Single-crystal-to-single-crystal synthesis of a pseudostarch via topochemical azide–alkyne cycloaddition polymerization. Issue 35 (12th August 2021)

• Record Type: Journal Article
• Authors: Ravi, Arthi; Shijad, Amina; Sureshan, Kana M.
• Is Part Of: Chemical science. Volume 12:Issue 35(2021)
• Page Start: 11652
• Page End: 11658
• Publication Date: 2021-08-12
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1sc03727g
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Prudent crystal engineering allows head-to-tail arrangement of inositol monomer molecules pre-organizing azide and alkyne units of adjacent monomers in a ready-to-react manner. On heating regiospecific SCSC polymerization yields a starch-like polymer. Abstract : There is high demand for polysaccharide-mimics as enzyme-stable substitutes for polysaccharides for various applications. Circumventing the problems associated with the solution-phase synthesis of such polymers, we report here the synthesis of a crystalline polysaccharide-mimic by topochemical polymerization. By crystal engineering, we designed a topochemically reactive crystal of a glucose-mimicking monomer decorated with azide and alkyne units. In the crystal, the monomers arrange in head-to-tail fashion with their azide and alkyne groups in a ready-to-react antiparallel geometry, suitable for their topochemical azide–alkyne cycloaddition (TAAC) reaction. On heating the crystals, these pre-organized monomer molecules undergo regiospecific TAAC polymerization, yielding 1, 4-triazolyl-linked pseudopolysaccharide (pseudostarch) in a single-crystal-to-single-crystal manner. This crystalline pseudostarch shows better thermal stability than its amorphous form and many natural polysaccharides.