Rationally designed phenanthrene derivatized triazole as a dual chemosensor for fluoride and copper recognition

Shainaz M Landge; Deanna Y Lazare; Christian Freeman; Jessica Bunn; Jesus I Cruz; Domonique Winder; Clifford Padgett; Karelle S Aiken; Debanjana Ghosh

doi:10.1016/j.saa.2019.117758

Rationally designed phenanthrene derivatized triazole as a dual chemosensor for fluoride and copper recognition

Spectrochim Acta A Mol Biomol Spectrosc. 2020 Mar 5:228:117758. doi: 10.1016/j.saa.2019.117758. Epub 2019 Nov 9.

Authors

Shainaz M Landge¹, Deanna Y Lazare¹, Christian Freeman¹, Jessica Bunn¹, Jesus I Cruz¹, Domonique Winder¹, Clifford Padgett², Karelle S Aiken¹, Debanjana Ghosh³

Affiliations

¹ Department of Chemistry and Biochemistry, Georgia Southern University (Statesboro Campus), 521 College of Education Drive, Statesboro, GA 30460-8064, USA.
² Department of Chemistry and Biochemistry, Georgia Southern University (Armstrong Campus), 11935 Abercorn Street, Savannah, GA 31419, USA.
³ Department of Chemistry and Biochemistry, Georgia Southern University (Statesboro Campus), 521 College of Education Drive, Statesboro, GA 30460-8064, USA. Electronic address: dghosh@georgiasouthern.edu.

PMID: 31753648
DOI: 10.1016/j.saa.2019.117758

Abstract

A 1,2,3-triazole chemosensor containing phenanthrene and phenol moieties (PhTP) was efficiently synthesized via copper (I)-catalyzed azide-alkyne cycloaddition, "click chemistry". PhTP is a dual analyte sensor for fluoride and copper (II) ions in homogeneous medium. Deprotonation of the phenolic OH proton by the fluoride ion is responsible for a change in fluorescence color from blue (PhTP) to yellowish-orange (PhTP-fluoride adduct), while a charge transfer between the triazole nitrogen of the chemosensor and Cu²⁺ revealed a turn-off fluorescence output. The detection capability of PhTP was analyzed with a series of anions (F^-, Cl^-, Br^-, I^-, H₂PO₄^-, ClO₄^-, OAc^-, BF₄^-) and cations (Fe³⁺, Fe²⁺, Cu²⁺, Ag⁺, Cr³⁺, Al³⁺, Co²⁺, Ni²⁺, Cd²⁺, Zn²⁺). With anions, competitive fluorescence responses under UV lamp were observed for acetate and dihydrogen phosphate anions, but maximum response from fluoride ion was substantiated from steady state absorption and fluorescence experiments. With cations, PhTP displayed a selective and sensitive recognition towards Cu²⁺ ion through spectral modulation in absorption spectroscopy and a turn-off fluorescence response. Nuclear magnetic resonance (NMR) spectroscopic titration studies supported the results obtained through photophysical studies and provided evidence for the ion-binding sites on the probe.

Keywords: 1,2,3-Triazole; Click chemistry; Copper (II); Fluorescence sensor; Fluoride; Phenanthrene; Turn-off fluorescence.