metal-organic compounds
Poly[μ-aqua-bis(μ5-2,4-dichlorobenzoato)dipotassium]
aScience and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia
*Correspondence e-mail: g.smith@qut.edu.au
In the title compound, [K2(C7H3Cl2O2)2(H2O)]n, the potassium salt of 2,4-dichlorobenzoic acid, the repeating unit in the polymeric structure consists of two identical irregular KO6Cl units related by twofold rotational symmetry, linked by a bridging water molecule lying on the twofold axis. The about the K+ ion comprises a carboxylate O atom and a Cl-atom donor from a bidentate chelate ligand interaction, four O-atom donors from a doubly bridging bidentate carboxylate O,O′-chelate interaction and the water molecule. A two-dimensional polymeric structure lying parallel to (100) is generated through a series of conjoined cyclic bridges between K+ ions and is stabilized by water–carboxylate O—H⋯O hydrogen-bonding interactions.
CCDC reference: 976400
Related literature
For the structures of potassium salts with coordinating carbon-bound Cl ligands, see: Gowda et al. (2007); Molčanov et al. (2011). For an analogous complex with a Cs—Cl bond in a bidentate chelate mode, see: Smith (2013). For the structure of ammonium 2,4-dichlorobenzoate, see: Smith (2014).
Experimental
Crystal data
|
Data collection: CrysAlis PRO (Agilent, 2012); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 2012); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON.
Supporting information
CCDC reference: 976400
https://doi.org/10.1107/S1600536813033503/wm2791sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813033503/wm2791Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536813033503/wm2791Isup3.cml
The title compound was synthesized by heating together for 10 minutes, 0.5 mmol of 2,4-dichlorobenzoic acid and 0.5 mmol of K2CO3 in 15 ml of 10% ethanol–water at boiling temperature. Partial room temperature evaporation of the solution gave colourless crystal plates of the title complex from which a specimen was cleaved for the X-ray analysis.
Carbon-bound hydrogen atoms were placed in calculated positions [C—H = 0.95 Å] and allowed to ride in the
with Uiso(H) = 1.2Ueq(C). The hydrogen atom of the coordinating water molecule was located in a difference-Fourier synthesis but was subsequently allowed to ride, with Uiso(H) = 1.5Ueq(O).The structural references for 2,4-dichlorobenzoic acid (2,4-CLBA) or its compounds are absent from the crystallographic literature. The reaction of 2,4-CLBA with potassium carbonate in aqueous ethanol afforded crystals of the title salt, [K2(C7H3Cl2O2)2(H2O)]n, and the structure is reported herein.
The repeating unit in the polymeric structure consists of two identical irregular KO6Cl units related by twofold rotational symmetry, linked by a bridging water molecule lying on the twofold axis. The irregular KO6Cl coordination sphere comprises a carboxyl O-atom (O11) and a Cl-atom (Cl2) from a bidentate chelate 2,4-DCBA ligand interaction, four O-atom donors from a doubly bridging bidentate carboxyl O,O'-chelate interaction and the bridging water molecule (O1W) (Fig. 1, Table 1). Polymeric extensions in the layered structure, which lies parallel to (100), are through a series of conjoined ring systems including a centrosymmetric carboxyl O-bridged cage [K1···K1ii = 4.0310 (9) and a doubly bridged water–carboxyl-O cage [K1···K1v = 4.1118 (9) Å] (Figs. 2, 3) [for symmetry code (v): -x, y, -z + 1/2; for symmetry code (ii), see: Table 1].
