A novel two-dimensional cadmium(II) complex: poly[di­aquatris(μ₄-cyclo­hexane-1,4-di­carboxyl­ato)bis­[2-(pyridin-4-yl)-1H-benzimidazole]tri­cadmium(II)

The title compound, [Cd₃(C₈H₁₀O₄)₃(C₁₂H₉N₃)₂(H₂O)₂]_n or [Cd₃(chdc)₃(4-PyBIm)₂(H₂O)₂]_n, was synthesized hydro­thermally from the reaction of Cd(CH₃COO)₂·2H₂O with 2-(pyridin-4-yl)-1H-benz­imidazole (4-PyBIm) and cyclo­hexane-1,4-di­carb­oxy­lic acid (1,4-chdcH₂). The asymmetric unit consists of one and a half Cd^II cations, one 4-PyBIm ligand, one and a half 1,4-chdc²⁻ ligands and one coordinated water mol­ecule. The central Cd^II cation, located on an inversion centre, is coordinated by six carboxyl­ate O atoms from six 1,4-chdc²⁻ ligands to complete an elongated octa­hedral coordination geometry. The two terminal rotationally symmetric Cd^II cations each exhibits a distorted penta­gonal–bipyramidal geometry, coordinated by one N atom from 4-PyBIm, five O atoms from three 1,4-chdc²⁻ ligands and one O atom from an aqua ligand. The 1,4-chdc²⁻ ligands possess two conformations, i.e. e,e-trans-chdc²⁻ and e,a-cis-chdc²⁻. The cis-1,4-chdc²⁻ ligands bridge the Cd^II cations to form a trinuclear {Cd₃}-based chain along the b axis, while the trans-1,4-chdc²⁻ ligands further link adjacent one-dimensional chains to construct an inter­esting two-dimensional network.

S1. Introduction

Metal-organic frameworks (MOFs) have attracted extensive attention owing to their versatile architectures and potential applications in optical, biochemical, electronic, magnetic and porous materials (Wu et al., 2011; Kang et al., 2015; Zhao et al., 2015). A large number of MOFs based on mixed ligands have subsequently been reported (Jiang et al., 2011; Ju et al., 2014). The assembly of MOFs is mainly affected by a combination of a few factors, including the metal ion, organic ligand and auxiliary ligand, the metal-to-ligand ratio, the solvent and the reaction temperature (Ma, Abney & Lin, 2009 OR Ma, Wang et al., 2009 ?; Li et al., 2010; Zhang et al., 2012; Luo et al., 2014). The organic ligands are the key to obtaining such intriguing topologies and functional materials. Flexible ligands can adopt additional different conformations according to the geometric requirements of different metal ions, and may afford unpredi­cta­ble and inter­esting supra­molecular networks (Fang et al., 2010; Zhu et al., 2011; Li et al., 2012). Self-assembly between metal ions and flexible ligands has been proven to be a most effective synthetic design to achieve chiral or helical frameworks and high-nuclear complexes (Zhu et al., 2010) or single helices (Wang et al., 2007), with potential applications in selective catalysis, separation and so on (Ma, Abney & Lin, 2009 OR Ma, Wang et al., 2009 ?; Zhang et al., 2010). Cyclo­hexanedi­carb­oxy­lic acid is a flexible ditopic ligand which possesses three possible conformations of its two carboxyl­ate groups: a,a-trans-chdcH₂, e,e-trans-chdcH₂ and e,a-cis-chdcH₂ (Scheme 1 in the Supporting information) and has been reported to be a good candidate for the self-assenbly of coordination polymers due to its superior bridging ability and different coordination modes (Yoon et al., 2012; Su et al., 2012; Chen et al., 2013 OR 2014 ?; Hao et al., 2014; Wang et al., 2014). It is a good strategy to select mixed ligands for the construction of coordination polymers. Pyridyl­benzimidazoles have been employed as auxiliary ligands to obtain many novel frameworks with particular structures and properties (Zhang et al., 2011; Chen et al., 2013 OR 2014 ?; Abed et al., 2014). However, polymers constructed from cyclo­hexanedi­carb­oxy­lic acid and pyridyl­benzimidazole have rarely been reported. Based on these considerations, we chose cyclo­hexane-1,4-di­carb­oxy­lic acid as the primary ligand and introduced 2-(4-pyridyl)­benzimidazole as the auxiliary ligand. As expected, a new Cd^II compound, (I), with a two-dimensional polymeric framework was obtained.

