Betti base and its modified phthalonitrile derivative for the turn on fluorimetric detection of Hg2+ and Cr3+ ions

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 382; p. 111904
• Main Authors: Amitha, G.S., Rajan, Vijisha K., Amritha, B., Muraleedharan, K., Vasudevan, Suni
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.09.2019; Elsevier BV
• Subjects: Aromatic compounds; BBPN; Benzaldehyde; Betti Base (BB); Chromium; Coupling (molecular); Density functional theory; Density functional theory (DFT-B3YLP); Electron transfer; Fluorescence; Fluorescent indicators; Limit of detection (LOD); Mannich aminoalkylations; Mercury (metal); Metal ions; Naphthol; Photoinduced electron transfer (PET); Single crystals; Trivalent chromium; Betti Base (BB); BBPN; Density functional theory (DFT-B3YLP); Mannich aminoalkylations; Limit of detection (LOD); Photoinduced electron transfer (PET)
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2019.111904

[Display omitted] •Betti Base (BB) was prepared by modified Mannich type reaction.•BB modified phthalonitrile (BBPN) was synthesized by aromatic ipso nitro substitution reaction.•BB and BBPN were exhibited a selective fluorescence trun on detection of Hg2+ and Cr3+ ions respectively with a considerable low limit detection LOD values.•The binding stoichiometry of two compounds was verified experimentally and theoretically.•The selective chemo sensing behavior of two compounds were explained on the basis of Photo induced Electron Transfer (PET). The Betti Base Phenyl-(2-pyridinylamino)-methyl-2-naphthalenol (BB) derived by the multicomponent Mannich aminoalkylations reaction from 2-naphthol, 2-aminopyridine and benzaldehyde. The modified phthalonitrile 4-((1-(phenyl(pyridin-2-ylamino)methyl)naphthalen-2-yl)oxy)phthalonitrile BBPN was obtained by aromatic nucleophilic coupling reaction of 4-nitrophthalonitrile with BB. The compounds were successfully characterized by common spectroscopic and single crystal XRD techniques. The compounds BB and BBPN was exhibited a selective and sensitive fluorescence detection tendency towards mercuric Hg2+ and chromium Cr3+ ions respectively by the fluorescence turn on processes. Job’s plot method is employed to obtain idea about the stoichiometric interaction of metal ions with fluorescent probes. Theoretical calculation was done by Density Functional Theory DFT-B3YLP in order to get atomistic insights into the coordination geometry of Hg2+ and Cr3+ with BB and BBPN respectively. The limit of detection (LOD) of Hg2+ with BB and Cr3+ with BBPN was estimated respectively as 9.7 × 10−7 mol/L and 7.03 × 10−6 mol/L. The fluorescence enhancement of both compounds were induced by the inhibition of Photoinduced Electron Transfer (PET) process in which electron transfer happens from amino group to the fluorophore naphthol unit. The PET process was blocked upon binding of the sensors BB and BBPN with Hg2+ and Cr3+ respectively.