Trichlorido[(methyl{2-[methyl(2-pyridylmethyl)amino]ethyl}amino)acetonitrile]iron(III) methanol hemisolvate

The title compound, [FeCl3(C12H18N4)]·0.5CH3OH, contains an FeIII ion in a distorted octahedral coordination environment. The neutral N,N′,N′′-tridentate ligand adopts a fac coordination mode, and chloride ligands lie trans to each of the three coordinated N atoms. In the crystal, the complexes form columns extending parallel to the approximate local threefold axes of the FeN3Cl3 octahedra, and the columns are arranged so that the uncoordinated nitrile groups align in an antiparallel manner and the pyridyl rings form offset face-to-face arrangements [interplanar separations = 2.95 (1) and 3.11 (1) Å; centroid–centroid distances = 5.31 (1) and 4.92 (1) Å]. The methanol solvent molecule is disordered about a twofold rotation axis.

The title compound, [FeCl 3 (C 12 H 18 N 4 )]Á0.5CH 3 OH, contains an Fe III ion in a distorted octahedral coordination environment. The neutral N,N 0 ,N 00 -tridentate ligand adopts a fac coordination mode, and chloride ligands lie trans to each of the three coordinated N atoms. In the crystal, the complexes form columns extending parallel to the approximate local threefold axes of the FeN 3 Cl 3 octahedra, and the columns are arranged so that the uncoordinated nitrile groups align in an antiparallel manner and the pyridyl rings form offset face-toface arrangements [interplanar separations = 2.95 (1) and 3.11 (1) Å ; centroid-centroid distances = 5.31 (1) and 4.92 (1) Å ]. The methanol solvent molecule is disordered about a twofold rotation axis.
The solvent was removed under reduced pressure, then the residue was re-dissolved in water, adjusted to pH 8 with conc.
The title compound was then prepared as follows: Anhydrous FeCl 3 (15.8 mg, 0.097 mmol) was added to the mixed ligand product from above (23.3 mg, 0.098 mmol) in methanol (1.75 ml), and a few yellow blocks of (I) were deposited overnight.  The molecular structure of (I) with displacement ellipsoids shown at 50% probability for non-H atoms. The methanol molecule (C1S-O1S) is disordered around a 2-fold rotation axis.

Figure 2
Unit-cell contents of (I) projected along the b axis, which corresponds to the stacking directions of the "columns" referred to in the Abstract.

Trichlorido[(methyl{2-[methyl(2-pyridylmethyl)amino]ethyl}amino)acetonitrile]iron(III) methanol hemisolvate
Crystal data [FeCl 3 (C 12  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.48 e Å −3 Δρ min = −0.45 e Å −3 Special details 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (