TY - JOUR
T1 - An acid-base controllable hierarchical nanostructure from a NIR-absorbing conjugated polyrotaxane-based optical molecular switch
AU - Raju, Mandapati V.Ramakrishnam
AU - Raghunath, P.
AU - Lin, Ming-Chang
AU - Lin, Hong-Cheu
PY - 2013/9/10
Y1 - 2013/9/10
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84884190810&partnerID=8YFLogxK
U2 - 10.1021/ma401485b
DO - 10.1021/ma401485b
M3 - Article
AN - SCOPUS:84884190810
SN - 0024-9297
VL - 46
SP - 6731
EP - 6743
JO - Macromolecules
JF - Macromolecules
IS - 17
ER -