13924-55-5Relevant articles and documents
A new fluorene-based Schiff-base as fluorescent chemosensor for selective detection of Cr3?+ and Al3?+
Tajbakhsh, Mahmood,Chalmardi, Gholam Babaei,Bekhradnia, Ahmadreza,Hosseinzadeh, Rahman,Hasani, Nahid,Amiri, Mohammadreza Azizi
, p. 22 - 31 (2017/08/08)
2-((9H-fluoren-2-ylimino) methyl)phenol (F3) was synthesized by condensation reaction of 9H-fluoren-2-amine and 2-hydroxybenzaldehyde in EtOH and characterized by its melting point, 1H-,13C NMR and molecular mass. F3 exhibits a high selectivity for detection of Cr3?+ and Al3?+ ions as a fluorescent chemosensor and showed a single emission band at 536?nm upon excitation at 333?nm according to fluorescence emission studies. The addition of Cr3?+ and Al3?+ make a significant increase in fluorescent intensity at 536?nm in CH3CN, while other metal ions have almost no influence on the fluorescence. The fluorescence enhancement was attributed to the inhibited C[dbnd]N isomerization and the obstructed excited state intra-molecular proton transfer (ESIPT) of compound F3. Job's plot and DFT calculations data showed that the binding stoichiometries of F3 with Cr3?+ and Al3?+ are 2:1. The association constants (Ka) for Cr3?+ and Al3?+ were calculated and found to be 8.33?×?104?M??1 and 5.44?×?104?M??1, respectively. The detection limits were also calculated for Cr3?+ and Al3?+ and found to be 2.5?×?10??7?mol/L and 3.1?×?10??7?mol/L, respectively.
