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The structure determination of the title compound was undertaken as part of a project on the modification and synthesis of new spin-crossover (SCO) compounds based on octa-hedral Fe II bis-(pyrazol-yl)borate complexes. In the course of these investigations, the compound [Fe(C 6 H 8 BN 4 ) 2 (C 12 H 7 BrN 2 )] was synthesized, for which magnetic measurements revealed an incomplete spin-crossover behaviour. Crystallization of this compound from toluene led to the formation of crystals of the toluene disolvate, [Fe(C 6 H 8 N 4 B) 2 (C 12 H 7 N 2 Br)]·2C 7 H 8 . Its asymmetric unit comprises two discrete metal complex mol-ecules and two toluene solvent mol-ecules. One of the latter is severely disordered and its contribution to the diffracted intensities was removed using the SQUEEZE routine [Spek (2015 ▸). Acta Cryst . C 71 , 9-18]. In each complex mol-ecule, the Fe II cation is coordinated by the two N atoms of a 5-bromo-1,10-phenanthroline ligand and by two pairs of N atoms of chelating di-hydro-bis(pyrazol-1-yl)borate ligands in the form of a slightly distorted octa-hedron. The discrete complexes are arranged in columns along the a- axis direction with the toluene solvate mol-ecules located between the columns. The 5-bromo-1,10-phenanthroline ligands of neighbouring columns are approximately parallel and are slightly shifted relative to each other, indicating π-π inter-actions., (© Ossinger et al. 2020.)

The structure determination of [Fe(C 13 H 15 BN 5 ) 2 ] was undertaken as part of a project on the modification of the recently published spin-crossover (SCO) complex [Fe{H 2 B(pz)(pypz)} 2 ] (pz = pyrazole, pypz = pyridyl-pyrazole). To this end, a new ligand was synthesized in which two additional methyl groups are present. Its reaction with iron tri-fluoro-methane-sulfonate led to a pure sample of the title compound, as proven by X-ray powder diffraction. The asymmetric unit consists of one complex mol-ecule in a general position. The Fe II atom is coordinated by two tridentate N-binding {H 2 B(3,5-(CH 3 ) 2 -pz)(pypz)} - ligands. The Fe-N bond lengths range between 2.1222 (13) and 2.3255 (15) Å, compatible with Fe II 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 mol-ecules into rows extending parallel to [010], there are no remarkable inter-molecular inter-actions., (© Ossinger et al. 2020.)

The asymmetric unit of the title compound, [Zn(C 6 H 8 N 4 B) 2 (C 12 H 8 N 2 )], comprises one half of a Zn II cation (site symmetry 2), one di-hydro-bis-(pyrazol-1-yl)borate ligand in a general position, and one half of a phenanthroline ligand, the other half being completed by twofold rotation symmetry. The Zn II cation is coordinated in form of a slightly distorted octa-hedron by the N atoms of a phenanthroline ligand and by two pairs of N atoms of symmetry-related di-hydro-bis-(pyrazol-1-yl)borate ligands. The discrete complexes are arranged into columns that elongate in the c- axis direction with a parallel alignment of the phenanthroline ligands, indicating weak π-π inter-actions.