Hydrogen‐Bond‐Assisted Helical Folding of Propeller‐Shaped Molecules: Effects of Extended π‐Conjugation on Chiral Selection, Conformational Stability, and Exciton Coupling

Abstract

Cooperative interaction between multiple chiral centers dictates the absolute handedness of structural folding. We have designed and prepared a series of chiral C 3 -symmetric tris(Nsalicylidenamine) derivatives that adopt three-blade propeller-like conformations. Synthetic access to an expanded family of such constructs was aided by enzymatic resolution and C-C cross-coupling reactions of aryl-substituted chiral propargylic alcohol derivatives. These key structural components were integrated into molecular propellers of predetermined helical screw sense. Through comparative studies on a homologous set of molecules, we found that installation of phenylene-ethynylene-derived π-conjugation profoundly affected the stabilities of the helically folded structures, as evi-

Supramolecular Chirality in Dynamic Coordination Chemistry

“…such as small organic molecules [13][14][15][16][17][18][19], polymers [20][21][22][23], metamaterials [24], and assemblies [25][26][27][28], have been developed for chirality induction and switching in response to external stimuli, more sophisticated systems are required to mimic natural systems.…”