Study of binary complexes of nickel(II), copper(II), and vanadium(V) with acetazolamide in aqueous medium by voltammetry


Abstract: The voltammetric behaviour of acetazolamide, the systemic carbonic anhydrase inhibitor, in the presence of some metal ions (Cu(II), Ni(II), and V(V)) were investigated using square-wave and cyclic voltammetry in physiological pH (pH 7.4). Square-wave voltammogram of acetazolamide in the absence of metal ions gave only 1 reduction peak at -1.65 V attributed to a catalytic hydrogen peak. Three reversible peaks at -0.068, -0.262, and -0.434 V were observed for the solutions containing both copper(II) ions and acetazolamide in the SWV. The peak at -0.434 V was attributed to Cu(II)-acetazolamide complex. In the presence of acetazolamide, copper-acetazolamide complex formation was proved by a reversible peak with 2 electron transfers at -0.450 V. Complex formation of an adduct of trioxovanadate(V) with acetazolamide onto dropping mercury electrode was followed by a reduction peak at -0.480 V. Ni(II)-acetazolamide complex was observed to reduce at the more positive potential (-0.830 V) than that of the hydrated Ni(II) ions (-1.200 V) implying that acetazolamide is a catalyst for Ni(II) reduction at a mercury electrode. The UV-vis spectra of all the acetazolamide complexes were also discussed.

Keywords: Acetazolamide; Copper; Nickel; Vanadium; Binary complexes; Electronic Spectra; Voltammetry.

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