Video Experimental Relacionado
Updated: Jul 12, 2026
05:47
Preparation of Polyoxometalate-based Photo-responsive Membranes for the Photo-activation of Manganese Oxide Catalysts
Published on: August 7, 2018
Química de óxido metálico en solución: los primeros polioxoaniones de metales de transición
Science (New York, N.Y.)
|May 3, 1985
Resumen
Los primeros polioxoaniones de metales de transición, grandes grupos de metales-oxígeno, ahora se estudian en detalle utilizando técnicas avanzadas. Esto permite comprender su estructura, reactividad y crear nuevos derivados covalentes para la investigación de la química de superficies.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Ciencia de los materiales Ciencia de los materiales.
- Química del estado sólido.
Sus antecedentes:
- Los primeros elementos de transición forman grandes aniones metal-oxígeno polinucleares (polioxoaniones).
- Históricamente, los estudios estructurales y de reactividad detallados fueron limitados.
- Los polioxoaniones contienen hasta 200 átomos, construidos sobre matrices de oxígeno apretadas con centros metálicos intersticiales.
Objetivo del estudio:
- Investigar la estructura y la reactividad de los polioxoaniones de metales de transición tempranos.
- Aclarar los principios que rigen la estructura y la reactividad de los polioxoaniones.
- Explorar la preparación de nuevos derivados covalentes y sus posibles aplicaciones.
Principales métodos:
- Cristalografía de rayos X con rayos X.
- La espectroscopia de resonancia magnética nuclear (RMN) es una espectroscopia de resonancia magnética nuclear.
- Estudios sistemáticos en solventes inertes y apróticos.
Principales resultados:
- Permitió estudios detallados de estructura y reactividad de los polioxoaniones.
- Se aclararon los principios fundamentales de la química de los polioxoaniones.
- Facilitó la síntesis de nuevos derivados covalentes como CH(2)Mo(4)O(15)H(3-), C(5)H(5)TiMo(5)O(18)(3-), y (OC)(3)Mn(Nb(2)W(4)O(19))(3-).
Conclusiones:
- Las técnicas modernas permiten un estudio en profundidad de la estructura y la reactividad de los polioxoaniones.
- La química de los polioxoaniones proporciona información sobre las transformaciones bien definidas de la superficie de los óxidos metálicos.
- El campo ofrece oportunidades para crear nuevos materiales y comprender los procesos catalíticos.
Videos de Conceptos Relacionados
02:58Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
01:23Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
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...
02:48Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
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...
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...