Video Experimental Relacionado
Updated: Apr 24, 2026
08:47
Characterizing Single-Molecule Conformational Changes Under Shear Flow with Fluorescence Microscopy
Published on: January 25, 2020
5.5K
Utilizando los primeros pasos de la hidratación para la determinación de la conformación molecular de una sola
Jörg Henzl1, Konrad Boom, Karina Morgenstern
1Lehrstuhl für physikalische Chemie I, Ruhr-Universität Bochum , D-44780 Bochum, Germany.
Journal of the American Chemical Society
|September 3, 2014
Resumen
Este estudio utiliza las interacciones de las moléculas de agua para revelar la estructura molecular precisa de los derivados de azobenzeno. Este nuevo método supera las limitaciones de la microscopía de túnel de barrido para el análisis detallado de la conformación molecular.
Área de la Ciencia:
- Ciencias de la superficie Ciencias de la superficie.
- Imágenes moleculares de imágenes.
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- La microscopía de alta resolución tiene como objetivo determinar estructuras moleculares exactas.
- La resolución del microscopio de túnel de barrido (STM) está limitada por la extensión orbital molecular.
- Los cambios conformacionales sutiles son a menudo indistinguibles con el STM convencional.
Objetivo del estudio:
- Desarrollar un nuevo método para determinar estructuras moleculares precisas utilizando la hidratación.
- Para investigar la orientación intramolecular de los derivados del azobenzeno.
- Para superar los límites de resolución intrínsecos de la microscopía de túnel de barrido.
Principales métodos:
- Se empleó microscopía de túnel de barrido a baja temperatura (LT-STM).
- Se estudió la coadsorción de 4,4'-hidroxi-azobenzeno y moléculas de agua en Au{111}.
- Se analizó la posición de las moléculas de agua que interactúan con los grupos funcionales.
Principales resultados:
- Las moléculas de agua se unen selectivamente a los grupos terminales hidroxilo de los derivados de azobenzeno.
- Se determinó la orientación de los anillos fenilo y los grupos finales en relación con el grupo azo.
- La molécula de trans-azobenzeno se adsorbe predominantemente con grupos hidroxilo orientados de manera opuesta.
- El método fue validado utilizando 4-anilino-4'-nitro azobenzeno.
Conclusiones:
- El enfoque basado en la hidratación proporciona información de orientación intramolecular sin precedentes.
- Este método ofrece una estrategia general para la determinación de la estructura molecular utilizando grupos finales funcionales.
- La observación en el espacio real de la hidratación molecular permite un análisis estructural detallado.
Videos de Conceptos Relacionados
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
988
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...
988
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.3K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.3K
01:18Molecular Shapes
53.5K
Molecules have characteristic shapes that are crucial for their function. The arrangement of various electron groups around the central atom dictates their molecular geometry. Electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between the electron pairs by maximizing the distance between them. The valence electrons form either bonding pairs, located primarily between bonded atoms, or lone pairs.
Two regions of electron density in a diatomic...
Two regions of electron density in a diatomic...
53.5K
02:06Newman Projections
16.8K
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as...
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as...
16.8K
02:11Conformations of Cyclohexane
12.1K
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...
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...
12.1K