A two-dimensional cadmium(II) coordination polymer based on 5-(pyridin-4-yl)isophthalic acid: poly[[tetra­aqua­bis­[μ₃-5-(pyridin-4-yl)isophthalato]dicadmium(II)] penta­hydrate]

The title Cd^II compound, {[Cd₂(C₁₃H₇NO₄)₂(H₂O)₄]·5H₂O}_n, was synthesized by the hydro­thermal reaction of Cd(NO₃)₂·4H₂O and 5-(pyridin-4-yl)isophthalic acid (H₂L). The asymmetric unit contains two crystallographically independent Cd^II cations, two deprotonated L²⁻ ligands, four coordinated water mol­ecules and five isolated water mol­ecules. One of the Cd^II cations adopts a six-coordinate octa­hedral coordination geometry involving three O atoms from one bidentate chelating and one monodentate carboxyl­ate group of two different L²⁻ ligands, one N atom of another L²⁻ ligand and two coordinated water mol­ecules. The second Cd^II cation adopts a seven-coordinate penta­gonal–bipyramidal coordination geometry involving four O atoms from two bidentate chelating carboxyl­ate groups of two different L²⁻ ligands, one N atom of another L²⁻ ligand and two coordinated water mol­ecules. Each L²⁻ ligand bridges three Cd^II cations and, likewise, each Cd^II cation connects to three L²⁻ ligands, giving rise to a two-dimensional graphite-like 6³ layer structure. These two-dimensional layers are further linked by O—H...O hydrogen-bonding inter­actions to form a three-dimensional supra­molecular architecture. The photoluminescence properties of the title compound were also investigated.

S1. Introduction

In the past few decades, coordination polymers (CPs) have received a great deal of inter­est, not only for their potential applications in gas separation/storage (Li et al., 2009), catalysis (Liu et al., 2014), magnetism (Kurmoo, 2009) and luminescence (Cui et al., 2012), but also for their fascinating architectures and topologies. From the viewpoint of crystal engineering, the judicious selection of well designed organic bridging ligands containing modifiable backbones and known connective geometries, together with metal centres with different coordination preferences, has proven to be an efficient approach for the formation of target CPs. In this context, pyridyl­carboxyl­ate ligands have been documented as a very important type of organic ligand for the construction of CPs. For example, isonicotinate (Zhang et al., 2005), (pyridin-4-yl)acetate (Du et al., 2006), 3-(pyridin-3-yl)benzoate (Zhong et al., 2008), 3-(pyridin-4-yl)benzoate (Li et al., 2010) and 3-methyl-5-(pyridin-4-yl)benzoic acid (Zhang, Hu, Zhang et al., 2012) have been used widely to prepare numerous CPs. More recently, an elongated pyridinyl–di­carboxyl­ate ligand, i.e. deprotonated 5-(pyridin-4-yl)isophthalic acid (H₂L), has attracted much attention (Xiang et al., 2011; Liu et al., 2012; Zhang, Hu, Wang et al., 2012; Zhang et al., 2014). 5-(Pyridin-4-yl)isophthalate (L^2-) has some remarkable features as a ligand: (i) it contains pyridine and carboxyl­ate groups which can provide multiple coordination sites to construct CPs; (ii) it is a rigid ligand with a large backbone which may lead to the formation of large voids; and (iii) it has many N/O-atom donors which can regulate supra­molecular architectures through hydrogen-bonding inter­actions.

In our previous work, we have also prepared three luminescent Ln^III CPs (Zhang, Hu, Wang et al., 2012) and a nanotubular Zn^II CP (Zhang et al., 2014) by the reactions of 5-(pyridin-4-yl)isophthalic acid with Ln^III cations and Zn^II cations, respectively. In a continuation of our research in this area, we chose the Period 5 element cadmium as the metal centre because the d¹⁰ Cd^II cations can produce a variety of compounds with intriguing structures and properties (Wang et al., 2012; Deng et al., 2013; Haldar et al., 2014). Herein, we report the synthesis, crystal structure and photoluminescence properties of the two-dimensional cadmium(II) coordination polymer {[Cd₂(L)₂(H₂O)₄]·5H₂O}_n, (I).

