Molecules (Jul 2021)

Chiroptical Sensing of Amino Acid Derivatives by Host–Guest Complexation with Cyclo[6]aramide

  • Xuebin Wang,
  • Jiecheng Ji,
  • Zejiang Liu,
  • Yimin Cai,
  • Jialiang Tang,
  • Yunzhi Shi,
  • Cheng Yang,
  • Lihua Yuan

DOI
https://doi.org/10.3390/molecules26134064
Journal volume & issue
Vol. 26, no. 13
p. 4064

Abstract

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A hydrogen-bonded (H-bonded) amide macrocycle was found to serve as an effective component in the host–guest assembly for a supramolecular chirality transfer process. Circular dichroism (CD) spectroscopy studies showed that the near-planar macrocycle could produce a CD response when combined with three of the twelve L-α-amino acid esters (all cryptochiral molecules) tested as possible guests. The host–guest complexation between the macrocycle and cationic guests was explored using NMR, revealing the presence of a strong affinity involving the multi-point recognition of guests. This was further corroborated by density functional theory (DFT) calculations. The present work proposes a new strategy for amplifying the CD signals of cryptochiral molecules by means of H-bonded macrocycle-based host–guest association, and is expected to be useful in designing supramolecular chiroptical sensing materials.

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