Bis[2,6-bis(4,5-dihydro-1H-imidazol-2-yl)pyridine]manganese(II) bis(perchlorate) acetonitrile solvate

In the cation of the title compound, [Mn(C11H13N5)2](ClO4)2·CH3CN, the metal atom is located on a twofold rotation axis and is six-coordinated by six N atoms from two different 2,6-bis(4,5-dihydro-1H-imidazol-2-yl)pyridine (bip) ligands in a distorted octahedral geometry. The O atoms of the perchlorate anions are disordered with occupancies in the ratio 0.593 (10):0.407 (10). In the crystal, molecules are stabilized by two N—H⋯O hydrogen bonds, forming zigzag chains along the a axis, which are further interconnected by N—H⋯O hydrogen bonds and π–π interactions [centroid–centroid distance = 3.50 (1) Å] into a three-dimensional network.

In the cation of the title compound, [Mn(C 11 H 13 N 5 ) 2 ](ClO 4 ) 2 Á-CH 3 CN, the metal atom is located on a twofold rotation axis and is six-coordinated by six N atoms from two different 2,6bis(4,5-dihydro-1H-imidazol-2-yl)pyridine (bip) ligands in a distorted octahedral geometry. The O atoms of the perchlorate anions are disordered with occupancies in the ratio 0.593 (10):0.407 (10). In the crystal, molecules are stabilized by two N-HÁ Á ÁO hydrogen bonds, forming zigzag chains along the a axis, which are further interconnected by N-HÁ Á ÁO hydrogen bonds andinteractions [centroidcentroid distance = 3.50 (1) Å ] into a three-dimensional network.
Data collection: SMART (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL. The construction supramolecular architectures is currently of great interest owing to their intriguing network topologies and potential functions such as adsorption, ion exchange, shape-selective catalysis, non-linear and magnetic materials (Yaghi et al., 1998;Hagrman et al., 1999). The protonation and deprotonation of an imidazole ligand is believed to play an important role in the mechanism of the coordination chemistry (Bordo, et al., 2001). We described previously a number of such metal complexes, including imidazole ligand, and have concluded that hydrogen bonding involving this group influences the geometry around the metal atom and the crystallization mechanism (Ren, Ye, He et al., 2004;Ren, Ye, Zhu et al., 2004;Ren et al., 2007Ren et al., , 2009. We report here the preparation and crystal structure of a mononuclear coordination complex, [Mn(bip) 2 ](ClO 4 ) 2 .CH 3 CN (I) (bip is 2,6-bis(4,5-dihydro-1H-imidazol-2-yl)pyridine).
The crystal structure of (I) crystallizes in the monoclinic space group C2/c. As shown in Fig. 1, the title compound consists of a [Mn(bip) 2 ] 2+ cation, two perchlorate counter ions and one Acetonitride molecular. The manganese(II) atom in the cation is in a distorted tetrahedral geometry, being coordinated with six nitrogen atoms from two neutral tridentate ligands bip. The Mn(1)-N bond lengths of The equatorial 2.292 (4), 2.284 (4), 2.251 (4) Å, which are slightly shorter than the metal-imidazole (Stupka, et al., 2004;Hammes et al., 2005;Haga et al., 1996;Böca et al., 2005) and longer than the metal-imidazole (Ren, et al., 2009). The N-Mn(1)-N bond angle is in the range of 70.17 (15)-147.1 (2) /%. Two bip ligands of adjacent molecules are parallel to each other with a distance of 3.50 Å, showing the presence of π-π interaction. The molecules further interconnected into three-dimensional network through hydrogen bond between the oxygen atom of perchlorate counter-ion and the uncoordination nitrogen atoms of bip ligands.

S2. Experimental
All the reagents and solvents employed were commercially available and used as received without further purification.

S3. Refinement
The H atom attached to N(2) atom was refined isotropically. All the other H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with N-H and C-H distances of 0.90 Å and 0.96 Å, respectively, and U iso (H) = 1.2 times of those of their parent atoms (Å 2 ). The O atoms are resolved into two positions by PART instructions. The occupancy for the unprimed O atoms is set at 21 and that of the primed atoms at -21. The clorineoxygen distances were restrained to 1.44 Å (and the oxygen-oxygen interaction to 2.35 Å). Additionally, the vibration of the oxygen atoms were made isotropic by an ISOR restraint. The O atoms are resolved into two positions and give the site occupany of the major component.   where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.33 e Å −3 Δρ min = −0.27 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. (