Silicon based radicals, radical ions, diradicals and diradicaloids

Area of Science:

• Organic Chemistry
• Radical Chemistry
• Carbene Chemistry

Background:

• Radicals are key intermediates in chemical and biological processes, often with short lifetimes.
• Stable radicals can be isolated and stored, with recent advances in stabilization using singlet carbenes.
• Cyclic alkyl(amino) carbenes (cAACs) offer superior σ-donation and π-acceptance compared to N-heterocyclic carbenes (NHCs).

Purpose of the Study:

• To review the generation of stable radical centers on carbene carbon atoms using cAACs.
• To focus on developing synthetic routes for stable, isolable radicals containing silicon.
• To discuss the reactivity of short-lived radical species and their initiated chemical reactions.

Main Methods:

• Synthesis of stable and isolable radicals, particularly silicon-containing ones.
• Characterization using single crystal X-ray analysis, EPR spectroscopy, and magnetic susceptibility measurements.
• Electrochemical studies via cyclic voltammetry and theoretical calculations.

Main Results:

• Successful generation of stable radical centers utilizing the unique properties of cAACs.
• Development of new synthetic pathways for silicon-centered radicals.
• Characterization of mono- and di-radicals, including their electronic properties and reactivity.

Conclusions:

• cAACs provide a powerful platform for stabilizing radical species.
• New stable silicon-centered radicals have been synthesized and characterized.
• Understanding the reactivity of both stable and short-lived radicals is crucial for chemical synthesis and biological processes.