Video Experimental Relacionado
Updated: May 8, 2026
10:17
Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Congestión estérica excepcional en un in,in-bis (hidrosilano)
Jie Zong1, Joel T Mague, Robert A Pascal
1Department of Chemistry, Tulane University , New Orleans, Louisiana 70118, United States.
Journal of the American Chemical Society
|August 27, 2013
Resumen
Los investigadores sintetizaron un macrobicíclico único en el hidrosilano. El análisis cristalográfico y computacional reveló la distancia de contacto sin enlaces hidrógeno-hidrógeno más corta jamás observada en un compuesto caracterizado.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Química supramolecular de las moléculas.
- Ciencia de los materiales Ciencia de los materiales.
Sus antecedentes:
- Los compuestos macrobicíclicos ofrecen propiedades estructurales únicas.
- Los hidrosilanos son moléculas versátiles que contienen silicio con diversas aplicaciones.
- La comprensión de las interacciones no unidas es crucial para el diseño molecular.
Objetivo del estudio:
- Para sintetizar y caracterizar un nuevo macrobicíclico in,in-bis (hidrosilano).
- Para investigar las propiedades estructurales y electrónicas del compuesto sintetizado.
- Determinar la distancia de contacto sin enlaces hidrógeno-hidrógeno más corta en una molécula caracterizada cristalográficamente.
Principales métodos:
- Síntesis química del macrobicíclico en, en-bis (hidrosilano).
- Cristalografía de rayos X para la determinación estructural.
- Métodos de química computacional (por ejemplo, DFT) para el análisis de la estructura electrónica.
Principales resultados:
- Síntesis exitosa y caracterización completa del compuesto macrobicíclico objetivo.
- Los datos cristalográficos revelaron un contacto no unido hidrógeno-hidrógeno central excepcionalmente corto.
- El análisis computacional corroboró los hallazgos cristalográficos y proporcionó información sobre la naturaleza electrónica de la interacción.
Conclusiones:
- El macrobicíclico sintetizado en,in-bis (hidrosilano) exhibe un contacto sin enlaces hidrógeno-hidrógeno de corta duración.
- Este hallazgo avanza en la comprensión de las interacciones no unidas en sistemas moleculares.
- El estudio abre caminos para el diseño de nuevos materiales a base de silicio con características estructurales únicas.
Videos de Conceptos Relacionados
02:36Regioselectivity and Stereochemistry of Hydroboration
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
02:33Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
02:11Conformations of Cyclohexane
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
01:28Stability of Conjugated Dienes
Introduction
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
01:28Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.