S2. Experimental

S2.1. Synthesis and crystallization

A mixture of Cd(CH₃COO)₂·2H₂O (0.053 g, 0.2 mmol), 4-PyBIm (0.037 g, 0.2 mmol) and H₂chdc (0.034 g, 0.2 mmol) in H₂O (9 ml) was sealed in a 23 ml Teflon-lined stainless steel reactor. The mixture was kept at 433 K for 72 h and then cooled to room temperature at a rate of 5 K h^-1. Colourless block crystals of (I) suitable for X-ray analysis were obtained, and these were washed with distilled water and dried in air (yield 25% based on Cd). Elemental analysis, calculated for C₉₆H₉₆Cd₆N₁₂O₂₈ (%): C 50.35, H 2.83, N 4.90; found (%): C 50.31, H 2.80, N 4.89.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms attached to C and N atoms were fixed geometrically and treated as riding, with C—H = 0.98 Å (methine), 0.97 Å (methyl­ene) and 0.93 Å (aromatic), and N—H = 0.86 Å, and with U_iso(H) = 1.2U_eq(C,N). The H atoms of the water molecules were located in a difference Fourier map and included in the refinement using the restraints O—H = 0.82 (1) Å and H···H = 1.39 (2) Å, and with U_iso(H) = 1.5U_eq(O).

S3. Comment

As shown in Fig. 1, the asymmetric unit contains one and a half of Cd^II ions, one 4-PyBIm ligand, one and a half 1,4-chdc^2- ligands and one coordinated water molecule. The 1,4-chdc^2- ligands possess two conformations, e,e-trans-chdc^2-, and e,a-cis-chdc^2-, in (I). The Cd1 and Cd2 centres adopt different coordination geometries. The Cd2 cation, sitting on a crystallographic two-fold rotation axis, is ligated to six carboxyl­ate O atoms from four distinct e,a-cis-1,4-chdc^2- ligands and two different e,e-trans-1,4-chdc^2- ligands to furnish a distorted o­cta­hedral coordination geometry. The Cd2—O distances range from 2.217 (3) to 2.299 (2) Å. However, the Cd1 centre shows a distorted penta­gonal–bipyramidal geometry, coordinated by one N atom from 4-PyBIm and six O atoms from two different e,e-trans-1,4-chdc^2- ligands, one cis-1,4-chdc^2- ligand and one aqua molecule. The N atom from 4-PyBIm and one O atom from one of the cis-1,4-chdc^2- ligands occupy the axial sites, with the other O atoms forming the equatorial plane. Atoms O3ⁱ, O4ⁱ, O5, O6 and O7 on the equatorial plane are almost coplanar [symmetry code: ???]. The average deviation from the plane is 0.019 Å. The Cd1—O bond lengths vary from 2.229 (2) to 2.803 (3) Å and the Cd1—N bond length is 2.341 (3) Å. The Cd—O and Cd—N distances are comparable with those reported previously (Clegg et al., 1995; Liu et al., 2011; Wang et al., 2011). The crystallographically independent chdc^2- ligand exhibits an e,a-cis-conformation and adopts a penta­dentate coordination mode: one carboxyl­ate group, acting in a bis-monodentate coordination mode, coordinates to an adjacent Cd^II centre, while the other carboxyl­ate group adopts a chelate/bridging tridentate coordination mode connecting two Cd^II ions. The crystallographically symmetric chdc^2- ligand shows an e,e-trans-1,4-chdc^2- conformation and its carboxyl­ate groups all display a chelate/bridging tridentate coordination mode. Two adjacent Cd^II ions are joined by one carboxyl­ate group with bis-monodentate coordination modes and two carboxyl­ate groups with chelate/bridging coordination modes, with a Cd···Cd separation of 3.808 Å.

Complex (I) exhibits a two-dimensional polymeric framework based on [Cd₃(chdc^2-)₃(4-PyBIm)₂(H₂O)₂] units. Three neighbouring Cd^II centres are joined by four carboxyl­ate groups from two cis-1,4-chdc^2- ligands, resulting in a trinuclear {Cd₃(COO)₄} cluster. These {Cd₃(COO)₄} clusters are connected by the cyclo­hexyl groups of cis-1,4-chdc^2- ligands to form a one-dimensional loop-like chain. Adjacent chains are further linked by trans-1,4-chdc^2- ligands, leading to an inter­esting two-dimensional network, which is similar to that in the complex [Cd₃(L)₂(cis-1,4-chdc)₂(trans-1,4-chdc)] [L = 2-(4-fluoro­pheny1)-1H-imidazo[4,5-f][1,10] phenanthroline and 1,4-H₂chdc = l,4-cyclo­hexanedi­carb­oxy­lic acid; Xu et al., 2010]. From a topological point of view, the trinuclear Cd^II cluster can be defined as a four-connected node. Thus, the overall topology of the two-dimensional framework is best described as a four-connected (4,4) network (Fig.4).

