Self-Assembly of Supramolecular Architectures by the Effect of Amino Acid Residues of Quaternary Ammonium Pillar[5]arenes

• Main Authors: Anastasia Nazarova, Dmitriy Shurpik, Pavel Padnya, Timur Mukhametzyanov, Peter Cragg, Ivan Stoikov
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: International Journal of Molecular Sciences
• Subjects: aggregation; (1S)-(+)-10-camphorsulfonic acid; host-guest systems; methyl orange dye; amino acid; pillar[5]arene
• Online Access: https://www.mdpi.com/1422-0067/21/19/7206

Novel water-soluble multifunctional pillar[⁵]arenes containing amide-ammonium-amino acid moiety were synthesized. The compounds demonstrated a superior ability to bind (1S)-(+)-10-camphorsulfonic acid (<i>S</i>-CSA) and methyl orange dye depending on the nature of the substituent, resulting in the formation one-to-one complexes with both guests. The formation of host-guest complexes was confirmed by ultraviolet (UV), circular dichroism (CD) and ¹H NMR spectroscopy. This work demonstrates the first case of using <i>S</i>-CSA as a chiral template for the non-covalent self-assembly of architectures based on pillar[5]arenes. It was shown that pillar[⁵]arenes with glycine or L-alanine fragments formed aggregates with average hydrodynamic diameters (d) of 165 and 238 nm, respectively. It was established that the addition of <i>S</i>-CSA to the L-alanine-containing derivative led to the formation of micron-sized aggregates with d of 713 nm. This study may advance the design novel stereoselective catalysts and transmembrane amino acid channels.