Supramolecular macrocycles reversibly assembled by Te(…)O chalcogen bonding.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27090355.
- Also identified by DOI 10.1038/ncomms11299 and PMC identifier 4838886.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Organic molecules with heavy main-group elements frequently form supramolecular links to electron-rich centres. One particular case of such interactions is halogen bonding. Most studies of this phenomenon have been concerned with either dimers or infinitely extended structures (polymers and lattices) but well-defined cyclic structures remain elusive. Here we present oligomeric aggregates of heterocycles that are linked by chalcogen-centered interactions and behave as genuine macrocyclic species. The molecules of 3-methyl-5-phenyl-1,2-tellurazole 2-oxide assemble a variety of supramolecular aggregates that includes cyclic tetramers and hexamers, as well as a helical polymer. In all these aggregates, the building blocks are connected by Te(…)O-N bridges. Nuclear magnetic resonance spectroscopic experiments demonstrate that the two types of annular aggregates are persistent in solution. These self-assembled structures form coordination complexes with transition-metal ions, act as fullerene receptors and host small molecules in a crystal.