A second polymorph of (Z)-3-amino-4-(2-phenyl-hydrazinyl-idene)-1H-pyrazol-5(4H)-one.
The mol-ecule of the title compound, C9H9N5O, is approximately planar (the r.m.s. deviation of all non-H atoms is 0.08 Å). The amine substituent is pyramidal at the N atom. An intra-molecular N-Hhydrazine⋯O=C hydrogen bond is present. In the crystal, mol-ecules are connected via N-H⋯N and N-H⋯O hydrogen bonds, forming infinite layers parallel to (010). This polymorph is triclinic, space group P-1, whereas the previously reported form was monoclinic, space group P21/c [Elgemeie et al. (2013 ▶). Acta Cryst. E69, o187], with stepped layers and a significantly lower density.
Chemistry Department, Faculty of Science, Ain Shams University, Abbassia 11566, Cairo, Egypt.
Abdel-Sattar S Hamad
AS
Elgazwy
Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Postfach 3329, 38023 Braunschweig, Germany.
Peter G
PG
Jones