Bis[N-(2-pyridylcarbonyl)pyridine-2-carboximidato]iron(III) perchlorate methanol solvate

In the title complex, [Fe(C12H8N3O2)2]ClO4·CH3OH, the iron(III) ion is surrounded by two tridentate N-(2-pyridylcarbonyl)pyridine-2-carboximidate (bpca) ligands and exhibits a distorted octahedral coordination by six bpca N atoms. A classical O—H⋯O hydrogen bond exists between the methanol solvent molecule and the perchlorate anion. Magnetic susceptibility measurements indicated the complex to be in the low-spin state in the temperature range 5–400 K.

In the title complex, [Fe(C 12 H 8 N 3 O 2 ) 2 ]ClO 4 ÁCH 3 OH, the iron(III) ion is surrounded by two tridentate N-(2-pyridylcarbonyl)pyridine-2-carboximidate (bpca) ligands and exhibits a distorted octahedral coordination by six bpca N atoms. A classical O-HÁ Á ÁO hydrogen bond exists between the methanol solvent molecule and the perchlorate anion. Magnetic susceptibility measurements indicated the complex to be in the low-spin state in the temperature range 5-400 K.

Related literature
For the structure and magnetic properties of methanol-free [Fe(bpca) 2 ]ClO 4 and related compounds, see: Wocadlo et al. (1993).

S2. Experimental
A methanolic solution (25 ml) containing the bpca ligand (0.2 mmol, 0.046 g) was added dropwise to Fe(ClO 4 ) 2 .6 H 2 O (0.1 mmol, 0.036 g). After stirring for 15 minutes, the dark solution was filtered. Red block-shaped crystals suitable for single-crystal X-ray diffraction were obtained by evaporating the resulting filtration in air for several days (yield: 56.2%).

S3. Refinement
C-bound H atoms were placed geometrically and allowed to ride during refinement with C-H = 0.93-0.96 Å with U iso (H) = 1.2 U eq (C). The hydroxy H atom of the methanol solvent molecule was located in a difference Fourier map and refined as riding with the parent atom with U iso (H) = 1.5U eq (O).  The molecular structure of the title compound, the thermal ellipsoids were drawn at 50% probability level.

Bis[N-(2-pyridylcarbonyl)pyridine-2-carboximidato]iron(III) perchlorate methanol solvate
Special details Experimental. The magnetic measurements were performed on Quantum Design SQUID, MPMS-5S magnetometer. Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.