Structural and chemosensor properties of FDA and FDP derivatives of fluorenylidene bridged cyclotetraphosphazenes

The first series of 4,4'-(9-fluorenylidene)diphenol (FDP) (5) and 4,4'-(9-fluorenylidene)dianiline (FDA) (6) bridged and open chained cyclotetraphosphazene derivatives (15-23) have been synthesized. Their florescence and chemosensor properties are reported. Nucleophilic substitution reactions of octachlorocyclotetraphosphazene (1) with mono-functional reagents [phenol (2), 2-naphthol (3) and 1-hydroxypyrene (4)] were carried out and the heptasubstituted derivatives (8, 11 and 14) were obtained. Then the reactions of 8, 11 and 14 with 4,4'-(9-fluorenylidene)diphenol (FDP) (5) and 4,4'-(9-fluorenylidene)dianiline (FDA) (6), respectively gave bridged and open chained compounds. The structures of the synthesized compounds (7-23) were verified by elemental analyses, mass spectrometry, DV Vis, H-1 and P-31 NMR techniques and fluorescence spectroscopy. The metal sensing properties of the novel bridged open chain cyclotetraphosphazene derivatives were also examined by fluorescence spectroscopy. These complexes showed high selectivity for Cu2+ and Fe3+ ions in solution. (C) 2016 Elsevier Ltd. All rights reserved.