Year: 2026
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide In this work, a series of carboxylic esters bearing strong electron-withdrawing groups (e.g., –NO 2 ) on the aromatic ring were designed. These activated esters undergo amidation with organic amines in aprotic solvents (e.g., acetonitrile) under mild conditions (room temperature, ambient pressure, and without any exogenous catalysts), a combination rarely achieved in conventional ester amidation protocols. By incorporating chromophores (e.g., nitrophenol) or fluorophores (e.g., 2-naphthol) onto the ester structures, the amidation processes can be conveniently monitored by UV–vis absorption or fluorescence spectroscopy. Notably, these esters, such as ester 1 and ester 6, exhibited remarkably high selectivity in their spectral responses toward tris(2-aminoethyl) amine (TAEA), which is attributed to the unique molecular structure of TAEA (possessing three –NH 2 groups), enabling synergistic interactions of these –NH 2 groups with the carbonyl group of the esters. Therefore, using UV–vis absorption spectra-based ester 1 and fluorescence spectra-based ester 6, the limits of detection (LOD) for TAEA were determined to be 1.10 and 0.19 μM, respectively. This work provides a proof-of-concept molecular spectral sensing system based on ester amidation, operating under mild, exogenous catalyst-free, homogeneous solution conditions with high selectivity and sensitivity.
Source: ACS Omega
Institutions: Xiamen Medical College, Huaqiao University
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
OpenAlex ID: W7166316441