(E)-3-Amino-4-(2-phenyl­hydrazinyl­idene)-1H-pyrazol-5(4H)-one

The mol­ecule of the title compound, C₉H₉N₅O, is essentially planar (r.m.s. deviation of all atoms = 0.02 Å) except for the NH₂ H atoms. An intra­molecular hydrazinyl­idene–carbonyl N—H...O=C hydrogen bond is present. In the crystal, mol­ecules are connected via N—H...N/O hydrogen bonds, forming thick layers parallel to (100).

Di-μ-oxido-bis­[bis­(diiso­propyl­aceta­midinato)-κN;κ²N,N′-germanium(IV)]

The title compound, [Ge₂(C₈H₁₇N₂)₄O₂], crystallizes with imposed twofold symmetry, which allows the monodentate amidinate ligands to be arranged in a cisoid fashion. The independent Ge—O distances within the central Ge₂O₂ ring, which is essentially planar (r.m.s. deviation = 0.039 Å), are 1.7797 (8) and 1.8568 (8) Å. The germanium centres adopt a distorted trigonal–bipyramidal geometry, being coordinated by the two O atoms and by one bidentate and one monodentate amidinate ligand (three N atoms). One N-isopropyl group is disordered over two positions; these are mutually exclusive because of `collisions' between symmetry-equivalent methyl groups and thus each has 0.5 occupancy.

Ethyl 5-amino-1-[(4-methyl­phen­yl)sulfon­yl]-1H-pyrazole-4-carboxyl­ate

In the title mol­ecule, C₁₃H₁₅N₃O₄S, the benzene and pyrazole rings are inclined to each other at 77.48 (3)°. Two amino H atoms are involved in bifurcated hydrogen bonds, viz. intra­molecular N—H...O and inter­molecular N—H...O(N). The inter­molecular hydrogen bonds link the mol­ecules related by translation in [100] into chains. A short distance of 3.680 (3) Å between the centroids of benzene and pyrazole rings from neighbouring mol­ecules shows the presence of π–π inter­actions, which link the hydrogen-bonded chains into layers parallel to the ab plane.