Topic
Hückel method
About: Hückel method is a research topic. Over the lifetime, 139 publications have been published within this topic receiving 2449 citations.
Papers published on a yearly basis
Papers
TL;DR: In this paper, the authors used the HMO theory to calculate energy level densities, bond orders, electron distributions, free valence, resonance energies, and heats of formation for several homologous series of large, hexagonally symmetric benzenoid polyaromatic molecules with well-defined edge structures containing up to 2300 carbon atoms.
Abstract: Hueckel molecular orbital (HMO) theory has been used to calculate energy level densities, bond orders, electron distributions, free valence, resonance energies, and heats of formation for several homologous series of large, hexagonally symmetric benzenoid polyaromatic molecules with well-defined edge structures containing up to 2300 carbon atoms. When extrapolated to the infinite limit, values for all properties converge to reasonable values. This is in contrast to several other ..pi..-electron theories that do not yield correct graphite limits. Carbon atoms at the edge of such large molecules are predicted to behave like those in small polynuclear aromatic molecules, with properties strongly dependent on local structure. Regardless of edge structure, interior carbons several bond lengths from an edge have properties similar to those in an infinite graphite sheet. Edge structure has a larger influence on heats of formation than that predicted by group additivity methods. Only a weak correlation was found between the energy of the highest occupied molecular orbital and the reactivity of the most reactive position.
264 citations
218 citations
TL;DR: In this article, a comprehensive theory of hydrogen and methyl chemisorption on Pt(111) is developed with the help of Crystal Orbital Hamilton Population formalism within the extended Huckel molecular orbital theory.
Abstract: Chemisorbed hydrogen and various intermediate hydrocarbon fragments play an important role in the important reaction of ethylene hydrogenation to ethane, which is catalyzed by Pt(111). As a first step toward building a theoretical mechanism of the ethylene hydrogenation process, binding site preferences and geometries of chemisorbed hydrogen, methyl, and ethyl on the Pt(111) surface are presented and rationalized. State-of-the-art Pseudopotential Planewave Density Functional Theory is employed for calculating accurate binding energies and geometries for the adsorbates. A comprehensive theory of hydrogen and methyl chemisorption on Pt(111) is developed with the help of Crystal Orbital Hamilton Population formalism within the extended Huckel molecular orbital theory. The symmetry properties of the surface Pt orbitals as well as the mixing of Pt s, p, and d orbitals in pure Pt is shown to be crucial in determining the strength of subsequent interaction with an adsorbate. It is suggested that hydrogen moves f...
211 citations
1 Jan 2023
TL;DR: We know that the Huckel rule is only applicable to compounds containing one planar ring in which each atom has a p orbital as in benzene as mentioned in this paper , and that it is not applicable to all planar rings.
Abstract: We know that Huckel rule (developed in 1931 by a German physicist Erich Huckel on the basis of mathematical calculations) is concerned with compounds containing one planar ring in which each atom has a p orbital as in benzene.
132 citations
TL;DR: In this paper, an orbital picture of the factors influencing the choice of three-versus four-coordination for solids containing Cu(I) and Ag(I), of importance in appreciating the mobility of these ions in ionic conductors, is presented.
Abstract: An orbital picture is presented of the factors influencing the choice of three-versus four-coordination for solids containing Cu(I) and Ag(I), of importance in appreciating the mobility of these ions in ionic conductors. The electronic preferences of both the nd orbital manifold and the (n+1)(s+p) orbital manifold are for the regular tetrahedral amangement, but mixing between the occupied nd and unoccupied (n+1)s orbitals on distortion, via a second-order Jahn-Teller effect, as in Orgel's model for Hg(II), favors the lower coordination number. This balance is shown by calculation tobe particularly sensitive at the end of the transition metal series
90 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2024 | 2 |
| 2023 | 2 |
| 2022 | 5 |
| 2021 | 1 |
| 2018 | 1 |
| 2017 | 1 |