title: (2E)-2-(2-Phenyl-hydrazin-1-yl-idene)propanoic acid.
abstract: The 13 non-H atoms comprising the title compound, C(9)H(10)N(2)O(2), are close to planar (r.m.s. deviation = 0.140 Å), with maximum deviations of 0.292 (1) and 0.210 (1) Å to either side of the least-squares plane exhibited by the hy-droxy and carbonyl O atoms, respectively. The observed conformation is stabilized by an intra-molecular O-H⋯N hydrogen bond. The conformation about the N=C double bond [1.2909 (16) Å] is E. The hy-droxy OH group also forms an inter-molecular hydrogen bond to a carbonyl O atom, and the amine H atom similarly forms an N-H⋯O hydrogen bond to a second carbonyl O atom. The result is the formation of a double layer with a flat topology. Layers stack along the a-axis direction connected by C-H⋯π inter-actions.
authors.forename: Md Abu
authors.initials: MA
authors.lastname: Affan
authors.forename: M A
authors.initials: MA
authors.lastname: Salam
authors.forename: Eleazar Veronica
authors.initials: EV
authors.lastname: Siew
authors.forename: Seik Weng
authors.initials: SW
authors.lastname: Ng
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink