The coordination polymer poly[bis[[mu]₂-2-(2,2'-bi-1H-imidazol-1-yl)acetato]­cadmium]

The title compound, [Cd(C₈H₇N₄O₂)₂]_n, crystallizes in the centrosymmetric triclinic space group P with an asymmetric unit consisting of a bivalent Cd^II atom and two 2-(2,2'-bi-1H-imidazol-1-yl)acetate (BDAC^-) anions. Two inversion-related BDAC^- ligands are oppositely arranged and bind two Cd^II ions to form a [Cd₂(BDAC)₂] rhomboid subunit which is bridged by another BDAC^- ligand to form an infinite ladder along the a direction containing parallelogram grids. The three-dimensional supra­molecular architecture is formed by hydrogen bonds and C-H...[pi] and [pi]-[pi] inter­actions.

S1. Comment

The design and synthesis of coordination polymers is an attractive area of research not only because of the diverse topologies and intriguing structures of these compounds but also because of their potential applications in optics, magnetism, gas storage, ion exchange and catalysis (Eddaoudi et al., 2001; Kitagawa et al., 2004; Ferey et al., 2005; Roy et al., 2009). From the viewpoint of crystal engineering, the most effective and facile approach to coordination polymers is to utilize an applicable ligand to link metal ions to give an infinite framework. Among them, the multipyridine and multicarboxylate spacers are good candidates for the construction of novel metal–organic compounds (Braverman et al., 2007; Chen et al., 2009; Liang et al., 2009; Wang et al., 2011).

2-(2,2'-Bi-1H-imidazol-1-yl)acetatic acid (HBDAC) is a typical example of a multidentate N- and O-donor ligand and, to the best of our knowledge, has not been explored to date. First, HBDAC is a flexible ligand with N- and O-donors on opposite sides, enabling the ligand to act as a linear bridge; second, the deprotonated BDAC^- ligand contains two bridging moieties, which can lead to a variety of connection modes with metal centres and provides abundant structural motifs; third, it can act not only as a hydrogen-bond donor but also as an acceptor, which makes it a wonderful candidate for the construction of supramolecular networks. Here, we have selected HBDAC as an organic linker, generating the title new Cd^II coordination polymer, poly[[µ₂-2-(2,2'-bi-1H-imidazol-1-yl)acetato]cadmium], (I), the crystal structure of which we now report.

Compound (I) crystallizes in the centrosymmetric triclinic space group P1 with an asymmetric unit comprising a divalent Cd^II atom and two BDAC^- anions (BDAC-A contains atoms N1–N4/O1/O2/C1–C8 and BDAC-B contains atoms N5–N8/O3/O4/C9–C16) (Fig. 1). The coordination environment at cadmium is best considered a distorted {CdN₄O₂} octahedron formed by four N atoms (N1, N2, N5 and N6) from two different chelating BDAC^- ligands and two cis-O atoms [O2ⁱ and O4ⁱⁱ; symmetry codes: (i) x-1, y, z; (ii) -x+1, -y+1, -z+2] from two other BDAC^- ligands. The Cd—O bond lengths are 2.224 (3) and 2.443 (3) Å, while the Cd—N bond lengths vary greatly from 2.329 (3) to 2.503 (3) Å. The average Cd—O and Cd—N distances in (I) are comparable to those in reported Cd-based compounds (Liu et al., 2008; Farnum et al., 2011). It is worth noting that all BDAC^- ligands linked to two Cd^II ions adopt an exobidentate chelating/bridging coordination mode.

Two symmetry-related BDAC-B ligands are oppositely arranged and bind two Cd^II ions to form a [Cd₂(BDAC-B)₂] rhomboid subunit (16-membered macrocycle). The Cd···Cd through-space distances across the dinuclear kernel are 7.017 Å. The rhomboid [Cd₂(BDAC-B)₂] subunit is further bridged by BDAC-A ligands to form an infinite ladder (Fig. 2) containing a parallelogram grid (dimensions 7.97 × 12.92 Å based on Cd···Cd distances) arranged parallel to the a direction. The Cd···Cd contact distances through the crystallographically distinct BDAC^- ligands are 8.126 and 7.017 Å. These differences are provided by conformational variances within the distinct BDAC^- ligands. In BDAC-A, the carboxylate group is twisted by 81.9° relative to the plane of the imidazole ring. The related torsion angle in BDAC-B is 68.7°.

