Video Experimental Relacionado
Updated: Jun 29, 2026
09:45
Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
La estructura molecular de un catión de vinilo sustituido por ciclopropilo
Andrea Klaer1, Wolfgang Saak, Detlev Haase
1Institute for Pure and Applied Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky Str. 9-11, D-26211 Oldenburg, Federal Republic of Germany.
Journal of the American Chemical Society
|October 16, 2008
Resumen
La estructura molecular del catión vinilo 1 muestra una conjugación sigma extendida. Esta conjugación involucra el anillo ciclopropilo y los enlaces beta-carbono-silicio, confirmados por experimentos.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química computacional es la química computacional.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Los cationes de vinilo son reactivos intermedios cruciales en la síntesis orgánica.
- Comprender su estructura electrónica es clave para predecir la reactividad.
- Estudios anteriores sugirieron una posible deslocalización electrónica en cationes vinílicos sustituidos.
Objetivo del estudio:
- Determinar experimentalmente la estructura molecular del catión vinílico 1.
- Para investigar las propiedades electrónicas y la unión en el catión vinílico 1.
- Proporcionar evidencia directa de la conjugación sigma que involucra al silicio.
Principales métodos:
- Cálculos de química computacional de alto nivel (por ejemplo, teoría G4MP2).
- Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN).
- Espectroscopia de infrarrojos (IR). espectroscopía de infrarrojos (IR). espectroscopía de infrarrojos (IR). espectroscopía de infrarrojos (IR). espectroscopía de infrarrojos (IR). espectroscopía de infrarrojos (IR). espectroscopía de infrarrojos (IR).
Principales resultados:
- Estructura experimentalmente determinada del catión vinílico 1.
- Evidencia clara de la conjugación sigma extendida.
- Delocalización significativa de la densidad de electrones a través del anillo ciclopropilo y los enlaces beta-C-Si.
Conclusiones:
- El anillo de ciclopropilo y los enlaces beta-C-Si participan en una significativa conjugación sigma.
- El catión vinilo 1 exhibe propiedades electrónicas únicas debido a esta conjugación extendida.
- Estos hallazgos avanzan en la comprensión de la unión en cationes orgánicos que contienen silicio.
Más Videos Relacionados
Videos de Conceptos Relacionados
02:28Cycloalkanes
Cycloalkanes are saturated cyclic hydrocarbons with carbon atoms arranged in the form of rings. They have two fewer hydrogen atoms than the corresponding acyclic alkane; therefore, their general formula is CnH2n. The structural formulas of cycloalkanes are simplified using the line-angle representation. The regular polygons are used to represent the cycloalkane rings, with each side representing a carbon-carbon bond.
The IUPAC nomenclature of cycloalkanes follows similar rules that apply to...
The IUPAC nomenclature of cycloalkanes follows similar rules that apply to...
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Removing one hydrogen from the intervening CH2 group with both...
02:30Stability of Substituted Cyclohexanes
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
02:10Carbocations
Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...
01:18Aromatic Hydrocarbon Anions: Structural Overview
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous overlap of p...
Due to the absence of continuous overlap of p...
01:18π Molecular Orbitals of the Allyl Cation and Anion
An allyl group is a three-carbon conjugated system where the sp³-hybridized allylic carbon is bonded to a CH=CH2 group via a single bond. Allyl anions can be obtained by treating propene with a strong base that can deprotonate methyl groups. Allyl cations are formed as intermediates during substitution reactions involving allylic halides. In both cases, the hybridization of the allylic carbon changes from sp3 to sp2, giving rise to a carbon chain with three sp2-hybridized carbons, each with an...