Trialkoxysilane Exchange: Scope, Mechanism, Cryptates and pH-Response.

Area of Science:

• Materials Science
• Organic Chemistry
• Supramolecular Chemistry

Background:

• Dynamic covalent chemistry (DCvC) offers unique molecular assembly opportunities.
• The silicon-oxygen (Si-O) bond's DCvC is underexplored due to harsh reaction conditions.
• Existing methods require high temperatures or strong acids/bases for Si-O bond exchange.

Purpose of the Study:

• To investigate the dynamic covalent chemistry of the Si-O bond under mild conditions.
• To develop a facile method for assembling discrete molecular architectures using Si-O bonds.
• To explore the potential of resulting structures in host-guest chemistry and beyond.

Main Methods:

• Experimental study of trialkoxysilane and alcohol reactions.
• Computational modeling to understand reaction mechanisms.
• Systematic variation of substituents, solvents, and salts.
• Characterization of sila-orthoester cryptates.

Main Results:

• Identified mild conditions for rapid Si-O bond exchange in aprotic solvents.
• Uncovered substituent, solvent, and salt effects influencing the reaction.
• Successfully synthesized sila-orthoester cryptates.
• Demonstrated a sharp, divergent pH-response in the cage structures.

Conclusions:

• Mild conditions for Si-O bond DCvC have been established.
• This facilitates the construction of novel sila-orthoester cryptates.
• The pH-responsive nature of these cages opens avenues for applications in drug delivery and advanced materials.