Bis[4-(dimethylamino)pyridinium] bis[4-(dimethylamino)pyridine-κN 1]tetrakis(thiocyanato-κN)manganate(II)

In the crystal structure of the title compound, (C7H11N2)2[Mn(NCS)4(C7H10N2)2], the manganese(II) cations are coordinated by four N-bonded thiocyanate anions and two N-bonded 4-(dimethylamino)pyridine ligands into discrete complex dianions. For charge balance, two 4-(dimethylamino)pyridine counter cations are present, which do not coordinate to the metal cation. The asymmetric unit consists of one manganese(II) cation, four thiocyanate anions and two 4-(dimethylamino)pyridine ligands, as well as two protonated 4-(dimethylamino)pyridinium cations. The discrete complex anions are connected to the non-coordinating pyridinium cations by weak N—H⋯S hydrogen-bonding interactions.

In the crystal structure of the title compound, (C 7 H 11 N 2 ) 2 [Mn(NCS) 4 (C 7 H 10 N 2 ) 2 ], the manganese(II) cations are coordinated by four N-bonded thiocyanate anions and two N-bonded 4-(dimethylamino)pyridine ligands into discrete complex dianions. For charge balance, two 4-(dimethylamino)pyridine counter cations are present, which do not coordinate to the metal cation. The asymmetric unit consists of one manganese(II) cation, four thiocyanate anions and two 4-(dimethylamino)pyridine ligands, as well as two protonated 4-(dimethylamino)pyridinium cations. The discrete complex anions are connected to the non-coordinating pyridinium cations by weak N-HÁ Á ÁS hydrogen-bonding interactions.

Bis[4-(dimethylamino)pyridinium] bis[4-(dimethylamino)pyridine-κN 1 ]tetrakis-(thiocyanato-κN)manganate(II) Susanne Wöhlert, Inke Jess and Christian Näther Comment
The structure determination was performed during a project on the synthesis, thermal and magnetic properties of coordination compounds based on transition metal thiocyanates and neutral N-donor co-ligands (Boeckmann & Näther, 2011. In order to investigate the influence of the co-ligand, N,N′-dimethylaminopyridine was reacted with manganese(II) thiocyanate which resulted in the formation of crystals of the title compound that were identified by single-crystal X-ray diffraction.
In the crystal structure of the title compound each manganese(II) cation is coordinated by four N-bonded thiocyanato anions and two N-bonded dimethylaminopyridine ligands (Fig. 1)

Experimental
MnSO 4 xH 2 O, Ba(NCS) 2 x3H 2 O and N,N′-dimethylaminopyridine were obtained from Sigma Aldrich. 0.15 mmol (26 mg) Mn(NCS) 2 and 0.3 mmol (58.3 mg) dimethylaminopyridine were reacted with 1 mL ethanol in a snap cap vial. After three days yellow colored block-shaped single crystals of the title compound were obtained.

Refinement
All C-H and N-H H atoms were located in difference map but were positioned with idealized geometry (methyl H atoms allowed to rotate but not to tip) and were refined isotropic with U iso (H) = 1.2 U eq (C, N) (1.5 for the methyl H atoms) using a riding model with C aromatic = 0.95 Å, CmethylH = 0.98 Å and N-H = 0.88 Å.  Crystal structure of the title compound with labeling and displacement ellipsoids drawn at the 50% probability level.

Figure 2
Crystal structure of the title compound with view along the crystallographic b-axis. Intermolecular hydrogen bonding is shown as dashed lines.

Bis[4-(dimethylamino)pyridinium] bis[4-(dimethylamino)pyridine-κN 1 ]tetrakis(thiocyanato-κN)manganate(II)
Crystal data (C 7 where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.80 e Å −3 Δρ min = −0.72 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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