Switching of inherent chirality driven by self-assembly

Abstract

Dynamic chirality of iminoresorcin[4]arenes that originates from regioselective and diastereoselective keto-enol tautomerisation was switched by non-covalent interactions with achiral molecules, as demonstrated by experimental electronic circular dichroism (ECD) spectra supported by TD DFT calculations.

A chiral member of the family of organic hexameric cages

“…28 Both types of products are stabilized by directional seams of intramolecular hydrogen bonds, which, in addition to stabilization, results in inherent chirality of the molecules. 29 Currently, we used a bifunctional semi-rigid building block -hydrazineexpecting formation of covalently connected cages ( Fig. 1).…”

The templation effect as a driving force for the self-assembly of hydrogen-bonded peptidic capsules in competitive media

“…These bands are the most sensitive to conformational inherent chirality and symmetry of these molecules, as they come from the HOMO-LUMO transition involving an inherently chiral chromophore. 25 These results indicate that the capsular dimers indeed retain a hydrogenbonded ordered structure in competitive medium. It is also important to note that there are no traces of dynamic exchange between species at the NMR timescale, indicating that the complexes are also kinetically persistent in this solvent, which is quite surprising considering that semi-open cavitands are also present in the solution.…”

Self‐Assembly and Ordering of Peptide‐Based Cavitands in Water and DMSO: The Power of Hydrophobic Effects Combined with Neutral Hydrogen Bonds

“…We have previously found that self-assembly has a pronounced effect on ECD spectra. [14,17,18] This is primarily due to the increased rigidity and conformational order of self-assembled structures compared to the conformationally labile cavitands.A fter self-assembly,r otations about partial double bonds becomeh indered, and inherently chiral conformations are generated, which result in as ignificant intensity increase (by even two orders of magnitude)o fE CD bands [18] or inversion of the sign of the Cotton effect. [17] In the current experiments,t he increase of band intensity indicates that, during the templated reactions, highly ordereds pecies must be formed that are fundamentally different from the cavitands obtained by nontemplated procedures.…”