Preorganizing linear (self-complementary) quadruple hydrogen-bonding arrays using intramolecular hydrogen bonding as...

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Materials Science

Background:

• Designing molecules with specific self-assembly properties is crucial for creating advanced materials.
• Controlling the spatial arrangement of binding sites is key to predictable molecular assembly.
• Hydrogen bonding is a fundamental interaction for molecular recognition and self-assembly.

Purpose of the Study:

• To present a rational design strategy for creating self-assembling molecules with multiple cooperative binding sites.
• To demonstrate the use of intramolecular hydrogen bonding for preorganizing molecular structures.
• To explore novel self-assembly pathways leading to extended supramolecular networks.

Main Methods:

• Synthesis of amidinourea-based molecular constructs (1a-e and 2a,b).
• Investigation of self-assembly using electrospray ionization mass spectrometry (ESI-MS).
• Structural characterization of self-assembled structures via single-crystal X-ray diffraction.

Main Results:

• Constructs 1a-e and 2a,b successfully formed hydrogen-bonded dimers, preorganized by intramolecular hydrogen bonds.
• The amidinourea backbone served as a versatile platform for diverse self-assembling systems.
• Most dimers exhibited an unusual self-assembly mode involving intermolecular four-membered ring hydrogen bonds, leading to extended networks.

Conclusions:

• A rational approach for designing preorganized self-assembling systems based on intramolecular hydrogen bonding has been established.
• The study showcases the utility of the amidinourea backbone in constructing complex supramolecular architectures.
• Novel self-assembly pathways were discovered, expanding the possibilities for creating advanced supramolecular materials.