X-ray and DFT-calculated structures of bis­[N-(quinolin-8-yl)benzamidato-[kappa]²N,N']copper(II)

The application of transition metal chelates as chemotherapeutic agents has the advantage that they can be used as a scaffold around which ligands with DNA recognition elements can be anchored. The facile substitution of these components allows for the DNA recognition and binding properties of the metal chelates to be tuned. Copper is a particularly inter­esting choice for the development of novel metallodrugs as it is an endogenous metal and is therefore less toxic than other transition metals. The title compound, [Cu(C₁₆H₁₁N₂O)₂], was synthesized by reacting N-(quinolin-8-yl)benzamide and the metal in a 2:1 ratio. Ligand coordination required deprotonation of the amide N-H group and the isolated complex is therefore neutral. The metal ion adopts a flattened tetra­hedral coordination geometry with the ligands in a pseudo-trans con­fig­uration. The free rotation afforded by the formal single bond between the amide group and phenyl ring allows the phenyl rings to rotate out-of-plane, thus alleviating nonbonded repulsion between the phenyl rings and the quinolyl groups within the complex. Weak C-H...O inter­actions stabilize a dimer in the solid state. Density functional theory (DFT) simulations at the PBE/6-311G(dp) level of theory show that the solid-state structure (C1 symmetry) is 79.33 kJ mol^-1 higher in energy than the lowest energy gas-phase structure (C2 symmetry). Natural bond orbital (NBO) analysis offers an explanation for the formation of the C-H...O inter­actions in electrostatic terms, but the stabilizing effect is insufficient to support the dimer in the gas phase.

S1. Introduction

The application of transition metal chelates as chemotherapeutic agents has been an area of research inter­est for several years (Marzano et al., 2009; Hambley, 2007; Guo & Sadler, 1999). One of the main advantages of transition-metal chelates is that they can be used as a scaffold around which ligands with DNA recognition elements can be anchored. The facile substitution of these components allows for the DNA recognition and binding properties of the metal chelates to be tuned (Zeglis et al., 2007).

Copper is a particularly inter­esting choice for the development of novel metallodrugs as it is an endogenous metal and is therefore less toxic than other transition metals (Marzano et al., 2009). Additionally, the d⁹ electronic configuration of copper(II) has a biologically accessible redox potential and the associated reduction–oxidation reactions of copper(II) in a cellular environment are largely deemed responsible for their cytotoxicity (Halliwell & Gutteridge, 1990). A comprehensive review of copper-based chemotherapeutics has been reported by Marzano et al. (2009). The pathway by which copper(II) chelates catalyse production of reactive oxygen species in vivo, a key factor in their cytotoxicity, is described by Koppenol (2001).

A search of the Cambridge Structural Database (Groom & Allen, 2014) using Conquest (Version 1.17; Bruno et al., 2002) shows that literature on the solid-state structures of N-(quinolin-8-yl)benzamidate transition metal chelates is scarce; the title compound is the first example of a mononuclear bis­[N-(quinolin-8-yl)benzamidate]–metal chelate. This ligand has been shown to form polynuclear structures when coordinated to yttrium(III) (Zhang et al., 2012) and silicon(II) (Wagler & Schwarz, 2014). In both cases, the ligands have acted as bidentate N-donor ligands to one metal centre, with the amide O atom coordinating a second metal ion, leading to tri- and binuclear chelates for yttrium(III) and silicon(II), respectively. The solid-state structure of a ruthenium(II) chelate, with N-(quinolin-8-yl)benzamidate acting as a bidentate ligand, has been studied as a suspected inter­mediate in the synthesis of iso­quinolines from 8-amino­quinoline (Allu & Swamy, 2014). A related ligand comprising two quinolyl­amide moieties bridged by a phenyl ring yielding a potentially tetra­dentate ligand has been coordinated to copper(II) (Begum et al., 2014). The resulting metal chelate is dinuclear with two independent ligands bridging two copper(II) centres. Derivatives of the free-base ligand with o-nitro (Lei et al., 2008a), m-nitro (Lei et al., 2008b) and p-nitro (Lei et al., 2008c) substitution have been studied by X-ray crystallography.

We report herein the solid-state structure of bis­[N-(quinolin-8-yl)benzamidato]copper(II), (1). The stability of the solid-state inter­actions and their influence on the conformation of the chelate are probed using molecular simulations. The limited solubility of the chelate in biological media precludes the complex from cytotoxicity and DNA binding studies.

