A spirobenzopyran-based multifunctional chemosensor for the chromogenic sensing of Cu2+ and fluorescent sensing of hydrazine with practical applications

Recent Developments in Fluorometric and Colorimetric Chemodosimeters Targeted towards Hydrazine Sensing: Present Success and Future Possibilities

“…More recently, Yuan's laboratory designed a spirobenzopyran‐based multifunctional sensor 87 which behaved not only as a Cu 2+ ‐selective colorimetric sensor but also as a fluorometric turn‐off probe in tris‐HCl/ethanol (1:1, v / v , pH 7.40) buffer solution (Figure ). Probe 87 was used for quantitative detection of Cu 2+ and hydrazine in real samples such as pharmaceutical, drinking water, and river water and also qualitative detection of gaseous hydrazine.…”

Recent progress in the development of fluorescent probes for hydrazine

“…The adjacent hydroxyl group can activate the aldehyde moiety and promote a condensation reaction to afford the phenylhydrazone via intramolecular hydrogen bonding and hydrazine capturing. A fluorescent on–off type probe ( 76 ) for hydrazine based on a spirobenzopyran dye was prepared and successfully applied to living cells . Commercially available Alizarin red S ( 77 ) can also be used as a colorimetric probe for hydrazine …”

Mechanistic Insight into Selective Sensing of Hazardous Hg2+ and Explosive Picric Acid by Using a Pyrene‐Azine‐Hydroxyquinoline Framework in Differential Media

“…[1,2] These multiple target sensors have many advantages over single ion recognition based traditional chemosensors such as easy synthetic protocols, cost effectiveness, superb efficiency towards multiple targets of interest, easy sample preparation, real time responses, operational simplicity and recoverability. [3][4][5][6][7] Azine based Schiff base molecular systems, which are recognized with easy synthetic protocols, provide ample opportunities to develop push-pull architectures with D-π-A type conjugation through azine linkages in conjunction with excellent chromophoric units. This structural design rationale provides distinct optical feedbacks through different channels in response to coordination of receptors with specific analytes through the involvement of N lone pair of electrons and chromophoric functionalities.…”

“…[13,14] The fleeting fluorescence of aggregation caused quenching (ACQ) prone traditional chemosensors in solution (typically at high concentration) and solid state has much encouraged to develop aggregation induced emission enhancement (AIEE) active FCs. The in-depth exploration of fundamental mecha-nisms underlying AIEE activation of probe-analyte ensemble has revealed the governing role of (1) restriction of intramolecular rotations/vibrations/motions (RIR/RIV/RIM) in which the extent of luminescence redemption upon aggregation is governed by molecular structure (conformationally flexible/ rigid, structurally twisted/planar), (2) nature of inter-/intramolecular non-covalent interactions within aggregates (Hbonding, van der Waal's interactions, electrostatic forces, metal-ligand co-ordinate bonds), (3) molecular packing arrangements (J-type/H-type/irregular) that can effectively block the excited state non-radiative dissipation energy channels, (4) close packing leading to weak intermolecular face-to-face π-π interaction minimizing the formation of detrimental species like excimer, (5) presence of other luminescence enhancement mechanisms (excited state intramolecular proton transfer, restriction of twisted intramolecular charge transfer) and (6) deactivation of photophysical quenching mechanisms (such as PET, intramolecular charge transfer (ICT), etc.). [15][16][17][18] The quest to design efficient sensor for selective screening of detrimental heavy and soft metal ions, especially mercury ions (Hg 2 + ), has gained mass global interest because of severe toxicity of these ions which eventually threatens human life by perturbing the entire balance of global ecological cycle.…”