There are extensive inter- and intramolecular hydrogen bonds of the N—H···O and C—H···O types connecting the one-dimensional chains of (I). Hydrogen bonds are found between N8 and O1/O4 with donor–acceptor distances of 3.049 (4) and 2.794 (4) Å, respectively. The carbonyl O2 atom acts as an acceptor in two hydrogen-bonding interactions; one involves the alkyl atom C7 of a neighbouring complex, with an O···C distance of 3.231 (5) Å, while the second (stronger) hydrogen bond is directed to atom N4, with an O···N distance of 2.792 (4) Å, forming eight-membered rings, which extend the structure to form a two-dimensional sheet. Furthermore, the carbonyl O3 atom acts as an acceptor in three further hydrogen-bonding interactions, involving the alkyl atoms C7, C10 and C15, with O···C distances of 3.299 (5), 3.317 (5) and 3.461 (5) Å, respectively, forming six-membered rings, which further extend the structure into a three-dimensional network (Fig. 3). It is interesting that the packing in the unit cell is also stabilized by weak π–π interactions. The centroid of the N1/C1/C2/N3/C3 ring, Cg1, is involved in a weak π–π interaction with the centroid of the N2/C4/N4/C6/C5 ring, Cg2, the distance between the interleaved ligands being 3.613 (2) Å. In addition, a C—H···π interaction (Fig. 4) is observed between the C15—H15B group and the centroid of the N2/C4/N4/C6/C5 ring, Cg3, with C15···Cg3 = 3.593 (4) Å, H3B···Cg3 = 2.89 Å and C3—H3B···Cg3 = 130°.

Related literature

For related literature, see: Braverman & LaDuca (2007); Chen et al. (2009); Eddaoudi et al. (2001); Farnum et al. (2011); Ferey et al. (2005); Kitagawa et al. (2004); Liang et al. (2009); Roy et al. (2009); Wang et al. (2011).

S2. Experimental

A mixture of Cd(NO₃)₂.6H₂O (34.6 mg, 0.1 mmol), HBDAC (19.2 mg, 0.1 mmol), KOH (11.2 mg, 0.2 mmol) in H₂O (10 ml) was sealed in a 16 ml Teflon-lined stainless steel container and heated at 463 K for 72 h. After cooling to room temperature, colourless block-shaped crystals of (I) were collected by filtration and washed by water and ethanol several times (yield 33.1%, based on HBDAC). Elemental analysis calculated for C₁₆H₁₄CdN₈O₄: C 38.84, H 2.85, N 22.65%; found: 38.72, H 2.87, N 22.56%.

S3. Refinement

All N- and C-bound H atoms were placed in calculated positions and refined using a riding model, with N—H = 0.86 Å, C—H = 0.93 (imidazole) or 0.97 Å (methylene) and U_iso(H) = 1.2U_eq(N or C).

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: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (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 50% probability level and H atoms are shown as small spheres of arbitrary radii. [Symmetry codes: (i) x-1, y, z; (ii) -x+1, -y+1, -z+2.]
	Fig. 2. A single [Cd(BDAC)]n chain in (I).
	Fig. 3. A perspective view of the three-dimensional supramolecular structure of (I), incorporating C—H···O and N—H···O hydrogen bonds.
	Fig. 4. A projection of (I) showing C—H···π and π–π interactions.

poly[[µ₂-2-(2,2'-bi-1H-imidazoly-1-yl)acetato]cadmium]

Crystal data

[Cd(C16H14N8O4)]	V = 868.5 (3) Å^3
Mr = 494.76	Z = 2
Triclinic, P1	F(000) = 492
Hall symbol: -P 1	Dx = 1.892 Mg m^−3
a = 8.1262 (14) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.5663 (19) Å	µ = 1.30 mm^−1
c = 10.8076 (19) Å	T = 273 K
α = 73.150 (3)°	Block, white
β = 78.568 (3)°	0.19 × 0.17 × 0.15 mm
γ = 83.055 (3)°

