Dimers linked by type-I C-F•••F-C contacts in (Z)-3-methyl-4-[2-(4-methylphenyl)hydrazinylidene]-1-(pentafluorophenyl)-1H-pyrazol-5(4H)-one

The title compound, C17H11F5N4O, is described and compared with two closely related analogues in the literature. There are two independent molecules in the asymmetric unit, linked by N-H center dot center dot center dot O hydrogen bonds and pi-pi interactions into dimeric entities, presenting a noticeable noncrystallographic C-2 symmetry. These dimers are in turn linked by a medium-strength type-I C-F center dot center dot center dot F-C interaction into elongated tetramers. Much weaker C-H center dot center dot center dot F contacts link the tetramers into broad two-dimensional substructures parallel to (101).