Divalent Benzimidazolium-Based Axles for Self-Reporting Pseudorotaxanes

J Org Chem. 2022 Dec 2;87(23):15783-15795. doi: 10.1021/acs.joc.2c01758. Epub 2022 Nov 15.

Abstract

Mono- and (bis)benzimidazoliums were evaluated both experimentally and computationally for their potential as pseudopolyrotaxane axle building blocks. Their aggregation and photophysical behavior, along with their potential to form a [2]pseudorotaxane with dibenzyl-24-crown-8, was studied through the synergistic application of 1D/2D and diffusion-ordered NMR spectroscopy, mass spectrometry, ultraviolet-visible and fluorescence spectroscopy, and time-dependent density functional theory. Their photophysical behavior was measured and modeled as a function of protonation state, solvent, and concentration. The axles show strong solvochromaticism and a very pronounced concentration-dependent optical profile, including self-quenching when a pseudorotaxane is formed. This axle with multiple recognition sites has the potential to form pseudorotaxanes with tunable optical behavior.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Magnetic Resonance Spectroscopy / methods
  • Models, Molecular
  • Rotaxanes* / chemistry

Substances

  • Rotaxanes