Malononitrile‐Substituted Indole Compounds as Highly Effective Catalysts in the Catalytic Electrooxidation of Hydrazine

Novel malononitrile‐substituted indole compounds, namely, 2‐((5‐(2‐(2,5‐dimethylphenyl)‐1‐methyl‐1H‐indol‐3‐yl)thiophene‐2‐yl)methylene)malononitrile (10) , 2‐((5‐(2‐(2,5‐dimethyl phenyl)‐1‐methyl‐1H‐indol‐3‐yl)furan‐2‐yl)methylene)malononitrile (11) , and 2‐(4‐(2‐(2,5‐dimethylphenyl)‐1‐methyl‐1H‐indol‐3‐yl)benzylidene)malononitrile (12) were synthesized by using Suzuki–Miyaura coupling, Knoevenagel condensation, electrophilic cyclization, and Sonogashira coupling reactions. The yields were obtained in 94%, 93%, and 97%, respectively. Electrochemical measurements, including cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS), were performed to investigate the electrocatalytic behavior of compounds 10 , 11 , and 12 . The specific activity of compound 12 for hydrazine electrooxidation was determined as 3.941 mA/cm 2 with long‐term stability.