Chalcogen complexes of anionic N-heterocyclic carbenes

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• N-Heterocyclic Carbene Chemistry

Background:

• N-heterocyclic carbenes (NHCs) are versatile ligands in coordination chemistry.
• Weakly coordinating anions (WCAs) are crucial for stabilizing reactive species.
• Group 16 elements (O, S, Se, Te) play vital roles in various chemical and biological processes.

Purpose of the Study:

• To synthesize and characterize novel group 16 adducts stabilized by a weakly coordinating borate-supported NHC ligand.
• To explore the reactivity of these adducts, including protonation and oxidation reactions.
• To expand the scope of NHC-metal complexes with group 16 elements.

Main Methods:

• Deprotonation of ketone or thione precursors with n-butyllithium.
• Reaction of lithiated species with tris(pentafluorophenyl)borane (B(C6F5)3).
• Direct reaction with elemental selenium and tellurium.

Main Results:

• Successful synthesis of [(WCA-IDipp)E]Li(solv.) adducts for E = O, S, Se, Te.
• Protonation of oxygen, sulfur, and selenium adducts yielded (WCA-IDipp)EH derivatives.
• Oxidation of sulfur and selenium adducts produced neutral disulfide and diselenide species, (WCA-IDipp)2E2.

Conclusions:

• The study demonstrates the successful preparation of a new class of group 16 adducts stabilized by a WCA-supported NHC ligand.
• The synthesized compounds exhibit interesting reactivity, allowing for further functionalization.
• These findings contribute to the development of novel organometallic compounds with potential applications.