Video Experimental Relacionado
Updated: Jun 8, 2026
10:52
Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Cristales polimórficos concomitantes de alta emisión de un complejo de renio dinuclear con cristales polimórficos de
Elsa Quartapelle Procopio1, Matteo Mauro, Monica Panigati
1Dipartimento di Chimica Inorganica Metallorganica e Analitica Lamberto Malatesta, Università degli Studi di Milano, via Venezian 21, I-20133 Milano, Italy.
Journal of the American Chemical Society
|September 28, 2010
Resumen
Este estudio revela dos polimorfas de estado sólido de un complejo de renio dinuclear, que exhiben distintas propiedades de fotoluminiscencia. Estos polimorfos experimentan una transición de fase reversible, destacando el impacto de la organización cristalina en el comportamiento fotofísico.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Química del estado sólido.
- La fotoquímica es la fotoquímica.
Sus antecedentes:
- Los complejos dinucleares de renio pueden exhibir polimorfismo.
- El embalaje en estado sólido influye en las propiedades moleculares.
- La fotoluminiscencia es sensible al entorno molecular.
Objetivo del estudio:
- Para investigar las propiedades de estado sólido de un complejo de renio dinuclear.
- Comprender la relación entre la estructura cristalina y la fotoluminiscencia.
- Para explorar las transiciones de fase en materiales cristalinos.
Principales métodos:
- Cristalización para obtener distintos polimorfos (1Y y 1O).
- Espectroscopia de fotoluminiscencia para medir el rendimiento cuántico y los espectros de emisión.
- Difracción de rayos X de temperatura variable para estudiar las transiciones de fase.
Principales resultados:
- Se obtuvieron dos polimorfos (1Y y 1O) con diferentes tasas de cristalización.
- Ambos polimorfos mostraron una fotoluminiscencia significativamente mejorada en estado sólido en comparación con la solución.
- Se observó una transición de fase de un solo cristal a otro (1O → 1Y) a 443 K.
- Los polimorfos mostraron diferentes máximos de absorción y emisión a pesar de las débiles interacciones intermoleculares.
Conclusiones:
- La organización local de los dipolos moleculares en el cristal tiene un impacto significativo en las propiedades fotofísicas.
- El polimorfismo en complejos de renio dinucleares puede conducir a comportamientos ópticos distintos.
- Las estrategias de ingeniería de cristales pueden ajustar la fotoluminiscencia de los complejos metálicos.
Videos de Conceptos Relacionados
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:57Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
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...
02:52Stereoisomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...