Bis(2,2′-bipyridyl-κ2 N,N′)bis(dicyanamido-κN)manganese(II)

In title complex, [Mn(C2N3)2(C10H8N2)2], the MnII ion is coordinated in a slightly distorted octahedral geometry by six N atoms. Four of the N atoms are from two chelating bipyridine ligands and two are from a pair of cis-coordinated dicyanamide ligands. The dihedral angle formed by the mean planes of the bipyridine rings is 85.93 (14)°. The central N atom of one of the dicyanamide ligands was refined as disordered over two sites with equal occupancies.

In title complex, [Mn(C 2 N 3 ) 2 (C 10 H 8 N 2 ) 2 ], the Mn II ion is coordinated in a slightly distorted octahedral geometry by six N atoms. Four of the N atoms are from two chelating bipyridine ligands and two are from a pair of cis-coordinated dicyanamide ligands. The dihedral angle formed by the mean planes of the bipyridine rings is 85.93 (14) . The central N atom of one of the dicyanamide ligands was refined as disordered over two sites with equal occupancies.  Lumme & Lindell (1988); Li et al. (2002).
The molecular structure of the title complex is shown in figure 1. The coordination of the Mn II ion is slightly distorted octahedral, for which four sites are from two 2,2-bipyridine ligands and the other two are occupied by two N atoms of the two dicyanamido ligands. The distances between the central Mn II ion and the N atoms of the 2,2′-bipyridine ligands are in agreement with the Mn-N bond lengths in other manganese complexes contaning bipyridine ligands (Lopes et al., 2011;Knight et al., 2010;McCann et al., 1998;Lumme & Lindell, 1988;Li et al., 2002). The Mn-N dicyanamido bond lengths are slightly shorter than the Mn-N bipyridine lengths.

Experimental
The synthesis of the title complex was carried out by reacting Mn(ClO 4 ) 2 .6H 2 O, 2,2′-bipyridine and sodium dicyanamide in a molar ratio of 1:2:2 in methanol. After the mixture was stirred for about 15 minutes at room temperature, it was filtrated. The filtrate was left to slowly evaperate in air for about one week to obtain single-crystals suitable for X-ray diffraction with the yield about 50%.

Refinement
All H atoms bonded to the C atoms were placed using the HFIX command in SHELXL-97 (Sheldrick, 2008) with C-H distances of 0.93 Å, and were allowed for as riding atoms with U iso (H) = 1.2U eq (C). The atom N6 of one the dicyanamido ligands is disordered and was refined with over two sites with equall occupancies.

Crystal data
[Mn(C 2 N 3 ) 2 (C 10 H 8 N 2 ) 2 ] M r = 499.41 Monoclinic, P2 1 /c Hall symbol: -P 2ybc a = 9.232 (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.