ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis of azobenzene-containing macrocycles exhibiting unexpected fluorescence

Ege Hosgor and Akin Akdag

Department of Chemistry, Middle East Technical University, Ankara, Turkey

E-mail: aakdag@metu.edu.tr

Received: 29 December 2021  Accepted: 13 February 2022

Abstract:

Polyfunctional macrocycles have been studied extensively for their responsive properties. In this study, three electron- deficient novel azo-containing crown ethers were successfully synthesized. The synthesized macrocycles were characterized and their photophysical along with photoisomerization were studied. The results were compared with their acyclic derivative. It was found that these compounds did not convert to their cis-isomer completely due to the rigidity of the cycles. The fluorescence studies revealed that the macrocycles were fluorescent while the acyclic azo derivative was found not to show fluorescence. The macrocycles were also tested for alkali metal cation-binding abilities. It was shown with DFT calculations that not only the ring size of macrocycles but also the conformation places an important role in recognition of these cations.

Graphical abstract

Keywords: Azobenzene; Macrocylces; Cis-trans isomerization; Azobenzene-fluorescence

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02133-z

Chemical Papers 76 (6) 3891–3898 (2022)