Tetra dansylamides substituted cyclen and cyclam macrocycles as fluorescent sensing probes for metal ions and temperature-responsive materials in dopped polymers

Abstract

PM003/2016). The financial support by the Bulgarian National Science Fund (BNSF) under grant – “Novel styryl and polymethine fluorophores as potential theranostic agents ”contract N◦ КП-06-М59/1 from November 15, 2021 is gratefully acknowledged by A.K. This work is also developed and acknowledged by A.K. as part of contract N◦: BGRRP-2.004-0002-C01, Laboratory of Organic Functional Materials (Project BiOrgaMCT), Procedure BG-RRP-2.004 „Establishing of a network of research higher education institutions in Bulgaria“, funded by BULGARIAN NATIONAL RECOVERY AND RESILIENCE PLAN“. G. D. thanks to the European Regional Development Fund within the Operational Programme Science and Education for Smart Growth 2014–2020 under the Project Center of Excellence: National center of mechatronics and clean technologies - BG05M2OP001-1.001-0008 for the financial support. © 2024 The Authors. Published by Elsevier Ltd.Two novel tetra-dansyl derivatives incorporating cyclen (1,4,7,10-tetraazacyclododecane) and cyclam (1,4,8,11-tetraazacyclotetradecane) macrocycles have been synthesized, thoroughly characterized, and their photophysical properties examined, both in solution and in the solid state. These compounds exhibit fluorescence emission with quantum yields up to 40 %, varying significantly with different solvents. They also display positive solvatofluorochromic behavior, with emissions ranging from green to yellow colours. Kamlet-Taft studies were conducted to better understand solute-solvent interactions. Furthermore, aggregation-induced emission was observed in solutions with high water content, confirmed via dynamic light scattering. Given the intrinsic properties of these compounds, their potential for environmental remediation was explored through metal ion sensing studies. Compounds L1 and L2 demonstrated high sensitivity to Cu2+ and Hg2+ ions, significantly modulating their emission, with L2 capable of detecting and quantifying Hg2+ concentrations as low as 2–3 μM. Additionally, the solid-state emission of these compounds encouraged an investigation into their potential as temperature sensors. Several doped polymer thin films were fabricated, establishing a linear relationship with temperature beyond their melting point. These findings suggest that these tetra-chromophoric compounds hold promise as molecular thermometers.publishersversionpublishe