A two-dimensional coordination polymer: poly[di­aqua­(μ₄-4,4′-oxy­di­benzo­ato)(μ₂-4,4′-oxy­di­benzo­ato)dilead(II)]

In a new two-dimensional coordination polymer, [Pb(C₁₄H₈O₅)(H₂O)]_n, the asymmetric unit consists of a Pb^II cation, two halves of two crystallographically distinct fully deprotonated 4,4′-oxydibenzoate ligands and one aqua ligand. Single-crystal X-ray diffraction analysis reveals that the compound is a coordination polymer with the point symbol {5³}₂{5⁴.8²}. In addition, it exhibits a strong fluorescence emission in the solid state at room temperature.

S1. Introduction

Recent research on coordination polymers has tended to focus not only on their diverse topologies and intriguing structures but also on their potential applications in molecular magnetism, enanti­oselective catalysis and separation, gas sorption and nonlinear optics (Cao et al., 1992; Dincǎ et al., 2006; Plabst et al., 2009). It is well known that the construction of coordination polymers is strongly dependent on a number of factors, such as the solvent system, temperature, organic ligands and metal atoms (Kan et al., 2012; Liu et al., 2012). Among these factors, the organic ligands play a key role in determining the final architectures. A popular method for the construction of coordination polymers is to utilize carboxyl­ate-containing ligands, due to their excellent coordination capability and flexible coordination patterns. The members of an important family of multidentate O-donor ligands, the semi-rigid V-shaped di­carboxyl­ate ligands, such as 4,4'-(hexa­fluoro­iso­propyl­idene)bis­(benzoic acid), 4,4'-sulfonyl­bis­(benzoic acid) and 4-(4-carb­oxy­benzoyl)­benzoic acid, have been used extensively in constructing new coordination polymers (Chen et al., 2011; Song et al., 2007; Su et al., 2010; Tanaka et al., 2008; Tao, 2013; Wang et al., 2013). We have employed the V-shaped di­carboxyl­ate ligand 4,4'-oxybis(benzoic acid) (H₂OBA) and have successfully synthesized a new two-dimensional coordination polymer, [Pb(OBA)(H₂O)]_n, (I), and report herein its synthesis, crystal structure and physical properties.

S2. Experimental

All reagents and solvents used in the experiment were purchased from commercial sources and used without further purification. The IR spectra were recorded from KBr pellets in the range 4000–400 cm^-1 on a VECTOR 22 spectrometer. Elemental analysis was carried out using a Perkin–Elmer 240C elemental analyser. The fluorescence spectrum was recorded on a Fluoro Max-P spectrophotometer.

S2.1. Synthesis and crystallization

The pH of a mixture of Pb(NO₃)₂ (0.1656 g, 0.5 mmol) and H₂OBA (0.1292 g, 0.5 mmol) in distilled water (8 ml) was adjusted to 6.3 by the addition of tri­ethyl­amine. The resultant solution was heated at 423 K in a Teflon-lined stainless steel autoclave for 7 d. The reaction system was then cooled slowly to room temperature. Colourless block-shaped crystals of (I) were collected by filtration and washed several times with water and ethanol (yield 32.3%, based on H₂OBA). Elemental analysis for C₁₄H₁₀PbO₆: C 34.93, H 2.09%; found: C 35.03, H 2.10%. Selected IR peaks (ν, cm^-1) : 3418 (w), 1593 (m), 1487 (s), 1415 (s), 1129 (w), 873 (s), 772 (s), 673 (m), 537 (w), 474 (w).

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms bonded to C atoms were placed in calculated positions and treated using a riding-model approximation, with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C). The two water H atoms were located in a difference Fourier map, idealized to O—H distances of 0.85 Å and refined as riding atoms, with U_iso(H) = 1.5U_eq(O).