S2. Experimental

S2.1. Synthesis and crystallization

All chemicals were of reagent grade, were obtained from commercial sources and were used without further purification. For the synthesis of (I), a mixture of H₂L (0.0243 g, 0.1 mmol) and Cd(NO₃)₂·4H₂O (0.0308 g, 0.1 mmol) in H₂O (5 ml) was placed in a Teflon-lined stainless steel vessel, which was heated to 393 K for 3 d, and then cooled to room temperature at a rate of 5 K h^-1. Colourless block-shaped crystals of (I) were obtained after filtration (yield 59.5%, based on H₂L). Elemental analysis, calculated for C₂₆H₃₂Cd₂N₂O₁₇: C 35.92, H 3.71, N 3.22%; found: C 35.96, H 3.64, N 3.26%. Spectroscopic analysis: IR (KBr, ν, cm^-1): 3374 (s), 1612 (s), 1558 (vs), 1448 (s), 1364 (vs), 1070 (w), 842 (w), 777 (w), 740 (m), 634 (m), 565 (w), 506 (w).

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms attached to C atoms were placed in geometrically idealized positions and included as riding atoms, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C) for aromatic H atoms. Water H atoms were either located in difference Fourier maps or placed in calculated positions so as to yield favourable hydrogen-bond inter­actions, as far as possible. They were then constrained to ride on their parent O atoms, with O—H = 0.85 (2) Å and U_iso(H) = 1.2U_eq(O).

S3. Results and discussion

Coordination polymer (I) crystallizes in the triclinic space group P1 and the asymmetric unit contains two crystallographically independent Cd^II cations, two deprotonated L^2- ligands, four coordinated water molecules and five isolated water molecules. As shown in Fig. 1, ion Cd1 adopts a six-coordinated o­cta­hedral geometry involving three O atoms (O1, O2 and O5) from one bidentate chelate and one monodentate carboxyl­ate group of two different L^2- ligands, one N atom [N2ⁱ; symmetry code: (i) x, y + 1, z] of another L^2- ligand and two coordinated water molecules (O9 and O10). Ion Cd2 adopts a seven-coordinated penta­gonal–bipyramidal geometry involving four O atoms [O3, O4, O7ⁱⁱ and O8ⁱⁱ; symmetry code: (ii) x - 1, y, z + 1] from two bidentate chelate carboxyl­ate groups of two different L^2- ligands, one N atom [N1ⁱⁱⁱ; symmetry code: (iii) x, y - 1, z] of another L^2- ligand and two coordinated water molecules (O11 and O12). The Cd—O and Cd—N bond lengths (Table 2) are in the ranges 2.282 (9)–2.583 (9) and 2.317 (8)–2.336 (10) Å, respectively, which are comparable with other Cd^II–carboxyl­ate compounds (Yang et al., 2013). In (I), the L^2- ligands exhibit two kinds of coordination mode. One is a µ₃-κ⁵N:O¹,O^1':O³,O^3' coordination mode and the other is a µ₃-κ⁴N:O¹,O^1':O³ coordination mode.

As shown in Fig. 2(a), each L^2- ligand bridges three Cd^II cations and, likewise, each Cd^II cation is connected to three L^2- ligands, giving rise to an extended two-dimensional coplanar layer structure with hexagonal windows. From a topological viewpoint, the Cd^II cations and L^2- ligands in (I) can both be regarded as 3-connected nodes and the layer can thus be simplified as a two-dimensional graphite-like 6³ topological network (Fig. 2a). Inter­estingly, these neighbouring two-dimensional layers are further linked by O—H···O hydrogen bonds between the coordinated water molecules and the carboxyl­ate O atoms (O9—H9A···O8^iv, O10—H10A···O5^v, O11—H11A···O1^vi and O12—H12A···O4^viii; see Table 3 for hydrogen-bond geometry and symmetry codes), to form a three-dimensional supra­molecular architecture with one-dimensional channels along the a axis (Fig. 2b). A particularly striking feature of this compound is that adjacent isolated water molecules are connected to each other by O—H···O hydrogen bonds (O13—H13B···O17, O14—H14B···O16, O14—H14A···O17, O15—H15A···O16 and O15—H15B···O13^x; Table 3) to form one-dimensional water chains within each one-dimensional channel of this framework. Similar one-dimensional water chains penetrating channels are found in other transition metal coordination polymers (Sang & Xu, 2010; Zhang et al., 2011; Liu et al., 2012). In addition, strong O—H···O hydrogen bonds are observed between the one-dimensional water chains and the host three-dimensional supra­molecular framework (O9—H9B···O14ⁱ, O10—H10B···O15^iv, O11—H11B···O15^vii, O12—H12B···O14^ix, O13—H13A···O2ⁱⁱⁱ, O16—H16A···O6^iv, O16—H16B···O3^x and O17—H17A···O7^iv; Table 3 and Fig. 2c), which can be considered to consolidate the three-dimensional supra­molecular framework structure of (I) further. After isolated water molecules have been removed, the effective free volume of the channels is 16.9% (calculated using PLATON; Spek, 2009) of the crystal volume (266 ų of the 1574.5 ų per unit-cell volume).

