DEUTERIUM EXCHANGE BETWEEN AN AROMATIC HYDROCARBON AND LIQUID DEUTERIUM CHLORIDE (DCl)

Journal Article · Sun Feb 11 04:00:00 EST 1962 · Doklady Akad. Nauk S.S.S.R.

OSTI ID:4794906

Kitova, A I; Varshavskii, Ya M

Hydrogen chloride enriched in deuterium (1.5 to 2.0%) was contacted with a hydrocarbon for a definite pertod of time in a thermostat at 20 or 25 deg C. The deuterium content of the hydrocarbon was then determined. The rate of isotopic exchange was expressed by a number n for the number of atoms exchanging in a given interval of time, and by a rate constant k tn sec/sup -1/. The exchange in benzene is slow: n = 2 and k = 4 x 10/sup -8/ sec/sup-1/. The value of k decreases with an increase in the duration of the experiment for naphthalene (k varies from 1 x 10/sup -4/ to 1 x 10/sup -5/), for phenanthrene (k varies from 0.9 x 10/sup -4/ to 0.6 x 10/sup -4/ sec/sup -1/), and for pyrene (k varies from 6 x 10/sup -4/ to 1 x 10/sup -4/ sec/sup -1/). Different hydrogen atoms have varying degrees of reactivity in these compounds. The hydrogen atoms of diphenyl are more reactive than those of benzene, but less reactive than those of naphthalene. The limiting value of n is 6 at the end of 4800 hours. The 4 hydrogen atoms in the meta position are very unreactive. The rate of hydrogen exchange for various monoalkylbenzenes such as toluene, ethylbenzene and isopropylbenzene is the same. The value of k for an ortho or para hydrogen is 1 x 10/sup -5/ sec/sup -1/ and for a meta hydrogen k = 3 x 10/sup -7/ sec/sup -1/. Hexamethylbenzene shows no hydrogen exchange, since the hydrogen atoms of the methyl groups do not exchange with DCl. Only the ortho and para hydrogen atoms in diphenylmethane and triphenylmethane exchange with DCl (k = 0.8 x 10/sup -6/ and 1.1 x 10/sup -7/ sec/sup -1/ respectively). The value of k for the first four hydrogen atoms in diphenylenemethane is 2.2 x 10/sup -4/ sec/sup -1/, and for the other hydrogen atoms k = 1.2 x 10/sup -5/ sec/sup -1/. The hydrogen atoms on the methenyl group do not exchange. Hydrogenation of one of the naphthalene rings increases the reactivity of the hydrogen atoms on the other ring (k = 2 x 10/sup -4/ sec/sup -1/ and n = 4 for tetralin after 6 hr). Introduction of an alpha group into naphthalene in the alpha position leads to an increase in reactivity of the hydrogen atoms on the ring (k = 5 x 10/sup -4/ sec/sup -1/ and n = 7 for beta -methylnaphthalene). The exchange is slowed down for alpha -chloro-, alpha -bromo- and alpha -nitronaphthalene (n = 0.4, 0.2, and 0.06 respectively). The addition of AlCl/sub 3/ accelerates the hydrogen exchange between benzene and DCl, but has no effect in promoting the exchange of hydrogen atoms on an aliphatic group. (TTT)

• Research Organization: Karpov Inst. of Physics and Chemistry, USSR
• NSA Number: NSA-16-014715
• OSTI ID: 4794906
• Journal Information: Doklady Akad. Nauk S.S.S.R., Journal Name: Doklady Akad. Nauk S.S.S.R. Vol. Vol: 142
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

ALUMINUM CHLORIDES
AROMATICS
ATOMS
BENZENE
BROMINATED HYDROCARBONS
CHEMISTRY
DEUTERIUM
ETHYL RADICALS
HYDROCHLORIC ACID
HYDROGEN
HYDROGEN-ORTHO
HYDROGEN-PARA
HYDROGENATION
ISOMERS
ISOTOPIC EXCHANGE
LIQUIDS
METHANE
METHYL RADICALS
NAPHTHALENE
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENANTHRENE
PHENYL RADICALS
PROPYL RADICALS
PYRENE
TOLUENE