S2. Experimental

S2.1. Synthesis and crystallization

S2.1.1. Synthesis of N-(quinolin-8-yl)benzamide

8-Amino­quinoline (0.288 g, 2.00 mmol) and tri­ethyl­amine (0.222 g, 2.20 mmol) were dissolved in dry di­chloro­methane (10 ml) and stirred at room temperature for 30 min. The solution was then cooled to ca 277 K in an ice bath. Benzoyl chloride (0.281 g, 2.00 mmol) was added dropwise and the resulting solution stirred overnight at ambient temperature. The reaction mixture was diluted with ethyl acetate (20 ml) and washed with water (10 ml). The organic layer was separated and washed with 1 M NaOH (3 × 10 ml portions). The organic layer was dried over MgSO₄ and the solvent removed under reduced pressure yielding a brown viscous oil. The oil was purified by silica-gel column chromatography with 5:1 hexane–ethyl acetate eluent and recrystallized by slow evaporation from hexane/ethyl acetate to afford white needles (yield 0.26 g, 52%). ¹H NMR (400 MHz, CDCl₃): δ 10.77 (br, s, 1H, NH), 8.97 (dd, J = 1.4, 7.5 Hz, 1H, NCH), 8.88 (dd, J = 1.6, 4.2 Hz, 1H, NHCCH), 8.21 (dd, J = 1.6, 8.3 Hz, 1H, NCHCHCH), 8.11 (dd, 2H, COCCH), 7.65–7.54 (m, 4H), 7.49 (q, 2H, COCCHCH). IR (powder, cm⁻¹): 3349 (s, ν (N—H), stretch), 1668 [s, ν(C═O), stretch], 1525 [s, ν(C—C) aromatic, in-ring], 686 [s, ν(C—H) aromatic, wag].

S2.1.2. Synthesis of bis­[N-(quinolin-8-yl)benzamidato]copper(II), (1)

CuCl₂·2H₂0 (0.200 g, 1.17 mmol) was dissolved in a minimum volume of methanol and added dropwise to two equivalents of N-(quinolin-8-yl)benzamide (0.582 g, 2.34 mmol) dissolved in methanol (30 ml). The resulting mixture was heated to reflux for 2 h. A green–grey precipitate formed and was collected by gravity filtration (yield 0.299 g, 46%). The complex was recrystallized by slow evaporation from a methanol solution. ESI–MS: 559.1323 m/z (M+1⁺). Analysis calculated for C₃₂H₂₂CuN₄O₂: C 68.87, H 3.97, N 10.04%; found: C 68.59, H 3.82, N 9.96%. IR (powder, cm⁻¹): 1596 [m, ν(C═O), stretch], 1554 [m, ν(C—C) aromatic, in-ring], 717 [s, ν(C—H) aromatic, wag].

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. A l l H atoms were placed in geometrically calculated positions, with aromatic C—H distances of 0.93 Å and with U_iso(H) = 1.2U_eq(C).

S3. Results and discussion

The solid-state structure of the title compound, (1), shows that two independent bidentate N-(8-quinolinyl)benzamide ligands coordinated the copper(II) ion with concomitant deprotonation yielding a neutral metal chelate (Fig. 1). The bis­(bidentate) ligand conformation leads to a distorted tetra­hedral coordination geometry. Selected bond parameters describing the coordination sphere of the copper(II) ion are summarized in Table 2 and highlight nominally tetra­hedral coordination geometry. The N1—Cu1—N2 and N3—Cu1—N4 bond angles are significantly more acute than the ideal angle for a tetra­hedral geometry; this is the result of the limited bite of the ligand and the resulting five-membered chelate ring. The N1—Cu1—N4 and N2—Cu1—N3 bond angles [mean value = 102.6 (2)°], which are not restricted by ligand bite, are significantly closer to the ideal angle of 109.5° for a tetra­hedron.

The C10—O1 and C26—O2 bond lengths are 1.230 (3) and 1.239 (3) Å, respectively. This coupled with the O1—C10—C11 and O2—C26—C27 bond angles of 117.2 (2) and 117.8 (2)°, respectively, highlight the sp²-hybridized nature of the central amide C atom. Both ligands show a significant deviation from planarity. Considering the quinolyl ring as a reference point, the amide O atoms and phenyl rings both show an out-of-plane rotation. The deviation from planarity of the amide O atom is illustrated by the C7—C6···C10—O1 and C23—C22···C26—O2 pseudo-torsion angles of 20.3 (3) and −3.9 (3)°, respectively. The mean bond length between the amide C and phenyl C atoms is 1.505 (6) Å, indicating a formal single C—C bond. The free rotation afforded by this single bond allows for a significant out-of-plane rotation by the phenyl rings relative to the quinolyl ring, as shown by the C7—C6···C11—C16 [163.6 (3)°] and C23—C22···C27—C28 [144.7 (3)°] pseudo-torsion angles. Seemingly, this rotation of the phenyl rings is required to alleviate potential steric strain between the phenyl rings and quinolyl moieties.