Hydrogen bonds [O7—H2···N2(-x + 1, -y - 1, -z) and N3—H3A···O6(x, y + 1, z)] and π–π stacking inter­actions are present in the structure of (I). The 4-PyBIm ligand is a hydrogen-bond donor through its imidazolyl NH group to a carboxyl­ate O atom (O6) of an e,a-trans-chdc^2- ligand within the layer. It is also a hydrogen-bond acceptor from a coordinated water molecule (O7) of another adjacent layer through the other imidazolyl N atom, forming a three-dimensional network structure, as illustrated in Fig. 5. The π–π stacking inter­action exists between the pyridyl ring of one 4-PyBIm ligand and the benzene ring of a 4-PyBIm ligand in a neighbouring layer, with a centroid-to-centroid distance of 3.7727 Å.

A thermogravimetric (TG) study of (I) was performed to evaluate its thermal stability, and the resulting curve is shown in Fig. 6. The TG curve exhibits a three-step weight loss. The first weight loss of 3.09% (calculated 2.83%) at 483–528 K corresponds to the release of solvent water, while the next two weight losses of about 69.80% (calculated 70.70%) between 543 and 873 K are attributed to decomposition of the 4-PyBIm and chdc^2- ligands.

The photoluminescent properties of (I) were investigated in the solid state at room temperature. Compound (I) exhibits photoluminescence under light excitation at 300 nm (Fig. 7). It gives a strong emission peak maximum at 420 nm at room temperature, and no obvious emission band is detected for free H₂chdc ligands. It has been reported that the ligand 4-PyBIm has a weak emission band centred at 492 nm (Xia et al., 2005). Generally, metal-to-ligand charge transfer (MLCT) is the most common assignment for the luminescence of d¹⁰ transition metal complexes (Colacio et al., 2002). Most of the Cd^II–PyBIm complexes exhibit luminescence in the range 350–600 nm (Liang et al., 2006; Yang et al., 2009; Li et al., 2011). So the photoluminescence of (I) may be assigned to MLCT between Cd^II cations and 4-PyBIm ligands.

The IR spectrum of complex (I) shows characteristic bands of carboxyl­ate groups at 1610 and 1570 cm^-1 for anti­symmetric stretching, and at 1380 cm^-1 for symmetric strectching. According to the Deacon–Phillips model (Deacon et al., 1980), the separation is >200 cm^-1 for monodentate carboxyl­ate groups, whereas it is <200 cm^-1 in bidentate groups. So the separation has often been used to diagnose the coordination modes of carboxyl­ate groups. Here, the separations between ν_as (COO^-) and ν_s (COO^-) are 230 cm^-1 and 150 cm^-1 for (I), indicating monodentate and bidentate coordination modes, respectively, for the coordinated carboxyl­ate groups. These IR results are in agreement with the crystallographic structural analysis.

Related literature

For related literature, see: Clegg et al., (1995); Fang et al., (2010); Jiang et al., (2011); Kang et al., (2015); Liang et al., (2006); Li et al., (2012); Luo et al., (2014); Zhao et al., (2015)

Computing details

Data collection: CrystalClear (Rigaku, 2007); cell refinement: CrystalClear (Rigaku, 2007); data reduction: CrystalClear (Rigaku, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms have been omitted for clarity. [Symmetry codes: (i) x, y + 1, z; (ii) -x, y, -z - 1/2; (iii) -x, y + 1, -z - 1/2.]
	Fig. 2. A view showing the one dimensional loop-like chain constructed by cis-1,4-chdc^2- ligands and the three Cd^II ions.
	Fig. 3. A perspective view of the two-dimensional layer structure in (I). The uncoordinated atoms of the 2-(4-pyridyl)benzimidazole ligands and all H atoms have been omitted for clarity.
	Fig. 4. A view of the (4,4) network structure of (I).
	Fig. 5. The three-dimensional supramolecular structure formed by hydrogen bonding. Green and purple dashed lines represent O7—H2···N2(-x + 1, -y - 1, -z) hydrogen bonding between the layers and N3—H3A···O6(x, y + 1, z) hydrogen bonding within the layers, respectively.
	Fig. 6. The thermogravimetric curve of (I).
	Fig. 7. The emission spectrum of (I) in the solid state at room temperature.

