Azulene-Based Organic Cages Formed with 1,3,5-Tris(aminomethyl)-2,4,6-triethylbenzene: Synthesis and Physicochemical Properties

This paper is dedicated to the memory of Professor Ovidiu Maior, an example of scientific excellence and mentorship.

Abstract

A novel [2+3] imine cage, derived from 1,3-diformylazulene and 1,3,5-tris(aminomethyl)-2,4,6-triethylbenzene, was synthesized and characterized. NMR spectroscopy and single crystal X-ray diffraction confirmed the formation of a symmetric hexaimine structure. The cage exhibits fluorescence, as well as characteristic azulene redox behavior. However, its stability in solution is sensitive to the acidity of the solvent. Reduction with NaBH₄ led to the isolation of a more stable hexaamine cage, providing a means to further stabilize the structure.

Key words

azulene-based cages - Schiff base - fluorescence - redox active - hexaamine macrocycle

Publication History

Received: 31 March 2025

Accepted after revision: 23 April 2025

Accepted Manuscript online:
23 April 2025

Article published online:
22 May 2025

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