PRIMARY PROCESSES IN REACTIONS INITIATED BY PHOTOEXCITED MERCURY ISOTOPES

Journal Article · Wed Jan 01 04:00:00 EST 1958 · Canadian Journal of Chemistry (Canada)

DOI:https://doi.org/10.1139/v58-010· OSTI ID:4334955

Gunning, H E

A study has been made of the reaction of Hg/sup 202/6(/sup 3/P/sub 1/) atoms, photoexcited in natural mercury vapor, with a number of substrates which form solid mercury compounds in mercury photosensitization. Some data are also given for reactions initiated by Hg/sup 198/6(/sup 3/P/sub 1/) atoms. The solid mercury compounds formed were examined for enrichment in the isotope initiating the reaction. Such enrichment would be evidence for the primary formation of the mercury compoumd. Three HgO-forming substrates were studied: water vapor, nitrous oxide, and oxygen. The Hg/sub 2/Cl/sub 2/-forming substrates studied included hydrogen chloride, methyl chloride, methylene chloride, chloroform, carbon tetrachloride, isopropyl chloride, and boron trichloride. One Hg/sub 2/Br/ sub 2/-forming substrate was examined--isopropyl bromide. Among the HgO-forming substrates only water vapor gave enrichment in Hg/sup 202/ in the HgO product. The Hg/sup 202/ content of the oxide was found to vary from 32 to 35%, depending on reaction conditions, compared to a natural abundance of 29.6%. With water vapor-butadiene mixtures, oxides containing as high as 90% Hg/sup 202/ were obtained. Similar enrichment factors were obtained for Hg/sup 198/6(/sup 3/P/sub 1/) reactions. Hydrogen chloride and the alkyl chlorides yielded calomels containing a maximum of 45% Hg/sup 202/. Methyl chloride gave similar enrichment factors in Hg/sup 198/ for the Hg/sup 198/6(/sup 3/P/sub 1/) reaction. The calomel forme d in the boron trichloride reaction showed no enrichment. Addends such as butudiene and benzene, when added to hydrogen chloride, increased the Hg/sup 202/ enrichment from 45% to 60%. For those reactions which yield mercury compounds enriched in the initiating mercury isotope, evidence is presented for a single primary process. Failure to obtain pure isotopes is attributed to exchnnge reactions with adsorbed natural mercury during recovery of the enriched mercury from the product. It is postulated that the addends react with the mercury product and reduce chemisorption of natural mercury on the product. The significance of these findings in the mechanisms of the reactions studied is discussed. (auth)

• Research Organization: Illinois Institute of Tech., Chicago
• Sponsoring Organization: USDOE
• NSA Number: NSA-12-005223
• OSTI ID: 4334955
• Journal Information: Canadian Journal of Chemistry (Canada), Journal Name: Canadian Journal of Chemistry (Canada) Vol. Vol: 36; ISSN CJCHA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ADSORPTION
ALKYL RADICALS
BENZENE
BORON CHLORIDES
BUTADIENE
CARBON TETRACHLORIDE
CHEMICAL REACTIONS
CHEMISTRY
CHLORIDES
CHLOROFORM
ENRICHMENT
EXCITATION
HYDROCHLORIC ACID
IMPURITIES
ISOPROPYL RADICALS
ISOTOPIC EXCHANGE
MERCURY
MERCURY 202
MERCURY CHLORIDES
MERCURY COMPOUNDS
MERCURY ISOTOPES
MERCURY OXIDES
METHYL RADICALS
METHYLENE RADICALS
NITROGEN OXIDES
ORGANIC CHLORINE COMPOUNDS
OXYGEN
PHOTOCHEMISTRY
QUANTITY RATIO
REACTION KINETICS
RECOVERY
SOLIDS
VAPORS
WATER