Poly[[{μ2-5-[(dimethylamino)(thioxo)methoxy]benzene-1,3-dicarboxylato-κ4O1,O1′:O3,O3′}(μ2-4,4′-dipyridylamine-κ2N4:N4′)cobalt(II)] dimethylformamide hemisolvate monohydrate]

The crystal structure of the title compound shows a layered arrangement parallel to the bc plane where [CoO4N2] octahedra are linked by dmtb2– and dpa ligands.


Structure description
The controllable synthesis of coordination polymers with desired structures is always a challenging subject in crystal engineering (Chung et al., 2023;Li et al., 2021;Yang et al., 2021).In many cases, it is difficult to achieve due to the complex interplay of different factors and synthesis parameters such as the preferred coordination environment of the central metal atom, the nature of ligand(s), reaction/incorporation of solvents, temperature, metal-to-ligand ratio, pH value, pressure etc. (Sun et al., 2016(Sun et al., , 2017(Sun et al., , 2018;;Vornholt et al., 2017).
According to our previous studies (Gu et al., 2023;Sun et al., 2019), the configuration of the secondary ligand can effectively adjust the steric hindrance within the crystal structure.When Zn 2+ is coordinated by dmtb 2À {5-[(dimethylamino)thioxomethoxy]-1,3-benzenedicarboxylate} and bipy (4,4 0 -bipyridine), the (dimethylamino)thioxomethoxy group of the dmtb 2-ligand increases the steric hindrance, and a di-periodic, i.e. layered, arrangement results.The rigid bipy ligand acts as a pillar in the structural organization (Gu et al., 2023).In this context and in comparison with the former synthesis, we used the slightly larger Co 2+ cation and the more flexible 4,4 0 -dipyridylamine (dpa) ligand for the current study.As a result, the title compound, (1), with a likewise layered structural arrangement, was obtained.
The asymmetric unit of (1) (Fig. 1) comprises one cobalt(II) cation, one dmtb 2À anion, one dpa ligand, two occupationally disordered solvent water and one DMF (dimethylformamide) solvent molecules, with occupancies of 0.5 for the water molecules and of 0.25 for the DMF solvent molecule.The Co-O/ N bond lengths are in the range 2.094 (3)-2.216(3) A ˚, comparable with those reported for other related Co 2+polycarboxylate compounds (Gu et al., 2022(Gu et al., , 2023;;Zhao et al., 2024).The Co 2+ cation is six-coordinated by four oxygen atoms from two different dmtb 2-anions and two nitrogen atoms from two different dpa ligands, forming a distorted octahedral environment.The mean deviation of the equatorial plane constructed by atoms O1, O4A, O5A and N2 is 0.13 A ˚.The dmtb 2-ligand bridges two Co 2+ cations in a � 2 -� 2 : � 2 coordination mode, so that each carboxylate group of the dmtb 2-anion chelates one Co 2+ cation.The dpa ligands connect the Co 2+ cations as a ditopic linker.Accordingly, two dmtb 2-and two dpa ligands bridge the Co 2+ cations into four different directions into a layered arrangement extending parallel to the bc plane (Fig. 2).The 5-(dimethylamino)thioxomethoxy groups dangling above and below a layer protrude into adjacent layers to display an interdigitated motif (Fig. 3).The disordered water and DMF molecules are located in the voids of this arrangement.Without these solvent mol-data reports

Figure 1
The extended asymmetric unit of (1) showing the coordination environment of the Co 2+ cation.Displacement ellipsoids are drawn at the 30% probability level.The solvent water and DMF molecules are not shown for clarity.[Symmetry codes: (A) The layered arrangement extending parallel to the bc plane in the crystal structure of (1).ecules, the void volume in (1) is 19.4%.The solvent molecules are linked to the layers by classical hydrogen-bonding interactions, which includes the amino group of the dpa ligand (entries 1 and 2 in Table 1) and the water molecules (entries 4-7 in Table 1) as donor groups, and the O atoms of the DMF solvent, of the water molecules and the carboxylate O atoms as acceptor groups.A weaker non-classical hydrogen bond between a CH group of a pyridyl ring and a carboxyate O atom consolidates the crystal packing (Fig. 4).

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2.The DMF molecule was located near a symmetry center and its occupancy was fixed at 0.5.After refinement, some residual electron density peaks still existed near the DMF molecule.They were assigned to the O atoms of water molecules, both refined with occupancies of 0.5.ISOR and SIMU instructions in SHELXL (Sheldrick, 2015b) were used for these solvent molecules.Hydrogen atoms of the water molecules were included in calculated positions for obtaining reasonable hydrogen bonds and were refined in a riding-model approximation with U iso (H) = 1.5 eq (O).

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.

Table 2
Experimental details.
Computer programs: APEX2 and SAINT