Crystal structure and photoluminescence properties of a new Cd^II coordination polymer catena-poly[bis­[4-bromo-2-({[2-(pyrrolidin-1-yl)eth­yl]imino}­meth­yl)phenolato-κ³N,N′,O]di-μ₃-chlorido-di-μ₂-chlorido-bis­(methanol-κO)tri­cadmium(II)]

Schiff base–metal complexes have been used widely as catalysts for many organic reactions, such as ring-opening polymerization and oxidation. In view of the importance of Cd^II coordination polymers and in an effort to enlarge the library of such complexes, the title novel polymeric Cd^II tridentate Schiff base complex, [Cd₃(C₁₃H₁₆BrN₂O)₂Cl₄(CH₄O)₂]_n, has been synthesized and characterized by elemental analyses, UV and IR spectroscopies, and single-crystal X-ray diffraction. The complex crystallizes in the triclinic P space group with two symmetry-independent Cd^II atoms, one of which lies on an inversion centre, and analysis of the crystal structure shows that both Cd^II atoms are six-coordinated; the environment around one Cd^II atom can be described as distorted octa­hedral, while that around the second Cd^II atom is octa­hedral. The Cd^II atoms are linked by chloride ligands to form a one-dimensional coordination polymer. The nonbonding inter­molecular Cd...Cd distances are 3.7009 (4) and 4.3563 (5) Å. Furthermore, the photoluminescence properties of the complex have been investigated and it displays a strong red emission in the solid state at room temperature.

S1. Introduction

In recent decades, the design and construction of coordination polymers (CPs) have gained much attention not only due to their fascinating structures but also due to their potential applications in many fields such as nonlinear optics, sensors, magnetism, catalysis, gas storage/separation etc. (Sezer et al., 2016; Spencer et al., 2006; Liu et al., 2010; Lin et al., 2014; Pinkowicz et al., 2015; Nagarkar et al., 2011). Moreover, polynuclear d¹⁰ metal complexes, such as Cd^II coordination polymers, have attracted extensive inter­est due to their high thermal stability and good photoluminescence and electroluminescence properties (Ford et al., 1999; Manjunatha et al., 2011). Although there are numerous factors, such as the nature of the metal ion, the structural characteristics of the ligand, the presence of solvents and counter-ions and the metal–ligand ratio, which play important roles in the construction of these CPs, the most effective way is to choose suitable N- and O-donor multidentate organic ligands (Yin et al., 2016; Zhao et al., 2015; Hopa & Cokay, 2016). Schiff base metal complexes have been used widely as catalysts for many organic reactions, such as ring-opening polymerization and oxidation (Keypour et al., 2015; Chen et al., 2006; Hung et al., 2008; Gupta & Sutar, 2008). Recently, our research group and others have reported the synthesss and structural characterization of transition metal complexes containing ONNO-, ONO- and NNO-type Schiff base ligands (Gungor & Kara, 2011, 2012; Kara, 2007, 2008a,b,c; Yahsi et al., 2011; Yahsi & Kara, 2013, 2014; Hung & Lin, 2009; Surati & Thaker, 2010; Khandar et al., 2015; Keypour et al., 2015). In view of the importance of Cd^II coordination polymers and in an effort to enlarge the library of such complexes, we report here the synthesis of a new dichloride-bridged one-dimensional polymeric Cd^II complex, namely catena-poly[bis­[4-bromo-2-({[2-(pyrrolidin-1-yl)ethyl]­imino}­methyl)­phenolato-κ³N,N',O]di-µ₃-chlorido-di-µ₂-chlorido-bis­(methanol-κO)tricadmium(II)], (I), along with its characterization, single-crystal X-ray structure, UV and IR spectroscopic data and photoluminescence study.

S2. Experimental

S2.1. Synthesis and crystallization

A solution of 5-bromo­salicyl­aldehyde (5-BrSal; 1 mmol) in methanol (40 ml) was added dropwise to a solution of 1-(2-amino­ethyl)­pyrrolidine (aep; 1 mmol) in methanol (40 ml). To the resulting yellow solution was added CdCl₂ (1 mmol) in methanol (40 ml). It turned light-yellow quickly and after stirring in air for 2 h it is allowed to stay at room temperature for a few weeks. And then the colourless crystals of complex (1) were filtered off, washed with methanol and dried in air (yield 68%, 0.38 g). Analysis calculated for C₂₈H₄₀Br₂Cd₃Cl₄N₄O₄: C 29.62, H 3.55, N 4.93%; found: C 30.01, H 3.50, N 4.98%. UV–Vis (DMSO): 330 and 390 nm.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms were included in idealized positions with isotropic displacement parameters constrained to 1.5U_eq(C) for methyl H atoms and to 1.2U_eq(C,O) otherwise.

