Poly[bis[μ2-2-(2-pyridylmethylamino)ethanesulfonato]cadmium(II)]

The title compound [Cd(C8H11N2O3S)2]n, is a two-dimensional coordination polymer based on a Cd2+ atom and deprotonated 2-(2-pyridylmethylamino)ethanesulfonic acid (Hpmt). The complex has molecular symmetry C i as a consequence of the CdII being located on an inversion centre. Two N atoms of each pmt− ligand coordinate to the Cd2+ ion and its sulfonate O atom bonds to an adjacent Cd2+ ion. 24-membered (–Cd—N—C—C—S—O–)4 rings are formed between neighbouring Cd2+ ions; these are interconnected, forming a two-dimensional layer structure. In respect to stereogenic amino N atom and the inversion symmetry of the complex, the compound is a 1:1 racemate. The crystal packing is stabilized by intermolecular N—H⋯O hydrogen bonds and further connected by π–π stacking interactions between the pyridyl rings [average interplanar distance and centroid–centroid separation = 3.582 (1) and 3.634 (1)Å, respectively], forming a three-dimensional supramolecular architecture.

The title compound [Cd(C 8 H 11 N 2 O 3 S) 2 ] n , is a two-dimensional coordination polymer based on a Cd 2+ atom and deprotonated 2-(2-pyridylmethylamino)ethanesulfonic acid (Hpmt). The complex has molecular symmetry C i as a consequence of the Cd II being located on an inversion centre. Two N atoms of each pmt À ligand coordinate to the Cd 2+ ion and its sulfonate O atom bonds to an adjacent Cd 2+ ion. 24membered (-Cd-N-C-C-S-O-) 4 rings are formed between neighbouring Cd 2+ ions; these are interconnected, forming a two-dimensional layer structure. In respect to stereogenic amino N atom and the inversion symmetry of the complex, the compound is a 1:1 racemate. The crystal packing is stabilized by intermolecular N-HÁ Á ÁO hydrogen bonds and further connected bystacking interactions between the pyridyl rings [average interplanar distance and centroidcentroid separation = 3.582 (1) and 3.634 (1)Å , respectively], forming a three-dimensional supramolecular architecture.
Compound 1 is a two-dimensional coordination polymer and the repeating unit comprises one Cd 2+ ion and two pmtligands( Fig. 1, Table 1). Cd 2+ ion situates on a centre of symmetry and is six-coordinated with four N atoms from two pmtligands along with two sulfonate O atoms belonging to another two ligands, showing a distorted octahedral geometry ( Table   1). The four N atoms from two pmtligands define the equatorial plane with the Cd centre located in the plane, and two O atoms are at the axial positions with O2A-Cd1-O2B angle of just 180°[Symmetry codes: Each pmtplays as a µ 2 bridge to connect two Cd 2+ ions and each Cd 2+ ion links four pmtligands, forming an infinite two-dimensional layer structure with (4, 4) topology ( Figure 2). The network is based on (Cd(pmt)) 4 rhombus, a 24-membered metal-ligand ring (-Cd-N-C-C-S-O-) 4 formed by four pmtand four quadruply connected Cd 2+ ions.
The edge Cd···Cd distance of the rhombus is 8.048 (3) Table 2). The interlayers are further connected by π-π stacking interactions of parallel pyridine rings of adjacent layers. The interplanar average distance and ringcentroid separation distance are 3.582 (1)Å and 3.634 (1) Å, respectively. Thus, the three-dimensional supramolecular architecture of (I) is formed (Figure 4).

Experimental
The ligand Hpmt was prepared according to the method of Li et al., 2006. A water solution (5 ml) of ligand Hpmt (2 mmol, 0.432 g) was added dropwise to a solution of CdCl 2 . 2.5H 2 O (0.228 g, 1.0 mmol) in methanol (8 ml), then the obtained mixture was stirred at 333 K for 3 h. After that, the mixture was basified with KOH (1 mol/l) to a pH of 7.5-8.0 and continued stirring for another 4 h, filtrated. Two weeks later, colourless claviform crystals were grown from the filtrate by slow evaporation. supplementary materials sup-2 Refinement H atoms bonded to C were positioned geometrically with C-H distance of 0.93-0.97 Å, and treated as riding atoms, with U iso (H)=1.2U eq (C). The N-H hydrogen atom was located in a difference Fourier map and refined isotropically.

Poly[bis[µ 2 -2-(2-pyridylmethylamino)ethanesulfonato]cadmium(II)]
Crystal data [Cd(C 8  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 Rfactors(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