A twofold inter­penetrating three-dimensional Cd^II coordination framework: poly[[μ₂-1,3-bis­(2-methyl-1H-imidazol-1-yl)benzene](μ₃-5-nitro­benzene-1,3-di­carboxyl­ato)cadmium(II)]

A twofold inter­penetrating three-dimensional Cd^II coordination framework, [Cd(C₈H₃NO₆)(C₁₄H₁₄N₄)]_n, has been prepared and characterized by IR spectroscopy, elemental analysis, thermal analysis and single-crystal X-ray diffraction. The asymmetric unit consists of a divalent Cd^II atom, one 1,3-bis­(2-methyl-1H-imidazol-1-yl)benzene (1,3-BMIB) lig­and and one fully deprotonated 5-nitro­benzene-1,3-di­carboxyl­ate (NO₂-BDC²⁻) ligand. The coordination sphere of the Cd^II atom consists of five O-donor atoms from three different NO₂-BDC²⁻ ligands and two imidazole N-donor atoms from two different 1,3-BMIB ligands, forming a distorted {CdN₂O₅} penta­gonal bipyramid. The NO₂-BDC ligand links three Cd^II atoms via a μ₁-η¹:η¹ chelating mode and a μ₂-η²:η¹ bridging mode. The title compound is a twofold inter­penetrating 3,5-connected network with the {4².6⁵.8³}{4².6} topology. In addition, the compound exhibits fluorescence emissions in the solid state at room temperature.

S1. Introduction

In recent years, research on coordination polymers has made considerable progress in the fields of supra­molecular chemistry and crystal engineering not only owing to their intriguing topological architectures but also because of their potential applications in many fields, such as gas storage, catalysis, magnetism and luminescence (Dybtsev et al., 2006; Ma et al., 2009; Wang et al., 2008; Zhang et al., 2009). It is well known that the structure of coordination polymers are usually influenced by various factors, such as the reaction conditions, the neutral ligands, the organic anions and the metal atoms (Cook et al., 2013; Yang et al., 2013). The imidazole-based ligands as an important family of N-donor ligands are frequently used in constructing coordination polymers because of their excellent coordinating capabilities (Schlechte et al., 2012; Luo et al., 2013). However, to the best of our knowledge, the compound containing 1,3-bis­(2-methyl-1H-imidazol-1-yl)benzene (1,3-BMIB) as a bent imidazole ligand has not been observed. On the other hand, 5-nitro­benzene-1,3-di­carb­oxy­lic acid (NO₂—H₂BDC) as a multidentate deprotonated di­carboxyl­ate ligand has been proven to be a good bridging ligand for the construction of novel coordination polymers because of the versatile bridging modes of the two carboxyl­ate groups and the single nitro group (Lu et al., 2012; Sarma et al., 2012; Sun et al., 2012; Zhao et al., 2012). On the basis of the aforementioned points, we explored the self-assembly of the Cd^II ion with NO₂—H₂BDC and 1,3-BMIB under hydro­thermal conditions, and obtained a novel three-dimensional coordination polymer, namely [Cd(NO₂—BDC)(1,3-BMIB)]_n (I). Herein, we report the synthesis, crystal structure and physical properties of (I).

S2. Experimental

1,3-Bis(2-methyl-1H-imidazol-1-yl)benzene (1,3-BMIB) was prepared according to the previously reported procedure of Schlechte et al. (2013). All other chemicals used in the experiment were purchased from commercial sources (Sigma–Aldrich) and used without further purification. The C and H elemental analyses were performed on a Vario EL III elemental analyzer (Elementar Analysensysteme GmbH). IR spectra were recorded from KBr pellets in the range 4000–400 cm^-1 on a Bruker VECTOR 22 spectrometer. The fluorescence spectrum was recorded on a Perkin–Elmer Fluoro Max-P spectrophotometer. The thermogravimetric analysis was performed on a Perkin–Elmer Pyris 1 TGA analyzer from 298 to 1073 K with a heating rate of 20 K min^-1 under nitro­gen (TA Instruments).

