Related Experiment Video
Updated: May 9, 2026
07:20
Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
Tuning uranium-nitrogen multiple bond formation with ancillary siloxide ligands.
Clément Camp1, Jacques Pécaut, Marinella Mazzanti
1Laboratoire de Reconnaissance Ionique et Chimie de Coordination, SCIB, UMR-E3 CEA-UJF, INAC, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble Cedex 09.
Journal of the American Chemical Society
|August 7, 2013
Summary
This study details the synthesis and characterization of novel uranium siloxide complexes. Reactions with azides yield diverse uranium imido, nitrido, and azido complexes, highlighting the role of coordination environment in U(III) chemistry.
Area of Science:
- Organometallic Chemistry
- Uranium Chemistry
- Coordination Chemistry
Background:
- Uranium's unique electronic properties make it a fascinating element for chemical research.
- Understanding the reactivity of low-valent uranium complexes is crucial for developing new synthetic methodologies.
Purpose of the Study:
- To explore the reactivity of homoleptic uranium(III) siloxide complexes with various azides.
- To synthesize and characterize new uranium imido, nitrido, and azido complexes.
- To investigate the influence of the coordination environment on the reaction outcomes.
Main Methods:
- Synthesis of uranium(III) siloxide complexes via reduction of uranium(IV) precursors.
- Reaction of uranium siloxides with organic and inorganic azides (e.g., adamantyl azide, trimethylsilyl azide, cesium azide).
- Isolation and characterization of products using X-ray crystallography and other analytical techniques.
Main Results:
- Isolation of a homoleptic uranium(III) siloxide complex [K(18c6)][U(OSi(O(t)Bu)3)4].
- Synthesis of dinuclear U(VI) imido, U(V) imido, U(IV) azido, and U(V) nitrido complexes.
- Structural characterization revealing a "cation-cation interaction" in a U(VI) complex and a rare U2N2 core in a U(V) nitrido complex.
- Formation of a diuranium(IV) complex with a bridging nitrido ligand and a cesium cation.
Conclusions:
- The coordination environment significantly dictates the reaction pathway and products when U(III) siloxides react with azides.
- Diverse oxidation states and structural motifs (imido, nitrido, azido) can be accessed.
- This work expands the known chemistry of low-valent uranium complexes and their transformations.
Related Concept Videos
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...
02:34Structural 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...
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...
02:42Valence 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...
01:27¹H 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.
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.
01:06Nuclear Overhauser Enhancement (NOE)
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling. This phenomenon, called the nuclear Overhauser enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring spin-active...