W. Parker
Jun 1, 1999
Citations
0
Influential Citations
12
Citations
Journal
Magnetic Resonance in Chemistry
Abstract
The chemical species formed upon adsorption and subsequent heat treatment of 2-butanone [15N]oxime (1) on the dried molecular sieve silicalite-1 were examined by 15N NMR spectroscopy. The weak acidity of silicalite-1, which provided weakly adsorbed organic species, facilitated detection without solid-state methods. Based on chemical shifts, the predominant species at 25 °C was a physisorbed oxime (−48 ppm). An H-bonded oxime (−71 ppm) form was detected at −25 °C. A sealed sample of 1 was heated off-line to attempt catalytic conversion to an amide (Beckmann rearrangement). At 200 °C, 1 was hydrolyzed to an amine (−364 ppm). Higher temperatures (400–500 °C) caused fragmentation of 1 to a nitrile (−135 ppm). No amides were detected. The large chemical shift range of 15N provides a powerful means for investigating chemical reactions in heterogeneous systems. Copyright © 1999 John Wiley & Sons, Ltd.