Highly Selective and Sensitive Dual Channel New Schiff base Chemosensor based on 5‐bromo‐2‐hydroxybenzaldehyde and its Co(II), Ni(II), Cu(II) and Zn(II) Complexes ‐ Synthesis, Spectral and Theoretical characterization and Pharmacological applications

Abstract

AbstractA new Schiff base N,N’‐Bis(5‐Bromosalicylidine)‐1,8‐diaminonaphthalene (BBSDN) and its Co(II),Ni(II),Cu(II) and Zn(II) complexes were synthesized. All the compounds were characterized by various spectral studies (IR, UV, 1H NMR, 13C NMR and EI‐Mass) and DFT calculations. Conductance measurements, magnetic study and metal estimation studies were performed for the complexes to establish the structure. Thermal studies were done to account for the coordination of water molecules. Redox property of the synthesized complexes was established by Cyclic Voltammetry studies. Synthesized compounds were screened against fungal and bacterial pathogens and in most of the cases the complexes were found to be more active than the Schiff base. MIC value for copper and zinc complexes against the fungal pathogen Candida albicans are determined as 25 ppm and 10 ppm respectively. Metal ion pertinency of the Schiff base was investigated by absorption and fluorescence methods and was found to be highly selective and sensitive for the detection of Cu(II) ion. Mode of interaction has been proved through 1H NMR titrations and the interaction is explained as due to CHEQ mechanism. Stability constant of the complex formed during the detection process was determined by Benesi‐Hildebrand plot. Detection limit was computed as 1.464×10‐6M. The chemosensor property of the Schiff base is applied in bioimaging studies on HeLa cell lines.