Kinetics of polyynes formation with the submerged carbon arc

The kinetics of the formation of a series of carbon chains known as polyynes having the general formula H(CC)nH with n = 2 , 3, 4, … were studied in a submerged carbon arc, an electric arc between graphite electrodes struck inside a series of solvents of different nature. The polyynes accumulate in the solvents where the arc is struck. Their formation rate is directly proportional to the arcing time and to the electric power of the arc. The highest polyynes formation constants are recorded when the solvents are cooled at low temperatures, the ideal conditions which avoid or reduce the vaporization of the carbon chains together with the solvent. The polyynes formation constant has been followed spectrophotometrically directly in the solvents where the submerged carbon arc was struck. The polyynes formation constant is independent from the volume of the solvent were the carbon arc is struck.