TY - JOUR
T1 - Hypofluorous acid and acetonitrile
T2 - the taming of a reagent
AU - Appelman, Evan H.
AU - Dunkelberg, Oliver
AU - Kol, Moshe
N1 - Funding Information:
*Dedicated to Professor Alois Haas on the occasion of his 60th birthday. See ref. 1. Work supported in part by the Office of Basic Energy Sciences, Division of Chemical Sciences, US Department of Energy, under Contact W-31-109-Eng-38. **Author to whom correspondence should be addressed.
Funding Information:
Aviv University for many helpful discussions and useful suggestions. We wish to express our particular gratitude to Professor Alois Haas, in whose laboratories a substantial portion of this work was carried out, and without whose interest and encouragement this project could not have been completed. EA acknowledges a grant from the Alexander von Humboldt Stiftung of Germany, during the tenure of which this work was initiated.
PY - 1992/2
Y1 - 1992/2
N2 - The strong oxidant produced by the reaction of elemental fluorine with acetonitrile containing ca. 10% water has been shown to be hypofluorous acid, HOF, which is stabilized by complexing to the solvent. The reaction represents a new and convenient method of preparing and handling HOF, a unique oxygenating reagent. The presence of acetonitrile results in subtle but significant changes in the chemical behavior of the HOF. Vibrational and NMR spectroscopic studies of the solutions resulting from this reaction, as well as of solutions prepared by dissolving neat HOF in dry acetonitrile, have shown that the complex is a 1:1 hydrogen-bridged entity, in which the HOF proton is most likely bonded to the nitrogen atom of the nitrile. The 19F NMR data indicate that the complexation reaction has an equilibrium constant of ca. 3 at room temperature, and that the enthalpy of formation of the complex is -14.3 ± 0.5 kJ mol-1. The success of this method of synthesizing hypofluorous acid is a consequence of the very slow reaction between HOF and low concentrations of water in acetonitrile. This reaction accelerates drastically as the water content increases. As the solution composition approaches 100% water, the rate constant appears to approach a limit of about 0.7 s-1 at 25 °C, which may be the actual rate of reaction of HOF with the water.
AB - The strong oxidant produced by the reaction of elemental fluorine with acetonitrile containing ca. 10% water has been shown to be hypofluorous acid, HOF, which is stabilized by complexing to the solvent. The reaction represents a new and convenient method of preparing and handling HOF, a unique oxygenating reagent. The presence of acetonitrile results in subtle but significant changes in the chemical behavior of the HOF. Vibrational and NMR spectroscopic studies of the solutions resulting from this reaction, as well as of solutions prepared by dissolving neat HOF in dry acetonitrile, have shown that the complex is a 1:1 hydrogen-bridged entity, in which the HOF proton is most likely bonded to the nitrogen atom of the nitrile. The 19F NMR data indicate that the complexation reaction has an equilibrium constant of ca. 3 at room temperature, and that the enthalpy of formation of the complex is -14.3 ± 0.5 kJ mol-1. The success of this method of synthesizing hypofluorous acid is a consequence of the very slow reaction between HOF and low concentrations of water in acetonitrile. This reaction accelerates drastically as the water content increases. As the solution composition approaches 100% water, the rate constant appears to approach a limit of about 0.7 s-1 at 25 °C, which may be the actual rate of reaction of HOF with the water.
UR - http://www.scopus.com/inward/record.url?scp=0042802418&partnerID=8YFLogxK
U2 - 10.1016/S0022-1139(00)81103-3
DO - 10.1016/S0022-1139(00)81103-3
M3 - מאמר
AN - SCOPUS:0042802418
VL - 56
SP - 199
EP - 213
JO - Journal of Fluorine Chemistry
JF - Journal of Fluorine Chemistry
SN - 0022-1139
IS - 2
ER -