Coordination complexes involving potassium with aromatic ring-bound Cl donors are uncommon in the crystallographic literature but two polymeric examples have been reported, viz. with 4-chlorobenzenesulfonic acid [K—Cl = 3.4051 (14), 3.4969 (14) Å] (Gowda et al., 2007) and with chloranil [K—Cl = 3.4103 (6), 3.5845 (6) Å] (Molčanov et al., 2011). These values are somewhat larger than those in the title complex [3.2670 (7) Å]. Also, a caesium salt having a Cs—Cl bond in a similar bidentate chelate coordination mode with a 2-chloro-substituted aromatic carboxylate ligand is known (Smith, 2013)
The π···π interactions are present [minimum ring centroid separation = 4.3407 (3) Å, the b-cell parameter].
of the title complex polymer is stabilized by intra-sheet waterO—H···Ocarboxyl hydrogen-bonding interactions (Table 2). A relatively short inversion-related Cl4···Cl4 contact [3.5419 (8) Å] is also present. Although the aromatic ring systems stack down [010] (Fig. 3), no inter-ringIn the 2,4-DCBA ligand the carboxylate group is significantly rotated out of the plane of the benzene ring [torsion angle C2—C1—C11—O11 = 138.2 (4)°] which is comparable with that in the ammonium salt (also a hemihydrate) [-137.2 (3)°] (Smith, 2014).
For the structures of potassium salts with coordinating carbon-bound Cl ligands, see: Gowda et al. (2007); Molčanov et al. (2011). For an analogous complex with a Cs—Cl bond in a bidentate chelate mode, see: Smith (2013). For the structure of ammonium 2,4-dichlorobenzoate, see: Smith (2014).
Data collection: CrysAlis PRO (Agilent, 2012); cell
CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 2012); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).Fig. 1. The configuration and atom-numbering scheme for the coordination polyhedron of the title complex, with non-H atoms drawn as 40% probability displacement ellipsoids. The bridging water molecule (O1W) lies on a twofold rotation axis. For symmetry codes, see: Table 1. | |
Fig. 2. A partial expansion of the KO6Cl coordination sphere in the polymeric structure. Probability code as in Fig. 1. For symmetry code (v): -x, y, -z + 1/2. For other symmetry codes, see: Table 1. | |
Fig. 3. The packing of the structure in the unit cell viewed down [100]. Hydrogen-bonding associations are shown as dashed lines. |
[K2(C7H3Cl2O2)2(H2O)] | F(000) = 952 |
Mr = 476.20 | Dx = 1.814 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 2539 reflections |
a = 31.520 (2) Å | θ = 3.6–28.5° |
b = 4.3407 (3) Å | µ = 1.18 mm−1 |
c = 12.7849 (9) Å | T = 200 K |
β = 94.427 (6)° | Plate, colourless |
V = 1744.0 (2) Å3 | 0.35 × 0.35 × 0.04 mm |
Z = 4 |
Oxford diffraction Gemini-S CCD-detector diffractometer | 1714 independent reflections |
