Bis(2,2′-bipyridine N,N′-dioxide)bis(tricyanomethanido)manganese(II)

In the title complex, [Mn(C4N3)2(C10H8N2O2)2], the MnII atom lies on an inversion center and is coordinated by two 2,2′-bipyridine N,N′-dioxide (dpdo) molecules and two tricyanomethanide (tcm) ligands to form a distorted octahedral geometry. Weak intermolecular C—H⋯O or C—H⋯N hydrogen bonds, involving either the O atom of the dpdo molecule and the pyridyl H atom, or the N atom of the tcm anion and the pyridyl H atom, result in the formation of a three-dimensional network structure.

Among the Cu I or Cd II tcm complexes with these coligands, numerous structure types range from doubly interpenetrated (4,4) sheet to three-dimensional rutile networks were observed (Batten et al., 2000(Batten et al., , 1998. By contrast, modification of the Mn II -tcm binary system with 4,4-bipyridyl as coligands leads to the formation of a one-dimensional chain-like structure (Manson & Schlueter, 2004). On the other hand, 2,2'-dipyridyl N,N'-dioxide (dpdo) is a novel coligand and has two potential oxygen donor atoms. However, no tcm complexes with dpdo as coligand have ever been reported. During our systematic investigation of the nature of dpdo coligand on the structures and properties of tcm complexes, we obtained a new tcm complex with dpdo as coligand, we herein report the synthesis and crystal structure of the new tricyanomethanide complex Mn(dpdo) 2 (C 4 N 3 ) 2 (I).
The Mn atom which lies on an inversion center displays an octahedral geometry in which the equatorial plane is formed by four O atoms (O1, O2, O1 i , O2 i ) of the dpdo molecules, and the apical sites are occupied by two N atom (N3, N3 i ) of the tcm ligands ( Fig. 1). The Mn-O(dpdo) distances are in the range from 2.1290 (13) Å to 2.1780 (13) Å, these value are comparable to the corresponding distances in manganese-nitroxide complexes (Liu et al., 2001). The Mn-N(tcm) distances are from 2.2336 (17) Å to 2.2337 (17) Å, and the data are similar to the corresponding distances observed in manganese tcm complex (Batten et al., 1999). Each tricyanomethanide moiety is almost planar. Bond distances and bond angles within the anions are in good agreement with those found in other tricyanomethanide complexes (Hoshino et al., 1999;Batten et al., 1999).
Weak intermolecular C-H···O or C-H···N hydrogen bonds involving either the O atom of the dpdo molecule and the pyridyl H atom or the N atom of the tcm anion and the pyridyl H atom, result in the formation of a three-dimensional network structure (Table 1, Fig. 2).
After stirred for another 5 min, the yellow solution was filtered and the filtrate was slowly evaporated in air. After two supplementary materials sup-2 week, yellow block crystals of I were isolated in 34% yield. Anal: Calculated for C28H16MnN10O4: C 55.00%, H 2.64%, N 22.91%. Found C 55.16%, H 2.73%, N 23.03%.

Refinement
In I the dpdo H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C-H distances of 0.93 Å and Uiso = 1.2U eq (C).

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 > σ(F 2 ) is used only for calculating Rfactors(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