Powder X-ray diffraction (PXRD) experiments were carried out on (I) in order to establish the crystalline phase purity for bulk sample preparation. As shown in Fig. 3, the PXRD pattern of the as-synthesized sample matches well with the simulated one derived from the single-crystal diffraction data, demonstrating the good phase purity of the crystalline product of (I).

The solid-state luminescent properties of (I) and free H₂L were investigated at room temperature. As shown in Fig. 4, upon excitation at 330 nm, (I) exhibits a strong purple luminescence with a maximum emission band around 390 nm. It should be pointed out that the emission of (I) is neither metal-to-ligand charge transfer (MLCT) nor ligand-to-metal charge transfer (LMCT) in nature, since Cd^II cations are difficult to oxidize or reduce because of their d¹⁰ electron configuration. The emission can probably be assigned to intra­ligand (π–π*) luminescence emission, because a similar emission is observed for free H₂L at 415 nm upon excitation at 330 nm. The small blue shift (25 nm) for the emission of (I) compared with that of the free H₂L molecule should result from the change in the ligand conformation according to Perkovic's hypothesis (Perkovic, 2000).

Computing details

Data collection: SMART (Bruker, 2007); cell refinement: SMART (Bruker, 2007); data reduction: SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The coordination environment of the Cd^II cations in (I), showing the atom-numbering scheme. All the isolated water molecules have been omitted for clarity. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) x, y + 1, z; (ii) x - 1, y, z + 1; (iii) x, y - 1, z.]
	Fig. 2. (a) The two-dimensional network and a schematic illustration of the 6^3 topology of (I) (the green sticks and turquoise polyhedra present the L^2- ligands and the Cd^II cations, respectively). (b) The three-dimensional supramolecular architecture of (I) linked by hydrogen-bonding interactions, with the one-dimensional water chains shown in space-filling mode. (c) Hydrogen bonds among the isolated water molecules, coordinated water molecules and carboxylate O atoms. [Symmetry codes: (iii) x, y - 1, z; (iv) -x + 1, -y + 1, -z + 1; (vii) -x + 1, -y + 1, -z + 2; (ix) x - 1, y, z; (x) x + 1, y, z; (xi) x + 1, y - 1, z.]
	Fig. 3. Powder X-ray diffraction patterns for (I).
	Fig. 4. The solid-state emission spectra of (I) and free H2L at room temperature.

Poly[[tetraaquabis[µ₃-5-(pyridin-4-yl)isophthalato]dicadmium(II)] pentahydrate]