S3. Results and discussion

The title compound, [Pb(OBA)(H₂O)]_n, (I) (Fig. 1), crystallizes in the orthorhombic space group Pccn with an asymmetric unit consisting of a Pb^II cation at a general position, two halves of two crystallographically distinct doubly deprotonated OBA^2- ligands (OBA-A consists of atoms O1–O3/C1–C7 and OBA-B of atoms O4–O6/C8–C14) and one aqua ligand. The OBA ligands sit astride twofold axes parallel to the crystallographic c axis. The coordination geometry of the Pb^II cation consists of two O atoms from a chelating carboxyl­ate group of an OBA-A ligand [Pb1—O1 = 2.418 (5) Å and Pb1—O2 = 2.549 (4) Å], two O atoms from monodentate carboxyl­ate groups of two different OBA-B ligands [Pb1—O4 = 2.428 (4) Å and Pb1—O4^iv = 2.723 (4) Å; symmetry code: (iv) -x + 1, y - 1/2, -z + 3/2] and one O atom from the aqua ligand [Pb1—O7 = 2.615 (5) Å] to give a distorted PbO₅ fragment with trigonal–bipyramidal geometry. The Pb—O bond distances thus range from 2.418 (5) to 2.723 (4) Å and the O—Pb—O bond angles vary from 52.55 (15) to 155.06 (15)°, which are comparable with the values reported for other Pb–carboxyl­ate compounds (Chen et al., 2008; Xu et al., 2006; Yang et al., 2007, 2008).

In compound (I), the OBA-A ligands adopt an exobidentate µ₂-κ⁴O,O':O'',O''' binding mode connecting two Pb1 atoms, while the OBA-B ligands adopt an exo­tetra­dentate µ₄-κ⁴O:O:O':O' binding mode joining four Pb1 atoms. As shown in Fig. 2, the Pb1 atoms and OBA-B dianions construct {[Pb(OBA-B)_0.5]⁺}_n nets that are arranged parallel to the (001) crystal planes. The {[Pb(OBA-B)_0.5]⁺}_n nets are further crosslinked into [Pb(OBA)]_n neutral layers by OBA-A ligands (Fig. 3). The most intriguing structural feature of (I) is that successive Pb^II centres are bridged by O4 atoms with a bond angle of 107.60 (16)° to form a –Pb–O–Pb– chain along the b axis (Fig. 4).

The two-dimensional layers of (I) can be simplified by considering the Pb1 atoms, OBA-B ligands and OBA-A ligands as 3-, 4- and 2-connected nodes, respectively. An analysis using the TOPOS software (Blatov et al., 2000) reveals that (I) has a 3,4-connected two-dimensional network with the point symbol {5³}₂{5⁴.8²} (Fig. 5).

Inter- and intra­molecular O—H···O hydrogen bonds connect the two-dimensional layers of (I). A hydrogen bond [O7—H7A···O5ⁱ; symmetry code: (i) -x + 1, y + 1/2, -z + 3/2] and an incidental contact (C7—H7···O1) are present within the layer (Table 2). Neighbouring two-dimensional layers are connected by O7—H7B···O5ⁱⁱ hydrogen bonds, stabilizing the three-dimensional structure (Fig. 6) [symmetry code: (ii) x, -y + 1/2, z + 1/2]. This framework is reinforced by a C—H···π inter­action [H10···Cg1ⁱⁱⁱ = 2.95 (3) Å, C10···Cg1ⁱⁱⁱ = 3.776 (8) Å and C10—H10···Cg1ⁱⁱⁱ = 149.2 (2)°; Cg1 is the centroid of the C2–C7 ring; symmetry code: (iii) x, -y - 1/2, -z - 1/2]. A C—O···π contact accompanies the C—H···π inter­action [O5···Cg1ⁱⁱⁱ = 3.991 (6) Å, C8···Cg1ⁱⁱⁱ = 4.745 (7) Å and C8—O5···Cg1ⁱⁱⁱ = 120.2 (4)°].

The solid-state photoluminescence of (I) has been investigated at ambient temperature. Upon excitation at 306 nm, the OBA^2- ligand exhibits a strong photoluminescence peak with an emission maximum at ca 383 nm, which is probably attributable to π*–n or π*–π transitions, as reported previously (Zhang et al., 2013). Irradiation of (I) with UV light (λ_ex = 320 nm) in the solid state results in an emission band centred at ~385 nm (Fig. 7). The emission curve of (I) is similar to that of H₂OBA. Thus, the emissive behaviour of (I) likely originates from the intra­ligand π → π* transitions of the OBA^2- ligands.

In conclusion, we have successfully synthesized a new lead(II) coordination polymer based on 4,4'-oxybis(benzoic acid), which has been characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal structure analysis of (I) reveals a two-dimensional framework with point symbol {5³}₂{5⁴.8²}. We are not aware of any previous occurrences of a net with this point symbol. In addition, (I) exhibits strong fluorescence emission in the solid state at room temperature.

Related literature

For related literature, see: Blatov et al. (2000); Cao et al. (1992); Chen et al. (2008, 2011); Dincǎ et al. (2006); Kan et al. (2012); Liu et al. (2012); Plabst et al. (2009); Song et al. (2007); Su et al. (2010); Tanaka et al. (2008); Tao (2013); Wang et al. (2013); Xu et al. (2006); Yang et al. (2007, 2008); Zhang et al. (2013).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The coordination of the Pb^II cations in (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. [Symmetry code: (iv) -x + 1, y - 1/2, -z + 3/2.]
	Fig. 2. A view of the {[Pb(OBA-B)0.5]^+}n layer substructure in (I).
	Fig. 3. A view of the full two-dimensional net of (I).
	Fig. 4. A view of the Pb—O—Pb chain in (I), which is propagated along the b axis.
	Fig. 5. A network representation of the 3,4-connected binodal net with point symbol {5^3}2{5^4.8^2}. Red nodes represent the OBA-B^2- ligands and bright-green spheres represent the Pb1 nodes.
	Fig. 6. A perspective view of the three-dimensional supramolecular structure of (I), incorporating O—H···O hydrogen bonds and C—H···O interactions (dashed lines). H atoms not involved in hydrogen bonding have been omitted.
	Fig. 7. The solid-state emission spectrum of (I), recorded at room temperature.

Poly[diaqua(µ₄-4,4'-oxydibenzoato)(µ₂-4,4'-oxydibenzoato)dilead(II)]

Crystal data

[Pb(C14H8O5)(H2O)]	Z = 8
Mr = 481.42	F(000) = 1792
Orthorhombic, Pccn	Dx = 2.493 Mg m^−3
Hall symbol: -P 2ab 2ac	Mo Kα radiation, λ = 0.71073 Å
a = 28.848 (2) Å	µ = 13.18 mm^−1
b = 7.6951 (6) Å	T = 296 K
c = 11.5552 (9) Å	Block, colourless
V = 2565.1 (3) Å^3	0.21 × 0.19 × 0.17 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2280 independent reflections
Radiation source: fine-focus sealed tube	1882 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.050
ϕ and ω scans	θmax = 25.1°, θmin = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −34→34
Tmin = 0.078, Tmax = 0.106	k = −9→4
11949 measured reflections	l = −13→13