Data collection

Bruker SMART CCD area-detector diffractometer	3072 independent reflections
Radiation source: fine-focus sealed tube	2637 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
ϕ and ω scans	θmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −9→9
Tmin = 0.781, Tmax = 0.822	k = −12→12
4352 measured reflections	l = −6→12

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)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.065	H-atom parameters constrained
S = 0.97	w = 1/[σ^2(Fo^2) + (0.0235P)^2] where P = (Fo^2 + 2Fc^2)/3
3013 reflections	(Δ/σ)max = 0.001
262 parameters	Δρmax = 0.54 e Å^−3
0 restraints	Δρmin = −0.39 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	0.70921 (3)	0.77295 (3)	0.78625 (3)	0.03370 (10)
O1	1.3941 (3)	0.8972 (3)	0.8252 (3)	0.0767 (11)
O2	1.5858 (3)	0.9786 (3)	0.6559 (3)	0.0468 (7)
O3	0.4252 (5)	0.3441 (4)	1.4593 (3)	0.0925 (12)
O4	0.4735 (4)	0.3433 (3)	1.2556 (3)	0.0746 (10)
N1	0.8999 (3)	0.9190 (3)	0.7910 (3)	0.0348 (7)
N2	0.9376 (3)	0.7719 (3)	0.6151 (3)	0.0353 (7)
N3	1.1347 (3)	1.0194 (3)	0.7073 (3)	0.0331 (7)
N4	1.1804 (3)	0.8439 (3)	0.5038 (3)	0.0394 (8)
H4	1.2697	0.8871	0.4792	0.047*
N5	0.6261 (3)	0.7236 (3)	1.0130 (3)	0.0362 (7)
N6	0.8332 (4)	0.5473 (3)	0.8894 (3)	0.0477 (8)
N8	0.7480 (4)	0.3737 (3)	1.0501 (3)	0.0421 (8)
H8	0.7005	0.3275	1.1254	0.051*
N7	0.6258 (3)	0.5859 (3)	1.2096 (3)	0.0314 (7)
C1	0.9113 (4)	1.0046 (4)	0.8601 (4)	0.0407 (9)
H1	0.8321	1.0183	0.9308	0.049*
C2	1.0564 (4)	1.0679 (4)	0.8106 (4)	0.0388 (9)
H2	1.0947	1.1312	0.8407	0.047*
C7	1.3032 (4)	1.0502 (4)	0.6393 (3)	0.0360 (9)
H7A	1.3163	1.1434	0.6265	0.043*
H7B	1.3191	1.0346	0.5534	0.043*
C8	1.4373 (4)	0.9678 (4)	0.7139 (4)	0.0392 (9)
C3	1.0365 (4)	0.9296 (3)	0.6992 (3)	0.0310 (8)
C4	1.0565 (4)	0.8506 (3)	0.6054 (3)	0.0303 (8)
C5	0.9885 (5)	0.7122 (4)	0.5163 (4)	0.0417 (9)
H5	0.9292	0.6508	0.4993	0.050*
C15	0.6448 (4)	0.4680 (3)	1.3186 (3)	0.0355 (9)
H15A	0.6499	0.4951	1.3961	0.043*
H15B	0.7501	0.4187	1.2969	0.043*
C16	0.4990 (4)	0.3773 (4)	1.3492 (4)	0.0360 (9)
C11	0.6659 (4)	0.6010 (3)	1.0792 (3)	0.0297 (8)
C12	0.7492 (4)	0.5058 (3)	1.0100 (3)	0.0333 (8)
C14	0.8873 (5)	0.4325 (4)	0.8530 (4)	0.0619 (13)
H14	0.9510	0.4291	0.7723	0.074*
C13	0.8351 (5)	0.3260 (4)	0.9506 (4)	0.0580 (12)
H13	0.8547	0.2377	0.9500	0.070*
C6	1.1376 (5)	0.7555 (4)	0.4472 (4)	0.0452 (10)
H6	1.1992	0.7302	0.3750	0.054*