Crystal data

[Cd2(C13H7NO4)2(H2O)4]·5H2O	Z = 2
Mr = 869.34	F(000) = 868
Triclinic, P1	Dx = 1.834 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 11.144 Å	Cell parameters from 1092 reflections
b = 11.599 Å	θ = 2.6–28.5°
c = 13.529 Å	µ = 1.43 mm^−1
α = 104.05°	T = 173 K
β = 97.18°	Block, colourless
γ = 108.05°	0.20 × 0.20 × 0.18 mm
V = 1574.4 Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	5540 independent reflections
Radiation source: fine-focus sealed tube	2771 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.097
Detector resolution: 8.33 pixels mm^-1	θmax = 25.0°, θmin = 2.6°
φ and ω scans	h = −13→13
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	k = −11→13
Tmin = 0.763, Tmax = 0.783	l = −16→15
9462 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)] = 0.074	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.195	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0572P)^2] where P = (Fo^2 + 2Fc^2)/3
5540 reflections	(Δ/σ)max < 0.001
424 parameters	Δρmax = 1.14 e Å^−3
6 restraints	Δρmin = −1.91 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
Cd1	0.17676 (9)	0.74890 (8)	0.57963 (7)	0.0381 (3)
Cd2	−0.32999 (9)	0.40072 (8)	1.07387 (7)	0.0377 (3)
O1	0.0531 (9)	0.6701 (8)	0.6975 (7)	0.046 (2)
O2	0.0628 (9)	0.8611 (8)	0.6910 (7)	0.049 (3)
O3	−0.2154 (9)	0.4730 (8)	0.9333 (7)	0.047 (2)
O4	−0.2811 (9)	0.5978 (8)	1.0465 (7)	0.046 (2)
O5	0.2172 (9)	0.5631 (7)	0.5468 (7)	0.046 (2)
O6	0.3052 (9)	0.6722 (8)	0.4458 (7)	0.049 (3)
O7	0.5395 (9)	0.4799 (8)	0.1864 (7)	0.047 (2)
O8	0.5500 (8)	0.2921 (8)	0.1834 (7)	0.044 (2)
O9	0.3618 (9)	0.8525 (8)	0.7080 (7)	0.056 (3)
H9A	0.3949	0.8154	0.7447	0.084*
H9B	0.4066	0.9313	0.7291	0.084*
O10	−0.0155 (8)	0.6610 (9)	0.4538 (7)	0.057 (3)
H10A	−0.0694	0.5985	0.4692	0.085*
H10B	0.0004	0.6319	0.3928	0.085*
O11	−0.1434 (9)	0.4759 (8)	1.1984 (8)	0.067 (3)
H11A	−0.1155	0.4317	1.2306	0.100*
H11B	−0.0907	0.5521	1.2210	0.100*
O12	−0.5138 (9)	0.3169 (10)	0.9411 (9)	0.085 (4)
H12A	−0.5816	0.3360	0.9369	0.127*
H12B	−0.5233	0.2482	0.8951	0.127*
O13	0.1128 (12)	0.1285 (11)	0.7709 (9)	0.098 (4)
H13A	0.0982	0.0486	0.7471	0.147*
H13B	0.1656	0.1673	0.7394	0.147*
O14	0.4910 (12)	0.1130 (11)	0.7637 (10)	0.107 (5)
H14A	0.4481	0.1575	0.7478	0.161*
H14B	0.5617	0.1638	0.7580	0.161*
O15	0.9758 (10)	0.2805 (9)	0.7308 (8)	0.077 (3)
H15A	0.8992	0.2671	0.7401	0.115*
H15B	0.9917	0.2120	0.7202	0.115*
O16	0.7259 (10)	0.2846 (9)	0.7441 (7)	0.078 (3)
H16A	0.7188	0.3081	0.6896	0.117*
H16B	0.7443	0.3488	0.7973	0.117*
O17	0.3456 (18)	0.2668 (15)	0.7100 (13)	0.183 (8)