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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.069	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0231P)^2 + 12.7633P] where P = (Fo^2 + 2Fc^2)/3
2280 reflections	(Δ/σ)max = 0.001
191 parameters	Δρmax = 1.02 e Å^−3
0 restraints	Δρmin = −0.98 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	0.5734 (2)	−0.1009 (9)	0.8956 (6)	0.0244 (15)
C2	0.6208 (2)	−0.1384 (8)	0.9392 (6)	0.0225 (14)
C3	0.6513 (2)	−0.2424 (9)	0.8764 (6)	0.0246 (15)
H3	0.6417	−0.2897	0.8064	0.030*
C4	0.6956 (2)	−0.2771 (9)	0.9154 (6)	0.0287 (16)
H4	0.7157	−0.3452	0.8720	0.034*
C5	0.7094 (2)	−0.2083 (9)	1.0209 (6)	0.0247 (15)
C6	0.6800 (2)	−0.1024 (10)	1.0835 (6)	0.0311 (16)
H6	0.6898	−0.0543	1.1532	0.037*
C7	0.6359 (2)	−0.0681 (9)	1.0422 (6)	0.0282 (16)
H7	0.6162	0.0033	1.0845	0.034*
C8	0.5771 (2)	0.1331 (8)	0.6408 (6)	0.0250 (15)
C9	0.6229 (2)	0.1623 (8)	0.6965 (6)	0.0250 (15)
C10	0.6630 (2)	0.0911 (10)	0.6504 (6)	0.0310 (16)
H10	0.6609	0.0208	0.5851	0.037*
C11	0.7057 (3)	0.1217 (11)	0.6988 (6)	0.0390 (19)
H11	0.7324	0.0750	0.6659	0.047*
C12	0.7084 (2)	0.2221 (11)	0.7965 (6)	0.0354 (18)
C13	0.6693 (3)	0.2891 (10)	0.8460 (6)	0.0366 (19)
H13	0.6716	0.3536	0.9138	0.044*
C14	0.6266 (2)	0.2623 (9)	0.7968 (6)	0.0304 (16)
H14	0.6002	0.3104	0.8302	0.037*
O1	0.54797 (16)	0.0003 (6)	0.9558 (4)	0.0325 (12)
O2	0.55922 (15)	−0.1621 (6)	0.8014 (4)	0.0300 (11)
O3	0.7500	−0.2500	1.0763 (6)	0.0366 (18)
O4	0.54129 (15)	0.1963 (6)	0.6909 (4)	0.0305 (11)
O5	0.57524 (16)	0.0527 (7)	0.5467 (4)	0.0359 (12)
O6	0.7500	0.2500	0.8559 (6)	0.057 (3)
O7	0.50051 (16)	0.3399 (7)	0.9030 (4)	0.0354 (13)
H7B	0.5215	0.3388	0.9547	0.053*
H7A	0.4756	0.3820	0.9306	0.053*
Pb1	0.487889 (8)	0.03283 (3)	0.81150 (2)	0.02513 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.025 (4)	0.018 (3)	0.030 (4)	−0.001 (3)	0.001 (3)	0.009 (3)
C2	0.018 (3)	0.023 (4)	0.026 (4)	0.000 (3)	−0.003 (3)	0.001 (3)
C3	0.017 (3)	0.031 (4)	0.026 (4)	0.001 (3)	−0.002 (3)	−0.004 (3)
C4	0.019 (3)	0.031 (4)	0.036 (4)	0.003 (3)	0.005 (3)	−0.007 (3)
C5	0.014 (3)	0.036 (4)	0.025 (4)	0.002 (3)	0.000 (3)	0.005 (3)
C6	0.021 (3)	0.047 (4)	0.026 (4)	−0.002 (3)	−0.003 (3)	−0.011 (3)
C7	0.017 (3)	0.035 (4)	0.033 (4)	0.008 (3)	0.002 (3)	−0.010 (3)
C8	0.021 (3)	0.021 (4)	0.033 (4)	−0.002 (3)	0.004 (3)	0.004 (3)
C9	0.026 (4)	0.022 (3)	0.027 (4)	−0.002 (3)	0.005 (3)	0.004 (3)
C10	0.031 (4)	0.034 (4)	0.027 (4)	−0.002 (3)	0.005 (3)	−0.004 (3)
C11	0.026 (4)	0.053 (5)	0.038 (4)	0.000 (4)	0.008 (4)	−0.007 (4)
C12	0.026 (4)	0.052 (5)	0.028 (4)	−0.013 (4)	−0.004 (3)	0.003 (4)
C13	0.042 (5)	0.039 (5)	0.029 (4)	−0.016 (4)	0.006 (3)	−0.006 (3)
C14	0.026 (4)	0.031 (4)	0.034 (4)	−0.004 (3)	0.007 (3)	−0.001 (3)
O1	0.020 (2)	0.039 (3)	0.038 (3)	0.011 (2)	−0.005 (2)	−0.001 (2)
O2	0.018 (2)	0.038 (3)	0.035 (3)	0.001 (2)	−0.007 (2)	0.000 (2)
O3	0.017 (3)	0.066 (5)	0.026 (4)	0.007 (3)	0.000	0.000
O4	0.019 (2)	0.025 (3)	0.048 (3)	0.000 (2)	0.008 (2)	0.005 (2)
O5	0.022 (2)	0.049 (3)	0.036 (3)	−0.001 (2)	0.001 (2)	−0.007 (3)
O6	0.024 (4)	0.121 (8)	0.027 (4)	−0.019 (5)	0.000	0.000
O7	0.032 (3)	0.037 (3)	0.038 (3)	0.009 (2)	−0.014 (2)	−0.012 (2)
Pb1	0.01752 (15)	0.02461 (16)	0.03327 (17)	0.00098 (11)	−0.00239 (12)	0.00287 (11)

