Aluminium nanorings: configuration deformation and structural transformation

Area of Science:

• Supramolecular Chemistry
• Nanomaterials Science
• Organometallic Chemistry

Background:

• Fatty acids are versatile building blocks for self-assembly.
• Aluminum clusters offer unique electronic and structural properties.
• Controlling the architecture of nanostructures is crucial for advanced applications.

Purpose of the Study:

• To report the first instance of aluminum nanoring assembly mediated by fatty acids.
• To investigate the structural diversity of aluminum nanorings modified with different alcohols.
• To explore the structural transformation and thermodynamic feasibility of these nanorings.

Main Methods:

• Fatty acid-directed self-assembly of aluminum nanorings.
• Modification of auxiliary alcohol sites with monohydric alcohols and diols.
• Structural characterization using spectroscopic and crystallographic techniques.
• Density-functional theory (DFT) calculations to study structural transformations.

Main Results:

• Successful synthesis of aluminum nanorings (Al10) using fatty acids.
• Monohydric alcohol modification yields coplanar nanorings (AlOC-33 to AlOC-35).
• Diol modification results in saddle-shaped nanorings (AlOC-36 to AlOC-38).
• A diol-modified nanoring (AlOC-36) spontaneously converts to a coplanar form (AlOC-33-B).
• AlOC-33-B exhibits a distinct supramolecular structure compared to AlOC-33 despite similar molecular structure.
• DFT calculations confirm the thermodynamic spontaneity of the structural transformation.

Conclusions:

• Fatty acids can effectively direct the self-assembly of aluminum nanorings.
• The choice of alcohol modifier dictates the nanoring's configuration (coplanar vs. saddle-shaped).
• Aluminum nanorings can undergo spontaneous, thermodynamically favorable structural transformations, offering dynamic material potential.