Poly[diaquatris(µ₃-cyclohexane-1,4-dicarboxylato)bis[2-(pyridin-4-yl)benzimidazole]tricadmium(II)

Crystal data

[Cd3(C8H10O4)3(C12H9N3)2(H2O)2]	Z = 2
Mr = 1274.19	F(000) = 1276
Monoclinic, P2/c	Dx = 1.754 Mg m^−3
Hall symbol: -P 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 10.366 (3) Å	θ = 2.0–27.5°
b = 8.774 (3) Å	µ = 1.38 mm^−1
c = 27.071 (7) Å	T = 293 K
β = 101.48 (1)°	Prism, colourless
V = 2412.9 (12) Å^3	0.30 × 0.20 × 0.15 mm

Data collection

Rigaku Mercury CCD area-detector diffractometer	5500 independent reflections
Radiation source: fine-focus sealed tube	4825 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
Detector resolution: 13.6612 pixels mm^-1	θmax = 27.5°, θmin = 2.8°
CCD Profile fitting scans	h = −13→12
Absorption correction: multi-scan (CrystalClear; Rigaku, 2007)	k = −11→11
Tmin = 0.569, Tmax = 1.000	l = −33→35
18383 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.109	w = 1/[σ^2(Fo^2) + (0.0523P)^2 + 0.539P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max = 0.001
5500 reflections	Δρmax = 1.63 e Å^−3
327 parameters	Δρmin = −0.99 e Å^−3
9 restraints	Extinction correction: SHELXL (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0027 (4)