Geometric parameters (Å, º)

C1—O2	1.254 (8)	C10—C11	1.375 (10)
C1—O1	1.276 (8)	C10—H10	0.9300
C1—C2	1.486 (9)	C11—C12	1.370 (10)
C2—C7	1.378 (9)	C11—H11	0.9300
C2—C3	1.394 (9)	C12—C13	1.366 (10)
C3—C4	1.379 (9)	C12—O6	1.400 (8)
C3—H3	0.9300	C13—C14	1.371 (10)
C4—C5	1.387 (9)	C13—H13	0.9300
C4—H4	0.9300	C14—H14	0.9300
C5—O3	1.374 (7)	O1—Pb1	2.418 (5)
C5—C6	1.380 (9)	O2—Pb1	2.549 (4)
C6—C7	1.384 (9)	O3—C5^i	1.374 (7)
C6—H6	0.9300	O4—Pb1	2.428 (4)
C7—H7	0.9300	O4—Pb1^ii	2.723 (4)
C8—O5	1.252 (8)	O6—C12^iii	1.400 (8)
C8—O4	1.279 (8)	O7—Pb1	2.615 (5)
C8—C9	1.488 (9)	O7—H7B	0.8500
C9—C10	1.386 (9)	O7—H7A	0.8501
C9—C14	1.395 (10)	Pb1—O4^iv	2.723 (4)
O2—C1—O1	121.0 (6)	C12—C11—H11	120.6
O2—C1—C2	121.4 (6)	C10—C11—H11	120.6
O1—C1—C2	117.5 (6)	C13—C12—C11	120.8 (7)
C7—C2—C3	118.4 (6)	C13—C12—O6	116.4 (7)
C7—C2—C1	120.5 (6)	C11—C12—O6	122.6 (7)
C3—C2—C1	121.1 (6)	C12—C13—C14	120.7 (7)
C4—C3—C2	121.7 (6)	C12—C13—H13	119.6
C4—C3—H3	119.2	C14—C13—H13	119.6
C2—C3—H3	119.2	C13—C14—C9	119.7 (7)
C3—C4—C5	118.6 (6)	C13—C14—H14	120.2
C3—C4—H4	120.7	C9—C14—H14	120.2
C5—C4—H4	120.7	C1—O1—Pb1	95.7 (4)
O3—C5—C6	114.6 (6)	C1—O2—Pb1	90.1 (4)
O3—C5—C4	124.4 (6)	C5—O3—C5^i	124.4 (8)
C6—C5—C4	120.6 (6)	C8—O4—Pb1	125.1 (4)
C5—C6—C7	119.7 (6)	C8—O4—Pb1^ii	127.3 (4)
C5—C6—H6	120.1	Pb1—O4—Pb1^ii	107.60 (16)
C7—C6—H6	120.1	C12—O6—C12^iii	121.2 (8)
C2—C7—C6	120.9 (6)	Pb1—O7—H7B	112.0
C2—C7—H7	119.5	Pb1—O7—H7A	112.2
C6—C7—H7	119.5	H7B—O7—H7A	110.0
O5—C8—O4	123.2 (6)	O1—Pb1—O4	89.68 (16)
O5—C8—C9	119.2 (6)	O1—Pb1—O2	52.55 (15)
O4—C8—C9	117.6 (6)	O4—Pb1—O2	76.49 (15)
C10—C9—C14	118.3 (7)	O1—Pb1—O7	73.43 (15)
C10—C9—C8	121.0 (6)	O4—Pb1—O7	71.07 (16)
C14—C9—C8	120.7 (6)	O2—Pb1—O7	115.97 (15)
C11—C10—C9	121.6 (7)	O1—Pb1—O4^iv	97.48 (15)