C10	0.5553 (4)	0.7059 (4)	1.2263 (4)	0.0389 (9)
H10	0.5149	0.7263	1.3055	0.047*
C9	0.5567 (4)	0.7885 (4)	1.1043 (4)	0.0404 (9)
H9	0.5160	0.8769	1.0857	0.049*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.03319 (16)	0.03693 (17)	0.02885 (16)	−0.01135 (11)	−0.00453 (11)	−0.00260 (12)
O1	0.0514 (18)	0.086 (3)	0.062 (2)	−0.0059 (16)	−0.0173 (17)	0.0331 (19)
O2	0.0259 (14)	0.0577 (18)	0.0543 (17)	−0.0053 (12)	−0.0058 (13)	−0.0112 (15)
O3	0.119 (3)	0.119 (3)	0.045 (2)	−0.087 (2)	0.012 (2)	−0.015 (2)
O4	0.073 (2)	0.118 (3)	0.0466 (19)	−0.069 (2)	0.0123 (16)	−0.034 (2)
N1	0.0288 (16)	0.0398 (18)	0.0334 (17)	−0.0069 (13)	−0.0030 (14)	−0.0060 (15)
N2	0.0374 (17)	0.0347 (18)	0.0307 (17)	−0.0085 (14)	−0.0027 (14)	−0.0037 (14)
N3	0.0283 (15)	0.0313 (17)	0.0373 (18)	−0.0065 (13)	−0.0082 (14)	−0.0020 (14)
N4	0.0307 (16)	0.0411 (19)	0.0430 (19)	−0.0039 (14)	−0.0030 (15)	−0.0076 (16)
N5	0.0402 (17)	0.0309 (18)	0.0335 (17)	−0.0038 (13)	−0.0042 (14)	−0.0036 (15)
N6	0.061 (2)	0.044 (2)	0.0327 (18)	−0.0112 (17)	0.0061 (16)	−0.0082 (16)
N8	0.0437 (18)	0.0327 (19)	0.0422 (19)	−0.0065 (14)	0.0053 (16)	−0.0051 (16)
N7	0.0362 (16)	0.0307 (17)	0.0267 (16)	−0.0115 (13)	−0.0057 (13)	−0.0032 (13)
C1	0.037 (2)	0.050 (2)	0.037 (2)	−0.0061 (18)	−0.0024 (18)	−0.016 (2)
C2	0.036 (2)	0.044 (2)	0.040 (2)	−0.0062 (17)	−0.0060 (18)	−0.0163 (19)
C7	0.0314 (19)	0.038 (2)	0.035 (2)	−0.0119 (16)	−0.0054 (16)	−0.0001 (17)
C8	0.037 (2)	0.038 (2)	0.042 (2)	−0.0055 (17)	−0.0094 (19)	−0.0071 (19)
C3	0.0253 (18)	0.031 (2)	0.033 (2)	−0.0029 (15)	−0.0075 (16)	−0.0002 (16)
C4	0.0254 (18)	0.031 (2)	0.029 (2)	0.0014 (15)	−0.0045 (16)	−0.0012 (16)
C5	0.045 (2)	0.042 (2)	0.042 (2)	−0.0041 (18)	−0.0119 (19)	−0.0119 (19)
C15	0.041 (2)	0.039 (2)	0.0257 (19)	−0.0126 (17)	−0.0109 (16)	0.0004 (17)
C16	0.039 (2)	0.035 (2)	0.030 (2)	−0.0126 (17)	−0.0048 (18)	0.0021 (18)
C11	0.0319 (19)	0.029 (2)	0.0268 (19)	−0.0082 (15)	−0.0038 (16)	−0.0033 (16)
C12	0.0352 (19)	0.030 (2)	0.034 (2)	−0.0084 (16)	−0.0067 (17)	−0.0045 (17)
C14	0.073 (3)	0.055 (3)	0.055 (3)	−0.012 (2)	0.018 (2)	−0.026 (2)
C13	0.063 (3)	0.038 (2)	0.065 (3)	−0.006 (2)	0.017 (2)	−0.020 (2)
C6	0.045 (2)	0.047 (3)	0.042 (2)	0.0060 (19)	−0.004 (2)	−0.015 (2)
C10	0.046 (2)	0.036 (2)	0.037 (2)	−0.0121 (17)	0.0001 (18)	−0.0145 (19)
C9	0.044 (2)	0.027 (2)	0.048 (2)	−0.0045 (17)	−0.0011 (19)	−0.0099 (19)

