1. “P. Poni” Institute of Macromolecular Chemistry, Iasi, Romania;2. Laboratoire de Physicochimie des Polymères et des Interfaces, Institut des Matériaux, Université de Cergy‐Pontoise, Neuville sur Oise, Cergy‐Pontoise Cedex, France;3. Jacobs University, School of Engineering and Science, Bremen, Germany
Abstract:
The synthesis of 2‐rotaxane (3?TMS‐αCD) through a condensation reaction between 3,5–diamino‐1,2,4‐triazole encapsulated into hexakis(2,3,6‐trimethylsilyl) α‐cyclodextrin cavity (TMS‐αCD ) and 1‐pyrenecarboxaldehyde is reported. The oxidative coupling of 3?TMS‐αCD afforded then pyrene‐triazole/TMS‐αCD PAMs polyrotaxane (4?TMS‐αCD) azomethine polyrotaxane. The optical, electrochemical, morphological, surface‐free energies, as well as transport properties of 3?TMS‐αCD and its corresponding 4?TMS‐αCD polyrotaxane have been investigated and compared with those of the reference polymer pyrene‐triazole azomethine. The polyrotaxane is soluble in toluene/dimethylformamide (DMF) 1:1, v/v, mixture and displays useful levels of thermal stability and higher fluorescence quantum yield (ΦPL) in DMF solutions. ΦPL improvement is further reflected in the fluorescence lifetime (τF), significantly longer than that of the starting monomer 3?TMS‐αCD (7.8 vs 0.89 ns). In addition, a smoother surface with the smaller grains uniformly distributed on the surface, as well as lower surface‐free energy, combined with energy gap (3.32 vs 3.76 eV) represent noticeable advantages of azomethine backbones encapsulation by TMS‐αCD.