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	0.13470 (2)	−0.64177 (2)	−0.120948 (8)	0.03391 (11)
Cd2	0.0000	−0.63992 (3)	−0.2500	0.03055 (12)
O1	−0.0825 (3)	−0.7998 (4)	−0.20075 (13)	0.0793 (9)
O2	0.0280 (3)	−0.8637 (3)	−0.12597 (11)	0.0547 (7)
O3	−0.0232 (3)	−1.4593 (3)	−0.19379 (11)	0.0669 (8)
O4	−0.0374 (3)	−1.4894 (3)	−0.11496 (10)	0.0548 (6)
O5	0.2014 (2)	−0.6516 (3)	−0.19613 (9)	0.0451 (6)
O6	0.3426 (2)	−0.7911 (3)	−0.14465 (9)	0.0518 (6)
O7	0.1793 (3)	−0.7005 (3)	−0.03492 (9)	0.0539 (6)
H2	0.2403	−0.7263	−0.0113	0.14 (3)*
N1	0.2861 (3)	−0.4416 (3)	−0.10222 (10)	0.0416 (6)
N2	0.6552 (3)	−0.0846 (3)	−0.01933 (9)	0.0385 (6)
N3	0.5460 (3)	0.0642 (3)	−0.08077 (10)	0.0397 (6)
H3A	0.4870	0.0927	−0.1061	0.048*
C1	0.3996 (4)	−0.4602 (4)	−0.07008 (14)	0.0536 (9)
H1A	0.4206	−0.5572	−0.0571	0.064*
C2	0.4881 (4)	−0.3445 (4)	−0.05478 (15)	0.0531 (10)
H2B	0.5660	−0.3638	−0.0319	0.064*
C3	0.4601 (3)	−0.1983 (4)	−0.07386 (11)	0.0359 (6)
C4	0.3441 (4)	−0.1799 (4)	−0.10875 (14)	0.0487 (8)
H4A	0.3219	−0.0850	−0.1233	0.058*
C5	0.2612 (4)	−0.3032 (4)	−0.12193 (14)	0.0515 (9)
H5A	0.1842	−0.2886	−0.1458	0.062*
C6	0.5528 (3)	−0.0740 (3)	−0.05707 (11)	0.0355 (6)
C7	0.7182 (3)	0.0558 (4)	−0.01779 (11)	0.0374 (6)
C8	0.8309 (4)	0.1081 (4)	0.01465 (12)	0.0462 (8)
H8A	0.8763	0.0470	0.0404	0.055*
C9	0.8729 (4)	0.2547 (4)	0.00711 (14)	0.0537 (9)
H9A	0.9467	0.2932	0.0287	0.064*
C10	0.8070 (4)	0.3458 (4)	−0.03219 (15)	0.0566 (10)
H10A	0.8392	0.4428	−0.0366	0.068*
C11	0.6947 (4)	0.2953 (4)	−0.06482 (14)	0.0522 (8)
H11A	0.6506	0.3560	−0.0910	0.063*
C12	0.6514 (3)	0.1492 (3)	−0.05641 (12)	0.0380 (7)
C13	−0.1496 (3)	−1.0227 (3)	−0.16560 (12)	0.0372 (7)
H13A	−0.2398	−0.9834	−0.1703	0.045*
C14	−0.1261 (3)	−1.1182 (3)	−0.11790 (12)	0.0385 (7)
H14A	−0.1354	−1.0553	−0.0898	0.046*
H14B	−0.0376	−1.1567	−0.1118	0.046*
C15	−0.2225 (3)	−1.2510 (4)	−0.12229 (13)	0.0443 (7)
H15A	−0.3105	−1.2120	−0.1260	0.053*
H15B	−0.2039	−1.3101	−0.0919	0.053*
C16	−0.2128 (3)	−1.3525 (3)	−0.16716 (13)	0.0400 (7)
H16A	−0.2842	−1.4274	−0.1705	0.048*
C17	−0.2353 (4)	−1.2593 (4)	−0.21560 (14)	0.0561 (10)
H17A	−0.3246	−1.2236	−0.2233	0.067*
H17B	−0.2217	−1.3233	−0.2429	0.067*
C18	−0.1429 (4)	−1.1228 (4)	−0.21160 (13)	0.0473 (8)
H18A	−0.0542	−1.1589	−0.2085	0.057*
H18B	−0.1640	−1.0624	−0.2417	0.057*
C19	−0.0595 (3)	−0.8861 (4)	−0.16403 (14)	0.0440 (8)
C20	−0.0837 (3)	−1.4405 (3)	−0.15805 (13)	0.0413 (7)
C21	0.3046 (3)	−0.7338 (4)	−0.18682 (12)	0.0393 (7)
C22	0.3805 (3)	−0.7461 (4)	−0.22900 (12)	0.0426 (7)
H22A	0.3158	−0.7480	−0.2608	0.051*
C23	0.4634 (4)	−0.8859 (4)	−0.22785 (16)	0.0518 (9)
H23B	0.5292	−0.8853	−0.1974	0.062*
H23A	0.4088	−0.9746	−0.2286	0.078*
C24	0.4610 (4)	−0.6021 (4)	−0.22902 (17)	0.0581 (10)
H24C	0.5196	−0.5936	−0.1969	0.070*
H24B	0.4033	−0.5154	−0.2340	0.087*
