Trimacrocyclic hexasubstituted benzene linked by labile octahedral [X(CHCl₃)₆]^- clusters

Area of Science:

• Supramolecular Chemistry
• Crystal Engineering
• Organic Chemistry

Background:

• Crystalline supramolecular architectures are typically formed using cations, anions, ion pairs, or neutral guests.
• The role of labile anionic solvate clusters in mediating the robust crystallization of designed receptors has not been previously explored.

Purpose of the Study:

• To investigate the synthesis and crystalline behaviors of a trimacrocyclic hexasubstituted benzene.
• To explore the role of guanidium halide salts and chloroform in the crystallization process.
• To demonstrate the stabilizing effect of labile ionic solvate clusters on supramolecular architectures.

Main Methods:

• Synthesis of trimacrocyclic hexasubstituted benzene 2.
• Crystallization experiments using guanidium halide salts and chloroform.
• Single-crystal structure determination.
• X-ray powder diffraction (XRPD).
• Thermogravimetric analysis (TGA).
• Scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS).
• NMR spectroscopy.

Main Results:

• Successful synthesis and crystallization of trimacrocyclic hexasubstituted benzene 2.
• Identification of halide hexasolvate clusters, specifically [Cl(CHCl3)6]−, [Br(CHCl3)6]−, and [I(CHCl3)6]−, as critical components in the crystallization process.
• Structural and spectroscopic evidence confirming the role of these solvate clusters in stabilizing the supramolecular architecture.

Conclusions:

• Labile ionic solvate clusters, particularly halide hexasolvate clusters, can play a significant and previously unrecognized role in stabilizing crystalline supramolecular architectures.
• This finding expands the understanding of crystal formation and design principles in supramolecular chemistry.
• The study highlights a novel approach to controlling and achieving robust crystallization of complex organic molecules.