Coordination polymers and hydrogen-bonded assemblies of 2,2'-[2,5-bis(carb­oxy­meth­oxy)-1,4-phenyl­ene]diacetic acid with ammonium, lanthanum and zinc cations

We report the synthesis of the 2,2'-[2,5-bis­(carb­oxy­meth­oxy)-1,4-phenyl­ene]diacetic acid (TALH₄) ligand and the structures of its adducts with ammonium, namely diammonium 2,2'-[2,5-bis­(carb­oxy­meth­yl)-1,4-phenyl­enedi­oxy]diacetate, 2NH₄⁺·C₁₄H₁₂O₁₀^2-, (I), lanthanum, namely poly[[aquabis­[[mu]₄-2,2'-(2-carb­oxylato­meth­yl-5-carb­oxy­meth­yl-1,4-phenyl­enedi­oxy)diacetato]dilanthanum(III)] monohydrate], {[La₂(C₁₄H₁₁O₁₀)₂(H₂O)]·H₂O}_n, (II), and zinc cations, namely poly[[{[mu]₄-2,2'-[2,5-bis­(carb­oxy­meth­yl)-1,4-phenyl­enedi­oxy]diacetato}­zinc(II)] trihydrate], {[Zn(C₁₄H₁₂O₁₀)]·3H₂O}_n, (III), and poly[[diaqua([mu]₂-4,4'-bipyrid­yl){[mu]₄-2,2'-[2,5-bis­(carb­oxy­meth­yl)-1,4-phenyl­enedioxy]diacetato}di­zinc(II)] dihydrate], {[Zn₂(C₁₄H₁₀O₁₀)(C₁₀H₈N₂)(H₂O)₂]·2H₂O}_n, (IV), the formation of all four being associated with deprotonation of TALH₄. Adduct (I) is a diammonium salt of TALH₂^2-, with the ions located on centres of crystallographic inversion. Its crystal structure reveals a three-dimensional hydrogen-bonded assembly of the component species. Reaction of TALH₄ with lanthanum trinitrate hexa­hydrate yielded a two-dimensional double-layer coordination polymer, (II), in which the La^III cations are nine-coordinate. With zinc dinitrate hexa­hydrate, TALH₄ forms 1:1 two-dimensional coordination polymers, in which every Zn^II cation is linked to four neighbouring TALH₂^2- anions and each unit of the organic ligand is coordinated to four different tetra­hedral Zn^II cation connectors. The crystal structure of this compound accommodates mol­ecules of disordered water at the inter­face between adjacent polymeric layers to give (III), and it has been determined with low precision. Another polymer assembly, (IV), was obtained when zinc dinitrate hexa­hydrate was reacted with TALH₄ in the presence of an additional 4,4'-bipyridyl ligand. In the crystal structure of (IV), the bipyridyl and TAL^4- entities are located on two different inversion centres. The ternary coordination polymers form layered arrays with corrugated surfaces, with the Zn^II cation connectors revealing a tetra­hedral coordination environment. The two-dimensional polymers in (II)-(IV) are inter­connected with each other by hydrogen bonds involving the metal-coordinated and noncoordinated mol­ecules of water. TALH₄ is doubly deprotonated, TALH₂^2-, in (I) and (III), triply deprotonated, viz. TALH^3-, in (II), and quadruply deprotonated, viz. TAL^4-, in (IV). This report provides the first structural characterization of TALH₄ (in deprotonated form) and its various supra­molecular adducts. It also confirms the potential utility of this tetra­acid ligand in the formulation of coordination polymers with metal cations.

S1. Comment

This study is part of our exploratory search for multidentate polycarboxylic acid ligands that can be utilized, in combination with metal cations, in the construction of coordination networks (Goldberg, 2005, 2008). These ligands can be readily deprotonated to balance the charge of the metal cations they interact with (and thus enjoy electrostatic attraction to the metal centres) without the need to incorporate foreign anions into the product. Much current research activity has been directed towards the programmed synthesis of open metal–organic frameworks (MOFs) in view of their potential utility in gas storage (e.g. Eddaoudi et al., 2002). Divergent disposition of the carboxylic acid sensor groups substituted on rigid aromatic backbones was found to be a crucial element in the design of microporous solids (Rossi et al., 2005; Eddaoudi et al., 2002). In this context, the present work expands in particular on earlier studies with the tetrafunctional ligand benzene-1,2,4,5-tetracarboxylic acid (e.g. Fabelo et al., 2006; Ghosh & Bharadwaj, 2004). We use the same aromatic backbone (the benzene ring) but with longer carboxylic acid substituents, by introducing in TALH₄ –CH₂– and –OCH₂– spacers between the acid groups and the benzene ring. By doing so, our design also imparts some additional conformational flexibility to the organic component, due to the aliphatic nature of the added spacer groups. It was anticipated that the –COOH functions in this ligand may orient in different directions, in and out of the plane of the aromatic core, and thus direct possible coordination to potential metal cation connectors in two- and three-dimensions to yield TALH₄-based robust metal–organic networks and frameworks.

Compound (I) was formed by serendipity, while attempting to coordinate TALH₄ to cadmium(II) cations in a mildly basic environment of ammonium hydroxide. It represents a 2:1 NH₄⁺–TALH₂^2- hydrogen-bonded trimer, with the organic ligand entities located on centres of inversion (Fig. 1). The nearly linear N—H···O hydrogen-bonding interactions are associated with double deprotonation of TALH₄, which occurs preferentially on the two more acidic carboxylic acid functions in the carboxymethoxy residues. As a result, the TALH₂^2- anion, which bears two carboxylate H-atom acceptors and two carboxylic acid H-atom donor groups is self-complimentary for hydrogen bonding (Table 1). Correspondingly, every TALH₂^2- unit associates via O—H···^-OOC charge-assisted hydrogen bonds to four neighbouring TALH₂^2- ligands. In addition, the two carboxylate functions interact via NH₄⁺···^-OOC hydrogen bonds with six adjacent ammonium cations (Fig. 2). The tetrahedral tetradentate functionality of the latter allows it to form hydrogen bonds to two carboxylate functionalities of a given ligand (Fig. 1), as well as to the carboxylate functions of two other ligands (Table 1). The supramolecular charge-assisted hydrogen bonding between the component species extends throughout the crystal structure in three dimensions (Fig. 2). Electrostatic interactions between the charged components further stabilize the three-dimensionally interlinked supramolecular assembly in (I). The structures of ammonium salts of the closely related benzene-1,2,4,5-tetracarboxylic acid reveal similar N—H···O and O—H···O hydrogen-bonding interactions between the component species (Dutkiewicz et al., 2007; Bergstrom et al., 2000; Jessen et al., 1992).

Reaction of the lanthanum salt with TALH₄ led to the formation of a two-dimensional coordination polymer of 1:1 La³⁺:TALH^3- stoichiometry, (II) (Fig. 3). The two crystallographically independent metal cations that form a dinuclear cluster are nine-coordinate (Table 2). Atom La1 coordinates to six carboxylate groups of different TALH^3- anions in a monodentate fashion, to another carboxylate group in a bidentate fashion, and also to the ether-O site of one of the ligands. Atom La2 coordinates to five carboxylate groups of adjacent TALH^3- anions in a monodentate fashion, to another carboxylate group in a bidentate fashion, to an ether-O site of one of the ligands, and finally to a water molecule (Table 2). In the resulting coordination network, adjacent La^III cations (whether within the dinuclear cluster or between clusters) are bridged by several organic ligands. This leads to the formation of robust polymeric arrays which extend parallel to the (101) plane of the crystal structure, in which the TALH^3- components are arranged in two layers, due to the multiple coordination capacity of the inorganic connectors and the spatial disposition of their coordination valencies (Fig. 4). The layered assemblies have corrugated surfaces lined with the metal-coordinated water molecules and the –COOH residues. In the crystal structure, the double-layer polymeric networks are held together by an extensive array of O—H···O hydrogen bonds, which involves the H atoms of the metal-coordinated water ligand O49, the carboxylic acid functions OH23 and OH48, and the non-coordinated water molecules O50 trapped in the structure (Table 3). The observed multiple coordination pattern of the oxophilic La^III cations to carboxylic acid/carboxylate/water ligands, within the range La—O = 2.4–2.7 Å, is similar to earlier documented findings in polymeric networks incorporating La³⁺ cations and deprotonated pyrromellitic acid anions (Wen et al., 2004; Chui et al., 2001; Wu et al., 1996).

A similar reaction between the tetraacid ligand and a zinc salt also resulted in the formation of a coordination polymer with two-dimensional connectivity, (III) (Fig. 5). In the layered arrays, rows of the TALH₂^2- ligand alternate with rows of the Zn^II cation connectors in both directions (Fig. 6). The latter are characterized by a tetrahedral coordination environment, linking in a monodentate manner to the carboxylate/carboxylic acid groups of four neighbouring ligands (Table 4). Each pair of neighbouring Zn^II cations in the layer is bridged by two ligand anions. The layered arrays are oriented perpendicular to the b axis of the crystal, being centred at y = 1/4 and 3/4. Although the Zn^II cation connectors are characterized by a tetrahedral coordination geometry, the observed coordination pattern is limited to two dimensions, the coordination directionality of the Zn^II cations not being matched by a complimentary spatial disposition of the COO/COOH ligating sites in the organic ligand. Rather, the adapted conformation of the aliphatic arms in TALH₂^2- minimizes the empty space within the coordinated layer (Fig. 6). Noncoordinated water molecules are intercalated between the coordination layers in zones centred at y = 0 and 1/2, and form hydrogen bonds between them. However, due to the poor quality of the crystals, associated with severe disorder of the crystallization solvent, these interactions could not be characterized reliably. The low quality of the diffraction data in this case is also affected by possible orientational in-layer disorder of the TALH₂^2- anions, which have a nearly square shape and a similar coordination environment in the four lateral directions. Considering also the loose packing of the layers along the normal axis, a random interchange between the positions of the –CH₂COO/-CH₂COOH and –OCH₂COO/-OCH₂COOH groups (the H atoms of these fragments could not be located) in selected/fault sites of the crystal structure cannot be excluded.

