Related Experiment Video
Updated: Mar 30, 2026
09:45
Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
10.9K
Metal-Metal Bonding in Trinuclear, Mixed-Valence [Ti3X12](4-) (X = F, Cl, Br, I) Face-Shared Complexes
Jinasena W Hewage1, Germán Cavigliasso2, Robert Stranger2
1Department of Chemistry, University of Ruhuna , Matara, Sri Lanka.
Inorganic Chemistry
|November 3, 2015
Summary
Density functional theory reveals strong metal-metal bonding in titanium clusters, explaining antiferromagnetic coupling and predicting weaker bonds down the halide group. The study also explores bond-stretch isomerism in these titanium halide systems.
Area of Science:
- Inorganic Chemistry
- Solid-State Chemistry
- Computational Chemistry
Background:
- Metal-metal bonding in transition metal halides is crucial for understanding material properties.
- Mixed-valence titanium halide clusters exhibit complex electronic structures and magnetic behaviors.
Purpose of the Study:
- Investigate the nature of metal-metal bonding in In4Ti3Br12 using density functional theory.
- Explain the observed strong antiferromagnetic coupling in the [Ti3Br12](4-) units.
- Explore the electronic structure and bonding in related [Ti3X12](4-) systems (X = F, Cl, I).
- Examine the phenomenon of bond-stretch isomerism in these titanium clusters.
Main Methods:
- Density Functional Theory (DFT) calculations were employed to model the electronic structure and bonding.
- Analysis of spin densities and magnetic coupling was performed.
- Calculations explored potential energy surfaces for bond-stretch isomerism.
Main Results:
- The antiferromagnetic configuration, with antiparallel electron spins on terminal Ti(III) and central Ti(II) sites, best explains the experimental data.
- A strong, partially delocalized, three-center sigma bond between titanium atoms (Ti-Ti bond order ~0.5) was identified.
- Metal-metal bonding strength decreases down the halide group (Br > I > Cl > F).
- Calculations predict a more stable asymmetric structure with differing Ti-Ti bond lengths, but a low interconversion barrier leads to observation of an averaged symmetric structure at room temperature.
Conclusions:
- The electronic structure and metal-metal bonding in In4Ti3Br12 are well-described by DFT, supporting an antiferromagnetic ground state.
- The observed magnetic coupling arises from strong sigma interactions between titanium atoms, with residual unpaired spin densities.
- Bond-stretch isomerism is possible, but dynamic averaging likely results in a symmetric structure under typical experimental conditions.
More Related Videos
16:11Thermochemical Studies of NiII and ZnII Ternary Complexes Using Ion Mobility-Mass Spectrometry
Published on: June 8, 2022
2.8K
12:18Co-localizing Kelvin Probe Force Microscopy with Other Microscopies and Spectroscopies: Selected Applications in Corrosion Characterization of Alloys
Published on: June 27, 2022
3.5K
Related Concept Videos
02:42Valence Bond Theory
11.7K
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...
11.7K
02:51Metal-Ligand Bonds
25.6K
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...
25.6K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
965
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...
965
01:19Complexation Equilibria: The Chelate Effect
1.6K
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...
1.6K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
49.7K
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,...
49.7K
02:32Bonding in Metals
56.0K
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
56.0K