Tris(5,6-dimethyl-1,10-phenanthroline-κ2 N,N′)iron(II) bis(tricyanomethanide)

The title compound, [Fe(C14H12N2)3](C4N3)2, consists of one [Fe(dimephen)3]2+ complex cation (dimephen = 5,6-dimethyl-1,10-phenanthroline) and two uncoordinating tcm anions (tcm = tricyanomethanide). In the complex cation, the FeII atom is coordinated by six N atoms from three chelating dimephen ligands at an average Fe—N distance of 1.963 (4) Å giving a distorted octahedral geometry. The crystal structure is stabilized by weak C—H⋯N hydrogen bonds and C N⋯π interactions between planar [maximum deviations of 0.024 (3) and 0.015 (3) Å] tcm anions and pyridine rings of dimephen [N2⋯centroid = 3.531 (3) and 3.726 (3) Å; C N⋯centroid = 96.4 (2) and 97.1 (2)°].

Structural analysis showed that crystal structure of the title compound is ionic and consists of one complex cation and two tcm counter-anions ( Fig. 1).
In the complex cation the Fe II ion is bonded to three bidentate dimephen ligands through their nitrogen atoms resulting in a distorted octahedral arrangement with the six Fe1-N distances ranging from 1.957 (2) to 1.968 (2) Å (Table 1). These The crystal packing in (I) is formed by weak C-H···N hydrogen bonds (Table 2) and C-N···Cg π-ring interactions. Weak hydrogen bonds occur between individual dimephen ligands and thus the structure of the cation is stabilized. Moreover, tcm anions interconnect two [Fe(dimephen) 3 ] 2+ cations through hydrogen bonds and these interactions lead to infinite chain-like structure running along z axis (Fig. 2).
Except hydrogen bonds, the crystal structure is stabilized by π-ring interactions between nitrogen atoms from tcm anions and corresponding pyridine rings. The N2···Cg8 i (i = x -1, y, z) and N6···Cg7 distances (3.531 (3) and 3.726 (3) Å, respectively, Cg8 and Cg7 are centroids of pyridine rings with N50 and N40 atoms, respectively), the distances of N2 and N6 atoms to the planes of the corresponding dimephen rings (3.505 and 3.677 Å, respectively) as well as the

Experimental
Single crystals of the title compound were obtained at the interfaces of layered systems, with the lower layer comprising an aqueous solution (5 ml) of iron(II) sulfate (0.1 mmol) and 5 ml of tcm (0.1 mmol) and the upper layer comprising a methanolic solution (3 ml) of dimephen (0.1 mmol). These layered systems were allowed to stand at room temperature.
Red crystals suitable for X-ray analysis were obtained and filtered off in several days and dried on air.

Refinement
Anisotropic displacement parameters were refined for all non-H atoms. The aromatic as well as methyl H atoms were placed in calculated positions and refined riding on their parent C atoms with C-H distances of 0.95 and 0.98 Å, respectively and U iso (H) = 1.2U eq (C) and 1.5U eq (C) for aromatic and methyl hydrogen atoms, respectively.

Computing details
Data

Figure 1
The structure of the title compound.  π-π interactions (dashed lines) between tcm and pyridine rings in the title compound (symmetry codes: (i) = x -1, y, z). Hatoms are omitted because of clarity.

Tris(5,6-dimethyl-1,10-phenanthroline-κ 2 N,N′)iron(II) bis(tricyanomethanide)
Crystal data   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