Stacked or Folded? : Impact of Chelate Cooperativity on the Self-Assembly Pathway to Helical Nanotubes from Dinucleobase Monomers

• Self-assembled nanotubesexhibit impressive biologicalfunctionsthat have always inspired supramolecular scientists in their effortsto develop strategies to build such structures from small moleculesthrough a bottom-up approach. One of these strategies employs moleculesendowed with self-recognizing motifs at the edges, which can undergoeither cyclization-stacking or folding-polymerizationprocesses that lead to tubular architectures. Which of these self-assemblypathways is ultimately selected by these molecules is, however, oftendifficult to predict and even to evaluate experimentally. We showhere a unique example of two structurally related molecules substitutedwith complementary nucleobases at the edges (i.e., G:C and A:U) for which the supramolecular pathway takenis determined by chelate cooperativity, that is, by their propensityto assemble in specific cyclic structures through Watson-Crickpairing. Because of chelate cooperativities that differ in severalorders of magnitude, these molecules exhibit distinct supramolecularscenarios prior to their polymerization that generate self-assemblednanotubes with different internal monomer arrangements, either stackedor coiled, which lead at the same time to opposite helicities andchiroptical properties.

Ämnesord

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

NATURVETENSKAP  -- Biologi -- Strukturbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Structural Biology (hsv//eng)

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