S3. Results and discussion

S3.1. Crystal structure

The X-ray structure analysis of (1) shows that the Schiff base ligand coordinates to the Cd2 atom in a tridentate manner using the phenolate O and the N atoms from the imine and pyrrolidine groups (Fig. 1). In complex (1), each Cd^II ion is six-coordinated and the environment around the Cd2 atom can be described as distorted o­cta­hedral, while that around Cd1 is o­cta­hedral, completed by four bridging chloride ligands in the equatorial plane and two axial O atoms (Fig. 2 and Table 2). The coordination spheres of the Cd1 and Cd2 atoms deviate slightly from planarity, with a Cd1—Cl1—Cd2—Cl2ⁱⁱⁱ torsion angle of 19.17(s.u.?)° [symmetry code: (iii) ???]. The Cd2 atom deviates by 0.112 Å from the NCl₃ coordination plane (atoms Cl2, N2, Cl1 and Cl2ⁱⁱⁱ) toward the apical N1 atom, while the deviation of the Cd1 atom from the Cl₄ coordination plane (atoms Cl1, Cl2ⁱⁱⁱ, Cl1ⁱ and Cl2ⁱⁱ) is 0.0 Å. The coordination sphere around the Cd2 atom is strictly planar, with a Cd2—Cl2—Cd2ⁱⁱⁱ—Cl2ⁱⁱⁱ torsion angle of 0°.

The bridging chloride ligands connect metal centres to generate a one-dimensional infinite chain along the [100] direction (Fig. 3). Selected Cd—Cl and Cd···Cd distances are compared in Table 3. The intra­molecular nonbonding Cd···Cd distances are comparable with the values (in the range 3.675-4.016 Å) found in previously reported chloride-bridged cadmium complexes (Park et al., 2010; Wen et al., 2011; Lu et al., 2013; Hopa et al., 2010; Chen et al., 2007). The bridging Cd—Cl bond lengths are also in good agreement within the range of values reported for the corresponding bond lengths of Cd^II complexes. Further analysis of the crystal packing of complex (1) reveals the existence of weak C14—H14···Cl1 and C5—H5B···C13 inter­actions between the chains (Fig. 4). Such inter­chain contacts extend the one-dimensional coordination arrays into a supra­molecular layer along the (001) plane and these layers are stacked in a parallel manner along the [001] direction without any inter­layer inter­actions. The hydrogen-bond geometry for complex (1) is given in Table 4.

S3.2. IR spectra

The IR spectral data for complex (1) are given in Table 5. The bands in the region of 1640 cm^-1 are assignable to the ν(C═N) stretches of the Schiff base ligands, suggesting that the imine N atoms coordinate to the metal atoms. The bands in the range 2835–2910 cm^-1 are characteristic of aliphatic ν(C—H) vibrations and the band observed at 3010 cm^-1 is attributed to the aromatic ν(C—H) vibrations of complex (1). The observed bands in the region of 634 cm^-1 are assignable to the ν(C—Br) vibrations of bromo­salicyl­idene­imine ligand. Thus, the IR data are found to be in good agreement with the structural features of complex (1).

S3.3. Photoluminescence properties

The solid-state luminescence properties of complex (1) and free 5-BrSal and aep were investigated at room temperature in the visible regions upon excitation at λ_ex= 349 nm (Fig. 5). Free 5-BrSal shows a broad emission band at λ_max = 600 nm, whereas free aep shows a broad emission band at λ_max = 590 nm which may be assigned to the n → π* or π → π* electronic transition (ILCT) (Feng et al., 2014). While the free ligands are combined with Cd^II in compound (1), a stronger red emission band is seen at λ_max = 650 nm. No emissions originating from metal-centred excited states are expected for Cd^II complexes, since they are difficult to oxidize or reduce due to their d¹⁰ configuration (Paira et al., 2007; Manjunatha et al., 2011). Thus, the observed emissions of complex (1) are probably contributed by the n → π* or π → π* intra­ligand fluorescence since a similar emission was also observed for the ligands (Che et al., 2001; Wu et al., 2006; Erkarslan et al., 2016). The observed red or blue shift of the emission maximum between the complex and the corresponding ligands was considered to mainly originate from the influence of the coordination of metal atom to the ligand (Feng et al., 2014; Song et al., 2015; Manjunatha et al., 2011). The enhancement of luminescence may be attributed to the chelation of the ligand to the central metal atom. The chelation enhances the `rigidity' of the ligand and thus reduces the loss of energy through a radiationless pathway (Chen et al., 2011; Ji et al., 2012; Zheng et al., 2001; Wang et al., 2006).

