Poly[dipotassium [(μ6-2,2′,2′′,2′′′-{[pyrazine-2,3,5,6-tetrayltetrakis(methylene)]tetrakis(sulfanediyl)}tetraacetato)disilver(I)] 5.2-hydrate]

The reaction of AgNO3 with the ligand 2,2′,2′′,2′′′-{[pyrazine-2,3,5,6-tetrayltetrakis(methylene)]tetrakis(sulfanediyl)}tetraacetic acid, in the presence of a potassium acetate buffer, lead to the formation of a silver(I)–potassium–organic framework.

The reaction of H 4 L1 (Pacifico & Stoeckli-Evans, 2021a) with AgNO 3 in the presence of a potassium acetate buffer resulted in deprotonation of the ligand and the formation of a heterobimetallic silver(I)-potassium-organic framework (I).
The asymmetric unit of I consists of half a binuclear silver complex, with the ligand coordinating in a bis-tetradentate manner (Fig. 1), a potassium cation and 2.6 disordered water molecules. Selected bond lengths and bond angles involving atom Ag1 are given in Table 1. The binuclear silver complex anions are linked via bridging AgÁ Á ÁSÁ Á ÁAg zigzag bonds to form a network lying parallel to the bc plane (Fig. 2) (5) and 2.466 (6) Å . Finally for the Ag-S(CH2) 2 -bond-length type there were over 1,000 hits with the bond length varying from 2.361 to 3.583 Å [mean value 2.596 (98) Å , median 2.565 Å and a skew value of 1.645]. In I the Ag-S(CH2) 2 -bond lengths vary from 2.604 (2) to 2.926 (2) Å , both values involve the bridging atom S1, while distance Ag1-S2 ii is 2.824 (2) Å (Table 1).
The three chelate rings are far from flat, as indicated by the torsion angles given in Table 1. This is also shown by the mean planes of the chelate rings calculated using PLATON (Spek, 2020): ring Ag1/N1/C2/C3/S1 is twisted on bond S1-C3, ring Ag1/N1/C2 ii /C6 ii /S2 ii has an envelope conformation with atom S2 ii as the flap, and ring Ag ii /S2/C7/C8/O4 has an envelope conformation with atom Ag1 ii as the flap [symmetry code: (ii) Àx, Ày + 1, Àz + 1].

Figure 2
A view along the a-axis of the network of the silver complex dianions in compound I. The silver atoms are shown as silver balls. For clarity, the potassium ions, the disordered water molecules, and the C-bound H atoms have been omitted.
In the crystal of I, the networks of the binuclear silver complex anions are linked by the bridging O carboxylate Á Á Á K + Á Á ÁO carboxylate bonds to form a framework ( Fig. 4; Table 1). The disordered water molecules are present near to the K + cations.

Synthesis and crystallization
The synthesis of the ligand H 4 L1 has been described (Pacifico & Stoeckli-Evans, 2021a).
Synthesis of poly{(l-2,2 0 0 0 ,2 0 0 00 0 AgNO 3 (20.5 mg, 0.121 mmol, 2 eq) and H 4 L1 (30 mg, 0.060 mmol, 1 eq) were mixed in 20 ml of a 1M potassium acetate buffer solution. The mixture was left at 323 K under stirring and nitrogen conditions for 1 h. The mixture was then filtered and left to evaporate in air for six weeks, yielding yellow rod-like crystals of compound I (m.p. 553 K decomposition).
Analysis  A view along the b-axis of the crystal packing of compound I. The silver atoms are shown as small silver balls and the potassium ions as large purple balls. The blue ellipse indicates the region occupied by the disordered water molecules. For clarity, the C-bound H atoms have been omitted.

Figure 3
A view of the environment of the potassium cation in compound I.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The occupancy factors for the disordered water molecules were initially freely refined and then fixed at rounded values; the final total is 5.2(H 2 O). It was not possible to locate the H atoms of the disordered water molecules of crystallization. The residual electron density peaks of 1.14 and À1.10 eÅ 3 are at distances of 0.96 and 0.91 Å , respectively, from atom Ag1.

data-2
IUCrData (2022). 7, x220077 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. The C-bound H atoms were included in calculated positions and treated as riding on their parent C atom: C -H = 0.99 Å with U iso (H) = 1.2U eq (C).