Unravelling the Supramolecular Driving Forces in the Formation of CO<sub>2</sub>-Responsive Pseudopeptidic Low-Molecular-Weight Hydrogelators

A new family of C<sub>2</sub>-symmetric pseudopeptides with a high functional density for supramolecular interactions has been synthetized through the attachment of four amino acid subunits to a diamino aliphatic spacer. The resulting open-chain compounds present remarkable properties as...

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Bibliographic Details
Main Authors: Ferran Esteve, Alexis Villanueva-Antolí, Belén Altava, Eduardo García-Verdugo, Santiago V. Luis
Format: Article
Language:English
Published: MDPI AG 2022-06-01
Series:Gels
Subjects:
Online Access:https://www.mdpi.com/2310-2861/8/6/390
Description
Summary:A new family of C<sub>2</sub>-symmetric pseudopeptides with a high functional density for supramolecular interactions has been synthetized through the attachment of four amino acid subunits to a diamino aliphatic spacer. The resulting open-chain compounds present remarkable properties as low-molecular-weight hydrogelators. The self-assembled 3D networks were characterized by SEM analyses, observing regular nanofibres with 80–100 nm diameters. Spectroscopic and molecular modelling experiments revealed the presence of strong synergic effects between the H-bonding and π–π interactions, with the best results obtained for the homoleptic tetra-pseudopeptide derived from <span style="font-variant: small-caps;">l</span>-Phe. In addition, these bioinspired hydrogels possessed pH- and CO<sub>2</sub>-responsive sol–gel transitions. The formation of ammonium carbamate derivatives in the presence of carbon dioxide led to a detrimental change in its adequate self-assembly. CO<sub>2</sub> desorption temperatures of ca. 70 °C were assigned to the thermodynamically favoured recovery of the supramolecular gel.
ISSN:2310-2861