trans-Bis(nitrato-κO)bis(1,10-phenanthroline-κ2 N,N′)manganese(II)

In the title compound, [Mn(NO3)2(C12H8N2)2], the MnII atom lies on a twofold rotation axis, and is six-coordinated in a distorted trans-N4O2 octahedral environment by four N atoms from two 1,10-phenanthroline ligands and two O atoms from two nitrate anions. The nitrate anion is disordered about a twofold rotation axis with fixed occupancy factors of 0.5. In the crystal, molecules are linked by weak C—H⋯O hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 4.088 (5) Å] into a three-dimensional supramolecular network.

In the title compound, [Mn(NO 3 ) 2 (C 12 H 8 N 2 ) 2 ], the Mn II atom lies on a twofold rotation axis, and is six-coordinated in a distorted trans-N 4 O 2 octahedral environment by four N atoms from two 1,10-phenanthroline ligands and two O atoms from two nitrate anions. The nitrate anion is disordered about a twofold rotation axis with fixed occupancy factors of 0.5. In the crystal, molecules are linked by weak C-HÁ Á ÁO hydrogen bonds andstacking interactions [centroid-centroid distance = 4.088 (5) Å ] into a three-dimensional supramolecular network.

Related literature
For the isotypic Cd compound, see: Shi et al. (2004).
Weak C-H···O hydrogen bonds involving the phen ligands and the [NO 3 ]anions, Table 1, are further linked to neighboring chains into a three dimensional supramolecular network along the a axis, Fig. 3.

Refinement
The C-bound hydrogen atoms were placed in geometrically idealized positions based on chemical coordinations and constrained to ride on their parent atom positions with a C-H distances of 0.93 Å and with U iso (H) = 1.2U eq (C) for the supplementary materials aromatic H atoms. The nitrate anions are disordered about a twofold rotation axis and were refined using a two site model. The site occupancy factors for the two orientations were then fixed to 0.5. The nitrogen-oxygen distances were restrained to 1.24 ± 0.01 Å and O···O of 2.15 Å, however, the anisotropic temperature factors were restrained to be nearly isotropic.

Figure 1
Displacement ellipsoid plot of a fragment at the 30% probability level containing the asymmetric unit with atom numbering and coordination environment of the metal centers of I.

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.