H17A	0.3812	0.3459	0.7426	0.275*
H17B	0.3290	0.2250	0.6458	0.275*
N1	−0.2719 (10)	1.2253 (9)	1.0137 (8)	0.033 (3)
N2	0.2287 (10)	−0.0752 (9)	0.5166 (9)	0.043 (3)
C1	0.0253 (12)	0.7690 (12)	0.7248 (10)	0.039 (3)
C2	−0.2270 (12)	0.5778 (11)	0.9699 (10)	0.034 (3)
C3	−0.0615 (12)	0.7739 (11)	0.8045 (9)	0.033 (3)
C4	−0.1051 (12)	0.6743 (11)	0.8458 (9)	0.033 (3)
H4	−0.0849	0.5998	0.8228	0.039*
C5	−0.1796 (12)	0.6840 (11)	0.9222 (9)	0.034 (3)
C6	−0.2094 (12)	0.7935 (11)	0.9524 (9)	0.033 (3)
H6	−0.2603	0.7999	1.0034	0.039*
C7	−0.1682 (12)	0.8933 (11)	0.9113 (9)	0.031 (3)
C8	−0.0940 (12)	0.8819 (12)	0.8363 (10)	0.040 (3)
H8	−0.0650	0.9489	0.8063	0.047*
C9	−0.2044 (12)	1.0078 (11)	0.9459 (9)	0.030 (3)
C10	−0.3061 (13)	1.0063 (12)	0.9941 (11)	0.056 (4)
H10	−0.3561	0.9296	1.0051	0.068*
C11	−0.3371 (15)	1.1131 (13)	1.0266 (13)	0.066 (5)
H11	−0.4081	1.1074	1.0597	0.080*
C12	−0.1766 (14)	1.2281 (12)	0.9665 (10)	0.049 (4)
H12	−0.1296	1.3060	0.9557	0.059*
C13	−0.1388 (14)	1.1224 (12)	0.9305 (10)	0.051 (4)
H13	−0.0689	1.1301	0.8959	0.061*
C14	0.2831 (13)	0.5727 (12)	0.4747 (10)	0.038 (3)
C15	0.5116 (13)	0.3819 (12)	0.2204 (11)	0.042 (4)
C16	0.3298 (13)	0.4717 (11)	0.4272 (9)	0.035 (3)
C17	0.3960 (11)	0.4774 (11)	0.3487 (9)	0.035 (3)
H17	0.4144	0.5501	0.3247	0.042*
C18	0.4370 (11)	0.3788 (10)	0.3033 (9)	0.027 (3)
C19	0.3977 (12)	0.2687 (11)	0.3327 (10)	0.036 (3)
H19	0.4190	0.1985	0.2979	0.043*
C20	0.3293 (11)	0.2563 (11)	0.4098 (9)	0.033 (3)
C21	0.2926 (12)	0.3577 (11)	0.4571 (10)	0.036 (3)
H21	0.2431	0.3508	0.5090	0.043*
C22	0.2928 (13)	0.1409 (12)	0.4465 (10)	0.040 (3)
C23	0.3606 (15)	0.0591 (13)	0.4320 (12)	0.059 (4)
H23	0.4313	0.0756	0.3983	0.071*
C24	0.3253 (14)	−0.0477 (12)	0.4666 (12)	0.057 (4)
H24	0.3721	−0.1038	0.4542	0.068*
C25	0.1603 (16)	−0.0001 (14)	0.5272 (14)	0.074 (5)
H25	0.0885	−0.0202	0.5592	0.089*
C26	0.1894 (16)	0.1071 (14)	0.4933 (14)	0.076 (6)
H26	0.1371	0.1582	0.5025	0.092*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0558 (7)	0.0342 (6)	0.0479 (7)	0.0263 (5)	0.0335 (6)	0.0295 (5)
Cd2	0.0560 (7)	0.0335 (6)	0.0465 (7)	0.0255 (5)	0.0332 (6)	0.0291 (5)
O1	0.071 (7)	0.048 (6)	0.050 (6)	0.039 (5)	0.043 (5)	0.034 (5)
O2	0.064 (7)	0.050 (6)	0.063 (6)	0.029 (5)	0.050 (5)	0.040 (5)
O3	0.074 (7)	0.034 (5)	0.050 (6)	0.022 (5)	0.034 (5)	0.029 (4)
O4	0.073 (7)	0.048 (6)	0.053 (6)	0.041 (5)	0.044 (5)	0.037 (5)
O5	0.073 (7)	0.031 (5)	0.056 (6)	0.031 (5)	0.041 (5)	0.025 (4)
O6	0.084 (7)	0.035 (5)	0.062 (6)	0.039 (5)	0.048 (6)	0.036 (5)
