TY - JOUR
T1 - Diazenes. III. Properties of Phenyldiazene
AU - Huang, Pih kuei C.
AU - Kosower, Edward M.
PY - 1968/4
Y1 - 1968/4
N2 - Phenyldiazene, C6H5N=NH, the first monosubstituted diazene to be observed directly, exhibits unusual chemical properties. The reaction of phenyldiazene with itself is cleanly bimolecular over a concentration range of 650, and its disappearance in this way accounts for the failure to isolate pure phenyldiazene at room temperature. The major products of the bimolecular reaction are benzene (65-80 %) and nitrogen (80-84 %). Hydrogen transfer is important in the rate-limiting transition state as shown by kH/kD ≄ 4-5. The activation energy for the bimolecular reaction is low (~9 kcal/mole) and the activation entropy very negative (–23 eu), indicating a highly organized transition state. A mechanism for the bimolecular reaction involving formation of a cage radical pair is suggested. The nitrogens of the diazene group are nonnucleophilic toward methyl chloroformate and benzenesulfonyl chloride, as would be expected for azo compounds. Phenyldiazene is very reactive toward oxygen, reacts with 1,4-benzoquinone, hydroxide ion, and diazene (diimide), and is unreactive toward azobenzene.
AB - Phenyldiazene, C6H5N=NH, the first monosubstituted diazene to be observed directly, exhibits unusual chemical properties. The reaction of phenyldiazene with itself is cleanly bimolecular over a concentration range of 650, and its disappearance in this way accounts for the failure to isolate pure phenyldiazene at room temperature. The major products of the bimolecular reaction are benzene (65-80 %) and nitrogen (80-84 %). Hydrogen transfer is important in the rate-limiting transition state as shown by kH/kD ≄ 4-5. The activation energy for the bimolecular reaction is low (~9 kcal/mole) and the activation entropy very negative (–23 eu), indicating a highly organized transition state. A mechanism for the bimolecular reaction involving formation of a cage radical pair is suggested. The nitrogens of the diazene group are nonnucleophilic toward methyl chloroformate and benzenesulfonyl chloride, as would be expected for azo compounds. Phenyldiazene is very reactive toward oxygen, reacts with 1,4-benzoquinone, hydroxide ion, and diazene (diimide), and is unreactive toward azobenzene.
UR - http://www.scopus.com/inward/record.url?scp=0001741848&partnerID=8YFLogxK
U2 - 10.1021/ja01011a029
DO - 10.1021/ja01011a029
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:0001741848
VL - 90
SP - 2367
EP - 2376
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 9
ER -