[1,2-Bis(diisopropylphosphanyl)ethane-κ2 P,P′](carbonato-κ2 O,O′)nickel(II)

In the crystal of the title compound, [Ni(CO3)(C14H32P2)], the metal center in each of three independent molecules shows slight tetrahedral distortion from ideal square-planar coordination geometry, with angles between the normals to the planes defined by the cis-P—Ni—P and cis-O—Ni—O fragments of 3.92 (17), 0.70 (16) and 2.17 (14)° in the three molecules. In the crystal, there are intermolecular C—H⋯O hydrogen bonds that show a laminar growth in the ab plane.

In the crystal of the title compound, [Ni(CO 3 )(C 14 H 32 P 2 )], the metal center in each of three independent molecules shows slight tetrahedral distortion from ideal square-planar coordination geometry, with angles between the normals to the planes defined by the cis-P-Ni-P and cis-O-Ni-O fragments of 3.92 (17), 0.70 (16) and 2.17 (14) in the three molecules. In the crystal, there are intermolecular C-HÁ Á ÁO hydrogen bonds that show a laminar growth in the ab plane.
The asymmetric unit consists of three [(dippe)Ni(CO 3 )] discrete molecules of the neutral complex ( Figure 1). The Ni(II) atom is coordinated by two P atoms of dippe ligand and two oxygen atoms of the carbonato anion. The metal center in 3 independent molecules A, B and C of [(dippe)Ni(CO 3 )] shows slight tetrahedral distortion from ideal square planar coordination geometry, with the angle between the normals to the planes defined by the two cis-P-Ni-P and cis-O-Ni-O fragments of 3.92 (17), 0.70 (16) and 2.17 (14)° respectively, these being larger than the limiting value of 0° for squareplanar coordination in [(dippe)Ni(CO) 2 ]CH 3 OH (González-Sebastián et al. 2012). Additionally the Ni(II) atom is situated 0.040 (1), 0.0057 (9), 0.0095 (9) Å above the P1/P2/O1/O2 plane in A, B and C molecules respectively. These deviations from planarity, which can be attributed to some steric efect of the dippe ligand and intermolecular interactions of the carbonato ligand, are somewhat shorter than the distortion from ideal square-planar coordination geometry observed on In the crystal packing, there are intermolecular contacts of the type hydrogen bond (Table 2) mainly between the carbon donor atom of the dippe to O oxygen atom acceptor of the metallic complex mainly. The C5A-H5A1···O3A (2.7 Å) and C4A-H4A3···O1A (2.69 Å) intermolecular interactions in molecule A forming a motif graph R 2 2 (8) along the a axes, while the C10B-H10F···O3B (2.52 Å) and C8C-H8C1···O3C (2.71 Å) intermolecular interactions in molecules B and C forming a C(8) motif along to c axis. All these interactions show a laminar growing in the a, b plane ( Figure 2).

Experimental
The compound [(dippe)NiCl 2 ] (98.0 mg, 0.25 mmol) was slowly added into a solution of commercially available KOH (28.0 mg, 0. 50 mmol) in H 2 O (5 ml) under constant stirring at room temperature. After 15 min of reaction, a red solution was observed. At this point the reaction mixture was evaporated to dryness under vacuum and the obtained red-wine residue was re-dissolved in THF (5 mL) and filtrated via cannula using a Schlenk flask. After a couple of days of cooling in the dry-box fridge at -30 °C, yellow crystals suitable for X ray diffraction studies were obtained.

Refinement
H atoms attached to C atoms were placed in geometrically idealized positions, and refined as riding on their parent atoms, with C-H distances fixed to 0.98 (methyl CH 3 ), 0.99 (methylene CH 2 ) and 1.00 Å (methine CH), and with U iso (H) = 1.5Ueq(methyl C) or 1.2Ueq(C).

Figure 1
The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as circles of arbitrary size.
Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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.