A supramolecular and liquid crystalline water-based alignment medium based on azobenzene-substituted 1,3,5-benzenetricarboxamides

Magn Reson Chem. 2022 Jun;60(6):563-571. doi: 10.1002/mrc.5266. Epub 2022 Mar 24.

Abstract

A supramolecular, lyotropic liquid crystalline alignment medium based on an azobenzene-containing 1,3,5-benzenetricarboxamide (BTA) building block is described and investigated. As we demonstrate, this water-based system is suitable for the investigation of various water-soluble analytes and allows for a scaling of alignment strength through variation of temperature. Additionally, alignment is shown to reversibly collapse above a certain temperature, yielding an isotropic solution. This collapse allows for isotropic reference measurements, which are typically needed in addition to those in an anisotropic environment, to be performed using the same sample just by varying the temperature. The medium described thus provides easy access to anisotropic NMR observables and simplifies structure elucidation techniques based thereon.

Keywords: 2H; BTAs; NMR; RDCs; alignment media; lyotropic liquid crystals; supramolecular chemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azo Compounds
  • Liquid Crystals* / chemistry
  • Magnetic Resonance Spectroscopy / methods
  • Water*

Substances

  • Azo Compounds
  • Water
  • azobenzene