A Review on Pyrazolines as Colorimetric Fluorescent Chemosensors for Cu.

The Pyrazoline derivatives display promising potential as sensitive and selective chemosensors for detecting Cu ions. It has undergone screening for its sensing behavior with various metals using absorption, emission spectroscopic techniques. Their unique structure incorporates both donating and accepting sites, characterized by delocalized orbitals. These derivatives exhibit notable chromogenic and fluorogenic capabilities facilitated by intramolecular charge transfer. The sensors based on pyrazoline demonstrate exceptional selectivity, low detection limits, and precise detection of metal ions, particularly Cu. This review offers a comprehensive summary of recent discoveries concerning as pyrazoline-based "On-Off" chemosensors. The discussion places emphasis on exploring the design and photophysical properties of these chemosensors, with the primary objective of detecting Cu metal ions. The unique features of pyrazoline derivatives make them promising candidates for practical applications in environmental and biological monitoring, showcasing their potential significance in advancing sensing technologies.