Bis(nitrato-κO)[(S)-2-(pyrrolidin-2-yl)-1H-benzimidazole]cadmium(II)

The title compound, [Cd(NO3)2(C11H13N3)2], was synthesized by hydrothermal reaction of Cd(NO3)2 and S-2-(pyrrolidin-2-yl)-1H-1,3-benzimidazole. The Cd atom lies on an inversion centre. The distorted octahedral Cd environment contains two planar trans-related N,N-chelating S-2-(pyrrolidin-2-yl)-1H-1,3-benzimidazole ligands in one plane and two monodentate nitrate ligands. N—H⋯O hydrogen bonds involving a nitrate O atom build up an infinite chain parallel to the a axis.


Related literature
For physical properties such as fluorescence and dielectric behaviors of metal-organic coordination compounds, see: Aminabhavi et al. (1986); Ye et al. (2008).

S1. Comment
Metal-organic coordination compounds provide a class of complexes displaying interesting chemical and physical properties such as fluorescence and dielectric behaviors (Aminabhavi et al., 1986;Ye et al., 2008). There has been very strong interest in employing crystal-engineering strategies to generate desirable materials by the hydrothermal reaction.

benzo[d]imidazole)-Cadmium).
In the title compound, the cadmium atom lies on an inversion centre. The distorted octahedral Cd environment contains two planar trans-related N,N-chelating S-2-(pyrrolidin-2-yl)-1H-benzo imidazole in one plane and two monodentate nitrate ( Fig. 1). N-H···O hydrogen bonds involving one O atom of the nitrate build up an infinite chain developing parallel to the a axis (Table 1).

S3. Refinement
Positional parameters of all the H atoms bonded to C or N atoms were calculated geometrically and were allowed to ride on the C atoms to which they are bonded, with U iso (H) = 1.2Ueq(C or N).   The crystal packing of the title compound viewed along the c axis and all hydrogen atoms not involved in hydrogen bonding (dashed lines) were omitted for clarity.

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.