An acid-base controllable hierarchical nanostructure from a NIR-absorbing conjugated polyrotaxane-based optical molecular switch

Mandapati V.Ramakrishnam Raju, P. Raghunath, Ming-Chang Lin, Hong-Cheu Lin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

To investigate the supramolecular interactions of the mechanically interlocked rotaxane pendants and conjugated polymer backbones, four analogous polymers were systematically synthesized by copolymerization of a 9-alkylidene-9H-fluorene monomer with various monomers, which contained a diketopyrrolopyrrole unit tethered with a dumbbell unit, a metalated [2]rotaxane, a demetalated orthogonal H-bonded [2]rotaxane, and a simple alkyl chain, to furnish P1, P2, P3, and P4, respectively. Prevailing 1H NMR and UV-vis to NIR titration profiles indicated that the novel polyrotaxane P3 showed a sensitive and reversible acid-base molecular switch capability via supramolecular interactions in contrast to the other polymers (P1, P2, and P4). Compared with the other polymers, P3 possessed a narrower bandgap, which was also confirmed by the computational study. Prominently, the monitoring of a controllable nanoself-assembly process of P3 was obtained by reversible acid-base molecular switch approaches. The orthogonal H-bonded pendant [2]rotaxane unit and the steric demand of P3 judiciously allowed to morph into a hierarchical nanostructure via interconvertible H-bonds, anion-π and π-π stackings, and hydrophobic interactions.

Original languageEnglish
Pages (from-to)6731-6743
Number of pages13
JournalMacromolecules
Volume46
Issue number17
DOIs
StatePublished - 10 Sep 2013

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