Zinc cations are known to be well coordinated by ligands with both O- and N- ligating sites. Correspondingly, on addition of the 4,4'-bipyridyl reagent (bpy) to the reaction mixture of zinc dinitrate and TALH₄, the two ligands may compete for coordination sites on the metal core. Indeed, compound (IV) represents a ternary product of 2:1:1 Zn²⁺:TAL^4-:bpy stoichiometry (Fig. 7), where the two multidentate organic linkers (which reside on two different inversion centres) are coordinated to the metal. The Zn^II cation connectors reveal a tetrahedral coordination geometry, each associated with the carboxylate groups of two neighbouring TAL^4- ligands (in a monodentate mode), the N-site of the bpy component and a molecule of water (Table 5). The TAL^4- tetraanion is linked simultaneously in the lateral directions to four different Zn^II cations, while the bidentate bpy ligand bridges two Zn^II cation nodes. As illustrated in Fig. 8, this results in the formation of two-dimensional coordination networks aligned parallel to the (210) plane of the crystal structure. The metal-bound water ligands are oriented perpendicular to the network mean plane in alternating directions. The thin shape of the bpy linkers in the grid networks creates open voids between them, which are penetrated from above and below by the O13 metal-bound water ligands of adjacent layers. In addition, non-coordinated water species O20 are accommodated between the layers. The two water molecules form bridges by hydrogen bonding between the interpentrating coordination networks (Table 6).

Coordination polymers sustained by zinc–carboxylate coordination synthons are abundant in the literature. The observed Zn—O and Zn—N coordination distances (Tables 4 and 5) are in the normally expected ranges for such polymeric compounds, as confirmed by a survey of Cambridge Structural Database (CSD, Version 5.31, May 2010 update; Allen, 2002). Among these related polymeric compounds, recent references to zinc–pyromellitate coordination compounds (Lu et al., 2005; Wang et al., 2007) and to those also incorporating the bpy ligand (Wu et al., 2001; Huang et al., 2009) are of particular relevance.

In summary, we have reported here the synthesis of a new tetracarboxylic acid ligand, TALH₄, and demonstrated its capacity to form coordination networks with metal cations. In spite of the conformational flexibility imparted to this ligand by inserting aliphatic spacers between the aromatic core and the four diverging –COOH groups, the formation of only two-dimensional coordination polymers has been observed so far. However, the coordination polymerization in (II)–(IV) is supplemented by hydrogen-bonding interactions along the third dimension.

Related literature

For related literature, see: Allen (2002); Bergstrom et al. (2000); Chui et al. (2001); Dutkiewicz et al. (2007); Eddaoudi et al. (2002); Fabelo et al. (2006); Ghosh & Bharadwaj (2004); Goldberg (2005, 2008); Huang et al. (2009); Jessen et al. (1992); Lu et al. (2005); Rossi et al. (2005); Spek (2009); Wang et al. (2007); Wen et al. (2004); Wu et al. (1996, 2001).

S2. Experimental

The tetraacid ligand was obtained in a three-step procedure. First, commercially available 2,5-dihydroxy-1,4-benzenediacetic acid (0.5 g, 2.21 mmol) was dissolved in absolute EtOH (50 ml), sulfuric acid (4 ml) was added dropwise, and the mixture was refluxed overnight. The solution was then evaporated and extracted with dichloromethane. The organic extracts were collected over anhydrous sodium sulfate. Subsequent removal of the solvent gave the diethyl-2,2'-(2,5-dihydroxy-1,4-phenylene)diacetate intermediate A in 85% yield. In the second step, a mixture of A (450 mg, 4.6 mmol), methyl bromoacetate (520 mg, 3.4 mmol) and potassium carbonate (630 mg, 4.6 mmol) was dissolved in acetone (50 ml) and refluxed for 5 h at 333 K. The resulting mixture was filtered and the residue dissolved in water to remove unreacted potassium carbonate. Intermediate B, 2,2'-[2,5-bis(2-methoxy-2-oxoethoxy)-1,4-phenylene]diacetate, was isolated by filtration and dried in vacuo (yield 61%). It was then dissolved in methanol (20 ml), 5 N NaOH (3 ml) was added, and the mixture was refluxed overnight. After removal of the reaction solvent by evaporation, the crude product was treated with 0.5 N HCl, washed with water and dried in vacuo, yielding a white precipitate (in 72% yield) as the final tetraacid product, 2,2'-[2,5-bis(carboxymethoxy)-1,4-phenylene]diacetic acid (TALH₄). ¹H NMR (DMSO-d⁶, δ, p.p.m.): 12.53 (bs, 4H, –COOH), 6.81 (s, 2H, Ar—H), 4.56 (s, 4H, –OCH₂), 3.53 (s, 4H, –CH₂).

Compound (I) was obtained by dissolving TALH₄ (5 mg, 0.015 mmol) and cadmium dinitrate tetrahydrate (9 mg, 0.03 mmol) in water (4 ml), with a few drops of ammonium hydroxide to assist in deprotonation of TALH₄. The mixture was heated for 2 d in a bath reactor at 353 K, to yield colourless crystals of (I) after gradual cooling to room temperature. It turned out that under the given experimental conditions the cadmium cations did not react with TALH₄, and instead the diaammonium salt of the acid was formed. FT–IR (KBr, ν, cm^-1): 2963 (bs), 1716 (s), 1525 (s), 1416 (s), 1340 (b), 1301 (b), 1218 (b), 1158 (b), 1091 (s), 896 (b), 721 (s), 678 (s), 628 (s), 564 (s), 441 (s).

Compound (II) was obtained by dissolving TALH₄ (3.3 mg, 0.01 mmol) and lanthanum trinitrate hexahydrate (8.2 mg, 0.02 mmol) in water (7 ml). This solution was placed in a sealed and tightly capped vessel, which was heated for 2 d at 393 K in a bath reactor. Colourless crystals of (II) precipitated in the reactor. FT–IR (KBr, ν, cm^-1): 3419 (bs), 2925 (s), 1584 (s), 1512 (s), 1391 (s), 1335 (s), 1210 (s), 1053 (s), 645 (bs).

In a similar procedure, TALH₄ (20 mg, 0.06 mmol) and zinc dinitrate hexahydrate (30 mg, 0.12 mmol) were dissolved in a 2:1:1 MeOH:DMF:water mixture (DMF is dimethylformamide) (4 ml) and heated for 2 d in a bath reactor at 373 K, yielding (III) as a colourless crystalline product. FT–IR (KBr, ν, cm^-1): 3193 (bs), 1610 (s), 1511 (s), 1403 (s), 1306 (s), 1270 (s), 1207 (s), 1083 (s), 943 (s), 788 (s), 703 (s), 649 (s), 608 (s).

In another experiment, TALH₄ (10 mg, 0.03 mmol), zinc dinitrate hexahydrate (18 mg, 0.06 mmol) and 4,4'-bipyridyl (5 mg, 0.03 mmol) were dissolved in a 6:2:1 MeOH:DMF:water mixture (4.5 ml). After heating the mixture for 2 d in a bath reactor at 373 K, followed by slow evaporation at room temperature for two weeks, X-ray quality colourless crystals of compound (IV) were obtained. FT–IR (KBr, ν, cm^-1): 3392 (bs), 1602 (s), 1388 (s), 1216 (s), 1077 (s), 733 (s).

S3. Refinement

In (I), the atomic coordinates of all the H atoms, initially included in calculated positions or located in difference Fourier maps, were refined, but with U_iso = 1.2U_eq(C) for H atoms bound to C atoms, and U_iso = 1.5U_eq(O, N) for H atoms bound to O and N atoms. In compounds (II)–(IV), H atoms bound to C atoms were included in calculated positions and constrained to ride on their parent atoms, with C—H = 0.95 and 0.99 Å and with U_iso(H) = 1.2U_eq(C). Those bound to O atoms were either located in difference Fourier maps or placed in calculated positions to correspond to idealized hydrogen-bonding geometries, with O—H = 0.79–1.00 Å. Their atomic positions were not refined, and they were constrained to ride on their parent atoms with U_iso(H) = 1.5U_eq(O).

Compound (III) is a trihydrate of a 1:1 zinc:TALH₂^2- adduct. It could be readily recognized by inspection of the difference Fourier map that the water molecules form hydration layers at the interface between the coordination networks. However, they were found to be severely disordered and could not be reliably modelled as discrete O and H atoms. Their contribution to the diffraction pattern was subtracted by the SQUEEZE procedure in PLATON (Spek, 2009). The total solvent-accessible void volume and the residual electron-density count in the unit cell were assessed by PLATON to be 270 ų and 86 e, respectively, which may correspond approximately to the presence of nearly three water molecules in the asymmetric unit, although independent evidence to this end could not be obtained. Moreover, the atoms of the TALH₂^2- anion exhibit large-amplitude in-plane atomic displacement parameters, and the H atoms of the –COOH residues could not be located. The disordered water solvent and these two H atoms have been included in the chemical formula and all values derived from it. The maximum residual electron-density peaks in (III) are near the peripheral aliphatic arms: 1.33 e Å^-3 at (0.036, 0.351, 0.631) and 1.01 e Å^-3 at (0.045, 0.355, 0.294). Correspondingly, the structure of this product could not be determined with high precision comparable with that of structures (I), (II) and (IV). It was included in this report for the sake of completeness.

Five residual peaks above 1.0 e Å^-3 were found in (II) near the aliphatic fragments and water species: 1.69 e Å^-3 at (0.426, 0.456, 0.424), 1.67 e Å^-3 at (0.468, 0.787, 0.028), 1.56 e Å^-3 at (0.305, 0.059, 0.039), 1.49 e Å^-3 at (0.460, 0.822, 0.099) and 1.47 e Å^-3 at (0.251, 0.301, 0.698).

Computing details

For all compounds, data collection: COLLECT (Nonius, 1999); cell refinement: DENZO (Otwinowski & Minor, 1997); data reduction: DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-labelling scheme. The TALH2^2- anions are located on centres of inversion, and only atoms in the asymmetric unit are labelled. Displacement ellipsoids are drawn at the 50% probability level at 110 (2) K and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are denoted by dashed lines.
	Fig. 2. The crystal structure of (I). Intermolecular hydrogen bonds are indicated by dashed lines. Note that the TALH2^2- anion is linked to four neighbouring TALH2^2- anions and six ammonium cations. H atoms have been omitted.
	Fig. 3. The molecular structure of (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level at 110 (2) K. The hydrogen bond is denoted by dashed lines. H atoms have been omitted.
	Fig. 4. A view of the layered coordination polymer in (II), aligned parallel to the (101) plane of the crystal structure, along with the noncoordinated molecules of water located in the interstitial voids. The La^III cations and water molecules in the otherwise wireframe illustration are denoted by small spheres.
	Fig. 5. The molecular structure of (III), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level at 110 (2) K. H atoms have been omitted. Note the large-amplitude atomic displacement parameters, possibly indicating some orientational disorder of the organic ligand in this structure.
	Fig. 6. A face-on view of the layered coordination polymer in (III), aligned perpendicular to the b axis of the crystal structure. The disordered molecules of water located in the interfacial zones between neighbouring polymers are not shown. The Zn^II cations are depicted as small spheres.
	Fig. 7. The molecular structure of (IV), showing the atom-labelling scheme. The TAL^4- anion and bpy ligand are located on centres of inversion, and only atoms in the asymmetric unit are labelled. Displacement ellipsoids are drawn at the 50% probability level at 110 (2) K. Hydrogen bonds to noncoordinated water molecules are denoted by dashed lines. H atoms have been omitted.
	Fig. 8. The layered ternary coordination polymer in (IV). The Zn^II cations and water molecules are indicated by small spheres. Note that the metal-bound water ligands are oriented in an alternating manner (either up or down) perpendicular to the layered arrays. The noncoordinated water molecules occupy interstitial voids within and between the layers.