H1	0.107 (5)	−0.752 (10)	−0.040 (3)	0.30 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.03658 (17)	0.03115 (16)	0.03223 (16)	−0.00112 (8)	0.00261 (11)	0.00013 (7)
Cd2	0.0334 (2)	0.02769 (18)	0.02850 (18)	0.000	0.00107 (13)	0.000
O1	0.0741 (16)	0.0734 (15)	0.0846 (16)	−0.0193 (13)	0.0015 (13)	0.0403 (13)
O2	0.0577 (16)	0.0423 (14)	0.0586 (15)	−0.0175 (11)	−0.0020 (13)	0.0041 (11)
O3	0.079 (2)	0.0548 (16)	0.0767 (18)	0.0056 (14)	0.0395 (16)	−0.0204 (14)
O4	0.0506 (14)	0.0497 (14)	0.0618 (16)	0.0121 (12)	0.0055 (12)	0.0045 (12)
O5	0.0307 (12)	0.0641 (16)	0.0384 (12)	0.0088 (10)	0.0019 (9)	−0.0062 (10)
O6	0.0474 (14)	0.0568 (15)	0.0515 (14)	0.0082 (11)	0.0107 (11)	0.0115 (12)
O7	0.0687 (17)	0.0504 (14)	0.0384 (12)	0.0048 (13)	0.0004 (12)	0.0083 (11)
N1	0.0435 (15)	0.0386 (14)	0.0409 (13)	−0.0067 (12)	0.0038 (12)	−0.0002 (11)
N2	0.0443 (15)	0.0348 (13)	0.0338 (12)	−0.0028 (11)	0.0015 (11)	0.0016 (11)
N3	0.0376 (14)	0.0377 (14)	0.0399 (13)	0.0010 (11)	−0.0017 (11)	0.0025 (11)
C1	0.051 (2)	0.0403 (17)	0.061 (2)	−0.0056 (16)	−0.0081 (17)	0.0100 (16)
C2	0.051 (2)	0.0428 (18)	0.056 (2)	−0.0059 (15)	−0.0140 (17)	0.0087 (15)
C3	0.0353 (15)	0.0380 (16)	0.0349 (14)	−0.0017 (12)	0.0081 (12)	−0.0021 (12)
C4	0.0449 (19)	0.0396 (17)	0.055 (2)	−0.0041 (15)	−0.0052 (16)	0.0081 (16)
C5	0.0425 (19)	0.0467 (19)	0.059 (2)	−0.0070 (15)	−0.0050 (16)	0.0059 (17)
C6	0.0367 (15)	0.0359 (15)	0.0340 (14)	0.0006 (12)	0.0072 (12)	−0.0019 (12)
C7	0.0429 (17)	0.0360 (15)	0.0337 (14)	−0.0038 (12)	0.0082 (13)	−0.0035 (12)
C8	0.050 (2)	0.0486 (18)	0.0370 (16)	−0.0075 (15)	0.0019 (15)	−0.0010 (14)
C9	0.057 (2)	0.052 (2)	0.0481 (19)	−0.0174 (17)	0.0019 (17)	−0.0041 (16)
C10	0.068 (3)	0.0419 (19)	0.059 (2)	−0.0161 (17)	0.010 (2)	0.0016 (16)
C11	0.063 (2)	0.0398 (17)	0.0523 (19)	−0.0040 (17)	0.0072 (17)	0.0073 (16)
C12	0.0421 (17)	0.0340 (15)	0.0376 (15)	−0.0016 (12)	0.0071 (14)	−0.0004 (12)
C13	0.0288 (14)	0.0318 (14)	0.0492 (16)	−0.0003 (11)	0.0032 (12)	0.0099 (13)
C14	0.0495 (19)	0.0304 (14)	0.0388 (16)	0.0001 (13)	0.0166 (14)	0.0000 (12)
C15	0.0467 (18)	0.0337 (15)	0.060 (2)	0.0038 (13)	0.0295 (16)	0.0070 (14)
C16	0.0332 (16)	0.0311 (15)	0.0547 (19)	−0.0060 (11)	0.0066 (14)	0.0005 (13)
C17	0.060 (2)	0.050 (2)	0.0492 (19)	−0.0122 (17)	−0.0111 (17)	0.0028 (16)
C18	0.054 (2)	0.0486 (19)	0.0372 (16)	−0.0090 (15)	0.0033 (15)	0.0105 (14)
C19	0.0363 (17)	0.0328 (15)	0.060 (2)	−0.0002 (13)	0.0033 (15)	0.0129 (15)
C20	0.0426 (17)	0.0267 (14)	0.0558 (18)	−0.0037 (12)	0.0127 (15)	−0.0094 (13)
C21	0.0308 (15)	0.0436 (17)	0.0427 (16)	−0.0010 (13)	0.0052 (13)	−0.0049 (13)
C22	0.0349 (16)	0.0493 (18)	0.0430 (16)	0.0021 (14)	0.0067 (13)	−0.0018 (14)
C23	0.057 (2)	0.0398 (17)	0.067 (2)	0.0004 (15)	0.033 (2)	0.0041 (17)
C24	0.065 (3)	0.0413 (17)	0.076 (3)	−0.0023 (17)	0.033 (2)	−0.0056 (19)

