(E)-1-(4-Chloro-phen-yl)ethanone semi-carbazone.

In the title compound, C(9)H(10)ClN(3)O, the semicarbazone group is approximately planar, with an r.m.s. deviation from the mean plane of 0.054 (1) Å. The dihedral angle between the least-squares planes through the semicarbazone group and the benzene ring is 30.46 (5)°. In the solid state, mol-ecules are linked via inter-molecular N-H⋯O and N-H⋯N hydrogen bonds, generating R(2) (2)(9) ring motifs which, together with R(2) (2)(8) ring motifs formed by pairs of inter-molecular N-H⋯O hydrogen bonds, lead to the formation of a seldom-observed mol-ecular trimer. Furthermore, N-H⋯O hydrogen bonds form R(2) (1)(7) ring motifs with C-H⋯O hydrogen bonds, further consolidating the crystal structure. Mol-ecules are linked by these inter-molecular inter-actions, forming two-dimensional networks parallel to (100).