(I) diammonium 2,2'-[2,5-bis(carboxymethyl)-1,4-phenylenedioxy]diacetate

Crystal data

2NH4^+·C14H12O10^2^−	F(000) = 396
Mr = 376.32	Dx = 1.576 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 4.8188 (3) Å	Cell parameters from 1652 reflections
b = 14.6889 (8) Å	θ = 2.3–26.3°
c = 11.2087 (8) Å	µ = 0.14 mm^−1
β = 91.855 (2)°	T = 110 K
V = 792.97 (9) Å^3	Needle, colourless
Z = 2	0.40 × 0.15 × 0.15 mm

Data collection

Nonius KappaCCD area-detector diffractometer	1243 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.051
Graphite monochromator	θmax = 26.3°, θmin = 2.3°
Detector resolution: 12.8 pixels mm^-1	h = 0→6
1 deg. ϕ and ω scans	k = 0→18
9862 measured reflections	l = −13→13
1598 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.102	Only H-atom coordinates refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0487P)^2 + 0.3554P] where P = (Fo^2 + 2Fc^2)/3
1598 reflections	(Δ/σ)max = 0.003
148 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Special details

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.8294 (4)	0.04845 (12)	0.07567 (17)	0.0166 (4)
C2	0.8154 (4)	0.06322 (13)	−0.04671 (17)	0.0168 (4)
H2	0.696 (5)	0.1067 (15)	−0.0789 (19)	0.020*
C3	1.0173 (4)	−0.01523 (12)	0.12399 (17)	0.0168 (4)
O4	0.6641 (3)	0.09384 (8)	0.15602 (11)	0.0181 (3)
C5	0.4886 (4)	0.16176 (13)	0.10272 (18)	0.0183 (4)
H5A	0.378 (5)	0.1356 (14)	0.039 (2)	0.022*
H5B	0.606 (5)	0.2098 (15)	0.0682 (19)	0.022*
C6	0.2924 (4)	0.20441 (12)	0.19049 (17)	0.0173 (4)
O7	0.1458 (3)	0.26711 (9)	0.14113 (12)	0.0214 (3)
O8	0.2751 (3)	0.17838 (9)	0.29544 (12)	0.0200 (3)
C9	1.0489 (4)	−0.03077 (13)	0.25620 (18)	0.0185 (4)
H9A	1.074 (4)	0.0274 (15)	0.2995 (19)	0.022*
H9B	1.220 (5)	−0.0699 (14)	0.2726 (19)	0.022*
C10	0.8145 (4)	−0.08245 (12)	0.31195 (17)	0.0186 (4)
O11	0.7183 (3)	−0.15015 (9)	0.24562 (12)	0.0216 (3)
H11	0.567 (5)	−0.1823 (15)	0.287 (2)	0.032*
O12	0.7324 (3)	−0.06467 (9)	0.41152 (12)	0.0249 (4)
N13	0.7511 (4)	0.13651 (13)	0.42955 (17)	0.0211 (4)
H13A	0.714 (5)	0.1672 (16)	0.500 (2)	0.032*
H13B	0.596 (6)	0.1456 (16)	0.380 (2)	0.032*
H13C	0.753 (5)	0.0723 (18)	0.443 (2)	0.032*
H13D	0.915 (6)	0.1590 (15)	0.393 (2)	0.032*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0130 (9)	0.0159 (9)	0.0210 (10)	−0.0018 (7)	0.0043 (8)	−0.0019 (7)
C2	0.0140 (10)	0.0149 (9)	0.0215 (10)	−0.0004 (8)	0.0009 (8)	0.0027 (8)
C3	0.0150 (10)	0.0146 (9)	0.0208 (10)	−0.0024 (7)	0.0018 (8)	0.0007 (7)
O4	0.0180 (7)	0.0178 (7)	0.0185 (7)	0.0053 (5)	0.0014 (5)	0.0003 (5)
C5	0.0189 (11)	0.0176 (10)	0.0183 (10)	0.0017 (8)	0.0002 (8)	0.0014 (8)
C6	0.0160 (10)	0.0165 (9)	0.0193 (10)	−0.0019 (8)	−0.0002 (8)	0.0003 (8)
O7	0.0225 (8)	0.0208 (7)	0.0211 (7)	0.0059 (6)	0.0026 (6)	0.0028 (5)
O8	0.0188 (8)	0.0212 (7)	0.0199 (7)	0.0010 (6)	0.0021 (6)	0.0007 (6)
C9	0.0172 (10)	0.0183 (10)	0.0201 (10)	0.0004 (8)	0.0018 (8)	0.0007 (8)
C10	0.0187 (10)	0.0193 (9)	0.0178 (10)	0.0027 (8)	−0.0010 (8)	0.0022 (8)
O11	0.0235 (8)	0.0207 (7)	0.0207 (7)	−0.0058 (6)	0.0035 (6)	−0.0021 (6)
O12	0.0276 (8)	0.0266 (8)	0.0209 (8)	−0.0036 (6)	0.0058 (6)	−0.0007 (6)
N13	0.0211 (10)	0.0238 (9)	0.0185 (9)	0.0018 (8)	0.0012 (8)	−0.0024 (7)

Geometric parameters (Å, º)

C1—C2	1.388 (3)	C6—O7	1.276 (2)
C1—O4	1.392 (2)	C9—C10	1.513 (3)
C1—C3	1.399 (3)	C9—H9A	0.99 (2)
C2—C3^i	1.394 (3)	C9—H9B	1.02 (2)
C2—H2	0.92 (2)	C10—O12	1.224 (2)
C3—C2^i	1.394 (3)	C10—O11	1.317 (2)
C3—C9	1.502 (3)	O11—H11	0.99 (2)
O4—C5	1.426 (2)	N13—H13A	0.93 (3)
C5—C6	1.522 (3)	N13—H13B	0.93 (3)
C5—H5A	0.96 (2)	N13—H13C	0.96 (3)
C5—H5B	0.99 (2)	N13—H13D	0.96 (3)
C6—O8	1.242 (2)
C2—C1—O4	123.64 (17)	O7—C6—C5	111.33 (16)
C2—C1—C3	119.82 (17)	C3—C9—C10	115.51 (16)
O4—C1—C3	116.54 (16)	C3—C9—H9A	111.1 (12)
C1—C2—C3^i	121.63 (18)	C10—C9—H9A	108.3 (12)
C1—C2—H2	120.2 (13)	C3—C9—H9B	108.7 (12)
C3^i—C2—H2	118.1 (13)	C10—C9—H9B	104.6 (12)
C2^i—C3—C1	118.54 (18)	H9A—C9—H9B	108.2 (18)
C2^i—C3—C9	119.61 (17)	O12—C10—O11	123.89 (18)
C1—C3—C9	121.82 (17)	O12—C10—C9	122.49 (17)
C1—O4—C5	114.08 (14)	O11—C10—C9	113.55 (16)
O4—C5—C6	112.93 (16)	C10—O11—H11	110.2 (13)
O4—C5—H5A	109.9 (13)	H13A—N13—H13B	106 (2)
C6—C5—H5A	107.7 (13)	H13A—N13—H13C	110 (2)
O4—C5—H5B	108.9 (13)	H13B—N13—H13C	104 (2)
C6—C5—H5B	109.5 (12)	H13A—N13—H13D	112 (2)
H5A—C5—H5B	107.7 (18)	H13B—N13—H13D	111 (2)
O8—C6—O7	125.44 (17)	H13C—N13—H13D	114 (2)
O8—C6—C5	123.20 (17)

Symmetry code: (i) −x+2, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H11···O7^ii	0.99 (2)	1.52 (2)	2.5123 (19)	175 (2)
N13—H13A···O7^iii	0.93 (3)	1.89 (3)	2.822 (2)	178 (2)
N13—H13B···O8	0.93 (3)	1.85 (3)	2.771 (2)	171 (2)
N13—H13C···O12	0.96 (3)	2.05 (3)	2.963 (2)	160 (2)
N13—H13D···O8^iv	0.96 (3)	2.10 (3)	3.043 (2)	167 (2)

Symmetry codes: (ii) −x+1/2, y−1/2, −z+1/2; (iii) x+1/2, −y+1/2, z+1/2; (iv) x+1, y, z.

(II) poly[[aquabis[µ₄-2,2'-(2-carboxylatomethyl-5-carboxymethyl-1,4- phenylenedioxy)diacetato]dilanthanum(III)] monohydrate]

Crystal data

[La2(C14H11O10)2(H2O)]·H2O	Z = 2
Mr = 992.31	F(000) = 968
Triclinic, P1	Dx = 2.118 Mg m^−3
a = 10.2508 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.1655 (3) Å	Cell parameters from 6510 reflections
c = 14.7606 (4) Å	θ = 2.0–27.2°
α = 79.5944 (12)°	µ = 2.81 mm^−1
β = 82.1510 (12)°	T = 110 K
γ = 69.9402 (17)°	Plate, colourless
V = 1555.74 (7) Å^3	0.15 × 0.15 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer	6850 independent reflections
Radiation source: fine-focus sealed tube	5610 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.062
Detector resolution: 12.8 pixels mm^-1	θmax = 27.2°, θmin = 2.0°
1 deg. ϕ and ω scans	h = 0→13
Absorption correction: multi-scan (Blessing, 1995)	k = −13→14
Tmin = 0.678, Tmax = 0.766	l = −18→18
25631 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.089	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0491P)^2 + 1.7278P] where P = (Fo^2 + 2Fc^2)/3
6850 reflections	(Δ/σ)max < 0.001
470 parameters	Δρmax = 1.69 e Å^−3
0 restraints	Δρmin = −1.78 e Å^−3

