The voltammetric behaviour of resazurin in the presence of Cd2+ and Zn2+ ions at a hanging mercury drop electrode (HMDE) was investigated by using square wave voltammetry (SWV), cyclic voltammetry (CV) and adsorptive square wave voltammetry (AdsSWV). The interaction of resazurin with Cd2+ and Zn2+ starts above pH 4 and seems to be completed at pH 5.2 with Cd2+ ions and at pH 7.5 with Zn2+ ions. A new peak appears at -0.93 V in the presence of Cd2+ and at -1.07 V in the presence of Zn2+. These peaks may be attributed to M2+-resazurin complexes and the logarithm of their stability constant was determined where log β14 = 4.22 for Cd2+-resazurin and log β1:1 = 4.74 for Zn2+-resazurin. Cyclic voltammetry was used to characterize the redox mechanism and to calculate voltammetric data of M2+-resazurin complexes. The amount of adsorbed M2+-resazurin complexes on the mercury drop electrode surface (Γ) is calculated as 5.48 x 10-12 mol cm-2 for Cd2+-resazurin and 1.10 x 10-11 mol cm-2 for Zn2+-resazurin. The voltammetric data were compared with the data obtained using spectrophotometric methods and were observed to be in good agreement.

O composto 4-(fenildiazenil)-2-{[tris(hidroximetil)metil]aminometileno}ciclohexa-3,5-dien -1(2H)-ona foi sintetizado e caracterizado por análise elementar, espectroscopia infravermelho, ressonância magnética nuclear, espectro eletrônico e voltametria cíclica. O equilíbrio tautomérico do 4-(fenildiazenil)-2-{[tris(hidroximetil)metil]aminometileno} ciclohexa-3,5-dien-1(2H)-ona em dimeteilsulfóxido deuterado é comprovado por dados de ¹H RMN. A natureza do processo eletroquímico do 4-(fenildiazenil)-2-{[tris(hidroximetil)metil]aminometileno} ciclohexa-3,5-dien-1(2H)-ona em solução tampão de Britton-Robinson (pH 2-9) foi estudada com o eletrodo gotejante de mercúrio utilizando voltametria de onda quadrada, onda quadrada adsortiva e voltametria cíclica. Os parâmetros eletroquímicos do composto (Ip/Ep, Ip/v, Ip/pH, Ip/t acc) foram determinados.

Newly synthesized 4-(phenyldiazenyl)-2-{[tris(hydroxymethyl)methyl]aminomethylene} cyclohexa-3,5-dien-1(2H)-one was characterized by elemental analysis, FT-IR, NMR, electronic spectra, voltammetry. Tautomeric equilibrium of 4-(phenyldiazenyl)-2-{[tris(hydroxymethyl) methyl]aminomethylene}cyclohexa-3,5-dien-1(2H)-one in DMSOd is supported by ¹H NMR data. The nature of electrochemical process of 4-(phenyldiazenyl)-2-{[tris(hydroxymethyl) methyl]aminomethylene}cyclohexa-3,5-dien-1(2H)-one in Britton-Robinson buffer (pH 2-9) was studied on the HMDE by square-wave (SWV), adsorptive stripping square-wave (AdSWV) and cyclic voltammetry (CV). The electrochemical parameters (Ip/Ep, Ip/v, Ip/pH, Ip/t acc) of the compound were determined.