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

¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as annulenes. In...
Spin–Spin Coupling: One-Bond Coupling01:17

Spin–Spin Coupling: One-Bond Coupling

Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
π Electron Effects on Chemical Shift: Overview01:27

π Electron Effects on Chemical Shift: Overview

An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...

También podría leer

Artículos Relacionados

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

Ordenar por
Same author

An interpretable predictive model for depression risk in diabetic patients: A web-based application using NHANES data.

Medicine·2026
Same author

NIR-responsive MnO<sub>2</sub>-functionalized mesoporous silica hydrogel: Fabrication and antibacterial activity evaluation.

Talanta·2026
Same author

Comprehensive Analysis and Prognostic Modeling of Epithelioid Trophoblastic Tumor.

Obstetrics and gynecology·2026
Same author

Aptamers: Current Applications in Leukemia Diagnostics and Therapeutics.

Nucleic acid therapeutics·2026
Same author

Disintegrated halophilic aerobic granular sludge restoration using zinc oxide nanoparticles: synergistic effects of fungal toxicity inhibition and extracellular polymeric substances production.

Bioresource technology·2026
Same author

Development of a Machine Learning‑Based Prognostic Model for Intermediate Trophoblastic Tumors: A Single-Center Study With Web-Based Tool Implementation.

JCO precision oncology·2026

Video Experimental Relacionado

Updated: May 30, 2026

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

Modulación de acoplamientos electrónicos dentro de marcos de Ru2-poliina.

Bin Xi1, Isiah P-C Liu, Guo-Lin Xu

  • 1Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.

Journal of the American Chemical Society
|August 23, 2011
PubMed
Resumen

Los dímeros de rutenio puenteados por hexatriyne se sintetizaron y reaccionaron con complejos de TCNE o cobalto. El acoplamiento electrónico entre los centros de rutenio fue modulado por estas reacciones, impactando sus propiedades de valencia mixta.

Más Videos Relacionados

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites
06:34

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites

Published on: September 19, 2020

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes
09:17

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes

Published on: January 30, 2015

Videos de Experimentos Relacionados

Last Updated: May 30, 2026

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites
06:34

Application of a Coupling Agent to Improve the Dielectric Properties of Polymer-Based Nanocomposites

Published on: September 19, 2020

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes
09:17

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes

Published on: January 30, 2015

Área de la Ciencia:

  • Química Inorgánica La Química Inorgánica es la química inorgánica.
  • Ciencia de los materiales Ciencia de los materiales.
  • La electroquímica es electroquímica.

Sus antecedentes:

  • Los dímeros basados en rutenio con ligandos puentes son de interés por sus propiedades electrónicas y fotofísicas.
  • Comprender la comunicación electrónica en sistemas de valencia mixta es crucial para el desarrollo de materiales avanzados.

Objetivo del estudio:

  • Para sintetizar y caracterizar nuevos dímeros de rutenio puenteado por 1,3,5-hexatriyn-diyl.yl.
  • Investigar el efecto de la adición de complejos de tetracianoeteno (TCNE) y cobalto en el acoplamiento electrónico entre los centros de rutenio.

Principales métodos:

  • Síntesis de dímeros de rutenio ([Ru(2) ((Xap) ((4))) ((2) (((μ-C ((6))))) que se encuentran en el núcleo de las moléculas.
  • Reacciones con el tetracianoeteno (TCNE) y los complejos de cobalto (Co) (dppm) (CO) (6))
  • Estudios voltamétricos y espectroelectroquímicos.
  • Análisis de difracción de rayos X Análisis de difracción de rayos X.
  • Cálculos de DFT sin restricciones de espín.

Principales resultados:

  • Síntesis exitosa de dímeros de rutenio puenteado por el 1,3,5-hexatriyn-diyl.yl.
  • Formación de productos de ciclo-adición/inserción con TCNE y adutos η(2) -Co(2) con complejos de cobalto.
  • Los dímeros de rutenio en el compuesto madre exhiben un acoplamiento electrónico significativo (clase II/III de Robin-Day).
  • El acoplamiento electrónico se debilita en los aductos de cobalto y se elimina por completo con la inserción de TCNE.

Conclusiones:

  • El acoplamiento electrónico entre los centros de rutenio en estos dímeros se puede ajustar efectivamente mediante modificaciones químicas.
  • La inserción de TCNE interrumpe significativamente la comunicación electrónica, mientras que la complejación de cobalto causa una atenuación moderada.
  • Los estudios estructurales y computacionales apoyan el comportamiento de acoplamiento electrónico observado.