Poly[(μ3-5-aminoisophthalato-κ4 O,O′:O′′:O′′′)[μ2-1,2-bis(4-pyridyl)ethane-κ2 N:N′]cobalt(II)]

In the title compound, [Co(C8H5NO4)(C12H12N2)]n, the CoII ion presents a distorted CoO4N2 octahedral coordination geometry, formed by three 5-aminoisophthalate dianions and two 1,2-bis(4-pyridyl)ethane ligands. One carboxylate group of the 5-aminoisophthalate dianion chelates a Co cation and the other carboxylate group bridges the other two Co cations, while the terminal N atoms of the 1,2-bis(4-pyridyl)ethane ligand coordinate the neighboring Co cations, forming a two-dimensional polymeric architecture. Two pyridine rings of the 1,2-bis(4-pyridyl)ethane ligand are twisted to each other with a dihedral angle of 50.94 (16)°. Weak C—H⋯O hydrogen bonding and N—H⋯π interactions are observed in the crystal structure. A void of 69 (5) Å3 is present in the crystal structure, but no solvent molecule can be located reasonably.

In the title compound, [Co(C 8 H 5 NO 4 )(C 12 H 12 N 2 )] n , the Co II ion presents a distorted CoO 4 N 2 octahedral coordination geometry, formed by three 5-aminoisophthalate dianions and two 1,2-bis(4-pyridyl)ethane ligands. One carboxylate group of the 5-aminoisophthalate dianion chelates a Co cation and the other carboxylate group bridges the other two Co cations, while the terminal N atoms of the 1,2-bis(4-pyridyl)ethane ligand coordinate the neighboring Co cations, forming a twodimensional polymeric architecture. Two pyridine rings of the 1,2-bis(4-pyridyl)ethane ligand are twisted to each other with a dihedral angle of 50.94 (16) . Weak C-HÁ Á ÁO hydrogen bonding and N-HÁ Á Á interactions are observed in the crystal structure. A void of 69 (5) Å 3 is present in the crystal structure, but no solvent molecule can be located reasonably.

D-HÁ
The title compound by X-ray crystallography reveals that the symmetric unit consist of one Co II ion, two 1,2-bis(4pyridyl)ethane (dpe) ligands and three aip ligands, as shown in Fig. 1. The Co II ion is six-coordinated with a slightly distorted octahedral geometry. The equatorial plane is occupied by two monodentate carboxylate oxygen atoms from two aip ligands and one bidentate carboxylate oxygen atoms from one aip ligand, while the axial sites are occupied by two nitrogen atoms of the pyridine groups from two dpe ligands (Table 1). Each aip ligand employs its two carboxylate groups in turn to coordinate to three metal centers, while the remains amino group in uncoordinated manner. The four symmetry-related metal centers are linked by two aip ligands and two dpe ligands to form a 30-membered macro cycle with Co···Co separation of 6.956 ( (Table 2).

Experimental
CoBr 2 (0.1097 g, 0.5 mmol), 5-aminoisophthalic acid, (0.0903 g, 0.5 mmol) and 1,2-bis(4-pyridyl)ethane (0.0913 g, 0.5 mmol) were mixed in 10 ml deionized water. After being stirred for 30 min, the mixture was placed in a 25 ml Teflon liner reactor and heated at 423 K in the oven for 24 h. The resulting solution was slowly cooled to room temperature. The purple transparent single crystals of the title compound were obtained in 46.45% yield (based on cobalt).

Refinement
H atoms were positioned geometrically with N-H = 0.86, C-H = 0.93 (aromatic) and 0.97 Å (methylene), and were refined using a riding model with U iso (H) = 1.2U eq (C,N). A voids of 69 Å 3 exists close to an inversion center in the crystal structure, a solvent water molecule with a fractional site occupancy factor was tried to located, however the refinement including the water molecule gave an abnormal large displacement paramenter and small SOF. Fig. 1. View of the title compound with the atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.

Figures
Crystal data [Co(C 8