Related Experiment Video
Updated: Jul 26, 2025
10:44
Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
10.9K
Revealing unbound β-diketiminate anions: structural dynamics from caesium complexes.
Hellen Videa1, Antonio J Martínez-Martínez1
1CIQSO - Centre for Research in Sustainable Chemistry and Department of Chemistry, University of Huelva, Campus El Carmen, Huelva ES-21007, Spain. antonio.martinez@ciqso.uhu.es.
Dalton Transactions (Cambridge, England : 2003)
|June 19, 2023
Summary
Researchers have structurally characterized unbound beta-diketiminate anions (BDI-) for the first time, revealing their dynamic cisoid-transoid exchange in caesium complexes. This breakthrough offers new insights into these strongly coordinating species.
Area of Science:
- Organometallic Chemistry
- Coordination Chemistry
- Supramolecular Chemistry
Background:
- Beta-diketiminate (BDI) anions are versatile ligands known for their strong coordination capabilities in various metal complexes.
- The structural and dynamic behavior of BDI anions in their unbound state has remained largely unexplored due to their inherent reactivity.
- Caesium complexes offer a unique platform for stabilizing reactive anionic species.
Purpose of the Study:
- To achieve the first structural elucidation of unbound beta-diketiminate (BDI-) anions.
- To investigate the behavior of BDI- anions within caesium complexes upon the addition of Lewis donor ligands.
- To characterize the dynamic exchange processes of liberated BDI- anions in solution.
Main Methods:
- Synthesis of beta-diketiminate caesium salts (BDICs).
- Reaction of BDICs with Lewis donor ligands.
- Structural elucidation techniques (e.g., X-ray crystallography, NMR spectroscopy).
- Solution-state dynamic studies.
Main Results:
- Successful synthesis and isolation of beta-diketiminate caesium salts (BDICs).
- Observation of free BDI- anions and donor-solvated Cs+ cations upon ligand addition.
- Unprecedented observation of dynamic cisoid-transoid exchange of the liberated BDI- anions in solution.
- Structural characterization of the unbound BDI- anion.
Conclusions:
- The study provides the first structural evidence of unbound beta-diketiminate (BDI-) anions.
- The findings demonstrate the ability of caesium complexes to stabilize and liberate reactive BDI- anions.
- The observed dynamic cisoid-transoid exchange in solution opens new avenues for understanding BDI- anion reactivity and applications.
More Related Videos
06:44From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
69.1K
07:24Quantitative Atomic-Site Analysis of Functional Dopants/Point Defects in Crystalline Materials by Electron-Channeling-Enhanced Microanalysis
Published on: May 10, 2021
6.1K
Related Concept Videos
01:23Complexation Equilibria: Overview
748
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...
748
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
43.2K
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,...
43.2K
03:45Formation of Complex Ions
23.8K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
23.8K
02:42Valence Bond Theory
8.8K
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...
8.8K
02:48Ionic Bonding and Electron Transfer
41.8K
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.
41.8K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
417
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
417