O7	0.048 (3)	0.047 (3)	0.047 (3)	0.0163 (13)	0.0116 (11)	0.0148 (12)
O8	0.063 (6)	0.051 (6)	0.054 (6)	0.037 (5)	0.047 (5)	0.036 (5)
O9	0.057 (6)	0.049 (6)	0.073 (7)	0.023 (5)	0.018 (5)	0.030 (5)
O10	0.058 (7)	0.067 (7)	0.060 (6)	0.022 (5)	0.038 (5)	0.033 (5)
O11	0.076 (7)	0.042 (6)	0.077 (7)	0.009 (5)	−0.016 (6)	0.038 (5)
O12	0.045 (7)	0.095 (9)	0.092 (9)	0.027 (6)	0.017 (6)	−0.017 (7)
O13	0.129 (11)	0.076 (8)	0.120 (11)	0.034 (8)	0.077 (9)	0.061 (7)
O14	0.108 (10)	0.076 (9)	0.130 (12)	0.016 (7)	0.050 (9)	0.024 (8)
O15	0.077 (8)	0.060 (7)	0.098 (9)	0.006 (6)	0.028 (7)	0.049 (6)
O16	0.129 (10)	0.069 (7)	0.047 (6)	0.039 (7)	0.022 (7)	0.028 (6)
O17	0.27 (2)	0.107 (13)	0.135 (15)	0.020 (14)	0.033 (15)	0.031 (11)
N1	0.050 (7)	0.028 (6)	0.035 (6)	0.026 (5)	0.022 (6)	0.009 (5)
N2	0.055 (8)	0.031 (6)	0.073 (8)	0.028 (6)	0.037 (7)	0.040 (6)
C1	0.043 (9)	0.043 (8)	0.049 (9)	0.020 (7)	0.032 (7)	0.031 (7)
C2	0.038 (8)	0.030 (7)	0.044 (8)	0.019 (6)	0.014 (7)	0.019 (6)
C3	0.058 (9)	0.033 (7)	0.034 (7)	0.030 (7)	0.035 (7)	0.028 (6)
C4	0.058 (9)	0.032 (7)	0.035 (7)	0.035 (7)	0.028 (7)	0.023 (6)
C5	0.053 (9)	0.029 (7)	0.025 (7)	0.014 (6)	0.019 (7)	0.014 (6)
C6	0.046 (8)	0.032 (7)	0.034 (7)	0.017 (6)	0.025 (6)	0.024 (6)
C7	0.038 (8)	0.037 (7)	0.032 (7)	0.024 (6)	0.020 (6)	0.018 (6)
C8	0.048 (9)	0.042 (8)	0.042 (8)	0.020 (7)	0.021 (7)	0.024 (6)
C9	0.048 (8)	0.028 (7)	0.031 (7)	0.022 (6)	0.018 (6)	0.022 (6)
C10	0.073 (11)	0.030 (7)	0.094 (12)	0.023 (7)	0.069 (10)	0.036 (8)
C11	0.082 (12)	0.042 (9)	0.104 (13)	0.032 (9)	0.071 (11)	0.033 (9)
C12	0.089 (12)	0.030 (8)	0.046 (9)	0.029 (8)	0.028 (9)	0.026 (7)
C13	0.076 (11)	0.049 (9)	0.046 (9)	0.031 (8)	0.037 (8)	0.024 (7)
C14	0.045 (9)	0.034 (8)	0.042 (8)	0.017 (7)	0.013 (7)	0.016 (6)
C15	0.055 (9)	0.032 (8)	0.057 (9)	0.015 (7)	0.038 (8)	0.031 (7)
C16	0.054 (9)	0.027 (7)	0.039 (8)	0.018 (6)	0.028 (7)	0.023 (6)
C17	0.048 (9)	0.034 (7)	0.041 (8)	0.021 (6)	0.021 (7)	0.028 (6)
C18	0.035 (8)	0.028 (7)	0.032 (7)	0.017 (6)	0.019 (6)	0.020 (5)
C19	0.043 (8)	0.031 (7)	0.043 (8)	0.017 (6)	0.026 (7)	0.014 (6)
C20	0.040 (8)	0.030 (7)	0.044 (8)	0.017 (6)	0.023 (7)	0.024 (6)
C21	0.052 (9)	0.032 (7)	0.037 (8)	0.021 (7)	0.021 (7)	0.022 (6)
C22	0.053 (9)	0.036 (7)	0.055 (9)	0.025 (7)	0.029 (7)	0.036 (7)
C23	0.081 (12)	0.052 (9)	0.088 (12)	0.041 (9)	0.063 (10)	0.052 (9)
C24	0.074 (11)	0.043 (9)	0.092 (12)	0.034 (8)	0.052 (10)	0.053 (8)
C25	0.095 (13)	0.054 (10)	0.126 (15)	0.046 (10)	0.084 (12)	0.062 (10)
C26	0.091 (13)	0.054 (10)	0.139 (16)	0.046 (9)	0.078 (12)	0.072 (11)