S2.1. Synthesis and crystallization

A mixture of NO₂—H₂BDC (21.1 mg, 0.1 mmol), 1,3-BMIB (23.8 mg, 0.1 mmol), Cd(NO₃)₂·6H₂O (34.5 mg, 0.1 mmol), KOH (16.8 mg, 0.3 mmol) and H₂O (8 ml) was placed in a Teflon-lined stainless steel vessel, heated to 423 K for 3 d, and then cooled to room temperature over a period of 24 h. Colourless crystals of (I) were obtained (yield 21.9%, based on Cd). Elemental analysis (%) calculated for C₂₂H₁₇CdN₅O₆: C 47.20, H 3.06, N 12.51; found: C 47.31, H 3.07, N 12.54. IR (KBr, cm^-1): 3571 (w), 2365 (w), 1638 (s), 1439 (s), 1201 (m), 926 (w), 781 (w), 690 (s).

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) for imidazole and benzene H atoms, or C—H = 0.96 Å and U_iso(H) = 1.5U_eq(C) for methyl H atoms. Atoms C1, O1 and O2 of (I) are disordered over two positions for which the site-occupation factors were 0.45 (2) and 0.55 (2); atoms C2, O3 and O4 are disordered over two positions for which the site-occupation factors were 0.52 (3) and 0.48 (3); and atoms N5, O5 and O6 are disordered over two positions for which the site-occupation factors were 0.20 (2) and 0.80 (2).

S3. Results and discussion

Single-crystal X-ray diffraction analysis revealed that the title compound, (I), crystallizes in the monoclinic space group P2₁/c with an asymmetric unit consisting of a divalent Cd^II atom, a 1,3-bis­(2-methyl-1H-imidazol-1-yl)benzene (1,3-BMIB) ligand and a fully deprotonated 5-nitro­benzene-1,3-di­carboxyl­ate (NO₂—BDC^2-) ligand. As shown in Fig. 1, the coordination sphere of the Cd^II atom consists of five O-donor atoms from three different NO₂—BDC^2- ligands and two imidazole N-donor atoms of two different 1,3-BMIB ligands, forming a distorted {CdN₂O₅} penta­gonal bipyramid. The equatorial plane of the penta­gonal bipyramid is occupied by four O atoms from two different NO₂—BDC^2- ligands, and by an imidazole N atom from one 1,3-BMIB ligand, while the axial positions are occupied by one imidazole N atom from another 1,3-BMIB ligand and an O atom from another NO₂—BDC^2- ligand (Table 2). As shown in the Scheme, the NO₂—BDC^2- ligand links three Cd^II atoms and exhibits two coordination patterns, one being a µ₁-η¹:η¹ chelating mode and the other being a µ₂-η²:η¹ bridging mode. {Cd₂O₂} binuclear rhomboid subunits are constructed by the carboxyl­ate end groups with a µ₂-η²:η¹ bridging mode of the NO₂—BDC^2- ligands. In the {Cd₂O₂} subunits, the Cd1···Cd1^iv and O3ⁱ···O3ⁱⁱⁱ through-space distances are 3.9089 (5) and 3.0786 (3) Å, respectively, while the Cd1—O3ⁱ—Cd1^iv and O3ⁱ—Cd1—O3ⁱⁱⁱ angles are 103.4 (1) and 76.6 (1)°, respectively [symmetry codes: (i) x, y, z+1; (iii) -x+1, -y+2, -z; (iv) -x+1, -y+2, -z+1]. The {Cd₂O₂} binuclear rhomboid subunits are joined by NO₂—BDC^2- ligands to form an infinite ladder-like one-dimensional [Cd(NO₂—BDC)]_n chain along [001], with a Cd1···Cd1^v separation of 9.857 (2) Å [yymmetry code: (v) x, y, z-1] (Fig. 2).

On the other hand, the planes of the imidazole rings are twisted with respect to those of the benzene rings (C13–C18), forming dihedral angles of 55.2 (2) and 62.7 (1)°, respectively, the with N1–N2/C9–C12 and N3–N4/C19–C22 imidazole rings of the 1,3-BMIB ligands. Adjacent [Cd(NO₂—BDC)]_n chains are conjoined into a three-dimensional [Cd(1,3-BMIB)(NO₂—BDC)]_n coordination polymer (Fig. 3) by bridging 1,3-BMIB ligands that bridge pairs of Cd^II atoms with a Cd1···Cd1^vi contact distance of 13.5898 (11) Å [symmetry codes: (vi) -x, y-1/2, -z+1/2].

