Of particular interest is the synthesis and study of new coordination compounds of nickel as active centers of Hydrogenazes[1-2]. In order to mimic the active centres of the Hydrogenazes, a Ni complex bis (4 - (p-metoxifenil)thiosemicarbazone)-2,3-butane was synthesized (Fig.1). According to the UV-Vis spectra of ligand and nickel complex the maximum of absorption peak is transferred in the red part indicating the decrease of the HOMO-LUMO energy gap (Fig. 2, and 3). Calculated (TDDFT, GAUSSIAN09 [3]) UV-Vis Fig.1. Structure of [NiL2](DMSO) spectra show a rather good agreement with the experimental ones. They can be classified as manly the ligand-ligand transitions. The compound shows electrocatalytic proton reduction in the cyclic voltammetry experiment with value of TOF ≥ 200 s-1.