Hydrogen-Bonded Fibrous Nanotubes Assembled from Trigonal Prismatic Building Blocks.

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• Reticular chemistry typically designs molecular building blocks for crystalline open frameworks.
• High symmetry in building blocks usually leads to highly symmetrical network outcomes.
• Synthesizing low-dimensional networks requires reducing the symmetry of molecular building blocks.

Purpose of the Study:

• To report the spontaneous formation of hydrogen-bonded fibrous structures from trigonal prismatic building blocks.
• To understand the growth mechanism of these structures using microscopic and spectroscopic techniques.
• To provide fundamental insights into the molecular design of tubular structures.

Main Methods:

• Design and synthesis of trigonal prismatic molecular building blocks.
• Utilizing microscopic (e.g., electron microscopy) and spectroscopic techniques (e.g., NMR, IR) to identify structures.
• Employing theoretical modeling alongside experimental evidence to understand nucleation and growth.

Main Results:

• Spontaneous formation of hydrogen-bonded fibrous structures from symmetrical building blocks.
• Formation of anisotropic, hydrogen-bonded porous organic nanotubes via preferential longitudinal incorporation.
• Entropy-driven anisotropic growth resulting in micrometer-scale unidirectional nanotubes with high porosity.
• Further evolution into higher-order fibrous structures (nano- and microfibers) and large-scale interconnected fiber-like structures.

Conclusions:

• Symmetrical building blocks can lead to anisotropic low-dimensional structures, challenging traditional reticular chemistry principles.
• Understanding nucleation and growth is key to designing tubular structures.
• The findings pave the way for innovative molecular designs in low-dimensional networks and fibrous materials.