A further insight into the nature of this intricate framework can be obtained using topological analysis with TOPOS software (Blatov et al., 2000). From the topological point of view, each Cd1 atom connects two 1,3-BIMB ligands and three NO₂—BDC^2- anions and is 5-connected. The NO₂—BDC^2- ligands are 3-connected and 1,3-BIMB ligands are 2-connected nodes. According to the simplification principle, the whole framework can be simplified as a 3,5-connected net with the {4².6⁵.8³}{4².6} topology.

There is a large void cavity in compound (I). In order to stabilize the framework, each net is inter­penetrated by each other leading to the formation of an unusual twofold inter­penetrating three-dimensional architecture (Fig. 4). The inter­penetration mode of compound (I) belongs to class Ia, twofold inter­penetration. The translational degree of inter­penetration (Z_t) of compound (I) is 2, so the overall network structure can be categorized into two topologically equivalent three-dimensional subsets related by the translation vector [100].

As shown in Fig. 5, thermogravimetric analysis of the compound (I) reveals that there is no weight loss until 593 K. After that temperature, the process of chemical decomposition was performed from 593 to 983 K. The remaining weight corresponds to the formation of CdO (observed 22.38%; calculated 22.94%).

Due to the excellent luminescence properties of coordination compounds containing d¹⁰ metal centers, the solid-state photoluminescent properties of compound (I) have been investigated at room temperature (Allendorf et al., 2009). Compound (I) exhibited a luminescence emission centred at ~390 nm upon excitation at 320 nm (Fig. 6). Because the Cd^II ion is difficult to oxidize or to reduce due to the d¹⁰ configuration, the emissions are neither metal-to-ligand charge transfer nor ligand-to-metal charge transfer (Guo et al., 2011; Wen et al., 2007). As a result, the emissive behaviour of compound (I) can be attributed to ligand-centred electronic transitions.

Related literature

For related literature, see: Allendorf et al. (2009); Blatov et al. (2000); Cook et al. (2013); Dybtsev et al. (2006); Guo et al. (2011); Lu et al. (2012); Luo et al. (2013); Ma et al. (2009); Sarma et al. (2012); Schlechte et al. (2012, 2013); Sun et al. (2012); Wang et al. (2008); Wen et al. (2007); Yang et al. (2013); Zhang et al. (2009); Zhao et al. (2012).

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL2013 (Sheldrick, 2008).

Figures

	Fig. 1. A view of the local coordination of the Cd^II cations in (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. [Symmetry codes: (i) x, y, z+1; (ii) -x, y+1/2, -z+1/2; (iii) -x, -y+2, -z.]
	Fig. 2. A view of [Cd(NO2-BDC)]n chain in (I).
	Fig. 3. Aiew of three-dimensional structure of (I). [Symmetry codes: (iii) -x+1, y+2, -z; (iv) -x+1, -y+2, -z+1; (v) x, y, z–1; (vi) -x, y-1/2, -z+1/2; (vii) x-1, -y+3/2, z-1/2; (viii) -x, y-1/2, -z-1/2; (ix) x-1, -y+3/2, z-3/2.]
	Fig. 4. A schematic representation of the twofold interpenetrating framework in (I).
	Fig. 5. The thermogravimetric curve of compound (I).
	Fig. 6. The solid-state emission spectrum of compound (I) recorded at room temperature.

Poly[[µ₂-1,3-bis(2-methyl-1H-imidazol-1-yl)benzene](µ₃-5-nitrobenzene-1,3-dicarboxylato)cadmium(II)]

Crystal data

[Cd(C8H3NO6)(C14H14N4)]	Z = 4
Mr = 559.80	F(000) = 1120
Monoclinic, P21/c	Dx = 1.718 Mg m^−3
a = 11.8377 (14) Å	Mo Kα radiation, λ = 0.71073 Å
b = 18.664 (2) Å	µ = 1.06 mm^−1
c = 9.8566 (11) Å	T = 296 K
β = 96.374 (2)°	Block, colorless
V = 2164.2 (4) Å^3	0.25 × 0.23 × 0.19 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	3599 reflections with I > 2σ(I)
ϕ and ω scans	Rint = 0.036
Absorption correction: multi-scan (SADABS; Bruker, 2013)	θmax = 26.0°, θmin = 1.7°
Tmin = 0.787, Tmax = 0.823	h = −14→14
18306 measured reflections	k = −23→21
4242 independent reflections	l = −11→12

