The Reaction of Recoil ³⁵S Atoms with Organic Compounds

Abstract

Recoil sulfur atoms from the nuclear transformation of 35 Cl(n,p) 3 5 S were allowed to react with gaseous ethane in the presence or absence of various additives. Hydrogen sulfide was one of the main products, with the yield remarkably affected by the addition of nitrogen monoxide. The yield was increased at low concentration levels of nitrogen monoxide, but decreased at high concentration levels. The primary yield of hydrogen sulfide was estimated to be ca. 7.8%, of which ca. 3.6% was scavengeable by oxygen. The scavengeable yield is considered to be a product of the reaction of thermalized sulfur atoms. The photochemically produced sulfur atoms are known to yield no hydrogen sulfide in reaction with ethane. The discrepancy between the recoil reaction and the photochemical reaction was investigated using various additives. Experimental MaterialsArgon from a cylinder was purified by passage through sodium hydroxide, phosphorous pentoxide and copper meshes heated at 800°C to remove trace amounts of carbon dioxide, water and oxygen, respectively. Other materials used in this experiments were purified in the same manner as reported previously [5 J. Thermal neutron irradiationThermal neutron irradiation was carried out by a TRIGA MARK II nuclear reactor (Institute for Atomic Energy, Rikkyo University) at a thermal neutron flux of about 1.5 X 10' 2 η cm" 2 s" 1 for 1 hour at a reactor temperature of about 40 °C. The mixture of ethane, dichlorodifluoromethane (as a chlorine source) and additives was irradiated in a quartz ampoule (ca. 5 ml) at total pressure of about 9.3 X 10* Pa, and the ratio of the ethane pressure to the dichlorodifluoromethane pressure was kept constant at 2.05 ±0.02 in all these runs. In the case of argon additives, the ratio of the ethane pressure to the argon pressure was varied from 0.01 to 7.0 at the total pressure of 9.7 Χ 10 4 ± 8.4 Χ 10 2 Pa.