2-Cyano-2-isonitrosoacetamide–3,4-dimethylpyrazole (1/1): a co-crystal of two molecules with agrochemical activities

In the structure of the title co-crystal, C 3 H 3 N 3 O 2 ·C 5 H 8 N 2 , the components are linked by a set of directional O—H...N, N—H...O, N—H...N and C—H...O hydrogen bonds to yield a two-dimensional mono-periodic arrangement. The structure propagates in the third dimension by extensive π–π stacking interactions of nearly parallel molecules of the two components, following an alternating sequence. The primary structure-defining interaction is very strong oxime-OH donor to pyrazole-N acceptor hydrogen bond [O...N = 2.587 (2) Å], while the significance of weaker hydrogen bonds and π–π stacking interactions is comparable. The distinct structural roles of different kinds of interactions agree with the results of a Hirshfeld surface analysis and calculated interaction energies. The title compound provides insights into co-crystals of active agrochemical molecules and features the rational integration in one structure of a fungicide, C 3 H 3 N 3 O 2 , and a second active component, C 5 H 8 N 2 , known for alleviation the toxic effects of fungicides on plants. The material appears to be well suited for practical uses, being non-volatile, air-stable, water-soluble, but neither hygroscopic nor efflorescent.