Crystal structure of bis{(3,5-dimethylpyrazol-1-yl)dihydro[3-(pyridin-2-yl)pyrazol-1-yl]borato}iron(II)

The structure determination of [Fe(C13H15BN5)2] was undertaken as part of a project on the modification of the recently published spin-crossover (SCO) complex [Fe{H2B(pz)(pypz)}2] (pz = pyrazole, pypz = pyridyl­pyrazole). To this end, a new ligand was synthesized in which two additional methyl groups are present. Its reaction with iron tri­fluoro­methane­sulfonate led to a pure sample of the title compound, as proven by X-ray powder diffraction. The asymmetric unit consists of one complex mol­ecule in a general position. The FeII atom is coordinated by two tridentate N-binding {H2B(3,5-(CH3)2-pz)(pypz)}− ligands. The Fe—N bond lengths range between 2.1222 (13) and 2.3255 (15) A, compatible with FeII in the high-spin state, which was also confirmed by magnetic measurements. Other than a very weak C—H⋯N non-classical hydrogen bond linking individual mol­ecules into rows extending parallel to [010], there are no remarkable inter­molecular inter­actions.