Special details

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
La1	−0.01271 (2)	−0.18754 (2)	0.164737 (15)	0.00868 (8)
La2	0.27791 (2)	0.68201 (2)	0.368677 (15)	0.00916 (8)
C1	−0.1622 (4)	0.1341 (4)	0.2239 (3)	0.0113 (8)
C2	−0.1260 (4)	0.1276 (4)	0.3124 (3)	0.0111 (8)
C3	−0.0883 (4)	0.2291 (4)	0.3312 (3)	0.0115 (9)
H3	−0.0650	0.2281	0.3915	0.014*
C4	−0.0845 (4)	0.3304 (4)	0.2633 (3)	0.0113 (9)
C5	−0.1203 (5)	0.3360 (4)	0.1741 (3)	0.0134 (9)
C6	−0.1599 (5)	0.2366 (4)	0.1551 (3)	0.0145 (9)
H6	−0.1854	0.2386	0.0952	0.017*
O7	−0.1955 (3)	0.0308 (3)	0.2035 (2)	0.0128 (6)
C8	−0.3343 (5)	0.0646 (4)	0.1743 (3)	0.0171 (10)
H8A	−0.3410	0.1178	0.1127	0.021*
H8B	−0.4033	0.1153	0.2185	0.021*
C9	−0.3644 (5)	−0.0571 (4)	0.1704 (3)	0.0154 (9)
O10	−0.4758 (4)	−0.0471 (3)	0.1426 (2)	0.0236 (8)
O11	−0.2697 (3)	−0.1635 (3)	0.1960 (2)	0.0156 (7)
C12	−0.1268 (4)	0.0148 (4)	0.3865 (3)	0.0115 (8)
H12A	−0.2071	−0.0125	0.3803	0.014*
H12B	−0.1398	0.0430	0.4479	0.014*
C13	0.0057 (4)	−0.0995 (4)	0.3814 (3)	0.0100 (8)
O14	0.0619 (3)	−0.1294 (3)	0.3019 (2)	0.0121 (6)
O15	0.0598 (3)	−0.1639 (3)	0.45328 (19)	0.0149 (7)
O16	−0.0452 (4)	0.4320 (3)	0.2750 (2)	0.0188 (7)
C17	−0.0140 (5)	0.4403 (4)	0.3647 (3)	0.0114 (9)
H17A	0.0684	0.3667	0.3847	0.014*
H17B	−0.0940	0.4394	0.4105	0.014*
C18	0.0153 (4)	0.5667 (4)	0.3565 (3)	0.0107 (8)
O19	−0.0590 (3)	0.6636 (3)	0.3064 (2)	0.0135 (6)
O20	0.1095 (3)	0.5653 (3)	0.4034 (2)	0.0139 (6)
C21	−0.1016 (5)	0.4405 (4)	0.0977 (3)	0.0180 (10)
H21A	−0.0023	0.4156	0.0740	0.022*
H21B	−0.1563	0.4440	0.0464	0.022*
C22	−0.1437 (5)	0.5730 (4)	0.1238 (3)	0.0154 (9)
O23	−0.2706 (3)	0.6174 (3)	0.1611 (2)	0.0216 (7)
H23	−0.2766	0.7035	0.1746	0.032*
O24	−0.0637 (3)	0.6367 (3)	0.1045 (2)	0.0153 (7)
C25	0.3786 (4)	0.3580 (4)	0.2885 (3)	0.0108 (8)
C26	0.3683 (4)	0.3818 (4)	0.1940 (3)	0.0119 (9)
C27	0.3203 (5)	0.3018 (4)	0.1542 (3)	0.0123 (9)
H27	0.3128	0.3163	0.0894	0.015*
C28	0.2833 (4)	0.2004 (4)	0.2092 (3)	0.0109 (8)
C29	0.2958 (4)	0.1776 (4)	0.3048 (3)	0.0119 (9)
C30	0.3432 (4)	0.2578 (4)	0.3435 (3)	0.0128 (9)
H30	0.3514	0.2437	0.4082	0.015*
O31	0.4243 (3)	0.4408 (3)	0.3298 (2)	0.0135 (6)
C32	0.5502 (5)	0.3727 (4)	0.3742 (3)	0.0171 (10)
H32A	0.6238	0.3288	0.3292	0.021*
H32B	0.5342	0.3066	0.4248	0.021*
C33	0.5958 (4)	0.4669 (4)	0.4125 (3)	0.0120 (9)
O34	0.6873 (3)	0.4222 (3)	0.46879 (19)	0.0135 (6)
O35	0.5383 (3)	0.5860 (3)	0.3862 (2)	0.0152 (7)
C36	0.3982 (5)	0.4968 (4)	0.1346 (3)	0.0127 (9)
H36A	0.4241	0.4799	0.0699	0.015*
H36B	0.4770	0.5118	0.1573	0.015*
C37	0.2685 (4)	0.6150 (4)	0.1391 (3)	0.0116 (9)
O38	0.2174 (3)	0.6453 (3)	0.21916 (19)	0.0123 (6)
O39	0.2113 (3)	0.6777 (3)	0.0681 (2)	0.0173 (7)
O40	0.2319 (3)	0.1198 (3)	0.1767 (2)	0.0142 (6)
C41	0.2226 (5)	0.1351 (4)	0.0796 (3)	0.0113 (9)
H41A	0.3172	0.1151	0.0474	0.014*
H41B	0.1689	0.2255	0.0572	0.014*
C42	0.1514 (5)	0.0458 (4)	0.0583 (3)	0.0123 (9)
O43	0.1411 (3)	−0.0471 (3)	0.1173 (2)	0.0130 (6)
O44	0.1086 (3)	0.0722 (3)	−0.0210 (2)	0.0159 (7)
C45	0.2572 (5)	0.0688 (4)	0.3650 (3)	0.0138 (9)
H45A	0.1928	0.0456	0.3325	0.017*
H45B	0.2057	0.1003	0.4225	0.017*
C46	0.3772 (5)	−0.0517 (4)	0.3911 (3)	0.0136 (9)
O47	0.3563 (3)	−0.1534 (3)	0.4255 (2)	0.0167 (7)
O48	0.5010 (3)	−0.0408 (3)	0.3770 (2)	0.0223 (8)
H48	0.5610	−0.1134	0.3899	0.033*
O49	0.3572 (3)	0.8184 (3)	0.2314 (2)	0.0205 (7)
H49A	0.4088	0.8589	0.2195	0.031*
H49B	0.3004	0.8634	0.1957	0.031*
O50	0.6828 (3)	−0.2582 (3)	0.4140 (2)	0.0181 (7)
H50A	0.7559	−0.2754	0.3705	0.027*
H50B	0.6404	−0.3157	0.4098	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
La1	0.01107 (13)	0.00782 (13)	0.00833 (13)	−0.00415 (10)	−0.00370 (9)	0.00016 (9)
La2	0.01044 (13)	0.00827 (13)	0.00985 (13)	−0.00381 (10)	−0.00407 (9)	−0.00012 (9)
C1	0.012 (2)	0.008 (2)	0.015 (2)	−0.0033 (17)	−0.0032 (17)	−0.0031 (17)
C2	0.008 (2)	0.013 (2)	0.012 (2)	−0.0039 (17)	−0.0002 (16)	−0.0001 (17)
C3	0.016 (2)	0.011 (2)	0.010 (2)	−0.0053 (17)	−0.0013 (16)	−0.0030 (16)
C4	0.012 (2)	0.011 (2)	0.014 (2)	−0.0067 (17)	−0.0041 (17)	0.0003 (17)
C5	0.018 (2)	0.017 (2)	0.009 (2)	−0.0089 (19)	−0.0033 (17)	−0.0025 (17)
C6	0.014 (2)	0.014 (2)	0.016 (2)	−0.0050 (18)	−0.0059 (18)	0.0004 (18)
O7	0.0139 (16)	0.0096 (15)	0.0176 (15)	−0.0048 (12)	−0.0065 (12)	−0.0031 (12)
C8	0.012 (2)	0.017 (2)	0.025 (2)	−0.0048 (19)	−0.0073 (18)	−0.0044 (19)
C9	0.016 (2)	0.014 (2)	0.016 (2)	−0.0050 (19)	−0.0050 (18)	0.0020 (17)
O10	0.0190 (18)	0.0192 (17)	0.037 (2)	−0.0097 (15)	−0.0117 (15)	−0.0002 (15)
O11	0.0154 (16)	0.0096 (15)	0.0221 (17)	−0.0040 (13)	−0.0042 (13)	−0.0012 (13)
C12	0.010 (2)	0.013 (2)	0.010 (2)	−0.0019 (17)	−0.0009 (16)	−0.0013 (16)
C13	0.013 (2)	0.012 (2)	0.010 (2)	−0.0097 (17)	−0.0026 (16)	−0.0015 (16)
O14	0.0123 (15)	0.0115 (15)	0.0124 (15)	−0.0031 (12)	−0.0029 (12)	−0.0014 (12)
O15	0.0187 (17)	0.0161 (16)	0.0079 (14)	−0.0029 (13)	−0.0038 (12)	−0.0001 (12)
O16	0.036 (2)	0.0179 (17)	0.0111 (15)	−0.0177 (15)	−0.0085 (14)	−0.0005 (13)
C17	0.016 (2)	0.013 (2)	0.0078 (19)	−0.0075 (18)	−0.0043 (16)	−0.0008 (16)
C18	0.013 (2)	0.009 (2)	0.011 (2)	−0.0040 (17)	0.0003 (16)	−0.0047 (16)
O19	0.0164 (16)	0.0108 (15)	0.0142 (15)	−0.0062 (13)	−0.0034 (12)	0.0010 (12)
O20	0.0200 (17)	0.0151 (16)	0.0112 (15)	−0.0121 (13)	−0.0051 (12)	0.0017 (12)
C21	0.029 (3)	0.014 (2)	0.015 (2)	−0.012 (2)	−0.0037 (19)	−0.0006 (18)
C22	0.026 (3)	0.014 (2)	0.008 (2)	−0.008 (2)	−0.0041 (18)	0.0003 (17)
O23	0.0196 (18)	0.0150 (17)	0.0321 (19)	−0.0065 (14)	−0.0033 (14)	−0.0058 (14)
O24	0.0239 (18)	0.0120 (15)	0.0140 (15)	−0.0108 (14)	−0.0018 (13)	−0.0022 (12)
C25	0.010 (2)	0.008 (2)	0.016 (2)	−0.0011 (16)	−0.0031 (16)	−0.0058 (16)
C26	0.008 (2)	0.010 (2)	0.018 (2)	−0.0027 (17)	−0.0010 (16)	−0.0031 (17)
C27	0.017 (2)	0.010 (2)	0.010 (2)	−0.0025 (18)	−0.0053 (17)	0.0004 (16)
C28	0.012 (2)	0.010 (2)	0.013 (2)	−0.0040 (17)	−0.0036 (16)	−0.0052 (16)
C29	0.009 (2)	0.013 (2)	0.014 (2)	−0.0034 (17)	−0.0019 (16)	−0.0032 (17)
C30	0.013 (2)	0.009 (2)	0.016 (2)	−0.0033 (17)	−0.0017 (17)	−0.0005 (17)
O31	0.0134 (16)	0.0075 (14)	0.0197 (16)	−0.0013 (12)	−0.0087 (13)	−0.0008 (12)
C32	0.013 (2)	0.011 (2)	0.027 (3)	−0.0008 (18)	−0.0148 (19)	0.0011 (18)
C33	0.011 (2)	0.015 (2)	0.010 (2)	−0.0054 (18)	0.0013 (16)	0.0001 (17)
O34	0.0150 (16)	0.0181 (16)	0.0097 (14)	−0.0080 (13)	−0.0068 (12)	0.0021 (12)
O35	0.0158 (16)	0.0086 (15)	0.0222 (17)	−0.0048 (13)	−0.0055 (13)	−0.0006 (13)
C36	0.017 (2)	0.010 (2)	0.012 (2)	−0.0041 (18)	−0.0035 (17)	−0.0017 (17)
C37	0.013 (2)	0.011 (2)	0.014 (2)	−0.0076 (17)	−0.0031 (17)	−0.0002 (17)
O38	0.0119 (15)	0.0150 (15)	0.0094 (14)	−0.0026 (13)	−0.0024 (11)	−0.0029 (12)
O39	0.0226 (18)	0.0152 (16)	0.0121 (15)	−0.0032 (14)	−0.0050 (13)	0.0001 (12)
O40	0.0201 (17)	0.0162 (16)	0.0108 (15)	−0.0102 (13)	−0.0039 (12)	−0.0024 (12)
C41	0.019 (2)	0.010 (2)	0.0077 (19)	−0.0058 (18)	−0.0027 (16)	−0.0041 (16)
C42	0.013 (2)	0.012 (2)	0.011 (2)	−0.0025 (17)	−0.0018 (16)	−0.0033 (17)
O43	0.0169 (17)	0.0125 (15)	0.0120 (15)	−0.0083 (13)	−0.0039 (12)	0.0018 (12)
O44	0.0229 (18)	0.0199 (17)	0.0108 (15)	−0.0128 (14)	−0.0112 (13)	0.0021 (12)
C45	0.013 (2)	0.015 (2)	0.015 (2)	−0.0081 (18)	−0.0028 (17)	0.0005 (17)
C46	0.017 (2)	0.019 (2)	0.008 (2)	−0.0082 (19)	−0.0043 (17)	−0.0028 (17)
O47	0.0217 (18)	0.0111 (15)	0.0187 (16)	−0.0077 (13)	−0.0055 (13)	0.0018 (13)
O48	0.0145 (17)	0.0157 (17)	0.035 (2)	−0.0055 (14)	−0.0076 (15)	0.0056 (15)
O49	0.0188 (18)	0.0239 (18)	0.0217 (17)	−0.0128 (15)	−0.0086 (14)	0.0063 (14)
O50	0.0180 (17)	0.0197 (17)	0.0200 (17)	−0.0109 (14)	−0.0016 (13)	−0.0023 (13)

