Limited supramolecular strategies have been utilized to synthesize sequence-defined polymers, despite the prominence of noncovalent interactions in materials design. Herein, we illustrate the utility of ‘sacrificial’ aryl-perfluoroaryl supramolecular synthons to...

The X-ray structure of a series of iodo-and bromo-phenylethynylpyridines designed to form self-complementary dimers in the solid state are reported. The perfluoroiodo-and perfluorobromophenylethynyl derivatives, 3-[(2-bromo-3,4,5,6tetrafluorophenyl)ethynyl]pyridine, 3-[(2,3,4,5-tetrafluoro-6-iodophenyl)ethynyl]pyridine, 2-[(3-bromo-2,4,5,6-tetrafluorophenyl)ethynyl]pyridine, and 2-[(2,4,6-trifluoro-3,5-diiodophenyl)ethynyl]pyridine, formed self-complementary halogen-bonded dimeric units in the solid state. In contrast, 3-[(2-bromo-4,5-difluorophenyl)ethynyl]pyridine formed a C−H•••N hydrogenbonded dimer.

Nano-dimensional crystals of aspirin generated through sonochemistry exhibit Young's modulus values an order of magnitude softer than macro-dimensional crystals.