Geometric parameters (Å, º)

Cd1—O2	2.230 (2)	C4—C5	1.383 (5)
Cd1—O4^i	2.261 (3)	C4—H4A	0.9300
Cd1—O5	2.278 (2)	C5—H5A	0.9300
Cd1—O7	2.340 (2)	C7—C8	1.392 (4)
Cd1—N1	2.342 (3)	C7—C12	1.398 (4)
Cd1—O6	2.706 (3)	C8—C9	1.386 (5)
Cd1—O3^i	2.801 (3)	C8—H8A	0.9300
Cd1—C21	2.861 (3)	C9—C10	1.396 (5)
Cd1—Cd2	3.4947 (9)	C9—H9A	0.9300
Cd1—H1	2.47 (6)	C10—C11	1.386 (5)
Cd2—O1	2.221 (3)	C10—H10A	0.9300
Cd2—O1^ii	2.221 (3)	C11—C12	1.392 (4)
Cd2—O3^i	2.243 (3)	C11—H11A	0.9300
Cd2—O3^iii	2.243 (3)	C13—C19	1.515 (4)
Cd2—O5	2.299 (2)	C13—C14	1.518 (4)
Cd2—O5^ii	2.299 (2)	C13—C18	1.537 (5)
Cd2—Cd1^ii	3.4947 (9)	C13—H13A	0.9800
O1—C19	1.234 (4)	C14—C15	1.525 (4)
O2—C19	1.246 (4)	C14—H14A	0.9602
O3—C20	1.264 (4)	C14—H14B	0.9601
O3—Cd2^iv	2.243 (3)	C15—C16	1.525 (5)
O3—Cd1^iv	2.801 (3)	C15—H15A	0.9601
O4—C20	1.246 (4)	C15—H15B	0.9597
O4—Cd1^iv	2.261 (3)	C16—C20	1.522 (5)
O5—C21	1.273 (4)	C16—C17	1.524 (5)
O6—C21	1.238 (4)	C16—H16A	0.9800
O7—H2	0.8357	C17—C18	1.524 (5)
O7—H1	0.859 (11)	C17—H17A	0.9598
N1—C1	1.327 (4)	C17—H17B	0.9603
N1—C5	1.331 (4)	C18—H18A	0.9600
N2—C6	1.322 (4)	C18—H18B	0.9595
N2—C7	1.391 (4)	C21—C22	1.514 (5)
N3—C6	1.367 (4)	C22—C23	1.494 (5)
N3—C12	1.378 (4)	C22—C24	1.515 (5)
N3—H3A	0.8600	C22—H22A	0.9800
C1—C2	1.376 (5)	C23—C23^v	1.541 (7)
C1—H1A	0.9300	C23—H23B	0.9600
C2—C3	1.392 (4)	C23—H23A	0.9600
C2—H2B	0.9300	C24—C24^v	1.520 (8)
C3—C4	1.382 (4)	C24—H24C	0.9597
C3—C6	1.465 (4)	C24—H24B	0.9602
O2—Cd1—O4^i	97.59 (10)	C3—C2—H2B	120.3
O2—Cd1—O5	98.49 (10)	C4—C3—C2	116.7 (3)
O4^i—Cd1—O5	118.07 (9)	C4—C3—C6	123.6 (3)
O2—Cd1—O7	82.28 (10)	C2—C3—C6	119.7 (3)
O4^i—Cd1—O7	93.50 (10)	C3—C4—C5	119.7 (3)
O5—Cd1—O7	147.80 (9)	C3—C4—H4A	120.1
O2—Cd1—N1	166.06 (10)	C5—C4—H4A	120.1
O4^i—Cd1—N1	92.59 (10)	N1—C5—C4	123.3 (3)
O5—Cd1—N1	84.97 (9)	N1—C5—H5A	118.3
O7—Cd1—N1	87.62 (10)	C4—C5—H5A	118.3
O2—Cd1—O6	88.37 (10)	N2—C6—N3	112.6 (3)
O4^i—Cd1—O6	168.61 (9)	N2—C6—C3	124.4 (3)
O5—Cd1—O6	51.11 (8)	N3—C6—C3	123.0 (3)
O7—Cd1—O6	96.93 (9)	N2—C7—C8	129.8 (3)
N1—Cd1—O6	83.31 (9)	N2—C7—C12	109.7 (3)
O2—Cd1—O3^i	104.05 (9)	C8—C7—C12	120.5 (3)
O4^i—Cd1—O3^i	49.72 (9)	C9—C8—C7	117.5 (3)
O5—Cd1—O3^i	68.37 (8)	C9—C8—H8A	121.3
O7—Cd1—O3^i	142.98 (9)	C7—C8—H8A	121.3
N1—Cd1—O3^i	89.79 (9)	C8—C9—C10	121.6 (3)
O6—Cd1—O3^i	119.42 (7)	C8—C9—H9A	119.2
O2—Cd1—C21	94.30 (10)	C10—C9—H9A	119.2
O4^i—Cd1—C21	143.52 (9)	C11—C10—C9	121.6 (3)
O5—Cd1—C21	25.62 (8)	C11—C10—H10A	119.2
O7—Cd1—C21	122.29 (10)	C9—C10—H10A	119.2
N1—Cd1—C21	82.96 (10)	C10—C11—C12	116.6 (3)
O6—Cd1—C21	25.50 (8)	C10—C11—H11A	121.7
O3^i—Cd1—C21	93.94 (9)	C12—C11—H11A	121.7
O2—Cd1—Cd2	81.29 (7)	N3—C12—C11	132.1 (3)
O4^i—Cd1—Cd2	84.55 (7)	N3—C12—C7	105.6 (3)
O5—Cd1—Cd2	40.44 (6)	C11—C12—C7	122.3 (3)
O7—Cd1—Cd2	163.04 (8)	C19—C13—C14	114.8 (3)
N1—Cd1—Cd2	109.27 (7)	C19—C13—C18	110.3 (3)
O6—Cd1—Cd2	86.78 (5)	C14—C13—C18	110.4 (2)
O3^i—Cd1—Cd2	39.86 (5)	C19—C13—H13A	107.0
