303157-04-2Relevant academic research and scientific papers
Shape-persistent and shape-adaptable macrocycles based on restricted rotation: Studies building toward 'macromolecular playdough'
Chong, Yong S.,Shimizu, Ken D.
, p. 1239 - 1244 (2007/10/03)
A rigid 48-membered macrocycle 1 was synthesized and studied that comprises two atropisomeric N,N′-diarylnaphthalenediimide building blocks that adopt stable syn and anti conformations due to restricted rotation about two Caryl-Nimide bonds. The resulting macrocycle maintains three distinct conformations: anti/anti; syn/anti and syn/syn conformers that are stable and separable at room temperatures, and each with distinct shapes and sizes as measured by GPC. At elevated temperatures, macrocycle 1 was conformationally flexible and showed interconversion of the respective isomers. Conformational preferences established at higher temperatures were preserved on cooling to room temperature as the restricted rotation was reestablished and the macrocycle becomes conformationally rigid.
Molecules with shape memory based on restricted rotation
Choi, Dong-Sook,Chong, Yong S.,Whitehead, Daniel,Shimizu, Ken D.
, p. 3757 - 3760 (2007/10/03)
Figure presented Diimide 1 and octaimide 2 both adopt two stable conformations at room temperature as a result of restricted rotation about two Caryl-Nimide single bonds, a compact "folded" and an open "unfolded" structure. Predictable ratios of folded and unfolded rotamers can be achieved by heating in solvents of appropriate polarity as measured by the Reichardt's parameter (ET30). On cooling to room temperature, the resulting conformational changes are "locked in" as restricted rotation is reestablished.