Radiation source: fine-focus sealed tube | 1534 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.084 |
Detector resolution: 16.077 pixels mm-1 | θmax = 26.0°, θmin = 3.4° |
ω–scans | h = −38→38 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012) | k = −5→5 |
Tmin = 0.706, Tmax = 0.980 | l = −15→15 |
9909 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.031 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.081 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0375P)2 + 0.3668P] where P = (Fo2 + 2Fc2)/3 |
1714 reflections | (Δ/σ)max < 0.001 |
114 parameters | Δρmax = 0.37 e Å−3 |
0 restraints | Δρmin = −0.23 e Å−3 |
[K2(C7H3Cl2O2)2(H2O)] | V = 1744.0 (2) Å3 |
Mr = 476.20 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 31.520 (2) Å | µ = 1.18 mm−1 |
b = 4.3407 (3) Å | T = 200 K |
c = 12.7849 (9) Å | 0.35 × 0.35 × 0.04 mm |
β = 94.427 (6)° |
Oxford diffraction Gemini-S CCD-detector diffractometer | 1714 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012) | 1534 reflections with I > 2σ(I) |
Tmin = 0.706, Tmax = 0.980 | Rint = 0.084 |
9909 measured reflections |
R[F2 > 2σ(F2)] = 0.031 | 0 restraints |
wR(F2) = 0.081 | H-atom parameters constrained |
S = 1.09 | Δρmax = 0.37 e Å−3 |
1714 reflections | Δρmin = −0.23 e Å−3 |
114 parameters |
Geometry. Bond lengths, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles |
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. |
x | y | z | Uiso*/Ueq | ||
K1 | 0.03304 (1) | 0.72596 (10) | 0.39507 (3) | 0.0247 (2) | |
Cl2 | 0.12895 (2) | 0.01261 (12) | 0.42912 (4) | 0.0310 (2) | |
Cl4 | 0.25235 (1) | 0.66649 (13) | 0.63591 (4) | 0.0323 (2) | |
O1W | 0.00000 | 0.3018 (4) | 0.25000 | 0.0308 (7) | |
O11 | 0.05794 (4) | 0.1264 (4) | 0.69714 (11) | 0.0316 (5) | |
O12 | 0.04771 (4) | 0.2297 (3) | 0.52587 (12) | 0.0277 (4) | |
C1 | 0.11633 (6) | 0.3174 (4) | 0.61306 (15) | 0.0207 (6) | |
C2 | 0.14444 (6) | 0.2455 (4) | 0.53714 (15) | 0.0216 (6) | |
C3 | 0.18614 (6) | 0.3470 (5) | 0.54411 (16) | 0.0238 (6) | |
C4 | 0.20012 (6) | 0.5325 (5) | 0.62714 (16) | 0.0240 (6) | |
C5 | 0.17357 (6) | 0.6139 (5) | 0.70386 (16) | 0.0279 (6) | |
C6 | 0.13220 (6) | 0.5016 (5) | 0.69632 (16) | 0.0255 (6) | |
C11 | 0.07044 (6) | 0.2136 (4) | 0.61080 (16) | 0.0217 (6) | |
H3 | 0.20480 | 0.28990 | 0.49260 | 0.0290* | |
H5 | 0.18340 | 0.74380 | 0.76040 | 0.0330* | |
H6 | 0.11410 | 0.55210 | 0.74980 | 0.0310* | |
H11W | 0.01850 | 0.19190 | 0.22930 | 0.0460* |
U11 | U22 | U33 | U12 | U13 | U23 | |
K1 | 0.0248 (3) | 0.0267 (3) | 0.0228 (3) | −0.0016 (2) | 0.0024 (2) | −0.0007 (2) |
Cl2 | 0.0301 (3) | 0.0387 (3) | 0.0251 (3) | −0.0074 (2) | 0.0079 (2) | −0.0099 (2) |
Cl4 | 0.0208 (3) | 0.0434 (3) | 0.0326 (3) | −0.0062 (2) | 0.0021 (2) | −0.0011 (2) |
