Comment

Previous work on structures related to the title compound, [Zn(S₂P(OR)₂)₂(NC₅H₄CH₂CH₂C₅H₄N)]_n, (I), has shown that when R = ⁱPr and Cy (Lai et al., 2004a), zigzag polymeric chains are found. By contrast, increasing the bulk of R to ⁱBu, results in the formation of a straight chain (Lai et al., 2004b).

The asymmetric unit in (I) comprises Zn[S₂P(OEt)₂]₂ and half each of two 1,2-di-4-pyridylethane ligands, as each of these is disposed about an inversion centre. The coordination geometry (Fig. 1) is distorted tetrahedral, with both dithiophosphate ligands coordinating in the monodentate mode. This is substantiated by the relatively narrow range of tetrahedral angles and the disparity in the P-S bond distances (Table 1). In keeping with expectation (Chen et al., 2006), the topology of the polymeric chain formed in (I) is zigzag (Fig. 2). Chains are linked via C-HS interactions (details in Table 2).

Figure 1 The asymmetric unit of (I), showing the atom-labelling scheme. Only the major component of the disorder is shown. Displacement ellipsoids are drawn at the 35% probability level (arbitrary spheres for the H atoms).

Figure 2 View of the linear polymer in (I). Colour code: Zn brown, S yellow, P pink, O red, N blue, C grey and H green.

Experimental

The title compound was prepared by refluxing the parent zinc dithiophosphate with 1,2-di-4-pyridylethane according to a literature procedure (Lai et al., 2004a). Colourless crystals of (I) were isolated by the slow evaporation of an acetonitrile/CHCl₃ (1:3) solution (m.p. 389-391 K).

Crystal data

[Zn(C4H10O2PS2)2(C12H12N2)] Mr = 620.03 Monoclinic, P 21 /c a = 11.6895 (2) Å b = 16.9503 (4) Å c = 14.6979 (3) Å = 103.599 (1)° V = 2830.6 (1) Å3 Z = 4 Mo K radiation = 1.30 mm-1 T = 120 (2) K 0.25 × 0.25 × 0.20 mm

Data collection

Bruker-Nonius 95mm KappaCCD diffractometer Absorption correction: multi-scan (SADABS; Sheldrick, 2003) Tmin = 0.829, Tmax = 1 (expected range = 0.639-0.770) 41164 measured reflections 6173 independent reflections 4828 reflections with I > 2(I) Rint = 0.043

Refinement

R[F2 > 2(F2)] = 0.042 wR(F2) = 0.142 S = 1.10 6173 reflections 307 parameters H-atom parameters constrained max = 1.00 e Å-3 min = -1.27 e Å-3

Table 1 Selected geometric parameters (Å, °) Zn-S1 2.3211 (9) Zn-S3 2.3228 (9) Zn-N1 2.048 (2) Zn-N2 2.071 (3) S1-P1 2.0153 (12) S2-P1 1.9437 (12) S3-P2 2.0174 (13) S4-P2 1.9303 (16) S1-Zn-S3 119.67 (3) S1-Zn-N1 110.85 (8) S1-Zn-N2 112.14 (8) S3-Zn-N1 114.64 (8) S3-Zn-N2 98.95 (7) N1-Zn-N2 97.59 (10)

Table 2 Hydrogen-bond geometry (Å, °) D-HA D-H HA DA D-HA C5-H5aS4i 0.99 2.80 3.770 (5) 165 C18-H18S1ii 0.95 2.87 3.805 (3) 168 Symmetry codes: (i) -x+1, -y, -z+1; (ii) .

H atoms were positioned geometrically (C-H = 0.95-0.99 Å) and refined as riding, with U_iso(H) = 1.2U_eq(C) or 1.5U_eq(methyl C). Disorder was modelled for the O4 ethyl group in that two positions were resolved for the atoms O4 and C7 [occupancy of the major component = 0.662 (9)] but not for the other atoms of this group. The atoms of the minor component were refined isotropically. The maximum and minimum residual electron-density peaks are located 0.96 and 0.78 Å, respectively, from atoms C14 and S4.

Data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: PATTY in DIRDIF92 (Beurskens et al., 1992); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2006) and ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.