Poly[aqua[μ-1,2-bis(pyridin-4-yl)ethene-κ2 N:N′][μ-5-(diphenylphosphinoyl)isophthalato-κ3 O 1,O 1′:O 3]nickel(II)]

In the title compound, [Ni(C20H13O5P)(C12H10N2)(H2O)]n, the NiII cation is coordinated by three O atoms from two 5-(diphenylphosphinoyl)isophthalate anions, two N atoms from two 1,2-bis(pyridin-4-yl)ethene ligands and one water molecule in a distorted octahedral geometry. Both 1,2-bis(pyridin-4-yl)ethene and 5-(diphenylphosphinoyl)isophthalate bridge the NiII cations to form polymeric layers parallel to (001). In the crystal, O—H⋯O hydrogen bonding links layers into a three-dimensional supramolecular structure.

X-ray crystallographic analysis revealed that the title compound crystallizes in monoclinic space group P2 1 /c. As shown in Fig. 1, the asymmetric unit consists of one Ni II atom, one L 2anion, one bpe ligand and one coordinated water molecule. Each metal center is six-coordinated by three O atoms from two L 2anions, one O atom from the coordinated water molecule and two N atoms from different 1,2-bis(pyridin-4-yl)ethene ligands. Four atoms O1W, O1, O2 and O3#1 comprise the equatorial plane; while N1, N2#2 occupies the axial position.
Each L 2ligand acts as a µ 2 -bridge linking two Ni II atoms with one carboxylate group in monodentate fashion and the other one in chelating mode to form an infinite Ni-L 2chain running along the a-axis. As depicted in Fig. 2, bpe ligand links adjacent chains running along the b-axis to form a (4,4)-layer with Ni1···Ni1 distance of 10.1866 (7) Å and 13.6980 (7) Å, respectively. Adjacent layers are associated together by O-H···O hydrogen bonds to achieve a threedimensional supramolecular structure (Fig. 3). A further investigation reveals a more striking feature of title compound, i.e. two sets of symmetric related supamolecular structures are interlocked with each other to display a twofold interpenetrating architecture.

Refinement
H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 Å, U iso (H) = -1.2U eq (C) for aromatic H. The H atoms of the water molecules were located from the Fourier difference map and refined with suitable geometric restraints.

Figure 1
Metal coordination and atom labeling in title compound (thermal ellipsoids at 50% probability level). Irrespective hydrogen atoms are omitted for clarity. Symmetry codes: #1: x + 1, y, z; #2: x, y -1, z.  The three-dimensional supramolecular structure connected by hydrogen bonds. Dotted lines represent hydrogen bonds.

Poly[aqua(µ-1,2-bis(pyridin-4-yl)ethene-κ 2 N:N′)[µ-5-(diphenylphosphinoyl)isophthalato-κ 3 O 1 ,O 1′ :O 3 ]nickel(II)]
Crystal data  Hydrogen site location: inferred from neighbouring sites H-atom parameters constrained where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.66 e Å −3 Δρ min = −0.33 e Å −3 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