O1W | 0.0339 (12) | 0.0233 (11) | 0.0356 (12) | 0.0000 | 0.0051 (9) | 0.0000 |
O11 | 0.0290 (8) | 0.0385 (9) | 0.0285 (8) | −0.0052 (7) | 0.0107 (6) | 0.0029 (7) |
O12 | 0.0215 (7) | 0.0325 (8) | 0.0289 (8) | −0.0002 (6) | 0.0002 (6) | −0.0023 (6) |
C1 | 0.0203 (10) | 0.0220 (10) | 0.0198 (10) | 0.0023 (8) | 0.0022 (7) | 0.0044 (8) |
C2 | 0.0248 (10) | 0.0217 (10) | 0.0183 (10) | 0.0010 (8) | 0.0019 (8) | 0.0018 (8) |
C3 | 0.0229 (10) | 0.0266 (11) | 0.0226 (10) | 0.0027 (8) | 0.0064 (8) | 0.0021 (9) |
C4 | 0.0176 (9) | 0.0287 (11) | 0.0256 (10) | −0.0003 (8) | 0.0019 (8) | 0.0042 (9) |
C5 | 0.0261 (11) | 0.0316 (11) | 0.0257 (11) | −0.0028 (9) | 0.0010 (8) | −0.0056 (9) |
C6 | 0.0238 (10) | 0.0310 (12) | 0.0222 (10) | 0.0012 (8) | 0.0045 (8) | −0.0032 (9) |
C11 | 0.0211 (10) | 0.0180 (9) | 0.0264 (11) | 0.0034 (8) | 0.0042 (8) | −0.0021 (8) |
K1—O1W | 2.7597 (12) | O1W—H11Wiv | 0.8100 |
K1—O12 | 2.7443 (15) | C1—C11 | 1.513 (3) |
K1—Cl2i | 3.2670 (7) | C1—C2 | 1.399 (3) |
K1—O12i | 2.7699 (15) | C1—C6 | 1.393 (3) |
K1—O11ii | 3.0826 (14) | C2—C3 | 1.383 (3) |
K1—O12ii | 2.8168 (14) | C3—C4 | 1.377 (3) |
K1—O11iii | 2.7815 (15) | C4—C5 | 1.384 (3) |
Cl2—C2 | 1.7503 (19) | C5—C6 | 1.389 (3) |
Cl4—C4 | 1.741 (2) | C3—H3 | 0.9500 |
O11—C11 | 1.259 (2) | C5—H5 | 0.9500 |
O12—C11 | 1.256 (2) | C6—H6 | 0.9500 |
O1W—H11W | 0.8100 | ||
O1W—K1—O12 | 85.58 (4) | K1v—O12—C11 | 122.38 (11) |
Cl2i—K1—O1W | 129.86 (2) | K1ii—O12—C11 | 99.47 (12) |
O1W—K1—O12i | 165.73 (4) | K1v—O12—K1ii | 99.05 (4) |
O1W—K1—O11ii | 65.80 (4) | K1—O1W—H11W | 112.00 |
O1W—K1—O12ii | 88.98 (3) | K1—O1W—H11Wiv | 115.00 |
O1W—K1—O11iii | 70.16 (4) | K1iv—O1W—H11W | 115.00 |
Cl2i—K1—O12 | 96.15 (3) | H11W—O1W—H11Wiv | 108.00 |
O12—K1—O12i | 103.85 (4) | K1iv—O1W—H11Wiv | 112.00 |
O11ii—K1—O12 | 120.28 (4) | C2—C1—C6 | 116.67 (17) |
O12—K1—O12ii | 87.10 (4) | C2—C1—C11 | 125.17 (17) |
O11iii—K1—O12 | 133.56 (5) | C6—C1—C11 | 118.16 (17) |
Cl2i—K1—O12i | 60.61 (3) | C1—C2—C3 | 122.28 (18) |
Cl2i—K1—O11ii | 142.72 (4) | Cl2—C2—C3 | 116.16 (15) |
Cl2i—K1—O12ii | 141.14 (3) | Cl2—C2—C1 | 121.55 (14) |
Cl2i—K1—O11iii | 73.16 (3) | C2—C3—C4 | 118.81 (18) |
O11ii—K1—O12i | 100.01 (4) | Cl4—C4—C3 | 119.31 (15) |
O12i—K1—O12ii | 80.95 (4) | C3—C4—C5 | 121.38 (18) |
O11iii—K1—O12i | 108.77 (5) | Cl4—C4—C5 | 119.32 (16) |
O11ii—K1—O12ii | 44.22 (4) | C4—C5—C6 | 118.51 (19) |
O11ii—K1—O11iii | 85.62 (4) | C1—C6—C5 | 122.31 (18) |
O11iii—K1—O12ii | 129.57 (4) | O11—C11—C1 | 115.87 (17) |
K1v—Cl2—C2 | 121.60 (7) | O12—C11—C1 | 118.73 (17) |
K1—O1W—K1iv | 96.31 (6) | O11—C11—O12 | 125.36 (17) |
K1ii—O11—C11 | 86.96 (11) | C2—C3—H3 | 121.00 |
K1vi—O11—C11 | 149.09 (14) | C4—C3—H3 | 121.00 |