Refinement

Refinement on F^2	228 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.028	H-atom parameters constrained
wR(F^2) = 0.066	w = 1/[σ^2(Fo^2) + (0.027P)^2 + 1.8751P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
4242 reflections	Δρmax = 1.14 e Å^−3
393 parameters	Δρmin = −0.80 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.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
N5	0.816 (2)	0.778 (2)	−0.048 (4)	0.049 (4)	0.20 (3)
O5	0.883 (2)	0.794 (3)	0.050 (3)	0.066 (5)	0.20 (3)
O6	0.844 (4)	0.736 (2)	−0.134 (4)	0.056 (5)	0.20 (3)
N5'	0.8041 (6)	0.7642 (5)	−0.0714 (9)	0.0422 (15)	0.80 (3)
O5'	0.8611 (9)	0.7624 (8)	0.0402 (6)	0.069 (3)	0.80 (3)
O6'	0.8259 (9)	0.7279 (5)	−0.1677 (11)	0.0496 (16)	0.80 (3)
C1	0.5155 (18)	0.912 (2)	0.1302 (16)	0.028 (2)	0.45 (5)
O1	0.4100 (15)	0.9248 (12)	0.115 (2)	0.029 (2)	0.45 (5)
O2	0.5742 (15)	0.9136 (13)	0.2454 (17)	0.032 (2)	0.45 (5)
C1'	0.5103 (16)	0.9081 (19)	0.1288 (13)	0.028 (2)	0.55 (5)
O1'	0.4169 (14)	0.9408 (11)	0.1072 (18)	0.031 (2)	0.55 (5)
O2'	0.5596 (13)	0.8942 (11)	0.2461 (14)	0.032 (2)	0.55 (5)
C2	0.512 (3)	0.8914 (15)	−0.3770 (14)	0.032 (2)	0.52 (7)
O3	0.459 (2)	0.9502 (11)	−0.391 (2)	0.033 (3)	0.52 (7)
O4	0.534 (2)	0.8512 (10)	−0.4731 (17)	0.036 (2)	0.52 (7)
C2'	0.518 (4)	0.8908 (16)	−0.3813 (16)	0.032 (2)	0.48 (7)
O3'	0.475 (3)	0.9524 (11)	−0.406 (3)	0.031 (3)	0.48 (7)
O4'	0.508 (2)	0.8405 (11)	−0.4684 (19)	0.036 (2)	0.48 (7)
C3	0.5688 (2)	0.88469 (14)	0.0080 (3)	0.0247 (6)
C4	0.5241 (2)	0.90264 (15)	−0.1237 (3)	0.0247 (6)
H4	0.4640	0.9349	−0.1366	0.030*
C5	0.5675 (2)	0.87346 (15)	−0.2368 (3)	0.0261 (6)
C6	0.6587 (2)	0.82673 (15)	−0.2180 (3)	0.0313 (7)
H6	0.6872	0.8053	−0.2922	0.038*
C7	0.7060 (2)	0.81282 (16)	−0.0870 (3)	0.0329 (7)
C8	0.6634 (2)	0.84067 (16)	0.0273 (3)	0.0322 (7)
H8	0.6975	0.8301	0.1146	0.039*
C9	0.1803 (3)	0.85404 (19)	0.4343 (4)	0.0468 (9)
H9	0.1609	0.8938	0.4837	0.056*
C10	0.1219 (3)	0.79140 (17)	0.4230 (4)	0.0418 (8)
H10	0.0559	0.7805	0.4619	0.050*
C11	0.2702 (2)	0.78508 (16)	0.3079 (3)	0.0323 (7)
C12	0.3531 (3)	0.75735 (19)	0.2173 (4)	0.0563 (11)
H12A	0.3533	0.7881	0.1392	0.084*
