Crystal structure of 1-(cyclo-pentyl-idene-amino)-3-(prop-2-en-1-yl)thio-urea.

In the title compound, C9H15N3S, the cyclo-pentyl ring adopts an envelope conformation with one of the methyl-ene C atoms as the flap. The thio-semicarbazide fragment is almost planar (r.m.s. deviation = 0.038 Å) and a short intra-molecular N-H⋯N contact occurs. In the crystal, mol-ecules are linked into helical (41 symmetry) chains propagating in [001] by N-H⋯N and N-H⋯S hydrogen bonds. A very weak C-H⋯S inter-action is also observed.