S4. Conclusions

A new dichloride-bridged Cd^II coordination polymer, (1), has been synthesized and its crystal structure determined by single-crystal X-ray diffraction analysis. The structural analysis of (1) shows that the Schiff base ligand coordinates to the Cd2 atom in an N,N',O-tridentate manner. In complex (1), each Cd^II ion is six-coordinated and the environment around the Cd2 atom can be described as distorted o­cta­hedral geometry, while that around the Cd1 atom is o­cta­hedral. The intra­molecular nonbonding Cd···Cd separations are 3.701(s.u.?) and 4.356(s.u.?) Å. The Cd—Cl and Cd···Cd distances for (1) are in good agreement with the values that found in other dichloride-bridged Cd^II complexes. The bridging chloride ligands connect metal centres to generate a one-dimensional infinite chain. Furthermore, analysis of the crystal packing of (1) reveals the existence of weak short-contact inter­actions between the chains. The photoluminescence studies of complex (1) indicate a red shift compared with its free ligands, and the emission intensity of (1) is stronger than that of the ligands. The luminescence properties show that the photoluminescence arose from an intra­ligand emission and that it is a novel potential candidate for application in optoelectronic devices.

Structure description

In recent decades, the design and construction of coordination polymers (CPs) have gained much attention not only due to their fascinating structures but also due to their potential applications in many fields such as nonlinear optics, sensors, magnetism, catalysis, gas storage/separation etc. (Sezer et al., 2016; Spencer et al., 2006; Liu et al., 2010; Lin et al., 2014; Pinkowicz et al., 2015; Nagarkar et al., 2011). Moreover, polynuclear d¹⁰ metal complexes, such as Cd^II coordination polymers, have attracted extensive inter­est due to their high thermal stability and good photoluminescence and electroluminescence properties (Ford et al., 1999; Manjunatha et al., 2011). Although there are numerous factors, such as the nature of the metal ion, the structural characteristics of the ligand, the presence of solvents and counter-ions and the metal–ligand ratio, which play important roles in the construction of these CPs, the most effective way is to choose suitable N- and O-donor multidentate organic ligands (Yin et al., 2016; Zhao et al., 2015; Hopa & Cokay, 2016). Schiff base metal complexes have been used widely as catalysts for many organic reactions, such as ring-opening polymerization and oxidation (Keypour et al., 2015; Chen et al., 2006; Hung et al., 2008; Gupta & Sutar, 2008). Recently, our research group and others have reported the synthesss and structural characterization of transition metal complexes containing ONNO-, ONO- and NNO-type Schiff base ligands (Gungor & Kara, 2011, 2012; Kara, 2007, 2008a,b,c; Yahsi et al., 2011; Yahsi & Kara, 2013, 2014; Hung & Lin, 2009; Surati & Thaker, 2010; Khandar et al., 2015; Keypour et al., 2015). In view of the importance of Cd^II coordination polymers and in an effort to enlarge the library of such complexes, we report here the synthesis of a new dichloride-bridged one-dimensional polymeric Cd^II complex, namely catena-poly[bis­[4-bromo-2-({[2-(pyrrolidin-1-yl)ethyl]­imino}­methyl)­phenolato-κ³N,N',O]di-µ₃-chlorido-di-µ₂-chlorido-bis­(methanol-κO)tricadmium(II)], (I), along with its characterization, single-crystal X-ray structure, UV and IR spectroscopic data and photoluminescence study.

