Video Experimental Relacionado
Updated: Jun 25, 2026
09:34
Synthesis of Information-bearing Peptoids and their Sequence-directed Dynamic Covalent Self-assembly
Published on: February 6, 2020
Caracterización directa y cuantitativa del intercambio dinámico de ligandos entre polígonos supramoleculares
Yao-Rong Zheng1, Peter J Stang
1Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, USA. Zheng@chem.utah.edu
Journal of the American Chemical Society
|February 27, 2009
Resumen
El intercambio dinámico de ligandos en polígonos supramoleculares de platino-nitrógeno se observó directamente utilizando el etiquetado de isótopos y la espectrometría de masas. Este estudio cuantifica la cinética de intercambio y la termodinámica, revelando la sensibilidad a las condiciones experimentales como la temperatura y el disolvente.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Coordinación Química de la Coordinación
- Química analítica Química analítica es un campo de estudio de la química analítica.
Sus antecedentes:
- El autoensamblaje impulsado por la coordinación forma complejas estructuras supramoleculares como polígonos.
- Comprender los procesos dinámicos como el intercambio de ligandos es crucial para controlar estos conjuntos.
- Las interacciones platino-nitrógeno son clave en la construcción de polígonos supramoleculares robustos.
Objetivo del estudio:
- Para observar directamente y caracterizar el intercambio dinámico de ligandos en polígonos supramoleculares Pt-N.
- Para determinar los parámetros termodinámicos y cinéticos que rigen el intercambio de ligandos.
- Investigar la influencia de las condiciones experimentales en el proceso de intercambio.
Principales métodos:
- Etiquetado de isótopos estables (1H/2D) de los donantes de piridil.
- Espectrometría de masas de ionización por electrospray (ESI-MS).
- Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN) Espectroscopía de Resonancia Magnética Nuclear (RMN).
Principales resultados:
- Observación directa del intercambio dinámico de ligandos en triángulos y rectángulos supramoleculares Pt-N.
- Los datos espectrales de masa cuantitativos permitieron la determinación de la termodinámica y cinética del intercambio.
- Se descubrió que las tasas de cambio de ligandos son altamente dependientes de la temperatura, el disolvente y las contraaniones.
Conclusiones:
- El estudio proporciona una visión directa sin precedentes de los mecanismos dinámicos de intercambio de ligandos en la química supramolecular.
- Los datos cinéticos y termodinámicos cuantitativos ofrecen una comprensión fundamental de estos procesos.
- Las condiciones experimentales modulan significativamente el comportamiento de los sistemas supramoleculares Pt-N, ofreciendo vías para el diseño dirigido.
Videos de Conceptos Relacionados
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
01:23Complexation Equilibria: Overview
Complexation reactions take place when dative or coordinate covalent bonds form between metal ions and ligands. The compounds formed in these reactions are called coordination compounds. The number of bonds formed between the metal ion and the ligands is called its coordination number. Generally, most metal ions in an aqueous solution are solvated by water molecules and thus exist as aqua complexes.
The equilibrium constant of the complexation reaction is represented as the formation constant...
The equilibrium constant of the complexation reaction is represented as the formation constant...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...