Bottom-Up Solid-State Molecular Assembly via Guest-Induced Intermolecular Interactions.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Solid-State Chemistry

Background:

• Constructing ordered supramolecular architectures in the solid state is more challenging than in solution.
• Controlling molecular motions in solids is key to advanced materials design.

Purpose of the Study:

• To develop a bottom-up molecular assembly approach for solid-state construction.
• To investigate the use of a novel pillararene analogue for creating ordered assemblies.
• To explore vapor-induced and thermally triggered transformations in molecular assemblies.

Main Methods:

• Design and synthesis of a skeleton-trimmed pillar[5]arene analogue (permethylated leggero pillar[5]arene, MeP[5]L).
• Utilizing an amorphous powder of MeP[5]L to form solid-state molecular assemblies via guest vapor uptake.
• Employing thermal treatment to induce phase-to-phase transformation into linker-free superstructures.

Main Results:

• An amorphous powder of MeP[5]L successfully formed ordered, linker-containing solid-state molecular assemblies upon exposure to specific guest vapors.
• These assemblies could be transformed into thermodynamically favored, linker-free superstructures through heating.
• Intermolecular interactions were identified as critical factors governing molecular arrangements.

Conclusions:

• The study demonstrates a novel method for controllable solid-state molecular assembly driven by vapor-induced motion and thermal transformation.
• This research provides new insights into manipulating molecular motions in the solid state for materials development.
• The findings offer new perspectives for supramolecular chemistry and the design of advanced solid-state materials.