A Highly Selective And Sensitive Pyrazole-Based Chemosensor For Naked-Eye And Spectroscopic Detection Of CU (II) Ions

A novel pyrazole derivative, 3-(1,3-bis(4-bromophenyl)-1H-pyrazol-4-yl)-2-(4-bromophenyl) acrylonitrile (BPPBPA), has been successfully synthesized and investigated as a highly selective and sensitive chemosensor for the detection of Cu (II) ions. Both absorption and emission spectroscopic studies clearly demonstrate the sensing capabilities of BPPBPA. Upon interaction with Cu (II) ions, the absorption spectrum exhibited a noticeable red-shift in wavelength accompanied by a decrease in intensity, indicating complex formation. Concurrently, the emission spectrum showed significant quenching, attributed to the coordination of Cu (II) ions with the pyrazole ring nitrogen atoms and the inherent paramagnetic nature of Cu (II). Further experimental evidence from Vibrating Sample Magnetometry (VSM) studies corroborated the paramagnetic characteristics of the BPPBPA-Cu (II) complex. The successful formation of the BPPBPA-Cu (II) complex was definitively confirmed through X-ray Photoelectron Spectroscopy (XPS), ESR and VSM analysis. This work highlights BPPBPA as a promising candidate for the selective and sensitive optical detection of Cu (II) ions in various applications