Video Experimental Relacionado

Updated: Apr 30, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

Columnas homoquirales construidas por autoclasificación quiral durante la organización helicoidal supramolecular de

Cécile Roche¹, Hao-Jan Sun, Margaret E Prendergast

¹Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.

Journal of the American Chemical Society

|April 25, 2014

Resumen

Los compuestos quirales de ciclotriveratrileno dendronizado (CTV) se autoensamblan en columnas helicoidales. Este estudio revela una auto-clasificación quiral sin precedentes en el estado cristalino, impactando las funciones complejas del sistema.

Área de la Ciencia:

Química supramolecular de las moléculas.
Ciencia de los materiales Ciencia de los materiales.
Química orgánica es la química orgánica.

Sus antecedentes:

Las coronas dendronizadas de ciclotriveratrileno (CTV) son conocidas por sus propiedades estructurales únicas.
El autoensamblaje de moléculas en estructuras ordenadas es crucial para el desarrollo de materiales avanzados.

Objetivo del estudio:

Para sintetizar y caracterizar una biblioteca de coronas CTV dendronizadas con varias cadenas de alquilo periféricas.
Investigar el comportamiento de autoensamblaje de estos derivados de CTV en solventes solvófobos y en estado a granel.
Para dilucidar las estructuras supramoleculares formadas y comprender los mecanismos de la autoclasificación quiral.

Principales métodos:

Síntesis de coronas CTV dendronizadas con cadenas alquilo quirales, racémicas y aquirales.
Caracterización utilizando dicroísmo circular (CD) y espectroscopia UV en solución y película delgada.
Análisis de las estructuras a granel mediante calorimetría de barrido diferencial (DSC) y difracción de rayos X de fibra.
Simulaciones por computadora y modelado molecular.
Espectroscopia de resonancia magnética nuclear (RMN) en estado sólido.

Principales resultados:

Los derivados de CTV se autoensamblan en columnas helicoidales en solventes solvófobos y a granel.
Las CTV enantiopuras forman columnas de una sola mano, mientras que los compuestos racémicos y aquirales también muestran autoensamblaje en estructuras helicoidales.
En estado a granel, las columnas supramoleculares forman una fase cristalina hexagonal en 3D (Φ(h) ((k)) o un cristal líquido hexagonal en columna en 2D (Φ(h)).
La fase cristalina de orden más alto consiste en columnas enantiopuras de una sola mano, que se asemejan a las hélices triples distorsionadas de 12 veces.
La desacemización ocurre en el estado cristalino a través de cambios de conformación molecular y transferencia intercolumnar de conformadores.

Conclusiones:

Las CTV dendronizadas exhiben un notable autoensamblaje en columnas helicoidales con quiralidad sintonizable.
El estudio demuestra una autoclasificación quiral supramolecular sin precedentes, incluso a partir de precursores racémicos y aquirales.
Estos hallazgos tienen implicaciones significativas para el diseño de materiales y sistemas funcionales complejos.

Más Videos Relacionados

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Published on: August 2, 2012

Videos de Conceptos Relacionados

Chirality

Chirality

Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...

Prochirality

Prochirality

The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...

Molecules with Multiple Chiral Centers

Molecules with Multiple Chiral Centers

Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...

Chirality at Nitrogen, Phosphorus, and Sulfur

Chirality at Nitrogen, Phosphorus, and Sulfur

Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...

High-Performance Liquid Chromatography: Introduction

High-Performance Liquid Chromatography: Introduction

High-performance liquid chromatography(HPLC), formerly referred to as High-pressure liquid chromatography, is a powerful technique used to separate, identify, and quantify components in complex mixtures. The term "high pressure" refers to using high pressure to push the liquid mobile phase through the tightly packed columns.
In HPLC, two phases play a critical role in the separation process:

¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons

¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons

Replacing each alpha-hydrogen in chloroethane by bromine (or a different functional group) yields a pair of enantiomers. Such protons are called prochiral or enantiotopic and are related by a mirror plane. Enantiotopic protons are chemically equivalent in an achiral environment. Because most proton NMR spectra are recorded using achiral solvents, enantiotopic hydrogens yield a single signal.
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...