Geometric parameters (Å, º)

Cd1—O4^i	2.224 (3)	N8—C12	1.336 (4)
Cd1—N5	2.329 (3)	N8—C13	1.356 (5)
Cd1—N1	2.332 (3)	N8—H8	0.8600
Cd1—N2	2.347 (3)	N7—C11	1.348 (4)
Cd1—O2^ii	2.443 (3)	N7—C10	1.373 (4)
Cd1—N6	2.503 (3)	N7—C15	1.463 (4)
O1—C8	1.226 (4)	C1—C2	1.363 (5)
O2—C8	1.247 (4)	C1—H1	0.9300
O2—Cd1^iii	2.443 (3)	C2—H2	0.9300
O3—C16	1.193 (4)	C7—C8	1.519 (5)
O4—C16	1.229 (4)	C7—H7A	0.9700
O4—Cd1^i	2.224 (3)	C7—H7B	0.9700
N1—C3	1.326 (4)	C3—C4	1.464 (5)
N1—C1	1.351 (5)	C5—C6	1.346 (5)
N2—C4	1.319 (4)	C5—H5	0.9300
N2—C5	1.365 (5)	C15—C16	1.539 (5)
N3—C3	1.343 (4)	C15—H15A	0.9700
N3—C2	1.373 (4)	C15—H15B	0.9700
N3—C7	1.446 (4)	C11—C12	1.449 (5)
N4—C4	1.347 (4)	C14—C13	1.345 (6)
N4—C6	1.364 (5)	C14—H14	0.9300
N4—H4	0.8600	C13—H13	0.9300
N5—C11	1.321 (4)	C6—H6	0.9300
N5—C9	1.356 (4)	C10—C9	1.353 (5)
N6—C12	1.321 (4)	C10—H10	0.9300
N6—C14	1.378 (5)	C9—H9	0.9300
O4^i—Cd1—N5	98.16 (10)	N3—C7—H7A	109.1
O4^i—Cd1—N1	169.50 (11)	C8—C7—H7A	109.1
N5—Cd1—N1	91.23 (10)	N3—C7—H7B	109.1
O4^i—Cd1—N2	102.63 (11)	C8—C7—H7B	109.1
N5—Cd1—N2	144.96 (10)	H7A—C7—H7B	107.9
N1—Cd1—N2	71.56 (10)	O1—C8—O2	124.6 (4)
O4^i—Cd1—O2^ii	90.67 (12)	O1—C8—C7	119.0 (3)
N5—Cd1—O2^ii	116.80 (9)	O2—C8—C7	116.4 (3)
N1—Cd1—O2^ii	80.84 (9)	N1—C3—N3	110.9 (3)
N2—Cd1—O2^ii	91.01 (9)	N1—C3—C4	118.8 (3)
O4^i—Cd1—N6	82.74 (12)	N3—C3—C4	130.3 (3)
N5—Cd1—N6	70.92 (10)	N2—C4—N4	110.7 (3)
N1—Cd1—N6	104.92 (10)	N2—C4—C3	118.7 (3)
N2—Cd1—N6	84.01 (10)	N4—C4—C3	130.6 (3)
O2^ii—Cd1—N6	170.65 (10)	C6—C5—N2	109.7 (4)
C8—O2—Cd1^iii	98.1 (2)	C6—C5—H5	125.2
C16—O4—Cd1^i	137.9 (2)	N2—C5—H5	125.2
C3—N1—C1	106.3 (3)	N7—C15—C16	112.1 (3)
C3—N1—Cd1	115.6 (2)	N7—C15—H15A	109.2
C1—N1—Cd1	138.0 (2)	C16—C15—H15A	109.2
C4—N2—C5	106.0 (3)	N7—C15—H15B	109.2
C4—N2—Cd1	115.3 (2)	C16—C15—H15B	109.2
C5—N2—Cd1	138.7 (3)	H15A—C15—H15B	107.9
C3—N3—C2	107.0 (3)	O3—C16—O4	126.3 (4)
C3—N3—C7	129.7 (3)	O3—C16—C15	118.6 (4)