Geometric parameters (Å, º)

La1—O44^i	2.417 (3)	O19—La1^iv	2.525 (3)
La1—O14	2.519 (3)	C21—C22	1.499 (6)
La1—O19^ii	2.525 (3)	C21—H21A	0.9900
La1—O24^ii	2.525 (3)	C21—H21B	0.9900
La1—O43	2.536 (3)	C22—O24	1.234 (5)
La1—O11	2.540 (3)	C22—O23	1.305 (6)
La1—O38^ii	2.579 (3)	O23—H23	0.9967
La1—O7	2.619 (3)	O24—La1^iv	2.525 (3)
La1—O39^ii	2.661 (3)	C25—C30	1.383 (6)
La1—C37^ii	2.993 (4)	C25—C26	1.384 (6)
La1—La2^ii	4.2365 (3)	C25—O31	1.422 (5)
La2—O20	2.450 (3)	C26—C27	1.399 (6)
La2—O34^iii	2.486 (3)	C26—C36	1.516 (6)
La2—O38	2.509 (3)	C27—C28	1.401 (6)
La2—O49	2.524 (3)	C27—H27	0.9500
La2—O35	2.543 (3)	C28—O40	1.366 (5)
La2—O47^iv	2.546 (3)	C28—C29	1.403 (6)
La2—O15^iv	2.625 (3)	C29—C30	1.388 (6)
La2—O14^iv	2.638 (3)	C29—C45	1.506 (6)
La2—O31	2.718 (3)	C30—H30	0.9500
La2—C13^iv	3.021 (4)	O31—C32	1.432 (5)
La2—La1^iv	4.2365 (3)	C32—C33	1.507 (6)
C1—C6	1.390 (6)	C32—H32A	0.9900
C1—C2	1.390 (6)	C32—H32B	0.9900
C1—O7	1.401 (5)	C33—O34	1.249 (5)
C2—C3	1.397 (6)	C33—O35	1.267 (5)
C2—C12	1.513 (6)	O34—La2^iii	2.486 (3)
C3—C4	1.377 (6)	C36—C37	1.522 (6)
C3—H3	0.9500	C36—H36A	0.9900
C4—O16	1.372 (5)	C36—H36B	0.9900
C4—C5	1.399 (6)	C37—O39	1.246 (5)
C5—C6	1.389 (6)	C37—O38	1.281 (5)
C5—C21	1.513 (6)	C37—La1^iv	2.993 (4)
C6—H6	0.9500	O38—La1^iv	2.579 (3)
O7—C8	1.446 (5)	O39—La1^iv	2.661 (3)
C8—C9	1.506 (6)	O40—C41	1.424 (5)
C8—H8A	0.9900	C41—C42	1.517 (6)
C8—H8B	0.9900	C41—H41A	0.9900
C9—O10	1.228 (5)	C41—H41B	0.9900
C9—O11	1.282 (5)	C42—O43	1.253 (5)
C12—C13	1.516 (6)	C42—O44	1.256 (5)
C12—H12A	0.9900	O44—La1^i	2.417 (3)
C12—H12B	0.9900	C45—C46	1.510 (6)
C13—O15	1.249 (5)	C45—H45A	0.9900
C13—O14	1.283 (5)	C45—H45B	0.9900
C13—La2^ii	3.021 (4)	C46—O47	1.233 (5)
O14—La2^ii	2.638 (3)	C46—O48	1.302 (5)
O15—La2^ii	2.625 (3)	O47—La2^ii	2.546 (3)
O16—C17	1.429 (5)	O48—H48	0.8400
C17—C18	1.522 (6)	O49—H49A	0.7901
C17—H17A	0.9900	O49—H49B	0.8098
C17—H17B	0.9900	O50—H50A	0.9083
C18—O20	1.257 (5)	O50—H50B	0.9045
C18—O19	1.264 (5)
O44^i—La1—O14	135.79 (10)	C1—O7—C8	114.7 (3)
O44^i—La1—O19^ii	141.58 (10)	C1—O7—La1	124.7 (2)
O14—La1—O19^ii	71.92 (9)	C8—O7—La1	117.6 (2)
O44^i—La1—O24^ii	79.43 (10)	O7—C8—C9	108.9 (4)
O14—La1—O24^ii	144.30 (9)	O7—C8—H8A	109.9
O19^ii—La1—O24^ii	74.51 (9)	C9—C8—H8A	109.9
O44^i—La1—O43	80.64 (9)	O7—C8—H8B	109.9
O14—La1—O43	67.71 (9)	C9—C8—H8B	109.9
O19^ii—La1—O43	136.88 (9)	H8A—C8—H8B	108.3
O24^ii—La1—O43	138.09 (10)	O10—C9—O11	125.4 (4)
O44^i—La1—O11	76.77 (10)	O10—C9—C8	118.1 (4)
O14—La1—O11	107.74 (10)	O11—C9—C8	116.5 (4)
O19^ii—La1—O11	67.95 (10)	C9—O11—La1	121.3 (3)
O24^ii—La1—O11	69.52 (10)	C2—C12—C13	113.1 (3)
O43—La1—O11	139.24 (10)	C2—C12—H12A	109.0
O44^i—La1—O38^ii	138.18 (10)	C13—C12—H12A	109.0
O14—La1—O38^ii	68.29 (9)	C2—C12—H12B	109.0
O19^ii—La1—O38^ii	69.33 (9)	C13—C12—H12B	109.0
O24^ii—La1—O38^ii	88.83 (10)	H12A—C12—H12B	107.8
O43—La1—O38^ii	82.07 (9)	O15—C13—O14	120.3 (4)
O11—La1—O38^ii	135.82 (9)	O15—C13—C12	120.9 (4)
O44^i—La1—O7	73.64 (10)	O14—C13—C12	118.9 (4)
O14—La1—O7	72.08 (9)	O15—C13—La2^ii	59.8 (2)
O19^ii—La1—O7	99.75 (9)	O14—C13—La2^ii	60.5 (2)
O24^ii—La1—O7	126.11 (10)	C12—C13—La2^ii	177.1 (3)
O43—La1—O7	81.92 (9)	C13—O14—La1	136.3 (3)
O11—La1—O7	59.40 (9)	C13—O14—La2^ii	94.4 (2)
O38^ii—La1—O7	140.34 (9)	La1—O14—La2^ii	110.46 (11)
O44^i—La1—O39^ii	88.88 (10)	C13—O15—La2^ii	95.9 (3)
O14—La1—O39^ii	109.37 (10)	C4—O16—C17	119.1 (3)
O19^ii—La1—O39^ii	107.55 (9)	O16—C17—C18	106.4 (3)
O24^ii—La1—O39^ii	69.84 (10)	O16—C17—H17A	110.4
O43—La1—O39^ii	73.28 (10)	C18—C17—H17A	110.4
O11—La1—O39^ii	138.69 (10)	O16—C17—H17B	110.4
O38^ii—La1—O39^ii	49.61 (9)	C18—C17—H17B	110.4
O7—La1—O39^ii	151.74 (9)	H17A—C17—H17B	108.6
O44^i—La1—C37^ii	113.46 (11)	O20—C18—O19	126.0 (4)
O14—La1—C37^ii	90.17 (10)	O20—C18—C17	116.0 (4)
O19^ii—La1—C37^ii	87.34 (10)	O19—C18—C17	117.9 (4)
O24^ii—La1—C37^ii	76.40 (11)	C18—O19—La1^iv	135.2 (3)
O43—La1—C37^ii	78.40 (10)	C18—O20—La2	129.8 (3)
O11—La1—C37^ii	141.95 (10)	C22—C21—C5	115.9 (4)
O38^ii—La1—C37^ii	25.19 (10)	C22—C21—H21A	108.3
O7—La1—C37^ii	157.43 (10)	C5—C21—H21A	108.3
O39^ii—La1—C37^ii	24.58 (10)	C22—C21—H21B	108.3
O44^i—La1—La2^ii	156.54 (7)	C5—C21—H21B	108.3
O14—La1—La2^ii	35.68 (7)	H21A—C21—H21B	107.4
O19^ii—La1—La2^ii	61.87 (7)	O24—C22—O23	123.6 (4)
O24^ii—La1—La2^ii	115.04 (7)	O24—C22—C21	120.3 (4)
O43—La1—La2^ii	76.43 (6)	O23—C22—C21	115.9 (4)
O11—La1—La2^ii	124.71 (7)	C22—O23—H23	103.4
O38^ii—La1—La2^ii	33.11 (6)	C22—O24—La1^iv	138.8 (3)
O7—La1—La2^ii	107.56 (6)	C30—C25—C26	121.7 (4)
O39^ii—La1—La2^ii	79.91 (7)	C30—C25—O31	119.5 (4)
C37^ii—La1—La2^ii	57.04 (8)	C26—C25—O31	118.7 (4)
O20—La2—O34^iii	76.24 (9)	C25—C26—C27	118.4 (4)
O20—La2—O38	71.50 (10)	C25—C26—C36	121.7 (4)
O34^iii—La2—O38	141.27 (10)	C27—C26—C36	119.8 (4)
O20—La2—O49	137.22 (10)	C26—C27—C28	120.5 (4)
O34^iii—La2—O49	146.47 (10)	C26—C27—H27	119.8
O38—La2—O49	67.96 (10)	C28—C27—H27	119.8
O20—La2—O35	126.11 (10)	O40—C28—C27	124.5 (4)
O34^iii—La2—O35	71.63 (10)	O40—C28—C29	115.5 (4)
O38—La2—O35	111.63 (10)	C27—C28—C29	120.0 (4)
O49—La2—O35	82.29 (10)	C30—C29—C28	119.0 (4)
O20—La2—O47^iv	142.81 (10)	C30—C29—C45	120.1 (4)
O34^iii—La2—O47^iv	81.02 (10)	C28—C29—C45	120.8 (4)
O38—La2—O47^iv	137.55 (10)	C25—C30—C29	120.4 (4)
O49—La2—O47^iv	70.81 (10)	C25—C30—H30	119.8
O35—La2—O47^iv	71.66 (10)	C29—C30—H30	119.8
O20—La2—O15^iv	75.10 (10)	C25—O31—C32	112.0 (3)
O34^iii—La2—O15^iv	80.20 (10)	C25—O31—La2	128.3 (2)
O38—La2—O15^iv	110.77 (9)	C32—O31—La2	117.8 (2)
O49—La2—O15^iv	107.08 (10)	O31—C32—C33	109.1 (3)
O35—La2—O15^iv	136.93 (10)	O31—C32—H32A	109.9
O47^iv—La2—O15^iv	72.29 (10)	C33—C32—H32A	109.9
O20—La2—O14^iv	82.71 (10)	O31—C32—H32B	109.9
O34^iii—La2—O14^iv	128.90 (9)	C33—C32—H32B	109.9
O38—La2—O14^iv	67.51 (9)	H32A—C32—H32B	108.3
O49—La2—O14^iv	69.82 (10)	O34—C33—O35	124.3 (4)
O35—La2—O14^iv	150.35 (9)	O34—C33—C32	117.7 (4)
O47^iv—La2—O14^iv	89.32 (9)	O35—C33—C32	118.0 (4)
O15^iv—La2—O14^iv	49.32 (9)	C33—O34—La2^iii	141.5 (3)
O20—La2—O31	75.42 (10)	C33—O35—La2	121.7 (3)
O34^iii—La2—O31	83.34 (9)	C26—C36—C37	109.0 (3)
O38—La2—O31	68.37 (9)	C26—C36—H36A	109.9
O49—La2—O31	101.25 (10)	C37—C36—H36A	109.9
O35—La2—O31	59.05 (9)	C26—C36—H36B	109.9
O47^iv—La2—O31	130.70 (10)	C37—C36—H36B	109.9
O15^iv—La2—O31	148.87 (9)	H36A—C36—H36B	108.3
O14^iv—La2—O31	134.99 (9)	O39—C37—O38	121.0 (4)
O20—La2—C13^iv	78.47 (11)	O39—C37—C36	121.6 (4)
O34^iii—La2—C13^iv	104.32 (10)	O38—C37—C36	117.4 (4)
O38—La2—C13^iv	89.80 (10)	O39—C37—La1^iv	62.6 (2)
O49—La2—C13^iv	88.20 (11)	O38—C37—La1^iv	59.0 (2)
O35—La2—C13^iv	150.82 (10)	C36—C37—La1^iv	169.4 (3)
O47^iv—La2—C13^iv	79.17 (10)	C37—O38—La2	143.6 (3)
O15^iv—La2—C13^iv	24.29 (10)	C37—O38—La1^iv	95.8 (2)
O14^iv—La2—C13^iv	25.05 (10)	La2—O38—La1^iv	112.73 (11)
O31—La2—C13^iv	150.13 (10)	C37—O39—La1^iv	92.8 (3)
O20—La2—La1^iv	70.20 (7)	C28—O40—C41	117.9 (3)
O34^iii—La2—La1^iv	143.56 (7)	O40—C41—C42	109.9 (3)
O38—La2—La1^iv	34.15 (7)	O40—C41—H41A	109.7
O49—La2—La1^iv	68.74 (7)	C42—C41—H41A	109.7
O35—La2—La1^iv	141.37 (7)	O40—C41—H41B	109.7
O47^iv—La2—La1^iv	118.64 (7)	C42—C41—H41B	109.7
O15^iv—La2—La1^iv	77.87 (6)	H41A—C41—H41B	108.2
O14^iv—La2—La1^iv	33.86 (6)	O43—C42—O44	125.0 (4)
O31—La2—La1^iv	101.19 (6)	O43—C42—C41	120.1 (4)
C13^iv—La2—La1^iv	55.73 (8)	O44—C42—C41	114.8 (4)
C6—C1—C2	121.9 (4)	C42—O43—La1	140.3 (3)
C6—C1—O7	119.9 (4)	C42—O44—La1^i	162.9 (3)
C2—C1—O7	118.2 (4)	C29—C45—C46	115.8 (4)
C1—C2—C3	117.8 (4)	C29—C45—H45A	108.3
C1—C2—C12	121.5 (4)	C46—C45—H45A	108.3
C3—C2—C12	120.7 (4)	C29—C45—H45B	108.3
C4—C3—C2	120.8 (4)	C46—C45—H45B	108.3
C4—C3—H3	119.6	H45A—C45—H45B	107.4
C2—C3—H3	119.6	O47—C46—O48	122.9 (4)
O16—C4—C3	124.6 (4)	O47—C46—C45	120.7 (4)
O16—C4—C5	114.3 (4)	O48—C46—C45	116.4 (4)
C3—C4—C5	121.1 (4)	C46—O47—La2^ii	135.8 (3)
C6—C5—C4	118.5 (4)	C46—O48—H48	109.5
C6—C5—C21	120.6 (4)	La2—O49—H49A	138.5
C4—C5—C21	120.6 (4)	La2—O49—H49B	118.2
C5—C6—C1	119.9 (4)	H49A—O49—H49B	96.4
C5—C6—H6	120.0	H50A—O50—H50B	103.4
C1—C6—H6	120.0