Geometric parameters (Å, º)

Cd1—O1	2.399 (9)	N1—Cd2^i	2.317 (8)
Cd1—O2	2.475 (8)	N2—C25	1.319 (16)
Cd1—O5	2.287 (7)	N2—C24	1.339 (16)
Cd1—O9	2.295 (9)	N2—Cd1^iii	2.336 (10)
Cd1—O10	2.328 (9)	C1—C3	1.537 (16)
Cd1—N2^i	2.336 (10)	C2—C5	1.511 (17)
Cd2—O3	2.583 (9)	C3—C4	1.385 (16)
Cd2—O4	2.312 (9)	C3—C8	1.394 (15)
Cd2—O7^ii	2.446 (9)	C4—C5	1.410 (16)
Cd2—O8^ii	2.435 (9)	C4—H4	0.9500
Cd2—O11	2.282 (9)	C5—C6	1.391 (15)
Cd2—O12	2.316 (10)	C6—C7	1.380 (17)
Cd2—N1^iii	2.317 (8)	C6—H6	0.9500
Cd1—C1	2.759 (12)	C7—C8	1.395 (16)
O1—C1	1.262 (14)	C7—C9	1.491 (15)
O2—C1	1.238 (15)	C8—H8	0.9500
O3—C2	1.250 (13)	C9—C10	1.374 (16)
O4—C2	1.271 (14)	C9—C13	1.384 (18)
O5—C14	1.297 (15)	C10—C11	1.373 (16)
O6—C14	1.270 (15)	C10—H10	0.9500
O7—C15	1.292 (15)	C11—H11	0.9500
O7—Cd2^iv	2.446 (9)	C12—C13	1.414 (16)
O8—C15	1.263 (13)	C12—H12	0.9500
O8—Cd2^iv	2.435 (8)	C13—H13	0.9500
O9—H9A	0.8502	C14—C16	1.468 (16)
O9—H9B	0.8498	C15—C18	1.478 (16)
O10—H10A	0.8740	C16—C17	1.369 (16)
O10—H10B	0.8740	C16—C21	1.431 (17)
O11—H11A	0.8499	C17—C18	1.396 (14)
O11—H11B	0.8500	C17—H17	0.9500
O12—H12A	0.8498	C18—C19	1.387 (17)
O12—H12B	0.8503	C19—C20	1.376 (16)
O13—H13A	0.8584	C19—H19	0.9500
O13—H13B	0.8500	C20—C21	1.399 (15)
O14—H14A	0.8500	C20—C22	1.497 (17)
O14—H14B	0.8500	C21—H21	0.9500
O15—H15A	0.8499	C22—C23	1.379 (17)
O15—H15B	0.8500	C22—C26	1.381 (19)
O16—H16A	0.8498	C23—C24	1.391 (18)
O16—H16B	0.8501	C23—H23	0.9500
O17—H17A	0.8532	C24—H24	0.9500
O17—H17B	0.8499	C25—C26	1.39 (2)
N1—C12	1.301 (16)	C25—H25	0.9500
N1—C11	1.345 (17)	C26—H26	0.9500
O1—Cd1—O2	53.8 (3)	O2—C1—C3	118.5 (11)
O5—Cd1—O1	85.7 (3)	O1—C1—C3	117.4 (11)
O9—Cd1—O10	174.7 (3)	O2—C1—Cd1	63.8 (7)
N2^i—Cd1—O2	85.2 (3)	O1—C1—Cd1	60.3 (6)
O5—Cd1—N2^i	135.3 (3)	C3—C1—Cd1	177.5 (9)
O5—Cd1—O9	91.8 (3)	O3—C2—O4	121.5 (12)
O5—Cd1—O10	93.5 (3)	O3—C2—C5	120.5 (12)
O9—Cd1—N2^i	88.6 (4)	O4—C2—C5	118.0 (10)
O10—Cd1—N2^i	87.9 (4)	C4—C3—C8	120.2 (11)
O9—Cd1—O1	92.7 (3)	C4—C3—C1	121.0 (10)
O10—Cd1—O1	87.2 (3)	C8—C3—C1	118.8 (11)
N2^i—Cd1—O1	139.0 (3)	C3—C4—C5	119.7 (10)
O5—Cd1—O2	139.5 (3)	C3—C4—H4	120.2
O9—Cd1—O2	89.0 (3)	C5—C4—H4	120.2
O10—Cd1—O2	86.7 (3)	C6—C5—C4	118.5 (12)
O5—Cd1—O6	53.0 (3)	C6—C5—C2	120.6 (11)
O9—Cd1—O6	91.6 (3)	C4—C5—C2	121.0 (10)
O10—Cd1—O6	92.0 (3)	C7—C6—C5	122.8 (12)
N2^i—Cd1—O6	82.4 (3)	C7—C6—H6	118.6
O1—Cd1—O6	138.5 (3)	C5—C6—H6	118.6
O2—Cd1—O6	167.5 (3)	C6—C7—C8	117.7 (11)
O5—Cd1—C1	112.8 (4)	C6—C7—C9	120.4 (11)
O9—Cd1—C1	91.1 (4)	C8—C7—C9	121.9 (12)
O10—Cd1—C1	86.4 (4)	C3—C8—C7	121.2 (12)
N2^i—Cd1—C1	111.8 (4)	C3—C8—H8	119.4
O1—Cd1—C1	27.2 (3)	C7—C8—H8	119.4
O2—Cd1—C1	26.7 (3)	C10—C9—C13	115.4 (11)
O6—Cd1—C1	165.6 (3)	C10—C9—C7	122.3 (12)
O4—Cd2—O3	53.1 (3)	C13—C9—C7	122.3 (12)
O4—Cd2—O7^ii	83.1 (3)	C11—C10—C9	121.5 (13)
O8^ii—Cd2—O7^ii	53.8 (3)	C11—C10—H10	119.2
O11—Cd2—O12	176.5 (3)	C9—C10—H10	119.2
N1^iii—Cd2—O3	82.1 (3)	N1—C11—C10	123.1 (13)
N1^iii—Cd2—O8^ii	88.7 (3)	N1—C11—H11	118.4
