Fluorescence properties of fluorenylidene bridged cyclotriphosphazenes bearing aryloxy groups

Abstract

The synthesis and characterization of the first series of aryloxy full-substituted fluorenylidene open chain and bridged cyclotriphosphazene derivatives (13-18) are reported in this study. The synthetic route utilized includes the reaction of penta-substituted cyclotriphosphazenes (5, 7, 9) with 4,4'-(9-fluorenylidene)diphenol (FDP) (11) and 4,4'-(9-fluorenylidene)dianiline (FDA) (12) to give bridged compounds (13, 15-17) and open chain compounds (14 and 18). The structural investigations of the compounds were verified by elemental analyses, mass spectrometry, UV-Vis, FT-IR, H-1 and P-31 NMR techniques, and X-ray crystallography (for 13 and 18). The fluorescence behavior of the studied cyclotriphosphazene derivatives were also examined in THF solution. Compound 16 showed a high emission among the studied compounds to investigate its metal sensing properties. This compound showed high selectivity for copper (Cu2+) and iron (Fe2+/Fe3+) ions in solution. (C) 2015 Elsevier Ltd. All rights reserved.