Novel Rearrangement Followed by Ring Contraction of Highly Selective and Sensitive Turn‐On Chromogenic and Fluorescent Chemodosimeters for Cu²⁺ Ions

Abstract

The dual chromogenic and fluorogenic chemodosimetric behaviour of substituted 5-amino-1,2-dihydro-2methyl-1,6-naphthyridine-8-carbonitriles was investigated. The reaction-based indicators operate by an unusualr earrangementf ollowed by ring contraction to generate ap yrro-lopyridine, with a" naked-eye"r esponse and chromofluorogenic selectives ensing for Cu 2 + ions. The structure of the pyrrolopyridine was confirmed by single-crystal X-ray analysis. Results and DiscussionThis report describes the design and synthesis of afluorometric assay towards the effective detection of Cu 2 + ions. We present, for the first time, [1,6]-naphthyridine derivatives as dosimeters with high sensitivity and selectivity,o wing to the surprising rearrangement andr ing contraction mediated by Cu 2 + ions. The dosimeters (1 and 2,S cheme 1) were synthesizedi no ne step according to our recently published work. [12] [a] P.

Highly Selective and Sensitive 2‐(2′‐Hydroxyphenyl)benzothiazole‐Based Turn‐On Fluorescent Probes for Detecting and Imaging Bisulfite in Living Cells

“…Compared with conventional detection methods such as titration, [14] electrochemical methods, [15] spectrophotometry, [16] and chromatography, [17,18] fluorescentp robes have received considerable attention due to their simplicity,h igh selectivity, outstanding sensitivity,r apid response time and ability to provide in vivo fluorescencei maging. [19,20] In recent decades, numerous fluorescent probes for the detection of HSO 3 À have been developed. [21][22][23][24][25][26][27][28][29][30][31] Their sensing mechanisms are mainly based on nucleophilic addition, deprotection of levulinate and coordination to metal ions.…”