Symmetry codes: (i) −x, −y, −z; (ii) x, y−1, z; (iii) −x+1, −y+1, −z+1; (iv) x, y+1, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O23—H23···O11^iv	1.00	1.60	2.593 (4)	174
O48—H48···O50	0.84	1.68	2.522 (5)	179
O49—H49A···O10^v	0.79	1.96	2.710 (5)	158
O49—H49B···O43^iv	0.81	2.00	2.797 (4)	170
O50—H50A···O19^vi	0.91	1.95	2.839 (4)	164
O50—H50B···O35^ii	0.90	1.86	2.753 (4)	171

Symmetry codes: (ii) x, y−1, z; (iv) x, y+1, z; (v) x+1, y+1, z; (vi) x+1, y−1, z.

(III) poly[[{µ₄-2,2'-[2,5-bis(carboxymethyl)-1,4-phenylenedioxy]diacetato}zinc(II)] trihydrate]

Crystal data

[Zn(C14H12O10)]·3H2O	F(000) = 944
Mr = 459.65	Dx = 1.711 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.9186 (4) Å	Cell parameters from 4095 reflections
b = 12.2656 (7) Å	θ = 2.5–26.3°
c = 16.3199 (8) Å	µ = 1.45 mm^−1
β = 91.384 (4)°	T = 110 K
V = 1784.75 (16) Å^3	Needle, colourless
Z = 4	0.30 × 0.10 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer	3624 independent reflections
Radiation source: fine-focus sealed tube	2367 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.078
Detector resolution: 12.8 pixels mm^-1	θmax = 26.3°, θmin = 2.5°
0.5 deg. ϕ and ω scans	h = 0→11
Absorption correction: multi-scan (Blessing, 1995)	k = 0→15
Tmin = 0.675, Tmax = 0.871	l = −20→20
15967 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.073	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.220	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.1335P)^2] where P = (Fo^2 + 2Fc^2)/3
3624 reflections	(Δ/σ)max = 0.005
226 parameters	Δρmax = 1.33 e Å^−3
0 restraints	Δρmin = −0.57 e Å^−3

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. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