C11—C10—H10	119.2	O4—Pb1—O4^iv	133.06 (11)
C9—C10—H10	119.2	O2—Pb1—O4^iv	71.91 (14)
C12—C11—C10	118.8 (7)	O7—Pb1—O4^iv	155.06 (15)
O2—C1—C2—C7	179.2 (6)	O2—C1—O1—Pb1	−8.3 (7)
O1—C1—C2—C7	1.2 (9)	C2—C1—O1—Pb1	169.7 (5)
O2—C1—C2—C3	0.3 (10)	O1—C1—O2—Pb1	7.8 (6)
O1—C1—C2—C3	−177.6 (6)	C2—C1—O2—Pb1	−170.0 (5)
C7—C2—C3—C4	0.6 (10)	C6—C5—O3—C5^i	−153.4 (7)
C1—C2—C3—C4	179.5 (6)	C4—C5—O3—C5^i	32.6 (5)
C2—C3—C4—C5	1.0 (10)	O5—C8—O4—Pb1	81.7 (8)
C3—C4—C5—O3	171.5 (6)	C9—C8—O4—Pb1	−100.1 (6)
C3—C4—C5—C6	−2.2 (10)	O5—C8—O4—Pb1^ii	−100.1 (7)
O3—C5—C6—C7	−172.6 (6)	C9—C8—O4—Pb1^ii	78.1 (7)
C4—C5—C6—C7	1.7 (11)	C13—C12—O6—C12^iii	−144.8 (8)
C3—C2—C7—C6	−1.2 (10)	C11—C12—O6—C12^iii	40.4 (6)
C1—C2—C7—C6	180.0 (7)	C1—O1—Pb1—O4	−68.7 (4)
C5—C6—C7—C2	0.0 (11)	C1—O1—Pb1—O2	4.4 (3)
O5—C8—C9—C10	−4.8 (10)	C1—O1—Pb1—O7	−139.1 (4)
O4—C8—C9—C10	176.9 (6)	C1—O1—Pb1—O4^iv	64.7 (4)
O5—C8—C9—C14	175.3 (6)	C8—O4—Pb1—O1	68.3 (5)
O4—C8—C9—C14	−3.0 (9)	Pb1^ii—O4—Pb1—O1	−110.17 (18)
C14—C9—C10—C11	−2.2 (11)	C8—O4—Pb1—O2	16.9 (5)
C8—C9—C10—C11	177.9 (7)	Pb1^ii—O4—Pb1—O2	−161.6 (2)
C9—C10—C11—C12	1.4 (12)	C8—O4—Pb1—O7	140.9 (6)
C10—C11—C12—C13	0.8 (12)	Pb1^ii—O4—Pb1—O7	−37.61 (16)
C10—C11—C12—O6	175.5 (7)	C8—O4—Pb1—O4^iv	−31.6 (5)
C11—C12—C13—C14	−2.2 (12)	Pb1^ii—O4—Pb1—O4^iv	149.86 (19)
O6—C12—C13—C14	−177.2 (7)	C1—O2—Pb1—O1	−4.4 (4)
C12—C13—C14—C9	1.4 (11)	C1—O2—Pb1—O4	95.8 (4)
C10—C9—C14—C13	0.8 (10)	C1—O2—Pb1—O7	35.0 (4)
C8—C9—C14—C13	−179.3 (7)	C1—O2—Pb1—O4^iv	−119.4 (4)

Symmetry codes: (i) −x+3/2, −y−1/2, z; (ii) −x+1, y+1/2, −z+3/2; (iii) −x+3/2, −y+1/2, z; (iv) −x+1, y−1/2, −z+3/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7A···O5^ii	0.85	1.99	2.791 (7)	158
O7—H7B···O5^v	0.85	2.06	2.844 (7)	154

Symmetry codes: (ii) −x+1, y+1/2, −z+3/2; (v) x, −y+1/2, z+1/2.