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Updated: Aug 7, 2025

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
An attempt to consider cooperativity in helical-sense preferences induced in fused macrocycles
Ryo Katoono1, Takaaki Kudo1, Shunsuke Kawai1
1Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan. katoono@sci.hokudai.ac.jp.
Abstract:
We synthesized bis and tris(macrocycle)s in which a two- or three-fold macrocycle was fused and each adopted twisted forms with M- or P-helicity. According to the sense of twisting in each element, diverse conformations can be generated in a molecule. We present two types of conformational preferences. One is the innate preference for a helical form with an identical sense of twisting throughout the entire molecule. The other is the helical-sense preference for a particular sense of twisting. We were interested in the relationship between K and (K1), where K is an equilibrium constant for the conformational interconversion between two helical forms (MM and PP, MMM and PPP) and n is the number of elements, since we considered that the relationship could be a metric to see the interinfluence among these macrocyclic elements in a single molecule. Through VT measurements in 1H NMR and CD spectroscopy, we attempted to quantify the helical-sense preferences induced in the fused macrocycles (n = 2 and 3) to compare K and (K1).
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