Crystal structure and magnetic properties of bis[butyltris(1H-pyrazol-1-yl)borato]iron(II)

Abstract

The asymmetric unit of the title compound, [Fe(C13H18BN6)2], contains two half independent complex molecules. In each complex, the FeII atom is located on an inversion center and is surrounded by two scorpionate ligand butyltris(1H-pyrazol-1-yl)borate molecules that coordinate to the iron(II) ion through the N atoms of the pyrazole groups. The two independent complex molecules differ essentially in the conformation of the butyl substituents. In the crystal, the complex molecules are linked by a series of C—H...π interactions, which generate a supramolecular three-dimensional structure. At 120 K, the average Fe—N bond distance is 1.969 Å, indicating the low-spin state of the iron(II) atom, which does not change upon heating, as demonstrated by high-temperature magnetic susceptibility measurements.

Keywords

• crystal structure
• polypyrazolyl borate
• iron(II) scorpionates
• magnetism
• C—H...π interactions