H12B	0.3316	0.7098	0.1877	0.084*
H12C	0.4278	0.7563	0.2666	0.084*
C13	0.1488 (2)	0.67453 (15)	0.3136 (3)	0.0311 (6)
C14	0.2276 (2)	0.62168 (17)	0.3494 (3)	0.0379 (7)
H14	0.2983	0.6335	0.3945	0.046*
C15	0.2012 (3)	0.55082 (17)	0.3182 (4)	0.0430 (8)
H15	0.2555	0.5153	0.3384	0.052*
C16	0.0946 (2)	0.53298 (17)	0.2573 (3)	0.0376 (7)
H16	0.0768	0.4854	0.2366	0.045*
C17	0.0141 (2)	0.58615 (15)	0.2270 (3)	0.0293 (6)
C18	0.0402 (2)	0.65755 (16)	0.2532 (3)	0.0303 (6)
H18	−0.0135	0.6932	0.2309	0.036*
C19	−0.1741 (2)	0.52377 (15)	0.2157 (3)	0.0299 (6)
C20	−0.1427 (3)	0.58669 (17)	0.0344 (3)	0.0361 (7)
H20	−0.1094	0.6164	−0.0258	0.043*
C21	−0.2450 (2)	0.55464 (16)	0.0123 (3)	0.0333 (7)
H21	−0.2945	0.5582	−0.0676	0.040*
C22	−0.1596 (3)	0.4936 (2)	0.3556 (3)	0.0576 (11)
H22A	−0.2328	0.4829	0.3838	0.086*
H22B	−0.1214	0.5279	0.4173	0.086*
H22C	−0.1152	0.4505	0.3565	0.086*
Cd1	0.41695 (2)	0.93743 (2)	0.36461 (2)	0.02473 (7)
N1	0.2737 (2)	0.84978 (13)	0.3609 (3)	0.0342 (6)
N2	0.17821 (19)	0.74810 (13)	0.3442 (3)	0.0339 (6)
N3	−0.09703 (19)	0.56686 (13)	0.1636 (2)	0.0303 (5)
N4	−0.26528 (18)	0.51570 (12)	0.1262 (2)	0.0272 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N5	0.056 (7)	0.066 (8)	0.028 (7)	0.034 (7)	0.017 (6)	0.002 (6)
O5	0.055 (8)	0.086 (11)	0.057 (9)	0.032 (9)	−0.001 (7)	−0.005 (9)
O6	0.064 (9)	0.075 (9)	0.028 (10)	0.023 (8)	0.009 (8)	0.009 (8)
N5'	0.051 (3)	0.052 (4)	0.024 (3)	0.021 (2)	0.006 (2)	0.004 (2)
O5'	0.074 (4)	0.090 (6)	0.039 (2)	0.052 (4)	−0.015 (2)	−0.008 (3)
O6'	0.060 (3)	0.056 (3)	0.034 (4)	0.030 (2)	0.010 (3)	−0.001 (2)
C1	0.033 (4)	0.025 (4)	0.026 (4)	−0.004 (4)	0.010 (3)	0.002 (3)
O1	0.031 (3)	0.025 (6)	0.034 (3)	−0.001 (3)	0.010 (3)	0.003 (4)
O2	0.042 (4)	0.031 (6)	0.022 (3)	−0.005 (4)	0.002 (3)	−0.001 (4)
C1'	0.036 (3)	0.025 (4)	0.025 (3)	−0.002 (3)	0.008 (3)	−0.002 (3)
O1'	0.031 (3)	0.027 (5)	0.038 (3)	0.000 (3)	0.013 (2)	−0.003 (4)
O2'	0.041 (3)	0.034 (5)	0.021 (2)	−0.007 (3)	0.004 (2)	−0.004 (3)
C2	0.027 (4)	0.048 (3)	0.020 (3)	−0.011 (3)	0.000 (3)	0.008 (3)
O3	0.026 (5)	0.044 (3)	0.027 (5)	−0.007 (3)	−0.005 (4)	0.014 (3)
O4	0.033 (5)	0.051 (4)	0.024 (3)	−0.020 (3)	0.003 (3)	0.002 (3)
