Jove
Visualize
Contáctanos
JoVE
x logofacebook logolinkedin logoyoutube logo
ACERCA DE JoVE
Visión GeneralLiderazgoBlogCentro de Ayuda JoVE
AUTORES
Proceso de PublicaciónConsejo EditorialAlcance y PolíticasRevisión por ParesPreguntas FrecuentesEnviar
BIBLIOTECARIOS
TestimoniosSuscripcionesAccesoRecursosConsejo Asesor de BibliotecasPreguntas Frecuentes
INVESTIGACIÓN
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchivo
EDUCACIÓN
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualCentro de Recursos para ProfesoresSitio de Profesores
Términos y Condiciones de Uso
Política de Privacidad
Políticas

Videos de Conceptos Relacionados

Structures of Solids02:22

Structures of Solids

14.1K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
14.1K
Ionic Crystal Structures02:42

Ionic Crystal Structures

14.3K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
14.3K
Chirality at Nitrogen, Phosphorus, and Sulfur02:30

Chirality at Nitrogen, Phosphorus, and Sulfur

5.7K
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...
5.7K
Preparation and Reactions of Sulfides02:26

Preparation and Reactions of Sulfides

4.8K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
4.8K
VSEPR Theory and the Basic Shapes02:52

VSEPR Theory and the Basic Shapes

68.3K
Overview of VSEPR Theory
68.3K
Metallic Solids02:37

Metallic Solids

18.4K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.4K

También podría leer

Artículos Relacionados

Artículos vinculados a este trabajo por autores compartidos, revista y gráfico de citas.

Ordenar por
Same author

Multiscale cathode design for high-temperature proton exchange membrane fuel cells.

Chemical Society reviews·2026
Same author

Catalyst-Support Synergy for CO<sub>2</sub>-Involved Electrochemical C-N Coupling Reactions.

ChemSusChem·2026
Same author

Zn-Mediated Synthesis of Sub-5 nm PtIr─Zn Nanocubes for Direct Ammonia Fuel Cells.

Angewandte Chemie (International ed. in English)·2026
Same author

Multi-interactions Regulate Perovskite Crystallization and Defect Passivation for Efficient and Stable Perovskite Photovoltaics.

Nano letters·2026
Same author

Overcoming size limits with dynamic templates enabling large area single crystal nanowire arrays for photodetectors.

Nature communications·2025
Same author

Efficient near-infrared harvesting in perovskite-organic tandem solar cells.

Nature·2025

Video Experimental Relacionado

Updated: Jul 2, 2025

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes
11:21

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

Published on: March 21, 2018

8.1K

Estructura del selenio amorfo: anillo pequeño, gran controversia

Wenbo Lu1,2, Zongbao Li3, Mingjie Feng1

  • 1Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.

Journal of the American Chemical Society
|February 20, 2024
PubMed
Resumen

Se debate la estructura del selenio amorfo (a-Se), pero este estudio encuentra que el a-Se depositado en vapor consiste en anillos, no en cadenas. Los métodos de caracterización pueden desencadenar transiciones de anillo a cadena, lo que afecta los resultados.

Más Videos Relacionados

Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials
09:23

Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials

Published on: May 17, 2024

1.6K
Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals
12:56

Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals

Published on: December 11, 2013

39.8K

Videos de Experimentos Relacionados

Last Updated: Jul 2, 2025

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes
11:21

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

Published on: March 21, 2018

8.1K
Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials
09:23

Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials

Published on: May 17, 2024

1.6K
Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals
12:56

Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals

Published on: December 11, 2013

39.8K

Área de la Ciencia:

  • Ciencias de los materiales
  • Física del estado sólido
  • Química de los calogenuros

Sus antecedentes:

  • El selenio (Se), un elemento calcógeno, tiene una larga historia desde su descubrimiento en 1817.
  • La estructura atómica precisa del selenio amorfo (a-Se) sigue siendo un tema de debate científico, particularmente con respecto a la prevalencia de las estructuras de anillo versus cadena.

Objetivo del estudio:

  • Para resolver la controversia que rodea el motivo estructural dominante (anillos frente a cadenas) en el selenio amorfo.
  • Identificar las causas subyacentes de las observaciones estructurales contradictorias en estudios anteriores.
  • Establecer métodos fiables para caracterizar con precisión la estructura del selenio amorfo.

Principales métodos:

  • Deposición por vapor de selenio amorfo.
  • Análisis comparativo de las propiedades estructurales entre el selenio amorfo depositado en vapor y el selenio amorfo extinguido en fusión.
  • Investigación de las transiciones estructurales inducidas por estímulos externos como la luz y el calor.
  • Espectroscopia de Raman que utiliza parámetros de excitación láser controlados (flujo de fotones, energía) y condiciones de temperatura.

Principales resultados:

  • El selenio amorfo depositado en el vapor está compuesto predominantemente por anillos desordenados, en contraste con el selenio amorfo extinguido por fusión.
  • La controversia estructural se deriva de la inestabilidad inherente de los anillos de selenio, que fácilmente pasan a ser cadenas.
  • Las técnicas de caracterización que implican una iluminación por encima de la brecha de banda (> 2,1 eV) o temperaturas elevadas (> 50 °C) pueden inducir inadvertidamente esta transición de anillo a cadena.

Conclusiones:

  • La estructura dominante en el selenio amorfo depositado en vapor consiste en anillos desordenados.
  • La caracterización estructural precisa del selenio amorfo requiere un control cuidadoso de las condiciones experimentales para evitar las transiciones de anillo a cadena inducidas por la fotoexcitación y el calor.
  • Se proporciona una hoja de ruta para obtener espectros de Raman confiables mediante la optimización de los parámetros de excitación y temperatura del láser, asegurando la preservación de la estructura de anillo nativa.