The asymmetric unit contains also 3 disordered molecules of water as crystallization solvent, which could not be resolved reliably by discrete atoms. Their contribution to the diffraction pattern was thus subtracted by the SQUEEZE procedure in PLATON (Spek, 2009). The H atoms of the two COOH groups could not be located as well.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Zn1	−0.43579 (7)	0.23131 (6)	0.70375 (4)	0.0372 (3)
C1	−0.1194 (6)	0.3255 (5)	0.4548 (4)	0.0451 (15)
C2	−0.0477 (7)	0.3433 (5)	0.3837 (3)	0.0424 (14)
C3	0.0954 (7)	0.3774 (5)	0.3867 (3)	0.0403 (14)
H3	0.1454	0.3903	0.3369	0.048*
C4	0.1723 (6)	0.3942 (5)	0.4604 (4)	0.0480 (16)
C5	0.0953 (7)	0.3729 (5)	0.5346 (3)	0.0436 (15)
C6	−0.0499 (7)	0.3386 (5)	0.5279 (3)	0.0396 (14)
H6	−0.1032	0.3236	0.5764	0.047*
O7	−0.2719 (4)	0.2925 (4)	0.4452 (2)	0.0477 (11)
C8	−0.3490 (7)	0.2658 (5)	0.5170 (4)	0.0463 (15)
H8A	−0.4582	0.2706	0.5052	0.056*
H8B	−0.3237	0.3204	0.5598	0.056*
C9	−0.3136 (8)	0.1542 (6)	0.5501 (4)	0.0552 (17)
O10	−0.3531 (5)	0.1321 (3)	0.6221 (2)	0.0450 (10)
O11	−0.2576 (7)	0.0843 (4)	0.5031 (3)	0.086 (2)
C12	−0.1290 (7)	0.3210 (6)	0.3009 (3)	0.0476 (15)
H12A	−0.2272	0.3587	0.3002	0.057*
H12B	−0.0691	0.3522	0.2564	0.057*
C13	−0.1547 (7)	0.2007 (6)	0.2839 (4)	0.0450 (15)
O14	−0.2702 (4)	0.1757 (3)	0.2403 (2)	0.0412 (9)
O15	−0.0643 (5)	0.1327 (4)	0.3119 (3)	0.0643 (14)
O16	0.3215 (5)	0.4255 (4)	0.4703 (2)	0.0485 (11)
C17	0.3945 (7)	0.4502 (5)	0.3985 (3)	0.0465 (15)
H17A	0.4880	0.4901	0.4129	0.056*
H17B	0.3299	0.4996	0.3652	0.056*
C18	0.4340 (7)	0.3520 (6)	0.3466 (3)	0.0471 (15)
O19	0.4951 (5)	0.3787 (4)	0.2786 (2)	0.0493 (11)
O20	0.4103 (6)	0.2567 (4)	0.3682 (3)	0.0527 (12)
C21	0.1813 (7)	0.3894 (6)	0.6153 (4)	0.0486 (15)
H21A	0.1095	0.3857	0.6605	0.058*
H21B	0.2249	0.4637	0.6156	0.058*
C22	0.3063 (7)	0.3081 (6)	0.6325 (4)	0.0472 (15)
O23	0.4192 (4)	0.3426 (3)	0.6753 (2)	0.0423 (10)
O24	0.2967 (6)	0.2143 (4)	0.6058 (3)	0.0640 (13)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0368 (4)	0.0432 (5)	0.0316 (4)	0.0019 (3)	0.0022 (3)	0.0052 (3)
C1	0.036 (3)	0.039 (4)	0.061 (4)	0.000 (3)	−0.001 (3)	−0.002 (3)
C2	0.055 (4)	0.036 (4)	0.036 (3)	0.006 (3)	−0.011 (3)	−0.002 (2)
C3	0.057 (4)	0.039 (4)	0.026 (3)	0.009 (3)	0.014 (2)	0.003 (2)
C4	0.030 (3)	0.030 (3)	0.084 (5)	0.002 (2)	−0.002 (3)	−0.003 (3)
C5	0.067 (4)	0.036 (4)	0.027 (3)	0.015 (3)	−0.008 (3)	−0.002 (2)
C6	0.048 (3)	0.036 (3)	0.035 (3)	0.011 (3)	0.019 (2)	0.007 (2)
O7	0.042 (2)	0.064 (3)	0.037 (2)	−0.006 (2)	0.0001 (17)	0.0039 (19)
C8	0.046 (4)	0.056 (4)	0.037 (3)	−0.003 (3)	0.015 (3)	0.001 (3)
C9	0.070 (4)	0.051 (4)	0.046 (4)	0.016 (3)	0.011 (3)	0.004 (3)
O10	0.055 (3)	0.042 (3)	0.039 (2)	0.0097 (19)	0.0099 (18)	0.0027 (17)
O11	0.144 (6)	0.066 (4)	0.049 (3)	0.041 (4)	0.028 (3)	−0.002 (3)
C12	0.049 (4)	0.058 (4)	0.036 (3)	−0.006 (3)	0.008 (3)	−0.003 (3)
C13	0.043 (4)	0.050 (4)	0.042 (3)	0.000 (3)	0.003 (3)	−0.008 (3)
O14	0.039 (2)	0.042 (3)	0.043 (2)	0.0005 (18)	0.0005 (17)	−0.0094 (18)
O15	0.055 (3)	0.047 (3)	0.089 (4)	0.017 (2)	−0.026 (3)	−0.019 (2)
O16	0.043 (2)	0.063 (3)	0.040 (2)	−0.008 (2)	0.0015 (18)	−0.0051 (19)
C17	0.052 (4)	0.049 (4)	0.039 (3)	−0.002 (3)	0.010 (3)	−0.001 (3)
C18	0.062 (4)	0.047 (4)	0.033 (3)	0.006 (3)	0.017 (3)	−0.002 (3)
O19	0.055 (3)	0.049 (3)	0.044 (2)	0.004 (2)	0.0091 (19)	−0.0072 (19)
O20	0.064 (3)	0.052 (3)	0.043 (2)	0.014 (2)	0.005 (2)	−0.0023 (19)
C21	0.046 (4)	0.057 (4)	0.044 (3)	0.004 (3)	0.004 (3)	−0.008 (3)
C22	0.039 (3)	0.044 (4)	0.059 (4)	0.005 (3)	0.006 (3)	0.008 (3)
O23	0.037 (2)	0.052 (3)	0.038 (2)	0.0023 (19)	0.0019 (17)	0.0066 (18)
O24	0.061 (3)	0.045 (3)	0.085 (4)	0.007 (2)	−0.012 (3)	−0.003 (3)

Geometric parameters (Å, º)

Zn1—O23^i	1.929 (4)	C9—O10	1.264 (7)
Zn1—O19^ii	1.931 (4)	C12—C13	1.517 (10)
Zn1—O14^iii	1.948 (4)	C12—H12A	0.9900
Zn1—O10	1.962 (4)	C12—H12B	0.9900
C1—C6	1.341 (8)	C13—O15	1.241 (8)
C1—C2	1.357 (8)	C13—O14	1.276 (7)
C1—O7	1.424 (7)	O14—Zn1^iv	1.948 (4)
C2—C3	1.343 (9)	O16—C17	1.387 (6)
C2—C12	1.543 (8)	C17—C18	1.519 (8)
C3—C4	1.385 (9)	C17—H17A	0.9900
C3—H3	0.9500	C17—H17B	0.9900
C4—O16	1.391 (7)	C18—O20	1.241 (7)
C4—C5	1.431 (8)	C18—O19	1.290 (7)
C5—C6	1.364 (8)	O19—Zn1^v	1.931 (4)
C5—C21	1.521 (8)	C21—C22	1.517 (9)
C6—H6	0.9500	C21—H21A	0.9900
O7—C8	1.412 (6)	C21—H21B	0.9900
C8—C9	1.502 (10)	C22—O24	1.233 (8)
C8—H8A	0.9900	C22—O23	1.283 (8)
C8—H8B	0.9900	O23—Zn1^vi	1.929 (4)
C9—O11	1.261 (8)
O23^i—Zn1—O19^ii	115.09 (17)	O10—C9—C8	117.9 (5)
O23^i—Zn1—O14^iii	99.11 (18)	C9—O10—Zn1	128.0 (4)
O19^ii—Zn1—O14^iii	117.83 (17)	C13—C12—C2	113.5 (5)
O23^i—Zn1—O10	122.41 (16)	C13—C12—H12A	108.9
O19^ii—Zn1—O10	97.32 (19)	C2—C12—H12A	108.9
O14^iii—Zn1—O10	106.05 (17)	C13—C12—H12B	108.9
C6—C1—C2	121.6 (6)	C2—C12—H12B	108.9
C6—C1—O7	123.5 (5)	H12A—C12—H12B	107.7
C2—C1—O7	114.8 (5)	O15—C13—O14	123.6 (6)
C3—C2—C1	119.1 (5)	O15—C13—C12	119.5 (6)
C3—C2—C12	120.9 (5)	O14—C13—C12	116.9 (6)
C1—C2—C12	119.9 (6)	C13—O14—Zn1^iv	128.7 (4)
C2—C3—C4	121.9 (5)	C17—O16—C4	115.5 (5)
C2—C3—H3	119.1	O16—C17—C18	114.7 (5)
C4—C3—H3	119.1	O16—C17—H17A	108.6
C3—C4—O16	126.4 (6)	C18—C17—H17A	108.6
C3—C4—C5	118.1 (5)	O16—C17—H17B	108.6
O16—C4—C5	115.4 (6)	C18—C17—H17B	108.6
C6—C5—C4	117.6 (5)	H17A—C17—H17B	107.6
C6—C5—C21	124.6 (5)	O20—C18—O19	124.2 (6)
C4—C5—C21	117.8 (6)	O20—C18—C17	123.0 (5)
C1—C6—C5	121.7 (5)	O19—C18—C17	112.8 (6)
C1—C6—H6	119.1	C18—O19—Zn1^v	121.0 (4)
C5—C6—H6	119.1	C5—C21—C22	115.2 (5)
C8—O7—C1	117.2 (5)	C5—C21—H21A	108.5
O7—C8—C9	114.0 (5)	C22—C21—H21A	108.5
O7—C8—H8A	108.7	C5—C21—H21B	108.5
C9—C8—H8A	108.7	C22—C21—H21B	108.5
O7—C8—H8B	108.7	H21A—C21—H21B	107.5
C9—C8—H8B	108.7	O24—C22—O23	123.1 (6)
H8A—C8—H8B	107.6	O24—C22—C21	120.3 (6)
O11—C9—O10	122.8 (6)	O23—C22—C21	116.6 (6)
O11—C9—C8	119.0 (6)	C22—O23—Zn1^vi	114.3 (4)

Symmetry codes: (i) x−1, y, z; (ii) x−1, −y+1/2, z+1/2; (iii) x, −y+1/2, z+1/2; (iv) x, −y+1/2, z−1/2; (v) x+1, −y+1/2, z−1/2; (vi) x+1, y, z.

