Z. Naturforsch. 2014,
69b, 839 – 843
doi:10.5560/ZNB.2014-4064
Solid-state and Calculated Electronic Structure of 4-Acetylpyrazole
Guido D.
Frey1,
Wolfgang W.
Schoeller2 and
Eberhardt
Herdtweck1
1 Department Chemie, Lehrstuhl für Anorganische Chemie, Technische Universität München, Lichtenbergstraße 4, 85747 Garching, Germany
2 Fakultät für Chemie, Theoretische Chemie, Universität Bielefeld, Universitätsstraße 25, 33615 Bielefeld, Germany
Received March 17, 2014 / published online July 8, 2014
The crystal structure of 1-(1H-pyrazol-4-yl)ethanone (commonly known as 4-acetylpyrazole; C5H6N2O) was determined from single-crystal X-ray data at 173 K: monoclinic, space group P21/n (no. 14), a = 3.865(1), b = 5.155(1), c = 26.105(8) Å, β =91.13(1)°, V = 520.0(2) Å3 and Z = 4. The adjacent molecules assemble into a wave-like ribbon structure in the solid state, linked by strong intermolecular N-H···N hydrogen bonds between the pyrazole rings and a weak C–H···O=C hydrogen bond involving the carbonyl
group. The ribbons are stacked in the solid state via weak π interactions between the pyrazole rings.
Key words: Crystal Structure, 4-Acetylpyrazole, Pyrazole