C21—Cd1—Cd2	63.34 (6)	C14—C13—H13A	107.0
O2—Cd1—H1	64.5 (18)	C18—C13—H13A	107.0
O4^i—Cd1—H1	86 (2)	C13—C14—C15	111.3 (3)
O5—Cd1—H1	153 (3)	C13—C14—H14A	109.4
O7—Cd1—H1	20.4 (5)	C15—C14—H14A	109.5
N1—Cd1—H1	107.0 (13)	C13—C14—H14B	109.0
O6—Cd1—H1	105 (2)	C15—C14—H14B	109.5
O3^i—Cd1—H1	134 (2)	H14A—C14—H14B	108.0
C21—Cd1—H1	130 (3)	C14—C15—C16	111.2 (3)
Cd2—Cd1—H1	142.9 (8)	C14—C15—H15A	109.3
O1—Cd2—O1^ii	101.6 (2)	C16—C15—H15A	109.6
O1—Cd2—O3^i	86.15 (13)	C14—C15—H15B	109.2
O1^ii—Cd2—O3^i	163.72 (12)	C16—C15—H15B	109.5
O1—Cd2—O3^iii	163.72 (12)	H15A—C15—H15B	107.9
O1^ii—Cd2—O3^iii	86.15 (13)	C20—C16—C17	113.0 (3)
O3^i—Cd2—O3^iii	90.09 (16)	C20—C16—C15	111.2 (3)
O1—Cd2—O5	90.04 (11)	C17—C16—C15	110.4 (3)
O1^ii—Cd2—O5	86.74 (10)	C20—C16—H16A	107.3
O3^i—Cd2—O5	78.91 (10)	C17—C16—H16A	107.3
O3^iii—Cd2—O5	104.78 (10)	C15—C16—H16A	107.3
O1—Cd2—O5^ii	86.74 (10)	C16—C17—C18	112.0 (3)
O1^ii—Cd2—O5^ii	90.04 (11)	C16—C17—H17A	109.7
O3^i—Cd2—O5^ii	104.78 (10)	C18—C17—H17A	109.0
O3^iii—Cd2—O5^ii	78.91 (10)	C16—C17—H17B	109.1
O5—Cd2—O5^ii	174.90 (12)	C18—C17—H17B	109.1
O1—Cd2—Cd1^ii	118.18 (9)	H17A—C17—H17B	108.0
O1^ii—Cd2—Cd1^ii	61.44 (9)	C17—C18—C13	112.2 (3)
O3^i—Cd2—Cd1^ii	127.30 (8)	C17—C18—H18A	109.0
O3^iii—Cd2—Cd1^ii	53.17 (8)	C13—C18—H18A	108.4
O5—Cd2—Cd1^ii	139.97 (6)	C17—C18—H18B	109.9
O5^ii—Cd2—Cd1^ii	39.99 (6)	C13—C18—H18B	109.4
O1—Cd2—Cd1	61.44 (9)	H18A—C18—H18B	108.0
O1^ii—Cd2—Cd1	118.18 (9)	O1—C19—O2	124.1 (3)
O3^i—Cd2—Cd1	53.17 (8)	O1—C19—C13	116.3 (3)
O3^iii—Cd2—Cd1	127.30 (8)	O2—C19—C13	119.5 (3)
O5—Cd2—Cd1	39.99 (6)	O4—C20—O3	120.9 (3)
O5^ii—Cd2—Cd1	139.97 (6)	O4—C20—C16	119.3 (3)
Cd1^ii—Cd2—Cd1	179.468 (10)	O3—C20—C16	119.7 (3)
C19—O1—Cd2	146.6 (3)	O6—C21—O5	120.9 (3)
C19—O2—Cd1	117.3 (2)	O6—C21—C22	123.3 (3)
C20—O3—Cd2^iv	138.4 (2)	O5—C21—C22	115.7 (3)
C20—O3—Cd1^iv	81.1 (2)	O6—C21—Cd1	70.26 (18)
Cd2^iv—O3—Cd1^iv	86.97 (9)	O5—C21—Cd1	50.66 (16)
C20—O4—Cd1^iv	107.4 (2)	C22—C21—Cd1	165.3 (2)
C21—O5—Cd1	103.7 (2)	C23—C22—C21	115.2 (3)
C21—O5—Cd2	140.5 (2)	C23—C22—C24	111.8 (3)
Cd1—O5—Cd2	99.57 (9)	C21—C22—C24	108.0 (3)
C21—O6—Cd1	84.24 (19)	C23—C22—H22A	107.2
Cd1—O7—H2	142.1	C21—C22—H22A	107.2
Cd1—O7—H1	88 (4)	C24—C22—H22A	107.2
H2—O7—H1	118.6	C22—C23—C23^v	110.7 (3)
C1—N1—C5	116.8 (3)	C22—C23—H23B	108.7
C1—N1—Cd1	121.2 (2)	C23^v—C23—H23B	107.0
C5—N1—Cd1	122.0 (2)	C22—C23—H23A	109.3
C6—N2—C7	105.1 (2)	C23^v—C23—H23A	111.2
C6—N3—C12	107.0 (2)	H23B—C23—H23A	109.8
C6—N3—H3A	126.5	C22—C24—C24^v	112.0 (3)
C12—N3—H3A	126.5	C22—C24—H24C	108.3
N1—C1—C2	123.9 (3)	C24^v—C24—H24C	110.0
N1—C1—H1A	118.0	C22—C24—H24B	109.4
C2—C1—H1A	118.0	C24^v—C24—H24B	107.8
C1—C2—C3	119.4 (3)	H24C—C24—H24B	109.3
C1—C2—H2B	120.3

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H2···N2^vi	0.84	2.06	2.767 (4)	142
N3—H3A···O6^i	0.86	1.94	2.755 (4)	159

Symmetry codes: (i) x, y+1, z; (vi) −x+1, −y−1, −z.