C2—N3—C7	122.7 (3)	O4—C16—C15	115.1 (3)
C4—N4—C6	107.1 (3)	N5—C11—N7	110.9 (3)
C4—N4—H4	126.4	N5—C11—C12	120.2 (3)
C6—N4—H4	126.4	N7—C11—C12	128.9 (3)
C11—N5—C9	106.0 (3)	N6—C12—N8	111.9 (3)
C11—N5—Cd1	115.6 (2)	N6—C12—C11	120.0 (3)
C9—N5—Cd1	138.1 (2)	N8—C12—C11	128.1 (3)
C12—N6—C14	104.2 (3)	C13—C14—N6	110.4 (4)
C12—N6—Cd1	108.0 (2)	C13—C14—H14	124.8
C14—N6—Cd1	136.9 (3)	N6—C14—H14	124.8
C12—N8—C13	107.5 (3)	C14—C13—N8	106.0 (4)
C12—N8—H8	126.2	C14—C13—H13	127.0
C13—N8—H8	126.2	N8—C13—H13	127.0
C11—N7—C10	106.9 (3)	C5—C6—N4	106.5 (3)
C11—N7—C15	129.6 (3)	C5—C6—H6	126.7
C10—N7—C15	123.4 (3)	N4—C6—H6	126.7
N1—C1—C2	109.7 (3)	C9—C10—N7	106.0 (3)
N1—C1—H1	125.2	C9—C10—H10	127.0
C2—C1—H1	125.2	N7—C10—H10	127.0
C1—C2—N3	106.0 (3)	C10—C9—N5	110.1 (3)
C1—C2—H2	127.0	C10—C9—H9	124.9
N3—C2—H2	127.0	N5—C9—H9	124.9
N3—C7—C8	112.4 (3)
O4^i—Cd1—N1—C3	−57.6 (7)	C1—N1—C3—C4	−178.1 (3)
N5—Cd1—N1—C3	149.0 (2)	Cd1—N1—C3—C4	−0.3 (4)
N2—Cd1—N1—C3	0.2 (2)	C2—N3—C3—N1	0.4 (4)
O2^ii—Cd1—N1—C3	−94.0 (2)	C7—N3—C3—N1	171.2 (3)
N6—Cd1—N1—C3	78.5 (2)	C2—N3—C3—C4	178.0 (3)
O4^i—Cd1—N1—C1	119.3 (6)	C7—N3—C3—C4	−11.2 (6)
N5—Cd1—N1—C1	−34.1 (4)	C5—N2—C4—N4	0.4 (4)
N2—Cd1—N1—C1	177.0 (4)	Cd1—N2—C4—N4	−179.3 (2)
O2^ii—Cd1—N1—C1	82.9 (4)	C5—N2—C4—C3	179.7 (3)
N6—Cd1—N1—C1	−104.7 (4)	Cd1—N2—C4—C3	−0.1 (4)
O4^i—Cd1—N2—C4	170.9 (2)	C6—N4—C4—N2	−0.4 (4)
N5—Cd1—N2—C4	−64.2 (3)	C6—N4—C4—C3	−179.6 (3)
N1—Cd1—N2—C4	0.0 (2)	N1—C3—C4—N2	0.2 (5)
O2^ii—Cd1—N2—C4	79.9 (2)	N3—C3—C4—N2	−177.3 (3)
N6—Cd1—N2—C4	−108.0 (3)	N1—C3—C4—N4	179.3 (3)
O4^i—Cd1—N2—C5	−8.8 (4)	N3—C3—C4—N4	1.9 (6)
N5—Cd1—N2—C5	116.2 (4)	C4—N2—C5—C6	−0.2 (4)
N1—Cd1—N2—C5	−179.7 (4)	Cd1—N2—C5—C6	179.4 (3)
O2^ii—Cd1—N2—C5	−99.7 (4)	C11—N7—C15—C16	−82.5 (4)
N6—Cd1—N2—C5	72.4 (4)	C10—N7—C15—C16	95.7 (4)
O4^i—Cd1—N5—C11	71.6 (3)	Cd1^i—O4—C16—O3	5.4 (8)
N1—Cd1—N5—C11	−113.1 (2)	Cd1^i—O4—C16—C15	−176.6 (3)
