Al(ii) transfer harnessing a well-defined cadmium precursor.

Area of Science:

• Main-group chemistry
• Organometallic chemistry
• Low-valent aluminum compounds

Background:

• The selective generation and transfer of low-valent aluminum(II) fragments are underexplored areas in main-group chemistry.
• Controlled aluminum(II) transfer is crucial for developing selective alumination and functionalization strategies.
• Understanding main-group reactivity provides conceptual guidance for novel synthetic and catalytic platforms.

Purpose of the Study:

• To investigate the role of heterometals as structural templates for controlling low-valent aluminum reactivity.
• To demonstrate the selective transfer of aluminum(II) fragments using covalent aluminum/cadmium frameworks.
• To explore the nuclearity-dependent reactivity of aluminum-cadmium compounds.

Main Methods:

• Synthesis and characterization of trimetallic [({N(TMS)₂})(Cp*)Al]₂Cd (1^tri) and bimetallic [{N(TMS)₂}(Cp*)Al-Cd{N(TMS)₂}] (1^bi) compounds.
• Reactions of 1^tri with free radicals, dichalcogenides, and benzophenone derivatives to induce aluminum transfer.
• Density Functional Theory (DFT) studies to elucidate reaction mechanisms, electronic structures, and compound stability.

Main Results:

• The trimetallic compound 1^tri selectively transfers aluminum complex fragments via cadmium extrusion.
• Reactions with various substrates confirmed the utility of aluminum transfer from 1^tri, including spin-trapping of aluminum(II) radicals.
• The bimetallic compound 1^bi exhibits distinct reactivity, promoting cadmium transfer instead of aluminum transfer, highlighting nuclearity dependence.

Conclusions:

• Heterometals can effectively template and direct low-valent aluminum reactivity within covalent frameworks.
• The trimetallic Al/Cd compound provides a platform for selective aluminum(II) fragment transfer, expanding synthetic possibilities.
• Nuclearity plays a critical role in determining the transfer behavior of aluminum-cadmium compounds.