Premium
Cyclodextrin‐Based [c2]Daisy Chain Rotaxane Insulating Two Diarylacetylene Cores
Author(s) -
Tsuda Susumu,
Komai Yoshitsugu,
Fujiwara Shinichi,
Nishiyama Yutaka
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202004505
Subject(s) - rotaxane , daisy chain , excimer , cyclodextrin , monomer , fluorescence , molecule , chemistry , chain (unit) , photochemistry , materials science , polymer chemistry , polymer , supramolecular chemistry , organic chemistry , optics , physics , astronomy , computer science , computer hardware
A [c2]daisy chain rotaxane with two diarylacetylene cores was efficiently synthesized in 53 % yield by capping a C 2 ‐symmetric pseudo[2]rotaxane composed of two diarylacetylene‐substituted permethylated α‐cyclodextrins (PM α‐CDs) with aniline stoppers. The maximum absorption wavelength of the [c2]daisy chain rotaxane remained almost unchanged in various solvents, unlike that of the stoppered monomer, indicating that the two independent diarylacetylene cores were insulated from the external environment by the PM α‐CDs. Furthermore, the [c2]daisy chain rotaxane exhibited fluorescence emission derived from both diarylacetylene monomers and the excimer, which implies that the [c2]daisy chain structure can undergo contraction and extension. This is the first demonstration of a system in which excimer formation between two π‐conjugated molecules within an isolated space can be controlled by the unique motion of a [c2]daisy chain rotaxane.