Poly[[[μ3-3-(2-carboxylatophenyl)propionato][μ2-N,N′-(ethane-1,2-diyl)bis(pyridine-4-carboxamide)]copper(II)] monohydrate], a layered coordination polymer with (4,4) topology

A layered CuII coordination polymer with (4,4) topology was prepared by hydrothermal methods and structurally characterized by single-crystal X-ray diffraction.

In the title compound, {[Cu(C 10 H 8 O 4 )(C 14 H 14 N 4 O 2 )]•H 2 O} n , the Cu II cations are coordinated in a square-pyramidal fashion, with trans pyridyl-N donor atoms from two N- (2-(pyridin-3-ylamino) (4,4) coordination polymer grids by the full span of the cpp and pein ligands.Individual layer motifs stack in an AAA pattern along the a axis by means of interlayer hydrogen-bonding interactions.
The asymmetric unit of the title compound contains a divalent copper atom, a fully deprotonated cpp ligand, a pein ligand, and a water molecule of crystallization.The central ethylenediamine segments of the pein ligands are disordered equally over two sets of positions.The copper atoms in the title compound display an [N 2 O 3 ] square pyramidal coordination environment (Fig. 1), with trans pyridyl-N donor atoms from two pein ligands in the basal plane.The other two trans basal-plane sites are taken up by a shorter-arm carboxylate O-atom donor from a cpp ligand and a longer-arm carboxylate O atom donor from another cpp ligand; the apical site shows an elongated bond to the copper atom and is filled by a longer-arm carboxylate O-atom donor belonging to a third cpp ligand.The trigonality factor � is 0.289 (Addison et al., 1984), indicating a significant distortion from idealized square-pyramidal geometry.Relevant bond lengths and angles within the coordination environment in the title complex are listed in Table 1.
The cpp ligand in the title complex exhibits an exotridentate binding mode in which the longer carboxylate arm bridges two Cu II atoms while the shorter carboxylate group acts as a monodentate donor to a single Cu II atom.A single carboxylate oxygen donor atom from the longer cpp terminus bridges two copper atoms, connecting to a basal site on one and an apical site on the other.Pairs of these interactions construct {Cu 2 O 2 } rhomboid dimeric units with a Cu� � �Cu distance of 3.50 (1) A ˚and internal angles of 103.67 ( 7   Coordination environment in the title compound with full ligand set.Displacement ellipsoids are drawn at the 50% probability level.Only one of the disordered components in pein is shown.Color code: Cu, dark blue; O, red; N, light blue; C, black; H, pink.Symmetry codes are as listed in Table 1.
( Blatov et al., 2014;Fig. 4) by means of interlayer hydrogenbonding donation between pein N-H groups and bound shorter-arm cpp carboxylate-O atoms.Isolated water molecules of crystallization are located in small pockets in the interlamellar regions, held to the coordination polymer layers by hydrogen-bonding donation to pein C O groups.Details regarding the hydrogen bonding in the title compound are listed in Table 2.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3. Atoms C17, C18 and N3 in the pein ligand are disordered over two sites (labeled A and B), and were refined with site occupancies fixed to 1/2.This part was refined with free coordinates, with no restraints applied to the geometry or to displacement parameters.

data reports
IUCrData (2023 ethyl)isonicotinamide (pein) ligands in the basal plane.The other three coordination sites are taken up by carboxylate Oatom donors from three different 3-(2-carboxyphenyl)propionate (cpp) ligands.The central ethylenediamine segments of the pein ligands are disordered equally over two sets of positions.{Cu 2 O 2 } rhomboid clusters are connected into [Cu(cpp)(pein)] n

Figure 4 AAA
Figure 4 AAA stacking of [Cu(cpp)(pein)] n coordination polymer layers along the aaxis.O atoms belonging to unligated water molecules of crystallization are depicted as orange spheres.

Table 3
Experimental details.