C2'	0.029 (5)	0.047 (4)	0.020 (3)	−0.010 (3)	−0.002 (3)	0.010 (3)
O3'	0.030 (6)	0.038 (3)	0.023 (4)	−0.005 (3)	−0.001 (4)	0.015 (3)
O4'	0.032 (5)	0.053 (4)	0.022 (3)	−0.019 (4)	0.003 (4)	−0.004 (3)
C3	0.0278 (14)	0.0267 (15)	0.0198 (14)	−0.0011 (11)	0.0029 (11)	0.0018 (11)
C4	0.0215 (13)	0.0245 (14)	0.0274 (15)	−0.0001 (11)	0.0000 (11)	0.0047 (12)
C5	0.0269 (14)	0.0293 (15)	0.0214 (14)	−0.0039 (12)	0.0004 (11)	0.0047 (11)
C6	0.0411 (16)	0.0321 (16)	0.0218 (15)	0.0045 (13)	0.0090 (12)	0.0029 (12)
C7	0.0359 (16)	0.0366 (17)	0.0269 (15)	0.0130 (13)	0.0064 (12)	0.0080 (13)
C8	0.0360 (16)	0.0418 (18)	0.0185 (14)	0.0069 (13)	0.0015 (12)	0.0084 (12)
C9	0.0449 (19)	0.0411 (19)	0.058 (2)	−0.0056 (16)	0.0228 (17)	−0.0153 (17)
C10	0.0285 (15)	0.0419 (19)	0.058 (2)	−0.0111 (14)	0.0187 (15)	−0.0154 (16)
C11	0.0289 (15)	0.0307 (16)	0.0372 (17)	−0.0008 (12)	0.0034 (13)	−0.0025 (13)
C12	0.055 (2)	0.037 (2)	0.084 (3)	−0.0056 (17)	0.034 (2)	−0.0149 (19)
C13	0.0293 (14)	0.0296 (16)	0.0344 (16)	−0.0060 (12)	0.0043 (12)	−0.0020 (13)
C14	0.0263 (15)	0.0384 (18)	0.047 (2)	−0.0042 (13)	−0.0042 (13)	−0.0009 (15)
C15	0.0321 (16)	0.0355 (19)	0.060 (2)	0.0033 (14)	0.0008 (15)	0.0046 (16)
C16	0.0347 (16)	0.0312 (17)	0.046 (2)	−0.0050 (13)	0.0029 (14)	0.0008 (14)
C17	0.0266 (14)	0.0322 (16)	0.0288 (15)	−0.0071 (12)	0.0014 (12)	0.0008 (12)
C18	0.0275 (14)	0.0309 (16)	0.0319 (16)	−0.0007 (12)	0.0003 (12)	−0.0005 (12)
C19	0.0282 (14)	0.0315 (16)	0.0299 (16)	−0.0058 (12)	0.0025 (12)	0.0004 (13)
C20	0.0350 (16)	0.0424 (18)	0.0303 (16)	−0.0087 (14)	0.0013 (13)	0.0078 (14)
C21	0.0318 (15)	0.0403 (18)	0.0264 (15)	−0.0024 (13)	−0.0024 (12)	0.0039 (13)
C22	0.046 (2)	0.088 (3)	0.0355 (19)	−0.025 (2)	−0.0082 (16)	0.0224 (19)
Cd1	0.02421 (11)	0.03152 (13)	0.01800 (11)	0.00172 (9)	0.00025 (7)	−0.00198 (9)
N1	0.0320 (13)	0.0294 (14)	0.0419 (15)	−0.0036 (11)	0.0075 (11)	−0.0058 (12)
N2	0.0282 (13)	0.0321 (14)	0.0412 (15)	−0.0073 (11)	0.0027 (11)	−0.0060 (11)
N3	0.0276 (12)	0.0342 (14)	0.0284 (13)	−0.0078 (10)	−0.0004 (10)	0.0017 (11)
N4	0.0248 (12)	0.0309 (13)	0.0252 (13)	−0.0009 (10)	−0.0007 (10)	−0.0006 (10)

