Poly[[(μ2-4,4′-bipyridyl-κ2 N:N′)bis{μ2-N-[2-(2-hydroxybenzoyl)carbamothioyl]acetamidato-κ4 O,N,O′:S}bis(nitrato-κ2 O,O′)dicadmium] dimethylformamide tetrasolvate]

The asymmetric unit of the title complex, {[Cd2(C10H10N3O3S)2(C10H8N2)(NO3)2]·4C3H7NO}n, consists of one CdII cation, one N-[2-(2-hydroxybenzoyl)carbamothioyl]acetamidate ligand, half a 4,4′-bipyridyl ligand, one coordinating nitrate anion and two dimethylformamide solvent molecules of crystallization. The bipyridine ligand is completed by inversion symmetry. The metal cation exhibits a distorted pentagonal–bipyramidal coordination geometry provided by two O and one N atoms of the thiosemicarbazide ligand, two O atoms of the nitrate anion, one S atom of a neighbouring thiosemicarbazide ligand and one 4,4′-bipyridine N atom. The bridging role of the thiosemicarbazide ligand through the S atom leads to centrosymmetric binuclear units, which are further linked by 4,4′-bipyridine units, forming polymeric chains extending along the b-axis direction. An intramolecular N—H⋯O hydrogen bond occurs. The crystal structure also features N—H⋯O and O—H⋯O hydrogen bonds, leading to the formation of a three-dimensional network.

The asymmetric unit of the title complex, {[Cd 2 (C 10 H 10 N 3 O 3 S) 2 (C 10 H 8 N 2 )(NO 3 ) 2 ]Á4C 3 H 7 NO} n , consists of one Cd II cation, one N-[2-(2-hydroxybenzoyl)carbamothioyl]acetamidate ligand, half a 4,4 0 -bipyridyl ligand, one coordinating nitrate anion and two dimethylformamide solvent molecules of crystallization. The bipyridine ligand is completed by inversion symmetry. The metal cation exhibits a distorted pentagonal-bipyramidal coordination geometry provided by two O and one N atoms of the thiosemicarbazide ligand, two O atoms of the nitrate anion, one S atom of a neighbouring thiosemicarbazide ligand and one 4,4 0 -bipyridine N atom. The bridging role of the thiosemicarbazide ligand through the S atom leads to centrosymmetric binuclear units, which are further linked by 4,4 0 -bipyridine units, forming polymeric chains extending along the b-axis direction. An intramolecular N-HÁ Á ÁO hydrogen bond occurs. The crystal structure also features N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds, leading to the formation of a three-dimensional network.

Experimental
Crystal data [Cd 2 (C 10 Table 1 Hydrogen-bond geometry (Å , ).  Thiosemicarbazones complexes have received considerable attentions in the past decades due to their interesting biological activities, including antibacterial, antimalarial, antiviral and antitumor activities (Quiroga & Ranninger, 2004;Kasuga et al., 2003;). In order to figure out their structure-property relationship, a great number of metal complexes based on thiosemicarbazone derivatives, particularly the 1,4-disubstituted ones have been prepared and their biological activities were investigated systematically (Floquet et al., 2009;Hassanien et al., 2008;Latheef et al., 2006;Babb et al., 2003). In this paper, we report the crystal structure of the title one-dimensional coordination polymer based on diacylthiosemicarbazone.
The asymmetric unit of the title complex consists of one cadmium(II) cation, one N-(2-(2-hydroxybenzoyl)carbamothioyl)acetamide ligand, one half of a 4,4′-bipyridine, one coordinated nitrate anion and two dimethylformamide molecules of crystallization ( Fig. 1). In the structure, each Cd center adopts a distorted pentagonal bipyramidal coordination geometry with the equatorial plane formed two O atoms and one N atom from the thiosemicarbazide ligand and two O atoms from the bidentate nitrate anion. These five atoms (O1, N2, O2, O4, O3) and the metal center are almost coplanar (maximum deviation from the least-squares plane is 0.6560 (3) Å for the O3 atom). The Cd1-O3 and Cd1-O4 bond lengths involving the nitrate anion are remarkably different (2.387 (4) and 2.553 (5) Å, respectively). The axial positions are occupied by one N atom from 4,4′-bipyridine and one S atom from a neighbouring thiosemicarbazide ligand. The Cd1-N4 bond distance is 2.360 (5) Å, indicating the strong coordination between Cd and 4,4′-bipyridine, while the Cd1-S1 i [symmetry code: (i) -x+2, -y, -z+1] bond length is 2.628 (5) Å, which is slightly shorter than that previously reported (2.7364 (8) Å) for a Cd complex with thiosemicarbazones (Wang et al., 2010). Due to the axial coordination of S atoms, two neighbouring cadmium(II) cations are interconnected to generate a centrosymmetric binuclear unit with a Cd···Cd separation of 5.6889 (12) Å (Fig. 2). Along the b axis, such binuclear units are further bridged by 4,4′-bipyridine linkers to form a one-dimensional zigzag coordination polymer. In the structure of the title complex, N-H···O and O-H···O hydrogen bonds (Table 1) play an important role in stabilizing the packing (Fig. 3).

Refinement
All C-and N-bound H atoms were placed in idealized positions using the riding-model approximation, with C-H = 0.93-0.96 Å, N-H = 0.86 Å, O-H = 0.86 Å, and with U iso (H) = 1.5U eq (C) for methyl groups and 1.2U eq (C, N, O) otherwise. In the last cycles of refinement, three outliers (-4 6 8, -3 5 6, 1 2 0) were omitted.    where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.70 e Å −3 Δρ min = −0.63 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