Bis[2-(2-pyridylmethyleneamino)benzenesulfonato-κ3 N,N′,O]manganese(II) dihydrate

The title complex, [Mn(C12H9N2O3S)2]·2H2O, is isotypic with the previously reported ZnII and CdII species. The complex was prepared by the reaction of the potassium salt of 2-(2-pyridylmethyleneamino)benzenesulfonic acid with MnCl2·6H2O in methanol. The complex displays twofold symmetry, with the ligands coordinated in a tridentate meridional-like arrangement through pyridyl N, imine N, and sulfonate O atoms. The metal center has a strongly distorted octahedral coordination geometry. The uncoordinated water molecules and the complexes participate in a hydrogen-bonding network, forming a two-dimensional structure parallel to the ab plane.

The title complex, [Mn(C 12 H 9 N 2 O 3 S) 2 ]Á2H 2 O, is isotypic with the previously reported Zn II and Cd II species. The complex was prepared by the reaction of the potassium salt of 2-(2pyridylmethyleneamino)benzenesulfonic acid with MnCl 2 Á6H 2 O in methanol. The complex displays twofold symmetry, with the ligands coordinated in a tridentate meridional-like arrangement through pyridyl N, imine N, and sulfonate O atoms. The metal center has a strongly distorted octahedral coordination geometry. The uncoordinated water molecules and the complexes participate in a hydrogen-bonding network, forming a two-dimensional structure parallel to the ab plane.

S1. Comment
In the past decades, Schiff-base complexes containing sulfonate have received much attention owing to the diverse coordination modes and bridging ability (Zhang et al., 2005;Li et al., 2007;Ou-Yang et al., 2009) (Cai et al., 2008;Ou-Yang et al., 2008). The six-coordinated Mn II ion lies on a twofold axis, and two deprotonated PabaH anions coordinate to Mn in a meridional arrangement as N,N′,O-tridentate donor ligands. The coordination mode of the complex is similar to that observed in other complexes with N,N′,O-tridentate donor ligands (Li et al., 2007(Li et al., , 2008Correia et al., 2003).
The O-H donor groups from the lattice water molecules and the SO acceptor groups of the Paba ligands participate in the hydrogen bonding through which the complex completes a two-dimensional network parallel to the ab plane (Fig. 2).

S2. Experimental
The potassium salt of 2-(2-pyridylmethyleneamino)benzenesulfonic acid (PabaK) was synthesized according to the literature methods (Casella & Gullotti, 1986). The ligand PabaK (1 mmol, 0.30 g) was dissolved in methanol (10 ml). To this solution, MnCl 2 6 H 2 O (0.5 mmol, 0.12 g) was added, and the resulting mixture was stirred at 333 K for 4 h. Then the mixture was filtrated and the filtrate was left to stand at room temperature. Yellow crystals suitable for X-ray diffraction were obtained after a week in a yield of 55%. Elemental analysis: found C 46.87, H 4.04, N 9.05, S 10.42%; calc. C 46.94, H 3.59, N 9.13, S 10.43%.

S3. Refinement
C-bonded H atoms were positioned geometrically with C-H distances of 0.93 Å, and treated as riding atoms, with U iso (H) = 1.2 U eq (carrier C). Water H atoms were placed in fixed positions and assigned U iso values of 1.5 U eq of the water O atom.      (7) C2-C3-H3 120.6