Cargando…

Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis

Two very different quantum mechanically based energy decomposition analyses (EDA) schemes are employed to study the dominant energy differences between the eclipsed and staggered ferrocene conformers. One is the extended transition state (ETS) based on the Amsterdam Density Functional (ADF) package...

Descripción completa

Detalles Bibliográficos
Autores principales: Wang, Feng, Islam, Shawkat, Vasilyev, Vladislav
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5458881/
https://www.ncbi.nlm.nih.gov/pubmed/28793673
http://dx.doi.org/10.3390/ma8115419
_version_ 1783241845298429952
author Wang, Feng
Islam, Shawkat
Vasilyev, Vladislav
author_facet Wang, Feng
Islam, Shawkat
Vasilyev, Vladislav
author_sort Wang, Feng
collection PubMed
description Two very different quantum mechanically based energy decomposition analyses (EDA) schemes are employed to study the dominant energy differences between the eclipsed and staggered ferrocene conformers. One is the extended transition state (ETS) based on the Amsterdam Density Functional (ADF) package and the other is natural EDA (NEDA) based in the General Atomic and Molecular Electronic Structure System (GAMESS) package. It reveals that in addition to the model (theory and basis set), the fragmentation channels more significantly affect the interaction energy terms (ΔE) between the conformers. It is discovered that such an interaction energy can be absorbed into the pre-partitioned fragment channels so that to affect the interaction energies in a particular conformer of Fc. To avoid this, the present study employs a complete fragment channel—the fragments of ferrocene are individual neutral atoms. It therefore discovers that the major difference between the ferrocene conformers is due to the quantum mechanical Pauli repulsive energy and orbital attractive energy, leading to the eclipsed ferrocene the energy preferred structure. The NEDA scheme further indicates that the sum of attractive (negative) polarization (POL) and charge transfer (CL) energies prefers the eclipsed ferrocene. The repulsive (positive) deformation (DEF) energy, which is dominated by the cyclopentadienyle (Cp) rings, prefers the staggered ferrocene. Again, the cancellation results in a small energy residue in favour of the eclipsed ferrocene, in agreement with the ETS scheme. Further Natural Bond Orbital (NBO) analysis indicates that all NBO energies, total Lewis (no Fe) and lone pair (LP) deletion all prefer the eclipsed Fc conformer. The most significant energy preferring the eclipsed ferrocene without cancellation is the interactions between the donor lone pairs (LP) of the Fe atom and the acceptor antibond (BD*) NBOs of all C–C and C–H bonds in the ligand, LP(Fe)-BD*(C–C & C–H), which strongly stabilizes the eclipsed (D(5h)) conformation by −457.6 kcal·mol(−1).
format Online
Article
Text
id pubmed-5458881
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-54588812017-07-28 Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis Wang, Feng Islam, Shawkat Vasilyev, Vladislav Materials (Basel) Article Two very different quantum mechanically based energy decomposition analyses (EDA) schemes are employed to study the dominant energy differences between the eclipsed and staggered ferrocene conformers. One is the extended transition state (ETS) based on the Amsterdam Density Functional (ADF) package and the other is natural EDA (NEDA) based in the General Atomic and Molecular Electronic Structure System (GAMESS) package. It reveals that in addition to the model (theory and basis set), the fragmentation channels more significantly affect the interaction energy terms (ΔE) between the conformers. It is discovered that such an interaction energy can be absorbed into the pre-partitioned fragment channels so that to affect the interaction energies in a particular conformer of Fc. To avoid this, the present study employs a complete fragment channel—the fragments of ferrocene are individual neutral atoms. It therefore discovers that the major difference between the ferrocene conformers is due to the quantum mechanical Pauli repulsive energy and orbital attractive energy, leading to the eclipsed ferrocene the energy preferred structure. The NEDA scheme further indicates that the sum of attractive (negative) polarization (POL) and charge transfer (CL) energies prefers the eclipsed ferrocene. The repulsive (positive) deformation (DEF) energy, which is dominated by the cyclopentadienyle (Cp) rings, prefers the staggered ferrocene. Again, the cancellation results in a small energy residue in favour of the eclipsed ferrocene, in agreement with the ETS scheme. Further Natural Bond Orbital (NBO) analysis indicates that all NBO energies, total Lewis (no Fe) and lone pair (LP) deletion all prefer the eclipsed Fc conformer. The most significant energy preferring the eclipsed ferrocene without cancellation is the interactions between the donor lone pairs (LP) of the Fe atom and the acceptor antibond (BD*) NBOs of all C–C and C–H bonds in the ligand, LP(Fe)-BD*(C–C & C–H), which strongly stabilizes the eclipsed (D(5h)) conformation by −457.6 kcal·mol(−1). MDPI 2015-11-16 /pmc/articles/PMC5458881/ /pubmed/28793673 http://dx.doi.org/10.3390/ma8115419 Text en © 2015 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons by Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Wang, Feng
Islam, Shawkat
Vasilyev, Vladislav
Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis
title Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis
title_full Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis
title_fullStr Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis
title_full_unstemmed Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis
title_short Ferrocene Orientation Determined Intramolecular Interactions Using Energy Decomposition Analysis
title_sort ferrocene orientation determined intramolecular interactions using energy decomposition analysis
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5458881/
https://www.ncbi.nlm.nih.gov/pubmed/28793673
http://dx.doi.org/10.3390/ma8115419
work_keys_str_mv AT wangfeng ferroceneorientationdeterminedintramolecularinteractionsusingenergydecompositionanalysis
AT islamshawkat ferroceneorientationdeterminedintramolecularinteractionsusingenergydecompositionanalysis
AT vasilyevvladislav ferroceneorientationdeterminedintramolecularinteractionsusingenergydecompositionanalysis