Crystal structures of two hydrazinecarbo-thio-amide derivatives: (E)-N-ethyl-2-[(4-oxo-4H-chromen-3-yl)methyl-idene]hydrazinecarbo-thio-amide hemi-hydrate and (E)-2-[(4-chloro-2H-chromen-3-yl)methyl-idene]-N-phenyl-hydrazinecarbo-thio-amide

The title compounds, C13H13N3O2S·0.5H2O, (I), and C17H14ClN3OS, (II), are hydrazinecarbo-thio-amide derivatives. Compound (I) crystallizes with two independent mol-ecules (A and B) and a water mol-ecule of crystallization in the asymmetric unit. The chromene moiety is essentially planar in mol-ecules A and B, with maximum deviations of 0.028 (3) and 0.016 (3) Å, respectively, for the carbonyl C atoms. In (II), the pyran ring of the chromene moiety adopts a screw-boat conformation and the phenyl ring is inclined by 61.18 (9)° to its mean plane. In the crystal of (I), bifurcated N-H⋯O and C-H⋯O hydrogen bonds link the two independent mol-ecules forming A-B dimers with two R 2 (1)(6) ring motifs, and R 2 (2)(10) and R 2 (2)(14) ring motifs. In addition to these, the water mol-ecule forms tetra-furcated hydrogen bonds which alternately generate R 4 (4)(12) and R 6 (6)(22) graph-set ring motifs. There are also π-π [inter-centroid distances = 3.5648 (14) and 3.6825 (15) Å] inter-actions present, leading to the formation of columns along the c-axis direction. In the crystal of (II), mol-ecules are linked by pairs of N-H⋯S hydrogen bonds, forming inversion dimers with an R 2 (2)(8) ring motif. The dimers are linked by C-H⋯π inter-actions, forming ribbons lying parallel to (210).