The X-ray structure analysis of (1) shows that the Schiff base ligand coordinates to the Cd2 atom in a tridentate manner using the phenolate O and the N atoms from the imine and pyrrolidine groups (Fig. 1). In complex (1), each Cd^II ion is six-coordinated and the environment around the Cd2 atom can be described as distorted o­cta­hedral, while that around Cd1 is o­cta­hedral, completed by four bridging chloride ligands in the equatorial plane and two axial O atoms (Fig. 2 and Table 2). The coordination spheres of the Cd1 and Cd2 atoms deviate slightly from planarity, with a Cd1—Cl1—Cd2—Cl2ⁱⁱⁱ torsion angle of 19.17(s.u.?)° [symmetry code: (iii) ???]. The Cd2 atom deviates by 0.112 Å from the NCl₃ coordination plane (atoms Cl2, N2, Cl1 and Cl2ⁱⁱⁱ) toward the apical N1 atom, while the deviation of the Cd1 atom from the Cl₄ coordination plane (atoms Cl1, Cl2ⁱⁱⁱ, Cl1ⁱ and Cl2ⁱⁱ) is 0.0 Å. The coordination sphere around the Cd2 atom is strictly planar, with a Cd2—Cl2—Cd2ⁱⁱⁱ—Cl2ⁱⁱⁱ torsion angle of 0°.

The bridging chloride ligands connect metal centres to generate a one-dimensional infinite chain along the [100] direction (Fig. 3). Selected Cd—Cl and Cd···Cd distances are compared in Table 3. The intra­molecular nonbonding Cd···Cd distances are comparable with the values (in the range 3.675-4.016 Å) found in previously reported chloride-bridged cadmium complexes (Park et al., 2010; Wen et al., 2011; Lu et al., 2013; Hopa et al., 2010; Chen et al., 2007). The bridging Cd—Cl bond lengths are also in good agreement within the range of values reported for the corresponding bond lengths of Cd^II complexes. Further analysis of the crystal packing of complex (1) reveals the existence of weak C14—H14···Cl1 and C5—H5B···C13 inter­actions between the chains (Fig. 4). Such inter­chain contacts extend the one-dimensional coordination arrays into a supra­molecular layer along the (001) plane and these layers are stacked in a parallel manner along the [001] direction without any inter­layer inter­actions. The hydrogen-bond geometry for complex (1) is given in Table 4.

The IR spectral data for complex (1) are given in Table 5. The bands in the region of 1640 cm^-1 are assignable to the ν(C═N) stretches of the Schiff base ligands, suggesting that the imine N atoms coordinate to the metal atoms. The bands in the range 2835–2910 cm^-1 are characteristic of aliphatic ν(C—H) vibrations and the band observed at 3010 cm^-1 is attributed to the aromatic ν(C—H) vibrations of complex (1). The observed bands in the region of 634 cm^-1 are assignable to the ν(C—Br) vibrations of bromo­salicyl­idene­imine ligand. Thus, the IR data are found to be in good agreement with the structural features of complex (1).

The solid-state luminescence properties of complex (1) and free 5-BrSal and aep were investigated at room temperature in the visible regions upon excitation at λ_ex= 349 nm (Fig. 5). Free 5-BrSal shows a broad emission band at λ_max = 600 nm, whereas free aep shows a broad emission band at λ_max = 590 nm which may be assigned to the n → π* or π → π* electronic transition (ILCT) (Feng et al., 2014). While the free ligands are combined with Cd^II in compound (1), a stronger red emission band is seen at λ_max = 650 nm. No emissions originating from metal-centred excited states are expected for Cd^II complexes, since they are difficult to oxidize or reduce due to their d¹⁰ configuration (Paira et al., 2007; Manjunatha et al., 2011). Thus, the observed emissions of complex (1) are probably contributed by the n → π* or π → π* intra­ligand fluorescence since a similar emission was also observed for the ligands (Che et al., 2001; Wu et al., 2006; Erkarslan et al., 2016). The observed red or blue shift of the emission maximum between the complex and the corresponding ligands was considered to mainly originate from the influence of the coordination of metal atom to the ligand (Feng et al., 2014; Song et al., 2015; Manjunatha et al., 2011). The enhancement of luminescence may be attributed to the chelation of the ligand to the central metal atom. The chelation enhances the `rigidity' of the ligand and thus reduces the loss of energy through a radiationless pathway (Chen et al., 2011; Ji et al., 2012; Zheng et al., 2001; Wang et al., 2006).

