Video Experimental Relacionado
Updated: Dec 23, 2025
08:40
Light-driven Molecular Motors on Surfaces for Single Molecular Imaging
Published on: March 13, 2019
11.9K
Arreglos regulares bidimensionales de interruptores moleculares montados en la superficie: conmutación monitoreada
Carina Santos Hurtado1, Guillaume Bastien1, Milan Mašát1
1Institute of Organic Chemistry and Biochemistry of the CAS, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
Journal of the American Chemical Society
|April 25, 2020
Resumen
Los investigadores utilizaron la espectroscopia de RMN de estado sólido 15N para detectar la isomerización cis / trans en matrices 2D de interruptores moleculares de azobenzeno. Este avance confirma que el cambio molecular no se ve afectado por las moléculas vecinas en las matrices montadas en la superficie.
Área de la Ciencia:
- Química supramolecular
- Ciencias de los materiales
- Espectroscopia
Sus antecedentes:
- Los derivados de azobenzeno se estudian ampliamente como interruptores moleculares.
- El control de la disposición molecular en matrices bidimensionales (2D) es crucial para los materiales avanzados.
- Los sistemas moleculares montados en la superficie ofrecen plataformas únicas para estudiar el comportamiento molecular.
Objetivo del estudio:
- Para sintetizar nuevos interruptores moleculares en forma de varilla para la formación de una matriz 2-D.
- Detectar y caracterizar la isomerización cis/trans en interruptores moleculares montados en la superficie utilizando RMN en estado sólido.
- Para investigar la influencia de la proximidad molecular en el comportamiento de conmutación en matrices 2D.
Principales métodos:
- Síntesis de nuevos interruptores moleculares en forma de varilla basados en azobenzeno.
- Formación de matrices regulares en dos dimensiones en nanocristales de tris (o-fenilenodióxido) ciclotrifosfeno (TPP) mediante métodos mecanoquímicos.
- Espectroscopia de RMN de estado sólido para la detección de isomerización cis/trans.
Principales resultados:
- Síntesis exitosa de interruptores moleculares capaces de formar matrices 2D en los nanocristales TPP.
- Detección por primera vez de la isomerización cis/trans en una matriz 2D de interruptores de azobenzeno montados en la superficie utilizando RMN de estado sólido de 15N.
- Demostrar que la conmutación molecular no se ve obstaculizada por la proximidad de las moléculas vecinas en las inclusiones de la superficie supramolecular.
Conclusiones:
- La RMN de estado sólido 15N es una herramienta poderosa para estudiar la isomerización en sistemas moleculares confinados en la superficie.
- Los interruptores moleculares desarrollados permiten la formación de matrices 2D ordenadas con funcionalidad retenida.
- El empaquetado cercano en matrices 2D no impide el comportamiento de conmutación foto-responsivo de las moléculas individuales de azobenzeno.
Videos de Conceptos Relacionados
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
2.5K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
2.5K
01:02Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview
4.2K
Ultraviolet–visible (UV–visible or UV–Vis) spectroscopy is an analytical technique that investigates the interaction between matter and UV–Vis light within the electromagnetic spectrum. This method is widely used for its versatility, simplicity, and relatively quick data acquisition, making it valuable for both qualitative and quantitative analysis. When UV–Vis radiation passes through a material, molecules absorb light depending on the energy required for...
4.2K
01:32UV–Vis Spectroscopy of Conjugated Systems
8.1K
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent of conjugation in...
One of the factors influencing λmax is the extent of conjugation in...
8.1K
01:14UV–Vis Spectrometers
3.2K
The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell.
3.2K
01:12Two-Dimensional (2D) NMR: Overview
1.3K
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
1.3K
01:29UV–Vis Spectroscopy: Woodward–Fieser Rules
27.8K
UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π → π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the...
27.8K