K1ii—O11—K1vi | 88.89 (4) | C4—C5—H5 | 121.00 |
K1—O12—C11 | 128.95 (11) | C6—C5—H5 | 121.00 |
K1—O12—K1v | 103.85 (5) | C1—C6—H6 | 119.00 |
K1—O12—K1ii | 92.90 (4) | C5—C6—H6 | 119.00 |
O12—K1—O1W—K1iv | 170.99 (3) | K1v—Cl2—C2—C3 | 178.56 (12) |
O1W—K1—O12—C11 | 166.16 (15) | K1ii—O11—C11—O12 | −20.38 (19) |
O1W—K1—O12—K1v | 10.86 (3) | K1ii—O11—C11—C1 | 157.18 (14) |
O1W—K1—O12—K1ii | −89.20 (3) | K1vi—O11—C11—O12 | −103.1 (3) |
Cl2i—K1—O12—C11 | 36.50 (15) | K1vi—O11—C11—C1 | 74.5 (3) |
Cl2i—K1—O12—K1v | −118.80 (4) | K1—O12—C11—O11 | 124.28 (17) |
Cl2i—K1—O12—K1ii | 141.14 (3) | K1—O12—C11—C1 | −53.2 (2) |
O12i—K1—O12—C11 | −24.70 (16) | K1v—O12—C11—O11 | −84.4 (2) |
O12i—K1—O12—K1v | −180.00 (4) | K1v—O12—C11—C1 | 98.07 (16) |
O12i—K1—O12—K1ii | 79.94 (4) | K1ii—O12—C11—O11 | 22.7 (2) |
O11ii—K1—O12—C11 | −135.26 (15) | K1ii—O12—C11—C1 | −154.80 (13) |
O11ii—K1—O12—K1v | 69.44 (6) | C6—C1—C2—Cl2 | 179.26 (15) |
O11ii—K1—O12—K1ii | −30.62 (6) | C6—C1—C2—C3 | 0.9 (3) |
O12ii—K1—O12—C11 | −104.64 (15) | C11—C1—C2—Cl2 | −1.4 (3) |
O12ii—K1—O12—K1v | 100.06 (5) | C11—C1—C2—C3 | −179.75 (18) |
O12ii—K1—O12—K1ii | 0.00 (3) | C2—C1—C6—C5 | 1.0 (3) |
O11iii—K1—O12—C11 | 109.06 (16) | C11—C1—C6—C5 | −178.47 (18) |
O11iii—K1—O12—K1v | −46.24 (7) | C2—C1—C11—O11 | 138.2 (2) |
O11iii—K1—O12—K1ii | −146.30 (5) | C2—C1—C11—O12 | −44.1 (3) |
O12—K1—Cl2i—C2i | −82.73 (8) | C6—C1—C11—O11 | −42.5 (2) |
O12—K1—O12i—K1i | 180.00 (5) | C6—C1—C11—O12 | 135.27 (19) |
O12—K1—O12i—C11i | 22.63 (14) | Cl2—C2—C3—C4 | 179.65 (16) |
O12—K1—O11ii—K1iv | −112.99 (5) | C1—C2—C3—C4 | −1.9 (3) |
O12—K1—O11ii—C11ii | 36.37 (13) | C2—C3—C4—Cl4 | −179.10 (16) |
O12—K1—O12ii—K1ii | 0.00 (4) | C2—C3—C4—C5 | 1.1 (3) |
O12—K1—O12ii—C11ii | −130.28 (11) | Cl4—C4—C5—C6 | −179.16 (16) |
O12—K1—O11iii—K1iv | 105.31 (5) | C3—C4—C5—C6 | 0.7 (3) |
O12—K1—O11iii—C11iii | 23.1 (3) | C4—C5—C6—C1 | −1.7 (3) |
K1v—Cl2—C2—C1 | 0.07 (18) |
Symmetry codes: (i) x, y+1, z; (ii) −x, −y+1, −z+1; (iii) x, −y+1, z−1/2; (iv) −x, y, −z+1/2; (v) x, y−1, z; (vi) x, −y+1, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H11W···O11vii | 0.81 | 1.92 | 2.7271 (19) | 169 |
Symmetry code: (vii) x, −y, z−1/2. |
K1—O1W | 2.7597 (12) | K1—O11ii | 3.0826 (14) |
K1—O12 | 2.7443 (15) | K1—O12ii | 2.8168 (14) |
K1—Cl2i | 3.2670 (7) | K1—O11iii | 2.7815 (15) |
K1—O12i | 2.7699 (15) |
Symmetry codes: (i) x, y+1, z; (ii) −x, −y+1, −z+1; (iii) x, −y+1, z−1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H11W···O11iv | 0.81 | 1.92 | 2.7271 (19) | 169 |
Symmetry code: (iv) x, −y, z−1/2. |
Acknowledgements
The author acknowledges financial support from the Science and Engineering Faculty and the University Library, Queensland University of Technology.
