Abstract

The title compound (C7N2H10, HCl, 1/2H(2)O) crystallizes in the space group C2/e with cell parameters: a=11.651(9), b=16.309(1), c=9.167(1)Angstrom, beta=94.95(3)degrees, Z=8, with d= 1.287 g cm(-3). One of the chlorine atoms lies on a twofold axis, the second and the oxygen atom of the water molecule have disordered positions. Intermolecular interactions through hydrogen bonds are established between nitrogen atoms of the pyrazole ring and chlorine atoms or the water molecule. In this way, chains of 'molecules' are built; these chains, through van der Waals interactions, form layers which are stacked in the a direction. The H-1,C-13, and N-15 NMR (this last using the double labelled compound) have been recorded in solution and the C-13 NMR spectrum also in the solid state (CP/MAS technique). The NMR parameters (delta and J's) thus obtained are discussed using the molecular structure.