A new dichloride-bridged Cd^II coordination polymer, (1), has been synthesized and its crystal structure determined by single-crystal X-ray diffraction analysis. The structural analysis of (1) shows that the Schiff base ligand coordinates to the Cd2 atom in an N,N',O-tridentate manner. In complex (1), each Cd^II ion is six-coordinated and the environment around the Cd2 atom can be described as distorted o­cta­hedral geometry, while that around the Cd1 atom is o­cta­hedral. The intra­molecular nonbonding Cd···Cd separations are 3.701(s.u.?) and 4.356(s.u.?) Å. The Cd—Cl and Cd···Cd distances for (1) are in good agreement with the values that found in other dichloride-bridged Cd^II complexes. The bridging chloride ligands connect metal centres to generate a one-dimensional infinite chain. Furthermore, analysis of the crystal packing of (1) reveals the existence of weak short-contact inter­actions between the chains. The photoluminescence studies of complex (1) indicate a red shift compared with its free ligands, and the emission intensity of (1) is stronger than that of the ligands. The luminescence properties show that the photoluminescence arose from an intra­ligand emission and that it is a novel potential candidate for application in optoelectronic devices.

Synthesis and crystallization

A solution of 5-bromo­salicyl­aldehyde (5-BrSal; 1 mmol) in methanol (40 ml) was added dropwise to a solution of 1-(2-amino­ethyl)­pyrrolidine (aep; 1 mmol) in methanol (40 ml). To the resulting yellow solution was added CdCl₂ (1 mmol) in methanol (40 ml). It turned light-yellow quickly and after stirring in air for 2 h it is allowed to stay at room temperature for a few weeks. And then the colourless crystals of complex (1) were filtered off, washed with methanol and dried in air (yield 68%, 0.38 g). Analysis calculated for C₂₈H₄₀Br₂Cd₃Cl₄N₄O₄: C 29.62, H 3.55, N 4.93%; found: C 30.01, H 3.50, N 4.98%. UV–Vis (DMSO): 330 and 390 nm.

Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms were included in idealized positions with isotropic displacement parameters constrained to 1.5U_eq(C) for methyl H atoms and to 1.2U_eq(C,O) otherwise.

Computing details

Data collection: CrysAlis PRO (Agilent, 2014); cell refinement: CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007; Palatinus & van der Lee, 2008; Palatinus et al., 2012); program(s) used to refine structure: OLEX2 (Dolomanov et al., 2009); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Figures

	Fig. 1. Part of the polymeric chain of complex (1), showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level. [Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) x-1, y, z; (iii) -x+2, -y+1, -z+1; (iv) x+1, y, z.]
	Fig. 2. The coordination environment for (a) atom Cd1 and (b) atom Cd2 in complex (1).
	Fig. 3. (a) A portion of the crystal packing of complex (1), viewed along the c axis and showing intramolecular hydrogen bonds (dashed lines). (b) A space-filling representation of complex (1) in the ab plane.
	Fig. 4. A perspective view of complex (1), showing the weak interchain C—H···Cl and C—H···C interactions.
	Fig. 5. The emission spectra of the free ligands and complex (1) in the solid samples at room temperature (λex = 349 nm).

catena-Poly[bis[4-bromo-2-({[2-(pyrrolidin-1-yl)ethyl]imino}methyl)phenolato-κ³N,N',O]di-µ₃-chlorido-di-µ₂-chlorido-bis(methanol-κO)tricadmium(II)]

Crystal data

[Cd3Cl4(C13H16BrN2O)2(CH4O)2]	Z = 1
Mr = 1135.51	F(000) = 547.8019
Triclinic, P1	Dx = 2.019 Mg m^−3
a = 8.1048 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.3928 (6) Å	Cell parameters from 3216 reflections
c = 11.5740 (6) Å	θ = 3.8–28.3°
α = 100.957 (5)°	µ = 4.16 mm^−1
β = 96.178 (4)°	T = 293 K
γ = 99.694 (5)°	Block, colorless
V = 933.59 (9) Å^3	0.48 × 0.44 × 0.14 mm

