Related Experiment Video
Updated: Feb 3, 2026
14:22
Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
Published on: April 15, 2013
20.8K
Isolation of a TMTAA-Based Radical in Uranium bis-TMTAA Complexes
Stephan Hohloch1,2, Mary E Garner1, Corwin H Booth3
1Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
Angewandte Chemie (International Ed. in English)
|October 18, 2018
Summary
Thorium and uranium complexes with tetramethyltetraazaannulene ligands exhibit high stability. The uranium complex demonstrates stable oxidation states, highlighting the ligand
Area of Science:
- Inorganic Chemistry
- Organometallic Chemistry
- Materials Science
Background:
- Actinide chemistry research is crucial for understanding fundamental bonding and electronic properties.
- Tetramethyltetraazaannulene (TMTAA) ligands offer unique coordination environments for metal ions.
- Sandwich complexes provide insights into electronic structures and redox behavior.
Purpose of the Study:
- To synthesize and characterize novel thorium(IV) and uranium(IV) bis-tetramethyltetraazaannulene complexes.
- To investigate the electronic structure and stability of these actinide complexes.
- To explore the redox properties of the uranium complex and the nature of the TMTAA ligand.
Main Methods:
- Synthesis of actinide bis-TMTAA complexes.
- Characterization using spectroscopic and analytical techniques.
- Electrochemical studies and isolation of oxidized species.
Main Results:
- Successful synthesis and characterization of thorium(IV) and uranium(IV) bis-TMTAA complexes.
- Demonstrated remarkable air and moisture stability, even at high temperatures.
- Uranium complex exhibited stability in three oxidation states.
- Isolation of oxidized species confirmed the non-innocent nature of the TMTAA ligand.
Conclusions:
- Thorium and uranium bis-TMTAA complexes are highly stable organometallic compounds.
- The TMTAA ligand plays a crucial role in stabilizing multiple oxidation states of uranium.
- These findings contribute to the understanding of actinide coordination chemistry and ligand non-innocence.
Related Concept Videos
01:16Radical Reactivity: Nucleophilic Radicals
2.7K
Radicals adjacent to electron-donating groups are called nucleophilic radicals. These radicals readily react with electrophilic alkenes. The SOMO–LUMO interactions are the driving force for the reaction, where the high-energy SOMO of the electron-rich, nucleophilic radicals interacts with the low-energy LUMO of the electron-deficient, electrophilic alkenes. Such SOMO–LUMO interactions are the basis of reactive radical traps, affecting the selectivity in radical reactions. For...
2.7K
01:02Radical Reactivity: Electrophilic Radicals
2.5K
Radicals adjacent to electron‐withdrawing groups are called electrophilic radicals. These radicals readily react with nucleophilic alkenes. For example, the malonate radical, in which the radical center is flanked by two electron‐withdrawing groups, reacts readily with butyl vinyl ether, which consists of an electron‐donating oxygen substituent. The reaction between electrophilic malonate radical and nucleophilic vinyl ether is favored because the radical has a...
2.5K
01:27Radicals
731
Roots, often written as radicals, identify the quantity that must be raised to a specific exponent to produce a given value. A radical expression consists of two main components: the radicand, which is the value placed inside the root symbol, and the index, which indicates the degree of the root being taken. The notation n√a indicates the principal nth root of a. If n equals 2, the operation is the square root, while n = 3 defines the cube root. When n is even, a negative radicand does...
731
01:20Radical Autoxidation
3.2K
The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...
3.2K
01:26Radical Equations
362
Radical equations are mathematical expressions in which the variable is found within a radical, most commonly a square root or cube root. These equations frequently arise in science, engineering, and real-world measurements involving nonlinear relationships. To solve a radical equation, the standard procedure is to isolate the radical expression and then eliminate the radical by raising each side to a power equal to the index of the radical. This process may lead to extraneous...
362
03:45Formation of Complex Ions
26.1K
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...
26.1K