocarbons: The dependence of total π-electron energy on molecular topology [PDF]

open access: yesJournal of the Serbian Chemical Society, 2005
In spite of the fact that research on the mathematical properties of the total π-electron energy E (as computed by means of the Hückel molecular orbital approximation) started already in the 1940s, many results in this area have been obtained also in the
Gutman Ivan
doaj   +1 more source

DOPANT EFFECT ON PHENALENE BANDGAP CONTROL: A HÜCKEL MOLECULAR ORBITAL PERSPECTIVE

open access: yesQuímica Nova, 2021
In this study, we investigate the effects of nitrogen and boron dopants on the properties of phenalene/phenalenyl systems based on the Hückel theory by using the Hueckel Molecular Orbital software. The dopants configurations are graphitic, pyridinic, and
Muhammad A Irham   +3 more
doaj   +1 more source

Calculations of Constant-Height STM Images of Fullerene C60 Adsorbed onto a Surface

open access: yesJournal of Spectroscopy, 2023
Constant-height scanning tunneling microscopy (STM) images of a C60 molecule adsorbed onto a surface were calculated using symmetry-adapted Hückel molecular orbitals (HMOs). Three adsorption orientations of C60 are considered. The interaction between the
Effat A. Rashed
doaj   +1 more source

Reactivity Indices for the Coronene Nanocrystals and Their Derivatives: Modeling Approach

open access: yesScientific Journal of King Faisal University: Basic and Applied Sciences, 2022
The modeling approach was applied for the study of the reactivity of pristine and the substitution and absorption of doped coronene nanocrystals with nitrogen and boron under different cases.
Abdelkareem Almeshal
doaj   +1 more source

The Hückel total π-electron energy puzzle [PDF]

open access: yesJournal of the Serbian Chemical Society, 2006
In spite of being based on drastic simplifications, the Hückel molecular orbital (HMO) quantum-mechanical model provides a reasonably good description of the properties of π-electrons in conjugated molecules.
Perić Miljenko   +2 more
doaj   +1 more source

Spreading Electron Density Thin: Increasing the Chromophore Size in Polyaromatic Wires Decreases Interchromophoric Electronic Coupling [PDF]

open access: yes, 2018
The development of novel polychromophoric materials using extended polycyclic aromatic hydrocarbons as a single large chromophore holds promise for long-range charge-transfer applications in photovoltaic devices and molecular electronics.
Hossain, Mohammad Mosharraf   +4 more
core   +4 more sources

The total π-electron energy saga: Continuation [PDF]

open access: yesKragujevac Journal of Science
The total π-electron energy, as calculated within the Hückel molecular orbital approximation, is a much studied quantum chemical characteristics of unsaturated conjugated compounds. Its theory, together with that of its modification called "graph energy",
Gutman Ivan
doaj   +1 more source

A Molecular-Orbital Model for Amorphous Group IV Semiconductors

open access: yesActive and Passive Electronic Components, 1997
A theoretical model based on standard molecular-orbital theory and extended Hückel approach is proposed. This model is valid for amorphous group IV semiconductors and represents a substantial improvement of the state of the art.
M. A. Grado-Caffaro, M. Grado-Caffaro
doaj   +1 more source

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