Colorimetric sensor for cyanide and acetate ion using novel biologically active hydrazones

•Two novel multidentate hydrazones (N1 and N2) were synthesized and characterized.•The sensitivity of hydrazones toward cyanide and acetate ions was studied with UV–vis and NMR titration.•Both hydrazones have been shown antimicrobial activity.•N1 and N2 were simply detected by naked eye test.

Hydrazones (1((1-phen-2-al(2,4-dinitrophenylhydrazone))-oxy)2′-(1-phen-2-al)oxy)2-ethoxyethane (N1) and 1,2′-bis[(1-phen-2-al(2,4-dinitrophenylhydrazone))-oxy]2-ethoxyethane (N2) were synthesized and characterized as colorimetric sensors for the recognition of cyanide and acetate ions in DMSO/H2O (95%). The hydrazones showed selective colorimetric changes with cyanide and acetate ions i.e., change in the color of ionophore solution, dark yellow color (for N1) and dark orange color (for N2) to violet color over the anions (F−, CI−, Br−, I−, IO3−, HPO42−, H2PO4−, N3−, NO2−, NO3−, SO42−, SO32− and C6H5O73−). The interaction between the ionophores and anions (CN− and AcO−) was studied with the help of UV–vis studies and NMR titrations and it was found that binding is the combined function of hydrogen bonding, electrostatic interactions and structure of binding site. The both ionophore N1 and N2 were found to be exhibit antifungal activity against Rhizoctonia solani and N1 showed antifungal activity against Pyricularia oryzae.

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