O11—Cd2—O4	89.9 (3)	C10—C11—H11	118.4
O11—Cd2—N1^iii	85.5 (3)	N1—C12—C13	124.1 (13)
O4—Cd2—N1^iii	134.5 (4)	N1—C12—H12	118.0
O4—Cd2—O12	91.3 (4)	C13—C12—H12	118.0
N1^iii—Cd2—O12	91.3 (3)	C9—C13—C12	119.5 (14)
O11—Cd2—O8^ii	91.2 (3)	C9—C13—H13	120.2
O4—Cd2—O8^ii	136.7 (3)	C12—C13—H13	120.2
O12—Cd2—O8^ii	90.2 (4)	O6—C14—O5	117.9 (11)
O11—Cd2—O7^ii	96.6 (3)	O6—C14—C16	120.8 (12)
N1^iii—Cd2—O7^ii	142.4 (4)	O5—C14—C16	121.3 (12)
O12—Cd2—O7^ii	86.8 (3)	O8—C15—O7	119.5 (12)
O11—Cd2—O3	94.1 (3)	O8—C15—C18	121.5 (11)
O12—Cd2—O3	84.1 (4)	O7—C15—C18	118.9 (11)
O8^ii—Cd2—O3	169.1 (3)	C17—C16—C21	119.0 (11)
O7^ii—Cd2—O3	134.7 (3)	C17—C16—C14	122.6 (12)
C1—O1—Cd1	92.5 (8)	C21—C16—C14	118.0 (12)
C1—O2—Cd1	89.6 (8)	C16—C17—C18	121.5 (12)
C2—O3—Cd2	86.7 (8)	C16—C17—H17	119.3
C2—O4—Cd2	98.8 (7)	C18—C17—H17	119.3
C14—O5—Cd1	101.6 (8)	C19—C18—C17	117.9 (11)
C14—O6—Cd1	87.6 (8)	C19—C18—C15	118.4 (10)
C15—O7—Cd2^iv	92.6 (7)	C17—C18—C15	123.5 (11)
C15—O8—Cd2^iv	93.9 (8)	C20—C19—C18	123.1 (11)
Cd1—O9—H9A	123.3	C20—C19—H19	118.4
Cd1—O9—H9B	128.0	C18—C19—H19	118.4
H9A—O9—H9B	108.6	C19—C20—C21	118.2 (12)
Cd1—O10—H10A	109.5	C19—C20—C22	123.7 (11)
Cd1—O10—H10B	109.3	C21—C20—C22	118.1 (12)
H10A—O10—H10B	109.3	C20—C21—C16	120.0 (12)
Cd2—O11—H11A	125.2	C20—C21—H21	120.0
Cd2—O11—H11B	126.4	C16—C21—H21	120.0
H11A—O11—H11B	108.4	C23—C22—C26	115.9 (13)
Cd2—O12—H12A	129.3	C23—C22—C20	120.7 (13)
Cd2—O12—H12B	117.0	C26—C22—C20	123.4 (11)
H12A—O12—H12B	112.5	C22—C23—C24	119.9 (14)
H13A—O13—H13B	108.3	C22—C23—H23	120.1
H14A—O14—H14B	93.0	C24—C23—H23	120.1
H15A—O15—H15B	110.0	N2—C24—C23	123.2 (13)
H16A—O16—H16B	108.7	N2—C24—H24	118.4
H17A—O17—H17B	132.6	C23—C24—H24	118.4
C12—N1—C11	116.3 (10)	N2—C25—C26	122.5 (15)
C12—N1—Cd2^i	123.3 (9)	N2—C25—H25	118.8
C11—N1—Cd2^i	120.4 (9)	C26—C25—H25	118.8
C25—N2—C24	117.1 (12)	C22—C26—C25	121.2 (14)
C25—N2—Cd1^iii	120.4 (10)	C22—C26—H26	119.4
C24—N2—Cd1^iii	122.5 (8)	C25—C26—H26	119.4
O2—C1—O1	124.0 (12)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O9—H9A···O8^v	0.85	1.95	2.792 (13)	172
O9—H9B···O14^i	0.85	1.93	2.775 (15)	172
O10—H10A···O5^vi	0.87	2.02	2.859 (13)	161
O10—H10B···O15^v	0.87	2.16	2.793 (14)	129
O11—H11A···O1^vii	0.85	1.93	2.779 (12)	179
O11—H11B···O15^viii	0.85	1.86	2.713 (13)	179
O12—H12A···O4^ix	0.85	1.93	2.766 (12)	169
O12—H12B···O14^x	0.85	2.13	2.951 (14)	164
O13—H13A···O2^iii	0.86	2.01	2.872 (14)	180
O13—H13B···O17	0.85	2.12	2.93 (2)	159
O14—H14A···O17	0.85	2.06	2.91 (2)	180
O14—H14B···O16	0.85	1.99	2.843 (16)	179
O15—H15A···O16	0.85	2.01	2.827 (15)	161
O15—H15B···O13^xi	0.85	2.03	2.768 (16)	144
O16—H16A···O6^v	0.85	1.90	2.735 (13)	169
O16—H16B···O3^xi	0.85	1.94	2.781 (12)	169
O17—H17A···O7^v	0.85	1.88	2.731 (17)	180

Symmetry codes: (i) x, y+1, z; (iii) x, y−1, z; (v) −x+1, −y+1, −z+1; (vi) −x, −y+1, −z+1; (vii) −x, −y+1, −z+2; (viii) −x+1, −y+1, −z+2; (ix) −x−1, −y+1, −z+2; (x) x−1, y, z; (xi) x+1, y, z.