N,O-diacylhydroxylamines-structures in crystals and solutions.
The structures of four N,O-diacylhydroxylamines (RCOHNOCOR', R, R'= Me, Ph) were determined in the solid state by X-ray diffraction and studied by NMR and IR spectroscopies in solution. The interpretation of the results was supported by ab-initio calculations of various tautomers and conformers, rotational barriers and chemical shifts. The results indicate the absence of OH tautomers (R-C(OH)=N-O-C(O)-R', N-acyloxyimidic acid); the NH tautomers (R-C(O)-NH-O-C(O)-R', O-acylhydroxamic acid) are present in DMSO solutions as equilibrium mixtures of a few conformers, their exchange being the likely source of 15N and 13C NMR line broadening.
Schraml
Jan
J
Institute of Chemical Process Fundamentals, Academy of Science of the Czech Republic, Rozvojova 135, 165 02, Prague 6, Czech Republic. schraml@icpf.cas.cz
Sýkora
Jan
J
Fiedler
Pavel
P
Roithová
Jana
J
Mindl
Jaromír
J
Blechta
Vratislav
V
Císarová
Ivana
I
Exner
Otto
O