Poly[octa-μ-aqua-tetraaquabis(μ4-5-sulfonatobenzene-1,3-dicarboxylato)nickel(II)tetrasodium]

In the crystal structure of the title compound, [Na4Ni(C8H3O7S)2(H2O)12]n, the NiII cation occupies an inversion centre and is coordinated by the carboxyl groups of the sulfoisophthalate trianions and water molecules in a distorted octahedral geometry. Two independent NaI atoms are connected by the carboxyl and sulfonate groups of the sulfoisophthalate ligands anions and water molecules in a distorted octahedral geometry. The sulfoisophthalate ligands and coordinated water molecules bridge the NiII and NaI cations, forming a three-dimensional polymeric structure. Weak π–π stacking is present between parallel benzene rings [centroid–centroid distance = 3.9349 (10) Å]. Extensive O—H⋯O and C—H⋯O hydrogen bonding helps to stabilize the crystal structure.

In the crystal structure of the title compound, [Na 4 Ni(C 8 H 3 -O 7 S) 2 (H 2 O) 12 ] n , the Ni II cation occupies an inversion centre and is coordinated by the carboxyl groups of the sulfoisophthalate trianions and water molecules in a distorted octahedral geometry. Two independent Na I atoms are connected by the carboxyl and sulfonate groups of the sulfoisophthalate ligands anions and water molecules in a distorted octahedral geometry. The sulfoisophthalate ligands and coordinated water molecules bridge the Ni II and Na I cations, forming a three-dimensional polymeric structure. Weakstacking is present between parallel benzene rings [centroid-centroid distance = 3.9349 (10) Å ]. Extensive O-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonding helps to stabilize the crystal structure.

ato)nickel(II)tetrasodium]
Bing-Yu Zhang, Jing-Jing Nie and Duan-Jun Xu S1. Comment As a part of investigation on π-π stacking between aromatic rings (Su & Xu, 2004;Pan et al., 2006), the title Ni II compound has recently been prepared in our laboratory, and its crystal structure is reported here.
A part of the three dimensional polymeric structure of the title compound is shown in Fig. 1. The Ni II compound is isomorphous with the Co II compound (Zhang et al., 2009). The Ni atom occupies a special position in an inversion centre and assumes a distorted NiO 6 octahedral geometry, The Ni-O bond distances (Table 1) are about 0.03 Å shorter than corresponding Co-O bond distances found in the isomorphous Co II compound. Both crystallograohically indenpendent Na I atoms are in distorted octahedral coordination geometry. The sulfoisophthalate trianions and water molecules bridge the metal atoms to form the polymeric structure.
The extensive O-H···O hydrogen bonding network presents in the crystal structue (Table 2), weak C-H···O hydrogen bonding also helps to stabilize the crystal structure. The distance between parallel the C2-benzne plane and C2 v -benzene plane is 3.551 (9) Å [symmetry code: (v) 1 -x, 1 -y, -z], and the centroids distance between the benzene rings is 3.9349 (10) Å. These findings suggest a weak π-π stacking involving sulfoisophthlate ligand.

S3. Refinement
Water H atoms were located in a difference Fourier map and refined as riding in as-found relative positions, with U iso (H) = 1.5U eq (O). Other H atoms were placed in calculated positions with C-H = 0.93 Å and refined in riding mode with

Poly[octa-µ-aqua-tetraaquabis(µ 4 -5-sulfonatobenzene-1,3-dicarboxylato)nickel(II)tetrasodium]
Crystal data 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.