Bis[chloridobis(1,10-phenanthroline)copper(II)] pentacyanidonitrosoferrate(II) dimethylformamide monosolvate

The title complex [CuCl(C12H8N2)2]2[Fe(CN)5(NO)]·C3H7NO, consists of discrete [Cu(phen)2Cl]+ cations (phen is 1,10-phenanthroline), [Fe(CN)5NO]2− anions and one dimethylformamide (DMF) solvent molecule of crystallization per asymmetric unit. The CuII atom is coordinated by two phenanthroline ligands and one chloride ion in a distorted trigonal–bipyramidal geometry. The dihedral angle between the phen ligands is 77.92 (7)°. The cation charge is balanced by a disordered nitroprusside counter-anion with the FeII atom located on an inversion center with a slightly distorted octahedral coordination geometry. In the crystal, weak C—H⋯N and C—H⋯Cl hydrogen bonds connect anions and cations into a two-dimensional network parallel to (100). In addition, π–π stacking interactions are observed with centroid–centroid distances in the range 3.565 (2)–3.760 (3)Å. The dimethylformamide solvent molecule was refined as disordered about an inversion center.

The title complex [CuCl(C 12 H 8 N 2 ) 2 ] 2 [Fe(CN) 5 (NO)]Á-C 3 H 7 NO, consists of discrete [Cu(phen) 2 Cl] + cations (phen is 1,10-phenanthroline), [Fe(CN) 5 NO] 2À anions and one dimethylformamide (DMF) solvent molecule of crystallization per asymmetric unit. The Cu II atom is coordinated by two phenanthroline ligands and one chloride ion in a distorted trigonal-bipyramidal geometry. The dihedral angle between the phen ligands is 77.92 (7) . The cation charge is balanced by a disordered nitroprusside counter-anion with the Fe II atom located on an inversion center with a slightly distorted octahedral coordination geometry. In the crystal, weak C-HÁ Á ÁN and C-HÁ Á ÁCl hydrogen bonds connect anions and cations into a two-dimensional network parallel to (100). In addition,stacking interactions are observed with centroid-centroid distances in the range 3.565 (2)-3.760 (3)Å . The dimethylformamide solvent molecule was refined as disordered about an inversion center.

Experimental
Crystal data [CuCl(C 12 Table 1 Hydrogen-bond geometry (Å , ). This work is a continuation of our research in the field of direct synthesis of coordination compounds (Buvaylo et al., 2005;Makhankova et al., 2002;Nesterova et al., 2004Nesterova et al., ,2005Nesterova et al., ,2008Pryma et al., 2003;Vinogradova et al., 2002;Vassilyeva et al., 1997). It was shown recently the possibility of using anionic complexes as a source of metalloligands or the second metal in direct synthesis of heterometallic compounds (Nikitina et al., 2008;Vreshch et al., 2009) Fig. 1) as well as dimethylformamide solvent molecules. The Cu II ion adopts a distorted trigonal-bipyramidal environment by coordinating with four nitrogen atoms from two phen ligands and chlorine atom. The dihedral angle between the two phen ligands (77.92 (7)° ) as well as the range of Cu-N bond distances of 1.996 (3) -2.177 (4) Å is in good agreement with the previously reported values for analagous complexes (Onawumi et al., 2010;Sui et al., 2006;Xiao et al., 2004). The nitroprusside ion lies across an inversion center. Therefore, the CN and NO groups occupy the axial positions with equal occupancies. It has the usual distorted octahedral, pagoda-like, conformation with average Fe-C and Fe-N bond distances of 1.90 Å and 1.78 Å respectively, in a good agreement with literature values (Soria et al. (2002); Shevyakova et al. (2002). In the crystal, weak C-H···N and C-H···Cl hydrogen bonds connect anions and cations into a two-dimensional network parallel to (100) (Fig. 2). In addition, π···π stacking interactions are observed with centroid to centroid distances in the range 3.565 (2)-3.760 (3)Å.

Refinement
All H-atoms were placed in calculated positions with C-H = 0.93-1.00 Å and refined in riding-model approximation with U iso (H) = 1.2U eq (C).  The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level.  Part of the crystal structure with weak hydrogen bonds shown as dashed lines. Only H atoms involved in hydrogen bonds are shown. The disordered solvent molecule is not shown as it is not involved in the hydrogen bond motif.

Crystal data
[CuCl (C 12 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.