Szulc P, Luboch E, Okuniewski A, Wagner-Wysiecka E. Fluorescence of p-hydroxyazobenzocrowns - Tautomeric equilibrium effect.
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024;
308:123721. [PMID:
38086231 DOI:
10.1016/j.saa.2023.123721]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 11/26/2023] [Accepted: 11/28/2023] [Indexed: 01/13/2024]
Abstract
The spectroscopic properties of a series of para-hydroxyazobenzocrowns, including three novel compounds, were investigated using UV-Vis absorption and emission spectroscopy. This study presents, for the first time, determined quantum yield (QY) values for macrocycles of this category, ranging between 0.122 and 0.195. The highest values were obtained for crowns bearing two phenyl substituents in benzene rings. The impact of aromatic ring substituents and macroring size on the spectral characterization (1H NMR and FTIR) of p-hydroxyazobenzocrowns was examined in consideration of the azophenol ⇄ quinone-hydrazone tautomeric equilibrium. Dipole moments of p-hydroxyazobenzocrowns in the ground and excited states have been determined. The alignment between experimental findings and theoretical studies was established.
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