Electrochemical synthesis of carbyne catalyzed by nickel complex

Diiodoacetylene was electrolyzed at −2.0 V (vs. SCE) with a platinum cathode in dimethyl formamide containing a supporting electrolyte in the presence of a nickel complex, giving an insoluble black powder. Infrared spectrum of this product was similar to those of carbyne (polyyne) reported previously. A broad absorption at 2100 cm−1 due to a polyyne structure and broad absorptions ranged from 1700 to 1000 cm−1 due to a mixed structure of carbon-carbon double bond and other bonds were observed. The absorption at 2100 cm−1 reduced on a heat treatment under anaerobic conditions or on exposure to air. The electrical conductivity of pellet samples prepared from the black powder under a pressure of 600 kgf cm−2 was about 3 × 10−5 S cm−1.