Geometric parameters (Å, º)

N5—O5	1.219 (14)	C9—H9	0.9300
N5—O6	1.224 (15)	C10—N2	1.348 (4)
N5—C7	1.476 (16)	C10—H10	0.9300
N5'—O6'	1.216 (6)	C11—N1	1.315 (4)
N5'—O5'	1.226 (6)	C11—N2	1.370 (4)
N5'—C7	1.469 (5)	C11—C12	1.491 (4)
C1—O2	1.264 (11)	C12—H12A	0.9600
C1—O1	1.264 (13)	C12—H12B	0.9600
C1—C3	1.509 (11)	C12—H12C	0.9600
Cd1—C1	2.743 (12)	C13—C14	1.376 (4)
Cd1—O1	2.46 (2)	C13—C18	1.393 (4)
Cd1—O2	2.352 (18)	C13—N2	1.440 (4)
C1'—O1'	1.260 (11)	C14—C15	1.386 (4)
C1'—O2'	1.263 (10)	C14—H14	0.9300
C1'—C3	1.507 (9)	C15—C16	1.376 (4)
Cd1—C1'	2.738 (10)	C15—H15	0.9300
Cd1—O1'	2.538 (19)	C16—C17	1.386 (4)
Cd1—O2'	2.303 (14)	C16—H16	0.9300
C2—O4	1.258 (13)	C17—C18	1.386 (4)
C2—O3	1.263 (10)	C17—N3	1.438 (3)
C2—C5	1.501 (10)	C18—H18	0.9300
O3—Cd1^i	2.42 (2)	C19—N4	1.325 (3)
O3—Cd1^ii	2.56 (3)	C19—N3	1.359 (3)
O4—Cd1^i	2.562 (16)	C19—C22	1.482 (4)
C2'—O4'	1.268 (13)	C20—C21	1.347 (4)
C2'—O3'	1.273 (11)	C20—N3	1.378 (4)
C2'—C5	1.513 (11)	C20—H20	0.9300
O3'—Cd1^i	2.30 (2)	C21—N4	1.381 (4)
O3'—Cd1^ii	2.43 (3)	C21—H21	0.9300
O4'—Cd1^i	2.600 (18)	C22—H22A	0.9600
C3—C8	1.385 (4)	C22—H22B	0.9600
C3—C4	1.387 (4)	C22—H22C	0.9600
C4—C5	1.389 (4)	Cd1—O3'^iii	2.30 (2)
C4—H4	0.9300	Cd1—N4^iv	2.324 (2)
C5—C6	1.384 (4)	Cd1—N1	2.354 (2)
C6—C7	1.374 (4)	Cd1—O3^iii	2.42 (2)
C6—H6	0.9300	Cd1—O3'^ii	2.43 (3)
C7—C8	1.385 (4)	Cd1—O3^ii	2.56 (3)
C8—H8	0.9300	Cd1—O4^iii	2.562 (16)
C9—C10	1.357 (4)	Cd1—O4'^iii	2.600 (18)
C9—N1	1.388 (4)	N4—Cd1^v	2.324 (2)
O5—N5—O6	121.0 (19)	C14—C13—C18	120.9 (3)
O5—N5—C7	125 (2)	C14—C13—N2	119.3 (3)
O6—N5—C7	114 (3)	C18—C13—N2	119.8 (3)
O6'—N5'—O5'	122.8 (5)	C13—C14—C15	119.9 (3)
O6'—N5'—C7	119.8 (5)	C13—C14—H14	120.1
O5'—N5'—C7	117.4 (5)	C15—C14—H14	120.1
O2—C1—O1	122.7 (13)	C16—C15—C14	120.1 (3)
O2—C1—C3	119.3 (14)	C16—C15—H15	120.0
O1—C1—C3	117.6 (17)	C14—C15—H15	120.0
O2—C1—Cd1	58.8 (9)	C15—C16—C17	119.8 (3)
O1—C1—Cd1	63.9 (11)	C15—C16—H16	120.1
C3—C1—Cd1	170 (3)	C17—C16—H16	120.1
C1—O1—Cd1	88.6 (11)	C18—C17—C16	121.0 (3)
C1—O2—Cd1	93.8 (10)	C18—C17—N3	119.7 (3)
O1'—C1'—O2'	124.1 (11)	C16—C17—N3	119.3 (3)
O1'—C1'—C3	118.6 (14)	C17—C18—C13	118.3 (3)
O2'—C1'—C3	117.3 (12)	C17—C18—H18	120.8
O1'—C1'—Cd1	67.5 (9)	C13—C18—H18	120.8
O2'—C1'—Cd1	56.8 (7)	N4—C19—N3	110.3 (2)
C3—C1'—Cd1	173.2 (16)	N4—C19—C22	125.3 (3)
C1'—O1'—Cd1	85.2 (9)	N3—C19—C22	124.3 (3)
