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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 6, Number 5
BKCSDE 6(5)
May 20, 1985 

 
Title
Kinetic and Molecular Orbital Stuides on the Reaction of 5-nitrofurfural Hydrozone Formation
Author
Kyung-Hee Lee, Jong-Gi Jee
Keywords
Abstract
Kinetic measurements of the 5-nitrofurfural-hydrazine reaction in various pH ranges of aquous solution were carried out by ultraviolet spectrophotometry at 25°, 35°and 45℃. The observed rate of the reaction varies with the change in pH, which gives characteristic "bell-type" rate acidity profile. The maximum rate is shown in the vicinity of pH 4. This reaction procceds with rate-determining attack of hydrazine on the 5-nitrofurfural at low pH and undergoes a change in rate-determining step to dehydration of the addition intermediate as pH increases. The reaction has a "reactant-like transition state" which precedes intermediate in low pH and "product-like transition state" which follows it in neutral pH. The geometry of 5-nitrofurfural-hydrazine intermediate was estimated with PCILO method associated with CNDO/2 scheme.
Page
280 - 284
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