2417.     ----------------.  [NEGISHI, R., AND KAMIIKE, O.]  Hydrocarbons From Carbide.  IV.  Noncatalytic Polymerization Under Ordinary Pressure.  Acetylene Carbide System and General Remarks.  Bull. Chem. Soc. Japan, vol. 17, 1942, pp. 345-354; Chem. Abs., vol. 41, 1947, p. 4435.

        Results of the series of investigations, on the systems H₂, CO₂, CO, HCl, and C₂H₂ with CaC₂ are given; CO has a harmful effect, although CO₂ has a beneficial effect; HCl gives somewhat harmful effects only when its concentration is high; and C₂H₂ increases the total yield because it polymerizes.  When C₂H₂ is diluted with an inert gas, such as H₂ or CO₂, its effect on the total liquid yield disappears; the presence of a small amount of C₂H₂ has a striking effect on the suppression of the formation of free C₂H₂.  [The nascent C₂H₂ molecules, which related to polymerization, are suggested to have the structure n(C₂H₂)=(C₂H₂)_n.]  There are indications that the efficacy of the synthesis of hydrocarbon liquids from CaC₂ is higher than even the catalytic polymerization.