Data collection

Agilent Xcalibur Eos diffractometer	3810 independent reflections
Radiation source: Enhance (Mo) X-ray Source	3063 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
Detector resolution: 8.0667 pixels mm^-1	θmax = 26.4°, θmin = 3.0°
ω scans	h = −9→10
Absorption correction: analytical [CrysAlis PRO (Agilent, 2014), based on expressions derived by Clark & Reid (1995)]	k = −12→12
Tmin = 0.258, Tmax = 0.613	l = −13→14
7022 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)] = 0.037	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.082	w = 1/[σ^2(Fo^2) + (0.0334P)^2 + 0.0622P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max = 0.001
3810 reflections	Δρmax = 1.44 e Å^−3
209 parameters	Δρmin = −1.16 e Å^−3
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods

Special details

Experimental. Absorption correction: CrysAlisPro, Agilent Technologies, Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET) (compiled Aug 13 2014,18:06:01) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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

	x	y	z	Uiso*/Ueq
Cd1	0.5	0.5	0.5	0.02913 (13)
Cd2	0.91061 (4)	0.66122 (3)	0.43178 (3)	0.03185 (12)
Br1	1.47271 (10)	1.16649 (6)	0.95059 (5)	0.0753 (2)
Cl1	0.59816 (15)	0.67965 (12)	0.38107 (11)	0.0418 (3)
Cl2	1.20870 (14)	0.56760 (11)	0.52121 (10)	0.0354 (3)
O1	0.9191 (4)	0.7708 (3)	0.6176 (3)	0.0414 (8)
O2	0.3712 (4)	0.3379 (4)	0.3312 (3)	0.0435 (8)
H2	0.269 (3)	0.311 (5)	0.340 (5)	0.0653 (12)*
N1	0.9900 (5)	0.6193 (4)	0.2375 (3)	0.0321 (9)
N2	1.1034 (5)	0.8462 (4)	0.4305 (3)	0.0342 (9)
C1	0.4434 (8)	0.2237 (7)	0.2930 (6)	0.090 (3)
H1a	0.366 (3)	0.161 (2)	0.231 (3)	0.135 (4)*
H1b	0.547 (4)	0.2509 (10)	0.264 (4)	0.135 (4)*
H1c	0.466 (6)	0.182 (3)	0.3588 (13)	0.135 (4)*
C2	0.9993 (7)	0.4773 (5)	0.1929 (4)	0.0481 (14)
H2a	1.0716 (7)	0.4695 (5)	0.1314 (4)	0.0577 (16)*
H2b	1.0437 (7)	0.4391 (5)	0.2570 (4)	0.0577 (16)*
C3	0.8219 (8)	0.4083 (6)	0.1440 (5)	0.0630 (17)
H3a	0.8196 (8)	0.3382 (6)	0.0750 (5)	0.076 (2)*
H3b	0.7678 (8)	0.3693 (6)	0.2034 (5)	0.076 (2)*
C4	0.7329 (8)	0.5169 (6)	0.1098 (5)	0.0654 (17)
H4a	0.6967 (8)	0.4982 (6)	0.0247 (5)	0.078 (2)*
H4b	0.6346 (8)	0.5226 (6)	0.1501 (5)	0.078 (2)*
C5	0.8611 (7)	0.6442 (5)	0.1482 (4)	0.0470 (13)
H5a	0.8088 (7)	0.7169 (5)	0.1828 (4)	0.0564 (16)*
H5b	0.9122 (7)	0.6672 (5)	0.0809 (4)	0.0564 (16)*
C6	1.1536 (6)	0.7074 (5)	0.2503 (4)	0.0412 (12)
