Conformational pathways of simple six-membered rings

The conformational equilibria of cyclohexane (as well as its fluoro-, chloro-, methyl-, hydroxy-, and t-butyl derivatives), cyclohexanone, piperidine, tetrahydropyran (and its 2-hydroxy derivative) were studied by ab initio and DFT procedures. The transition states were calculated at HF/6-31G, B3LYP...

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Autor principal:	Stortz, Carlos Arturo
Publicado:	2010
Materias:	conformational analysis cyclohexane density functional calculations six-membered rings transition states Ab initio and DFT Basis sets Conformational analysis Conformational equilibrium Conformational pathways Cyclohexanones Density-functional calculations DFT method Energy data Energy dependence Experimental data HF/6-31G Hydroxyderivative Hydroxytetrahydropyran Intrinsic reaction coordinate Large deviations Six-membered rings Tetrahydropyran Transition state Cyclohexane Density functional theory Conformations
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08943230_v23_n12_p1173_Stortz http://hdl.handle.net/20.500.12110/paper_08943230_v23_n12_p1173_Stortz
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_08943230_v23_n12_p1173_Stortz
record_format	dspace
spelling	paper:paper_08943230_v23_n12_p1173_Stortz2023-06-08T15:47:46Z Conformational pathways of simple six-membered rings Stortz, Carlos Arturo conformational analysis cyclohexane density functional calculations six-membered rings transition states Ab initio and DFT Basis sets Conformational analysis Conformational equilibrium Conformational pathways Cyclohexanones Density-functional calculations DFT method Energy data Energy dependence Experimental data HF/6-31G Hydroxyderivative Hydroxytetrahydropyran Intrinsic reaction coordinate Large deviations Six-membered rings Tetrahydropyran Transition state Cyclohexane Density functional theory Conformations The conformational equilibria of cyclohexane (as well as its fluoro-, chloro-, methyl-, hydroxy-, and t-butyl derivatives), cyclohexanone, piperidine, tetrahydropyran (and its 2-hydroxy derivative) were studied by ab initio and DFT procedures. The transition states were calculated at HF/6-31G, B3LYP/6-31+G, and B3LYP/6-311+G levels, whereas the intrinsic reaction coordinates (IRCs) were evaluated at the B3LYP/6-31+G* level. The degree of puckering and energy data was nearly not basis set-dependent (using B3LYP) in most of the cases. However, DFT methods gave better agreement with experimental data than HF methods, as expected from electron correlation inclusion. Fluorocyclohexane and 2-hydroxytetrahydropyran showed the largest basis set-energy dependence. It was found that the conversion from chair to skew is direct in some cases, whereas in others it goes through the pseudorotational (skew/boat) pathway. The case of t-butylcyclohexane, with a skew form as stable as one of the chairs, is especially interesting. In this compound, as well as in cyclohexanone and 2-hydroxytetrahydropyran, large deviations from the known pseudorotation/inversion scheme are observed. Copyright © 2010 John Wiley & Sons, Ltd. Fil:Stortz, C.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08943230_v23_n12_p1173_Stortz http://hdl.handle.net/20.500.12110/paper_08943230_v23_n12_p1173_Stortz
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	conformational analysis cyclohexane density functional calculations six-membered rings transition states Ab initio and DFT Basis sets Conformational analysis Conformational equilibrium Conformational pathways Cyclohexanones Density-functional calculations DFT method Energy data Energy dependence Experimental data HF/6-31G Hydroxyderivative Hydroxytetrahydropyran Intrinsic reaction coordinate Large deviations Six-membered rings Tetrahydropyran Transition state Cyclohexane Density functional theory Conformations
spellingShingle	conformational analysis cyclohexane density functional calculations six-membered rings transition states Ab initio and DFT Basis sets Conformational analysis Conformational equilibrium Conformational pathways Cyclohexanones Density-functional calculations DFT method Energy data Energy dependence Experimental data HF/6-31G Hydroxyderivative Hydroxytetrahydropyran Intrinsic reaction coordinate Large deviations Six-membered rings Tetrahydropyran Transition state Cyclohexane Density functional theory Conformations Stortz, Carlos Arturo Conformational pathways of simple six-membered rings
topic_facet	conformational analysis cyclohexane density functional calculations six-membered rings transition states Ab initio and DFT Basis sets Conformational analysis Conformational equilibrium Conformational pathways Cyclohexanones Density-functional calculations DFT method Energy data Energy dependence Experimental data HF/6-31G Hydroxyderivative Hydroxytetrahydropyran Intrinsic reaction coordinate Large deviations Six-membered rings Tetrahydropyran Transition state Cyclohexane Density functional theory Conformations
description	The conformational equilibria of cyclohexane (as well as its fluoro-, chloro-, methyl-, hydroxy-, and t-butyl derivatives), cyclohexanone, piperidine, tetrahydropyran (and its 2-hydroxy derivative) were studied by ab initio and DFT procedures. The transition states were calculated at HF/6-31G, B3LYP/6-31+G, and B3LYP/6-311+G levels, whereas the intrinsic reaction coordinates (IRCs) were evaluated at the B3LYP/6-31+G* level. The degree of puckering and energy data was nearly not basis set-dependent (using B3LYP) in most of the cases. However, DFT methods gave better agreement with experimental data than HF methods, as expected from electron correlation inclusion. Fluorocyclohexane and 2-hydroxytetrahydropyran showed the largest basis set-energy dependence. It was found that the conversion from chair to skew is direct in some cases, whereas in others it goes through the pseudorotational (skew/boat) pathway. The case of t-butylcyclohexane, with a skew form as stable as one of the chairs, is especially interesting. In this compound, as well as in cyclohexanone and 2-hydroxytetrahydropyran, large deviations from the known pseudorotation/inversion scheme are observed. Copyright © 2010 John Wiley & Sons, Ltd.
author	Stortz, Carlos Arturo
author_facet	Stortz, Carlos Arturo
author_sort	Stortz, Carlos Arturo
title	Conformational pathways of simple six-membered rings
title_short	Conformational pathways of simple six-membered rings
title_full	Conformational pathways of simple six-membered rings
title_fullStr	Conformational pathways of simple six-membered rings
title_full_unstemmed	Conformational pathways of simple six-membered rings
title_sort	conformational pathways of simple six-membered rings
publishDate	2010
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08943230_v23_n12_p1173_Stortz http://hdl.handle.net/20.500.12110/paper_08943230_v23_n12_p1173_Stortz
work_keys_str_mv	AT stortzcarlosarturo conformationalpathwaysofsimplesixmemberedrings
_version_	1768546728167866368

Conformational pathways of simple six-membered rings

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