References
Agilent (2012). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, England. Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Gowda, B. T., Babitha, K. S., Svoboda, I. & Fuess, H. (2007). Acta Cryst. E63, m2222. Web of Science CSD CrossRef IUCr Journals Google Scholar
Molčanov, K., Kojić-Prodić, B., Bakić, D., Zilic, D. & Rakvin, B. (2011). CrystEngComm, 13, 5170–5178. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Smith, G. (2013). Acta Cryst. E69, m628. CSD CrossRef IUCr Journals Google Scholar
Smith, G. (2014). In preparation. Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The structural references for 2,4-dichlorobenzoic acid (2,4-CLBA) or its compounds are absent from the crystallographic literature. The reaction of 2,4-CLBA with potassium carbonate in aqueous ethanol afforded crystals of the title salt, [K2(C7H3Cl2O2)2(H2O)]n, and the structure is reported herein.
The repeating unit in the polymeric structure consists of two identical irregular KO6Cl units related by twofold rotational symmetry, linked by a bridging water molecule lying on the twofold axis. The irregular KO6Cl coordination sphere comprises a carboxyl O-atom (O11) and a Cl-atom (Cl2) from a bidentate chelate 2,4-DCBA ligand interaction, four O-atom donors from a doubly bridging bidentate carboxyl O,O'-chelate interaction and the bridging water molecule (O1W) (Fig. 1, Table 1). Polymeric extensions in the layered structure, which lies parallel to (100), are through a series of conjoined ring systems including a centrosymmetric carboxyl O-bridged cage [K1···K1ii = 4.0310 (9) and a doubly bridged water–carboxyl-O cage [K1···K1v = 4.1118 (9) Å] (Figs. 2, 3) [for symmetry code (v): -x, y, -z + 1/2; for symmetry code (ii), see: Table 1].
Coordination complexes involving potassium with aromatic ring-bound Cl donors are uncommon in the crystallographic literature but two polymeric examples have been reported, viz. with 4-chlorobenzenesulfonic acid [K—Cl = 3.4051 (14), 3.4969 (14) Å] (Gowda et al., 2007) and with chloranil [K—Cl = 3.4103 (6), 3.5845 (6) Å] (Molčanov et al., 2011). These values are somewhat larger than those in the title complex [3.2670 (7) Å]. Also, a caesium salt having a Cs—Cl bond in a similar bidentate chelate coordination mode with a 2-chloro-substituted aromatic carboxylate ligand is known (Smith, 2013)
The crystal structure of the title complex polymer is stabilized by intra-sheet waterO—H···Ocarboxyl hydrogen-bonding interactions (Table 2). A relatively short inversion-related Cl4···Cl4 contact [3.5419 (8) Å] is also present. Although the aromatic ring systems stack down [010] (Fig. 3), no inter-ring π···π interactions are present [minimum ring centroid separation = 4.3407 (3) Å, the b-cell parameter].
In the 2,4-DCBA ligand the carboxylate group is significantly rotated out of the plane of the benzene ring [torsion angle C2—C1—C11—O11 = 138.2 (4)°] which is comparable with that in the ammonium salt (also a hemihydrate) [-137.2 (3)°] (Smith, 2014).