catena-Poly[calcium-bis[μ-N-(dimethylphosphinoyl)benzenesulfonamidato]]

The crystal structure of the title calcium complex, [Ca(C8H11NO5PS)2]n, is composed of a polymeric chain, which is formed due to two bridging sulfonyl groups linking CaII ions in a O—S—O—Ca manner. Thus, the coordination environment of the CaII ions is composed of six O atoms belonging to the phosphoryl and sulfonyl groups of two chelate rings and two additional O atoms of two bridging sulfonyl groups. The coordination polyhedron of the central atom (2 symmetry) has a distorted octahedral geometry.

The crystal structure of the title calcium complex, [Ca(C 8 H 11 -NO 5 PS) 2 ] n , is composed of a polymeric chain, which is formed due to two bridging sulfonyl groups linking Ca II ions in a O-S-O-Ca manner. Thus, the coordination environment of the Ca II ions is composed of six O atoms belonging to the phosphoryl and sulfonyl groups of two chelate rings and two additional O atoms of two bridging sulfonyl groups. The coordination polyhedron of the central atom (2 symmetry) has a distorted octahedral geometry.

S1. Comment
The coordination compounds of Group 2 metals with O,O -donor ligands have attracted much recent interest as potential precursors for the deposition of a range of electro-ceramic oxides by metal-organic chemical vapour deposition (MOCVD) (Wojtczak et al., 1996;Purdy et al., 1989). Various β-diketonate complexes of Group 2 have been proposed to preparation of deposit films of metals and metal oxides (Oehr et al., 1988;Berry et al., 1988).
N -Phosphorylated sulfonylamides (PS) of a general formula RSO 2 NHPO(R′) 2 can be considered as SNPheterosubstituted structural analogues of β-diketones (HAD). They may be regarded as powerful chelating systems for various metal ions and coordination chemistry of HAD remains to be relatively wide elaborated (Pietraszkiewicz et al., 2002).
The sulfonylamido-group -SO 2 NH-has been found as a key structural motif shared by a large number of bioactive compounds, spanning a wide variety of biological effects, such as antimicrobial activity, specific enzyme inhibition, hormone regulation, and among others used as chemotherapics (Anand, 1996). There are no close contacts between the neighboring chains in the crystal (Fig. 1). The molecular species [Ca(sp) 2 ] forms a polymer around the symmetry centre at x,y, z + 3/2 on calcium atom which is situated in the special position; Ca is immersed in a six-coordination environment provided by two bidentate sp-anion through sulfonyl O1 and phosphoryl O3 O atoms, and O2 of sulfonyl group connected in the bridge manner to the neighboring Ca atom. The resulting coordination polyhedron has the shape of slightly distorted octahedron with phosphoryl oxygen atoms {O3 and O3 i } occupying the axial vertexes. The values of some bond lengths and angles are given in the The chelating frame O1S1N1P1 i O3 i is almost flat: the average deviation for all these atoms does not exceed 0.11Å with the maximum deviation recorded for P1 i (0.21 Å). In spite of this, the chelated metallo-cycle as a whole has an anomalous configuration: the value of angle between chelate and the plane Ca1O1O3 i is 158.5°. SO 2 group implementing the bridge function links the two calciums in a different manner (Scheme 1.).
Moreover, the distance metal-oxygen, implicated in metal-chelate somewhat longer than intermolecular bond Ca -O, which can be explained in the terms of packing effects. This fact, in turn, did not lead to the noticeable appropriate increase in the length of SO (1.4547 (15) Å) and 1.4603 (14) Å) contacts (as always in the complex under coordination) in the comparison with theoretically identical distances in free noncoordinated ligand (Moroz et al., 2009). Another bite bond lengths and angles around the atoms of phosphorus, nitrogen and sulfur have typical values for the appropriate substituted amidophosphates and sulfamides.

S3. Refinement
All hydrogen atoms were located from electron density difference maps and included in the refinement in the riding motion approximation with U iso constrained to be 1.5 times U eq of the carrier atom for the methyl groups and 1.2 times U eq of the carrier atom for the other atoms.

Figure 1
The polymeric chain of [Ca(sp) 2 ], showing the formation of the cyclic motif (a); A view of [Ca(sp) 2 ] (b) with displacement ellipsoids shown at the 30% probability level. H atoms and C 6 H 5 groups have been omitted for clarity.

Special details
Experimental. Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. 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.