(IV) poly[[diaqua(µ₂-4,4'-bipyridyl){µ₄-2,2'-[2,5-bis(carboxymethyl)-1,4- phenylenedioxy]diacetato}dizinc(II)] dihydrate]

Crystal data

[Zn2(C14H10O10)(C10H8N2)(H2O)2]·2H2O	Z = 1
Mr = 697.24	F(000) = 356
Triclinic, P1	Dx = 1.778 Mg m^−3
a = 7.7218 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.3520 (5) Å	Cell parameters from 2455 reflections
c = 10.7204 (6) Å	θ = 2.0–26.7°
α = 108.621 (3)°	µ = 1.92 mm^−1
β = 94.915 (3)°	T = 110 K
γ = 92.412 (3)°	Prism, colourless
V = 651.01 (6) Å^3	0.20 × 0.10 × 0.10 mm

Data collection

Nonius KappaCCD area-detector diffractometer	2794 independent reflections
Radiation source: fine-focus sealed tube	2330 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.059
Detector resolution: 12.8 pixels mm^-1	θmax = 27.0°, θmin = 2.0°
1 deg. ϕ and ω scans	h = 0→9
Absorption correction: multi-scan (Blessing, 1995)	k = −10→10
Tmin = 0.700, Tmax = 0.831	l = −13→13
7281 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.092	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0254P)^2 + 0.9668P] where P = (Fo^2 + 2Fc^2)/3
2794 reflections	(Δ/σ)max < 0.001
190 parameters	Δρmax = 0.48 e Å^−3
0 restraints	Δρmin = −0.71 e Å^−3

Special details

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Zn1	0.64853 (5)	0.35334 (5)	0.67884 (4)	0.01753 (13)
C1	1.0378 (4)	0.1350 (4)	−0.0481 (3)	0.0155 (7)
C2	0.9607 (4)	0.1625 (4)	0.0693 (3)	0.0161 (7)
H2	0.9340	0.2739	0.1176	0.019*
C3	0.9220 (4)	0.0295 (4)	0.1168 (3)	0.0152 (7)
O4	0.8396 (3)	0.0465 (3)	0.2291 (2)	0.0197 (5)
C5	0.8222 (4)	0.2147 (4)	0.3107 (3)	0.0168 (7)
H5A	0.7530	0.2747	0.2599	0.020*
H5B	0.9387	0.2759	0.3397	0.020*
C6	0.7325 (4)	0.2128 (4)	0.4305 (3)	0.0191 (7)
O7	0.7171 (3)	0.3634 (3)	0.5098 (2)	0.0204 (5)
O8	0.6809 (4)	0.0844 (3)	0.4519 (2)	0.0292 (6)
C9	1.0814 (4)	0.2794 (4)	−0.0984 (3)	0.0169 (7)
H9A	1.1850	0.2524	−0.1476	0.020*
H9B	1.1151	0.3818	−0.0209	0.020*
C10	0.9401 (5)	0.3233 (4)	−0.1874 (3)	0.0180 (7)
O11	0.7855 (3)	0.2555 (3)	−0.2018 (2)	0.0197 (5)
O12	0.9777 (3)	0.4316 (3)	−0.2403 (2)	0.0247 (6)
O13	0.4125 (3)	0.2444 (3)	0.6720 (2)	0.0217 (5)
H13A	0.3919	0.1362	0.6293	0.033*
H13B	0.3323	0.2822	0.6100	0.033*
N14	0.5879 (3)	0.5959 (3)	0.7833 (3)	0.0158 (6)
C15	0.4943 (4)	0.6114 (4)	0.8861 (3)	0.0201 (7)
H15	0.4500	0.5111	0.8996	0.024*
C16	0.4594 (4)	0.7656 (4)	0.9733 (3)	0.0184 (7)
H16	0.3957	0.7698	1.0461	0.022*
C17	0.5181 (4)	0.9151 (4)	0.9538 (3)	0.0149 (7)
C18	0.6101 (4)	0.8997 (4)	0.8445 (3)	0.0186 (7)
H18	0.6494	0.9979	0.8255	0.022*
C19	0.6437 (4)	0.7397 (4)	0.7635 (3)	0.0195 (7)
H19	0.7091	0.7316	0.6909	0.023*
O20	0.8341 (3)	0.6429 (3)	0.4561 (2)	0.0262 (6)
H20A	0.7952	0.5501	0.4734	0.039*
H20B	0.8955	0.6185	0.3855	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0220 (2)	0.0162 (2)	0.0159 (2)	0.00335 (15)	0.00553 (15)	0.00610 (15)
C1	0.0128 (15)	0.0163 (16)	0.0182 (16)	0.0021 (13)	0.0032 (13)	0.0061 (13)
C2	0.0130 (16)	0.0184 (16)	0.0166 (16)	0.0026 (13)	0.0037 (13)	0.0046 (13)
C3	0.0141 (15)	0.0193 (16)	0.0122 (15)	0.0029 (13)	0.0056 (13)	0.0039 (13)
O4	0.0268 (13)	0.0168 (12)	0.0167 (12)	0.0041 (10)	0.0118 (10)	0.0045 (9)
C5	0.0212 (17)	0.0162 (16)	0.0122 (16)	0.0020 (14)	0.0039 (13)	0.0027 (13)
C6	0.0177 (17)	0.0210 (18)	0.0174 (17)	0.0028 (14)	0.0034 (14)	0.0040 (14)
O7	0.0284 (13)	0.0157 (12)	0.0167 (12)	0.0029 (10)	0.0084 (10)	0.0026 (9)
O8	0.0433 (16)	0.0180 (13)	0.0286 (14)	0.0018 (11)	0.0185 (13)	0.0073 (11)
C9	0.0172 (16)	0.0154 (16)	0.0167 (16)	0.0025 (13)	0.0074 (14)	0.0015 (13)
C10	0.0286 (19)	0.0126 (16)	0.0133 (16)	0.0060 (14)	0.0074 (14)	0.0031 (13)
O11	0.0196 (12)	0.0208 (12)	0.0212 (12)	−0.0002 (10)	0.0041 (10)	0.0102 (10)
O12	0.0291 (14)	0.0229 (13)	0.0280 (14)	0.0012 (11)	0.0056 (11)	0.0159 (11)
O13	0.0236 (13)	0.0166 (12)	0.0242 (13)	0.0021 (10)	0.0040 (10)	0.0049 (10)
N14	0.0169 (14)	0.0159 (14)	0.0144 (13)	0.0028 (11)	0.0051 (11)	0.0036 (11)
C15	0.0229 (18)	0.0186 (17)	0.0197 (18)	0.0011 (14)	0.0021 (15)	0.0078 (14)
C16	0.0212 (17)	0.0190 (17)	0.0171 (17)	0.0029 (14)	0.0070 (14)	0.0075 (13)
C17	0.0119 (15)	0.0174 (17)	0.0162 (16)	0.0016 (13)	0.0010 (13)	0.0067 (14)
C18	0.0171 (17)	0.0175 (16)	0.0208 (17)	0.0004 (13)	0.0040 (14)	0.0051 (13)
C19	0.0183 (17)	0.0219 (18)	0.0191 (17)	0.0047 (14)	0.0068 (14)	0.0060 (14)
O20	0.0270 (14)	0.0257 (13)	0.0289 (14)	0.0003 (11)	0.0075 (11)	0.0121 (11)

Geometric parameters (Å, º)

Zn1—O7	1.957 (2)	C9—H9B	0.9900
Zn1—O11^i	1.983 (2)	C10—O12	1.248 (4)
Zn1—O13	1.988 (2)	C10—O11	1.275 (4)
Zn1—N14	2.073 (3)	O11—Zn1^iii	1.983 (2)
C1—C2	1.395 (4)	O13—H13A	0.8730
C1—C3^ii	1.398 (4)	O13—H13B	1.0025
C1—C9	1.507 (5)	N14—C15	1.345 (4)
C2—C3	1.394 (5)	N14—C19	1.344 (4)
C2—H2	0.9500	C15—C16	1.381 (4)
C3—O4	1.380 (4)	C15—H15	0.9500
C3—C1^ii	1.398 (4)	C16—C17	1.394 (5)
O4—C5	1.417 (4)	C16—H16	0.9500
C5—C6	1.514 (4)	C17—C18	1.396 (4)
C5—H5A	0.9900	C17—C17^iv	1.501 (6)
C5—H5B	0.9900	C18—C19	1.391 (4)
C6—O8	1.225 (4)	C18—H18	0.9500
C6—O7	1.290 (4)	C19—H19	0.9500
C9—C10	1.522 (5)	O20—H20A	0.8980
C9—H9A	0.9900	O20—H20B	0.8998
O7—Zn1—O11^i	124.79 (10)	C1—C9—H9B	108.0
O7—Zn1—O13	115.69 (10)	C10—C9—H9B	108.0
O11^i—Zn1—O13	100.83 (10)	H9A—C9—H9B	107.2
O7—Zn1—N14	106.20 (10)	O12—C10—O11	121.5 (3)
O11^i—Zn1—N14	110.06 (10)	O12—C10—C9	118.5 (3)
O13—Zn1—N14	95.44 (10)	O11—C10—C9	119.9 (3)
C2—C1—C3^ii	118.5 (3)	C10—O11—Zn1^iii	105.5 (2)
C2—C1—C9	121.0 (3)	Zn1—O13—H13A	119.1
C3^ii—C1—C9	120.5 (3)	Zn1—O13—H13B	107.4
C3—C2—C1	121.1 (3)	H13A—O13—H13B	95.5
C3—C2—H2	119.4	C15—N14—C19	117.1 (3)
C1—C2—H2	119.4	C15—N14—Zn1	116.7 (2)
O4—C3—C2	124.2 (3)	C19—N14—Zn1	126.0 (2)
O4—C3—C1^ii	115.5 (3)	N14—C15—C16	123.5 (3)
C2—C3—C1^ii	120.3 (3)	N14—C15—H15	118.3
C3—O4—C5	116.0 (2)	C16—C15—H15	118.3
O4—C5—C6	109.9 (3)	C15—C16—C17	119.7 (3)
O4—C5—H5A	109.7	C15—C16—H16	120.2
C6—C5—H5A	109.7	C17—C16—H16	120.2
O4—C5—H5B	109.7	C16—C17—C18	117.2 (3)
C6—C5—H5B	109.7	C16—C17—C17^iv	121.1 (3)
H5A—C5—H5B	108.2	C18—C17—C17^iv	121.8 (4)
O8—C6—O7	122.9 (3)	C19—C18—C17	119.5 (3)
O8—C6—C5	124.7 (3)	C19—C18—H18	120.2
O7—C6—C5	112.4 (3)	C17—C18—H18	120.2
C6—O7—Zn1	110.4 (2)	N14—C19—C18	123.1 (3)
C1—C9—C10	117.2 (3)	N14—C19—H19	118.5
C1—C9—H9A	108.0	C18—C19—H19	118.5
C10—C9—H9A	108.0	H20A—O20—H20B	112.9

Symmetry codes: (i) x, y, z+1; (ii) −x+2, −y, −z; (iii) x, y, z−1; (iv) −x+1, −y+2, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O13—H13A···O8^v	0.87	1.81	2.676 (3)	172
O13—H13B···O20^vi	1.00	1.65	2.632 (3)	164
O20—H20A···O7	0.90	1.82	2.714 (3)	179
O20—H20B···O12^vii	0.90	1.85	2.753 (3)	180

Symmetry codes: (v) −x+1, −y, −z+1; (vi) −x+1, −y+1, −z+1; (vii) −x+2, −y+1, −z.