Video Experimental Relacionado
Updated: Jul 7, 2025
16:24
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
18.7K
Interruptor macromolecular basado en el control conformacional ejercido por una cadena lateral achiral dentro de un
María Lago-Silva1, María Magdalena Cid2, Emilio Quiñoá1
1Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
Journal of the American Chemical Society
|December 27, 2023
Resumen
Los investigadores crearon nuevos polímeros multiquirales utilizando interruptores moleculares y química supramolecular. Estos polímeros permiten el control de sentido helicoidal (P o M) mediante el ajuste de un brazo achiral
Área de la Ciencia:
- Química de los polímeros
- Química supramolecular
- Ciencias de los materiales
Sus antecedentes:
- Los materiales sensibles a los estímulos ofrecen un control dinámico de las propiedades.
- Los polímeros multiquirales con sentido helicoidal ajustable son difíciles de sintetizar.
- La combinación de interruptores moleculares con interacciones supramoleculares es un enfoque prometedor.
Objetivo del estudio:
- Desarrollar un método para crear polímeros multiquirales sensibles a los estímulos.
- Para demostrar el control sobre el sentido helicoidal del polímero utilizando cambios de conformación.
- Explorar el potencial de los brazos achirales en el control de la quiralidad supramolecular.
Principales métodos:
- Síntesis de poli (fenilacetileno) con alenos quirales colgantes y brazos quirales flexibles.
- Utilizando el cambio de conformación del brazo achiral (extendido / doblado) para influir en la conformación del polímero.
- Utilizando interacciones supramoleculares para inducir selectivamente el sentido helicoidal P o M.
Principales resultados:
- La conformación del brazo achiral controlaba directamente el sentido helicoidal del polímero (P o M).
- Los sustituyentes de aleno permanecieron bloqueados por configuración, asegurando una quiralidad estable.
- Inducción selectiva demostrada de sentidos helicoidales opuestos dentro de la misma columna vertebral del polímero.
Conclusiones:
- Se pueden lograr materiales multicirales dinámicos complejos a través del diseño de monómeros.
- Los brazos achirales flexibles son herramientas efectivas para controlar la quiralidad supramolecular del polímero.
- Este trabajo abre caminos para materiales quirales avanzados que responden a estímulos.
Videos de Conceptos Relacionados
02:05Prochirality
3.8K
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...
3.8K
02:30Chirality in Nature
13.4K
Chirality is the most intriguing yet essential facet of nature, governing life’s biochemical processes and precision. It can be observed from a snail shell pattern in a macroscopic world to an amino acid, the minutest building block of life. Most of the snails around the world have right-coiled shells because of the intrinsic chirality in their genes. All the amino acids present in the human body exist in an enantiomerically pure state, except for glycine - the sole achiral amino acid.
13.4K
02:02Chair Conformation of Cyclohexane
14.7K
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
14.7K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
847
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
847
02:33Stereoisomerism of Cyclic Compounds
8.9K
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,...
8.9K
02:25Molecules with Multiple Chiral Centers
11.7K
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...
11.7K