Simple 1-dicyanomethylene-2-chloro-3-aminoindene push–pull chromophores: applications in cation and anion sensing

Abstract

Push-pull chromophores based on 1-dicyanomethylene-2-chloro-3-aminoindene are readily synthesized. These compounds undergo dramatic colour changes in the presence of metal cations as a result of the interaction of the amino substituent with the analytes. One of these compounds is a selective copper(ii) colorimetric probe in acetonitrile solution, displaying a dramatic colour change upon coordination of the amine group to the metal centre. These compounds are also selective cyanide sensors in acetonitrile solution because of the disruption of the intramolecular charge transfer process as the result of the nucleophilic addition of the anion to the indene moiety.

Sequential Knoevenagel Condensation/Cyclization for the Synthesis of Indene and Benzofulvene Derivatives

“…Since the properties of conjugated systems are of interest, dehydrogenation of indene products was examined. ,, Dehydrogenation of 9 proceeded by the reaction with DDQ (1 equiv) in benzene at room temperature to give benzofulvene 10 in 94% yield (Scheme ).…”

Small molecule sensors for the colorimetric detection of Copper(II): A review of the literature from 2010 to 2022

“…The sensors in this category were able to achieve the lowest LOD of copper(II) to date [40,[78][79][80][81][82][83][84]. ), anions (AcO -, F -, and S 2-) or cysteine.…”

Detection of Contaminants of High Environmental Impact by Means of Fluorogenic Probes

“…This fact paved the way to new applications in cation-and anion-sensing compounds. [25] The sensitivity of the system was tuned to amine sensing in water by anchoring the colorimetric probe to mesoporous silica, thus giving rise to new chromogenic probes in nanoscopic pockets in enhanced sensing protocols for amines in aqueous environments. The hybrid sensory material prepared in this way was highly selective and acted preferentially in response to the not too large, but lipophilic enough, amines nnonylamine and n-decylamine, whereas it remained silent in the presence of small hydrophilic or very large aliphatic amines ( Figure 4).…”

“…We quickly realized that not all halogen atoms in the structure shared the same chemistry, but the furthest halogen atom from the dicyanovinyl moiety was easily substituted by secondary amines, giving rise to deeply colored push‐pull chromophores that experienced dramatic color changes in the presence of a copper(II) cation or a cyanide anion in organic solvents. This fact paved the way to new applications in cation‐ and anion‐sensing compounds . The sensitivity of the system was tuned to amine sensing in water by anchoring the colorimetric probe to mesoporous silica, thus giving rise to new chromogenic probes in nanoscopic pockets in enhanced sensing protocols for amines in aqueous environments.…”