C1'—O2'—Cd1	95.9 (7)	C21—C20—N3	106.5 (3)
O4—C2—O3	125.4 (12)	C21—C20—H20	126.8
O4—C2—C5	117.1 (15)	N3—C20—H20	126.8
O3—C2—C5	116.9 (15)	C20—C21—N4	109.7 (3)
C2—O3—Cd1^i	93.7 (10)	C20—C21—H21	125.2
C2—O3—Cd1^ii	115 (2)	N4—C21—H21	125.2
Cd1^i—O3—Cd1^ii	103.4 (10)	C19—C22—H22A	109.5
C2—O4—Cd1^i	87.4 (8)	C19—C22—H22B	109.5
O4'—C2'—O3'	122.3 (13)	H22A—C22—H22B	109.5
O4'—C2'—C5	118.4 (17)	C19—C22—H22C	109.5
O3'—C2'—C5	118.6 (16)	H22A—C22—H22C	109.5
C2'—O3'—Cd1^i	98.5 (11)	H22B—C22—H22C	109.5
C2'—O3'—Cd1^ii	122 (2)	O3'^iii—Cd1—N4^iv	91.8 (6)
Cd1^i—O3'—Cd1^ii	111.1 (10)	O2'—Cd1—N4^iv	148.5 (4)
C2'—O4'—Cd1^i	85.0 (9)	N4^iv—Cd1—O2	142.8 (5)
C8—C3—C4	119.3 (2)	O3'^iii—Cd1—N1	103.5 (7)
C8—C3—C1'	119.9 (8)	O2'—Cd1—N1	108.4 (6)
C4—C3—C1'	120.6 (7)	N4^iv—Cd1—N1	83.05 (8)
C8—C3—C1	119.5 (9)	O2—Cd1—N1	118.0 (6)
C4—C3—C1	121.1 (9)	N4^iv—Cd1—O3^iii	88.5 (4)
C3—C4—C5	121.3 (3)	N1—Cd1—O3^iii	98.7 (7)
C3—C4—H4	119.3	N4^iv—Cd1—O1	99.1 (5)
C5—C4—H4	119.3	O2—Cd1—O1	54.8 (3)
C6—C5—C4	119.4 (2)	N1—Cd1—O1	88.5 (5)
C6—C5—C2	121.3 (10)	O3'^iii—Cd1—O3'^ii	68.9 (10)
C4—C5—C2	119.2 (10)	N4^iv—Cd1—O3'^ii	81.8 (6)
C6—C5—C2'	118.4 (12)	N1—Cd1—O3'^ii	162.8 (7)
C4—C5—C2'	122.2 (12)	N4^iv—Cd1—O3^ii	85.3 (4)
C7—C6—C5	118.4 (3)	N1—Cd1—O3^ii	167.6 (5)
C7—C6—H6	120.8	O3^iii—Cd1—O3^ii	76.6 (10)
C5—C6—H6	120.8	O2'—Cd1—O1'	54.6 (3)
C6—C7—C8	123.1 (3)	N4^iv—Cd1—O1'	96.3 (3)
C6—C7—N5'	116.7 (4)	N1—Cd1—O1'	94.7 (5)
C8—C7—N5'	120.1 (4)	N4^iv—Cd1—O4^iii	137.4 (4)
C6—C7—N5	125.8 (16)	N1—Cd1—O4^iii	84.9 (6)
C8—C7—N5	110.4 (15)	O3^iii—Cd1—O4^iii	53.3 (3)
C7—C8—C3	118.2 (3)	O3^ii—Cd1—O4^iii	100.9 (7)
C7—C8—H8	120.9	O3'^iii—Cd1—O4'^iii	53.6 (3)
C3—C8—H8	120.9	N4^iv—Cd1—O4'^iii	133.0 (5)
C10—C9—N1	109.6 (3)	N1—Cd1—O4'^iii	77.0 (6)
C10—C9—H9	125.2	O3'^ii—Cd1—O4'^iii	107.8 (9)
N1—C9—H9	125.2	C11—N1—C9	105.6 (3)
N2—C10—C9	106.5 (3)	C11—N1—Cd1	129.4 (2)
N2—C10—H10	126.8	C9—N1—Cd1	124.5 (2)
C9—C10—H10	126.8	C10—N2—C11	107.9 (2)
N1—C11—N2	110.5 (3)	C10—N2—C13	124.7 (2)
N1—C11—C12	124.3 (3)	C11—N2—C13	127.3 (2)
N2—C11—C12	125.2 (3)	C19—N3—C20	107.3 (2)
C11—C12—H12A	109.5	C19—N3—C17	127.2 (2)
C11—C12—H12B	109.5	C20—N3—C17	125.5 (2)
H12A—C12—H12B	109.5	C19—N4—C21	106.2 (2)
C11—C12—H12C	109.5	C19—N4—Cd1^v	128.42 (19)
H12A—C12—H12C	109.5	C21—N4—Cd1^v	124.55 (18)
H12B—C12—H12C	109.5

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