Formation of toroids by self-assembly of an α–α corner mimetic: supramolecular cyclization. Issue 36 (6th September 2017)

• Record Type: Journal Article
• Authors: Podder, Debasish; Bera, Santu; Debnath, Mintu; Das, Tanmay; Haldar, Debasish
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 36(2017)
• Page Start: 7583
• Page End: 7590
• Publication Date: 2017-09-06
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Biomedical materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7tb01711a
• Languages: English
• ISSNs: 2050-750X

Abstract

Abstract : An α–α corner mimetic self-assembles into a rod shape supramolecular structure which bends and closes end-to-end like a cyclization reaction to form toroids. Abstract : An α–α corner mimetic self-assembles to form a rod-like supramolecular structure which bends and closes end-to-end like a cyclization reaction to form uniform toroids. Each peptide fragment containingl -leucine, α-aminoisobutyric acid (Aib) andl -tyrosine forms rigid 310 helical structures stabilized by multiple intramolecular N–H⋯O hydrogen bonds. Two 310 helices are connected by the spacer 3-aminomethyl-benzylamine and maintain an angular distance of 120° and therefore mimic the α–α corner motif of a protein super secondary structure. The individual α–α corner subunits are themselves regularly interlinked through multiple water mediated intermolecular hydrogen-bonding interactions to form the rod-like supramolecular structure and toroids. The formation of the supramolecular structure has been proven with X-ray crystallography and other spectroscopic techniques. The cyclization of the supramolecular structure and toroid formation were studied by optical microscope, AFM and FE-SEM experiments. Despite other assignments such as exfoliation of graphene from graphite, the compound exhibits significant memory to finally produce the toroids.