Single-atom substitution enables supramolecular diversity from dipeptide building blocks. Issue 11 (18th February 2022)

• Record Type: Journal Article
• Authors: Scarel, Erica; Bellotto, Ottavia; Rozhin, Petr; Kralj, Slavko; Tortora, Mariagrazia; Vargiu, Attilio V.; De Zorzi, Rita; Rossi, Barbara; Marchesan, Silvia
• Is Part Of: Soft matter. Volume 18:Issue 11(2022)
• Page Start: 2129
• Page End: 2136
• Publication Date: 2022-02-18
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d1sm01824h
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : Halogenated heterochiral dipeptides self-assemble into hydrogels or crystals, and synchrotron-based techniques complement models, microscopy and spectroscopy, to elucidate supramolecular packing. Abstract : Dipeptides are popular building blocks for supramolecular gels that do not persist in the environment and may find various applications. In this work, we show that a simple substitution on the aromatic side-chain of phenylalanine with either fluorine or iodine enables supramolecular diversity upon self-assembly at neutral pH, leading to hydrogels or crystals. Each building block is characterized by 1 H- and 13 C-NMR spectroscopy, LC-MS, circular dichroism, and molecular models. The supramolecular behaviour is monitored with a variety of techniques, including circular dichroism, oscillatory rheology, transmission electron microscopy, attenuated total reflectance Fourier-transformed infrared spectroscopy, visible Raman spectroscopy, synchrotron-radiation single-crystal X-ray diffraction and UV Resonance Raman spectroscopy, allowing key differences to be pinpointed amongst the halogenated analogues.