Related Experiment Video
Updated: Jul 18, 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
Mononucleating bis(beta-diketonate) ligands and their titanium(IV) complexes
Vesela Ugrinova1, Bruce C Noll, Seth N Brown
1Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670, USA.
Inorganic Chemistry
|December 5, 2006
Summary
Novel bis(beta-diketone) ligands were synthesized and metalated with titanium(IV) isopropoxide. The linker structure dictates complex formation, with specific biphenyl-based ligands yielding stable mononuclear titanium complexes. These complexes exhibit robustness towards Lewis acids and can form cationic species.
Area of Science:
- Organometallic Chemistry
- Coordination Chemistry
- Titanium Complexes
Background:
- Bis(beta-diketone) ligands are versatile chelating agents in coordination chemistry.
- Titanium complexes with beta-diketonate ligands have applications in catalysis and materials science.
- The influence of linker structure on the properties of metal complexes is a key area of research.
Purpose of the Study:
- To synthesize novel bis(beta-diketone) ligands with different bridging moieties.
- To investigate the metalation of these ligands with titanium(IV) isopropoxide.
- To characterize the resulting titanium complexes and evaluate their structural and chemical properties.
Main Methods:
- Synthesis of novel bis(beta-diketone) ligands.
- Metalation reactions with titanium(IV) isopropoxide.
- Crystallographic analysis of titanium complexes.
- Reactions with Lewis acids and salt metathesis for cationic complex formation.
Main Results:
- Successfully synthesized bis(beta-diketones) linked by biphenyl, tolan, and bis(methylene)biphenyl groups.
- Titanium(IV) isopropoxide readily metalates these ligands, with complex formation dependent on the linker.
- Substituted biphenyl-bridged ligands form stable mononuclear titanium complexes, including a single diastereomer.
- These complexes demonstrate kinetic and thermodynamic robustness and can be converted to cationic species.
Conclusions:
- The linker structure of bis(beta-diketone) ligands significantly influences the formation and stability of titanium complexes.
- The R2Bob ligands provide a robust framework for stable mononuclear titanium complexes.
- These titanium complexes offer potential for further functionalization and applications in organometallic chemistry.
Related Concept Videos
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...
01:22EDTA: Chemistry and Properties
Polydentate ligands are most widely used in complexometric titrations because they form more stable complexes with the metal ions than mono- or bidentate ligands due to the chelate effect. Examples of polydentate ligands are ethylenediaminetetraacetic acid (EDTA), crown ethers, and cryptands. The most important feature of optimal polydentate ligands is the ability to form 1:1 complexes in a single-step process. Amino carboxylic acid derivatives are frequently used as complexing agents. EDTA is...
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...
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...
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...
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,...