N2—Cd1—N5—C11	−54.5 (3)	N7—C15—C16—O3	−127.4 (4)
O2^ii—Cd1—N5—C11	166.5 (2)	N7—C15—C16—O4	54.5 (5)
N6—Cd1—N5—C11	−7.8 (2)	C9—N5—C11—N7	−0.6 (4)
O4^i—Cd1—N5—C9	−115.3 (4)	Cd1—N5—C11—N7	174.5 (2)
N1—Cd1—N5—C9	59.9 (4)	C9—N5—C11—C12	−177.7 (3)
N2—Cd1—N5—C9	118.6 (4)	Cd1—N5—C11—C12	−2.6 (4)
O2^ii—Cd1—N5—C9	−20.4 (4)	C10—N7—C11—N5	0.5 (4)
N6—Cd1—N5—C9	165.3 (4)	C15—N7—C11—N5	179.0 (3)
O4^i—Cd1—N6—C12	−83.8 (3)	C10—N7—C11—C12	177.3 (3)
N5—Cd1—N6—C12	17.5 (2)	C15—N7—C11—C12	−4.3 (6)
N1—Cd1—N6—C12	103.6 (3)	C14—N6—C12—N8	0.0 (5)
N2—Cd1—N6—C12	172.6 (3)	Cd1—N6—C12—N8	151.0 (2)
O2^ii—Cd1—N6—C12	−129.2 (5)	C14—N6—C12—C11	−177.1 (3)
O4^i—Cd1—N6—C14	52.6 (4)	Cd1—N6—C12—C11	−26.2 (4)
N5—Cd1—N6—C14	153.9 (4)	C13—N8—C12—N6	−0.3 (5)
N1—Cd1—N6—C14	−120.0 (4)	C13—N8—C12—C11	176.6 (4)
N2—Cd1—N6—C14	−51.0 (4)	N5—C11—C12—N6	21.8 (5)
O2^ii—Cd1—N6—C14	7.2 (9)	N7—C11—C12—N6	−154.7 (4)
C3—N1—C1—C2	−0.2 (4)	N5—C11—C12—N8	−154.8 (4)
Cd1—N1—C1—C2	−177.2 (2)	N7—C11—C12—N8	28.6 (6)
N1—C1—C2—N3	0.4 (4)	C12—N6—C14—C13	0.2 (5)
C3—N3—C2—C1	−0.5 (4)	Cd1—N6—C14—C13	−137.2 (4)
C7—N3—C2—C1	−172.1 (3)	N6—C14—C13—N8	−0.4 (5)
C3—N3—C7—C8	−90.2 (4)	C12—N8—C13—C14	0.4 (5)
C2—N3—C7—C8	79.3 (4)	N2—C5—C6—N4	0.0 (4)
Cd1^iii—O2—C8—O1	20.4 (5)	C4—N4—C6—C5	0.3 (4)
Cd1^iii—O2—C8—C7	−160.2 (3)	C11—N7—C10—C9	−0.2 (4)
N3—C7—C8—O1	−7.6 (5)	C15—N7—C10—C9	−178.8 (3)
N3—C7—C8—O2	172.9 (3)	N7—C10—C9—N5	−0.2 (4)
C1—N1—C3—N3	−0.1 (4)	C11—N5—C9—C10	0.5 (4)
Cd1—N1—C3—N3	177.7 (2)	Cd1—N5—C9—C10	−173.0 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4···O2^iv	0.86	2.01	2.792 (4)	150
C7—H7B···O2^iv	0.97	2.28	3.231 (5)	166
N8—H8···O4	0.86	2.11	2.794 (4)	136
N8—H8···O1^v	0.86	2.46	3.049 (4)	126
C7—H7A···O3^vi	0.97	2.48	3.299 (5)	142
C10—H10···O3^vii	0.93	2.56	3.317 (5)	139
C15—H15A···O3^vii	0.97	2.57	3.461 (5)	153

Symmetry codes: (iv) −x+3, −y+2, −z+1; (v) −x+2, −y+1, −z+2; (vi) x+1, y+1, z−1; (vii) −x+1, −y+1, −z+3.