H6a	1.2378 (6)	0.6730 (5)	0.2953 (4)	0.0495 (14)*
H6b	1.1863 (6)	0.7081 (5)	0.1722 (4)	0.0495 (14)*
C7	1.1515 (7)	0.8493 (5)	0.3126 (4)	0.0451 (13)
H7a	1.0710 (7)	0.8862 (5)	0.2669 (4)	0.0541 (15)*
H7b	1.2626 (7)	0.9049 (5)	0.3201 (4)	0.0541 (15)*
C8	1.1941 (6)	0.9262 (4)	0.5196 (4)	0.0387 (11)
H8	1.2825 (6)	0.9870 (4)	0.5039 (4)	0.0464 (13)*
C9	1.1747 (6)	0.9331 (4)	0.6445 (4)	0.0334 (10)
C10	1.0403 (6)	0.8572 (4)	0.6857 (4)	0.0339 (11)
C11	1.0433 (7)	0.8809 (5)	0.8105 (4)	0.0419 (12)
H11	0.9561 (7)	0.8337 (5)	0.8408 (4)	0.0503 (14)*
C12	1.1684 (7)	0.9701 (5)	0.8889 (4)	0.0473 (13)
H12	1.1665 (7)	0.9818 (5)	0.9704 (4)	0.0567 (16)*
C13	1.2978 (7)	1.0426 (5)	0.8451 (4)	0.0445 (13)
C14	1.2996 (7)	1.0241 (4)	0.7264 (4)	0.0403 (11)
H14	1.3872 (7)	1.0738 (4)	0.6984 (4)	0.0484 (14)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0178 (3)	0.0307 (3)	0.0392 (3)	0.0013 (2)	0.00573 (19)	0.0102 (2)
Cd2	0.0250 (2)	0.0326 (2)	0.03467 (19)	−0.00278 (15)	0.00705 (14)	0.00509 (14)
Br1	0.0760 (5)	0.0579 (4)	0.0680 (4)	−0.0194 (3)	−0.0351 (3)	0.0085 (3)
Cl1	0.0265 (7)	0.0478 (7)	0.0582 (7)	0.0056 (6)	0.0070 (5)	0.0300 (6)
Cl2	0.0202 (6)	0.0345 (6)	0.0543 (7)	0.0048 (5)	0.0072 (5)	0.0155 (5)
O1	0.0269 (19)	0.044 (2)	0.0426 (18)	−0.0076 (16)	0.0107 (15)	−0.0066 (15)
O2	0.031 (2)	0.046 (2)	0.0460 (18)	−0.0054 (18)	0.0085 (16)	0.0022 (16)
N1	0.026 (2)	0.035 (2)	0.0338 (19)	0.0055 (18)	0.0019 (16)	0.0062 (16)
N2	0.033 (2)	0.030 (2)	0.038 (2)	0.0000 (18)	0.0068 (17)	0.0069 (17)
C1	0.053 (4)	0.079 (5)	0.110 (5)	−0.007 (4)	0.032 (4)	−0.043 (4)
C2	0.056 (4)	0.042 (3)	0.044 (3)	0.016 (3)	0.004 (3)	0.001 (2)
C3	0.071 (5)	0.054 (4)	0.055 (3)	−0.001 (3)	−0.001 (3)	0.006 (3)
C4	0.044 (4)	0.085 (5)	0.059 (3)	0.010 (4)	−0.003 (3)	0.003 (3)
C5	0.047 (3)	0.061 (4)	0.034 (2)	0.013 (3)	0.001 (2)	0.012 (2)
C6	0.033 (3)	0.053 (3)	0.038 (3)	0.002 (2)	0.011 (2)	0.011 (2)
C7	0.044 (3)	0.043 (3)	0.046 (3)	−0.007 (3)	0.013 (2)	0.016 (2)
C8	0.031 (3)	0.029 (2)	0.054 (3)	−0.002 (2)	0.007 (2)	0.014 (2)
C9	0.028 (3)	0.026 (2)	0.042 (2)	0.001 (2)	−0.003 (2)	0.005 (2)
C10	0.029 (3)	0.028 (2)	0.042 (3)	0.005 (2)	0.006 (2)	0.002 (2)
C11	0.041 (3)	0.037 (3)	0.045 (3)	0.005 (2)	0.006 (2)	0.003 (2)
C12	0.055 (4)	0.043 (3)	0.040 (3)	0.007 (3)	−0.005 (2)	0.007 (2)
C13	0.043 (3)	0.030 (3)	0.052 (3)	−0.001 (2)	−0.014 (2)	0.007 (2)
C14	0.038 (3)	0.027 (2)	0.054 (3)	0.001 (2)	0.000 (2)	0.014 (2)

Geometric parameters (Å, º)

Cd1—Cl1^i	2.5935 (12)	N1—C5	1.479 (6)
Cd1—Cl1	2.5935 (12)	N1—C6	1.455 (6)
Cd1—Cl2^ii	2.5972 (10)	N2—C7	1.463 (5)
Cd1—Cl2^iii	2.5972 (10)	N2—C8	1.265 (6)
Cd1—O2	2.337 (3)	C2—C3	1.492 (8)
Cd1—O2^i	2.337 (3)	C3—C4	1.528 (8)
Cd2—Cl1	2.5846 (12)	C4—C5	1.497 (8)
Cd2—Cl2	2.9140 (11)	C6—C7	1.517 (6)
Cd2—Cl2^ii	2.5917 (12)	C8—C9	1.461 (6)
Cd2—O1	2.222 (3)	C9—C10	1.415 (6)
Cd2—N1	2.386 (3)	C9—C14	1.396 (6)
Cd2—N2	2.268 (4)	C10—C11	1.415 (6)
Br1—C13	1.890 (5)	C11—C12	1.370 (7)
O1—C10	1.289 (5)	C12—C13	1.385 (7)
O2—C1	1.427 (7)	C13—C14	1.352 (6)
N1—C2	1.485 (6)
Cl1—Cd1—Cl1^i	180.0	Cd2—Cl2—Cd1^iv	152.28 (5)
Cl2^iii—Cd1—Cl1	94.52 (4)	C10—O1—Cd2	129.4 (3)
Cl2^ii—Cd1—Cl1^i	94.52 (4)	C1—O2—Cd1	120.7 (3)
Cl2^iii—Cd1—Cl1^i	85.48 (4)	C2—N1—Cd2	113.2 (3)
Cl2^ii—Cd1—Cl1	85.48 (4)	C5—N1—Cd2	111.3 (3)
Cl2^ii—Cd1—Cl2^iii	180.0	C5—N1—C2	103.3 (4)
O2^i—Cd1—Cl1^i	94.42 (9)	C6—N1—Cd2	103.9 (2)
O2^i—Cd1—Cl1	85.58 (9)	C6—N1—C2	111.9 (4)
O2—Cd1—Cl1^i	85.58 (9)	C6—N1—C5	113.6 (4)
O2—Cd1—Cl1	94.42 (9)	C7—N2—Cd2	112.8 (3)
O2—Cd1—Cl2^iii	88.81 (9)	C8—N2—Cd2	127.0 (3)
O2^i—Cd1—Cl2^ii	88.81 (9)	C8—N2—C7	118.3 (4)
O2—Cd1—Cl2^ii	91.19 (9)	C3—C2—N1	105.4 (4)
O2^i—Cd1—Cl2^iii	91.19 (9)	C4—C3—C2	105.3 (5)
O2^i—Cd1—O2	180.0	C5—C4—C3	105.6 (5)
Cl2^ii—Cd2—Cl1	85.78 (4)	C4—C5—N1	106.0 (4)
Cl2—Cd2—Cl1	160.89 (4)	C7—C6—N1	112.3 (4)
O1—Cd2—Cl1	90.95 (9)	C6—C7—N2	108.3 (4)
O1—Cd2—Cl2	86.11 (9)	C9—C8—N2	126.9 (4)
O1—Cd2—Cl2^ii	93.15 (9)	C10—C9—C8	125.0 (4)
N1—Cd2—Cl1	100.64 (9)	C14—C9—C8	115.5 (4)
N1—Cd2—Cl2^ii	107.56 (9)	C14—C9—C10	119.5 (4)
N1—Cd2—Cl2	89.04 (9)	C9—C10—O1	124.3 (4)
N1—Cd2—O1	156.81 (13)	C11—C10—O1	119.6 (4)
N2—Cd2—Cl1	115.26 (10)	C11—C10—C9	116.0 (4)
N2—Cd2—Cl2^ii	158.05 (10)	C12—C11—C10	123.2 (5)
N2—Cd2—Cl2	82.95 (10)	C13—C12—C11	119.1 (5)
N2—Cd2—O1	80.90 (12)	C12—C13—Br1	120.2 (4)
N2—Cd2—N1	76.01 (12)	C14—C13—Br1	119.9 (4)
Cd2—Cl1—Cd1^i	91.24 (4)	C14—C13—C12	119.9 (5)
Cd2^ii—Cl2—Cd1^iv	91.00 (3)	C13—C14—C9	122.3 (5)

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

Hydrogen-bond geometry (Å, º)

Cg11 is the centroid of the C9–C14 ring.

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1^i	0.88 (3)	1.78 (4)	2.612 (5)	165 (5)
C14—H14···Cl1^v	0.93	2.87	3.540 (4)	130
C5—H5A···C13^v	0.97	2.84	3.687 (5)	146
C7—H7B···Cg11^v	0.97	2.84	3.740 (6)	156

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