In the absence of any classical hydrogen-bond donors, the solid-state structure of (1) does not have any hydrogen bonding. However, the structure does exhibit both inter­molecular and intra­molecular C—H···O inter­actions (Fig. 2). The intra­molecular inter­action is between amide atom O2 and the quinolyl C23—H23 group. This yields a six-membered ring. Complementary C—H···O inter­actions between amide atom O1 and the quinolyl C7—H7 group of an adjacent molecule leads to a dimeric supra­molecular structure with crystallographically imposed inversion symmetry. Although inter­action distances are not always a measure of the strength of an inter­action (Steiner, 1997) due to packing constraints in the lattice, these inter­action distances are significantly shorter (0.366 Å) than the sum of the van der Waals radii of the inter­acting atoms. This would suggest that the inter­actions are genuine. The geometrical parameters describing these inter­actions are summarized in Table 3.

Density functional theory (DFT) simulations were used to better understand the nature of the solid-state inter­actions and the influence they have on the conformation of the metal chelate. The DFT simulations were run at the PBE/6–311 G(dp) level of theory (Perdew et al., 1996, 1997; McLean & Chandler, 1980; Raghavachari et al., 1980; Wachters, 1970; Hay, 1977; Raghavachari & Trucks, 1989) using GAUSSIAN09W (Frisch et al., 2009). The monomeric and dimeric input structures for the simulations were generated from the X-ray coordinates. Diffuse and polarization functions (dp) were added to increase the accuracy of the simulations. Analysis of the frequency data shows no negative Eigen values and the optimized structures are therefore likely to be the true minima on the global potential energy surface.

The gas-phase structure of (1) was compared to the solid-state structure using a least-squares fit, as shown in Fig. 3. The similarity of the structures is highlighted by the r.m.s. deviation, which is 0.302 Å for all 39 non-H atoms. The similarity of the two structures would suggest that the level of theory applied for the simulations is appropriate. The key bond parameters describing the coordination spheres of both the simulated and experimental structures are summarized in Table 2. The most notable difference between the two structures is the point symmetry. The experimental structure of (1) shows C1 point symmetry, while the simulated structure (i.e. the lowest energy conformation) in the absence of packing constraints in the lattice exhibits C2 symmetry. The gas-phase structure with the higher point symmetry is 79.33 kJ mol⁻¹ lower in energy than the solid-state structure. Seemingly the lower symmetry conformation of the solid-state structure leads to more favourable packing and stabilizing solid-state inter­actions which can offset the energy difference.

Analysis of the natural bond orbitals (NBOs) offers a possible explanation for the origins of the C—H···O inter­actions. The NBO simulations show that the amide O atoms carry the largest partial negative charge, i.e. −0.601 e, the quinolyl C—H group correspondingly carries the largest partial positive charge, i.e. 0.258 e. If the inter­action is to be considered as electrostatic in nature, then the NBO charges show the origins of the inter­actions.

Optimization of the dimeric structure in the gas phase yields an inter­esting result. Although the NBO analysis shows that there is the potential for an electrostatic inter­action between the amide O atom and a quinolyl C—H group in the gas phase, the C—H···O inter­actions are not sufficient to stabilize the supra­molecular structure (Fig. 4). The gas-phase structure maintains inversion symmetry, but shows a lateral displacement of the adjacent molecules relative to the solid-state structure. This lateral displacement increases the H···O distance from 2.37 Å in the solid-state structure to 2.932 Å in the gas phase. The distance of the `inter­action' in the gas phase is therefore longer than the sum of the van der Waals radii of the inter­acting atoms. This displacement is seemingly required as the weak electrostatic attraction between the quinolyl C—H group and amide O atom is insufficient to offset the nonbonded repulsion between the inter­acting groups in the gas phase. This is in contrast to the stronger N—H···N and N—H···Cl inter­actions which have been shown to be stable in the gas phase (Akerman & Chiazzari, 2014; Nyamato et al., 2014). These data show that although the solid-state inter­actions are electrostatically favourable, without additional stabilization from various inter­actions within the crystal lattice, the dimeric structure is not favoured.

Structure description

The application of transition metal chelates as chemotherapeutic agents has been an area of research inter­est for several years (Marzano et al., 2009; Hambley, 2007; Guo & Sadler, 1999). One of the main advantages of transition-metal chelates is that they can be used as a scaffold around which ligands with DNA recognition elements can be anchored. The facile substitution of these components allows for the DNA recognition and binding properties of the metal chelates to be tuned (Zeglis et al., 2007).

Copper is a particularly inter­esting choice for the development of novel metallodrugs as it is an endogenous metal and is therefore less toxic than other transition metals (Marzano et al., 2009). Additionally, the d⁹ electronic configuration of copper(II) has a biologically accessible redox potential and the associated reduction–oxidation reactions of copper(II) in a cellular environment are largely deemed responsible for their cytotoxicity (Halliwell & Gutteridge, 1990). A comprehensive review of copper-based chemotherapeutics has been reported by Marzano et al. (2009). The pathway by which copper(II) chelates catalyse production of reactive oxygen species in vivo, a key factor in their cytotoxicity, is described by Koppenol (2001).

A search of the Cambridge Structural Database (Groom & Allen, 2014) using Conquest (Version 1.17; Bruno et al., 2002) shows that literature on the solid-state structures of N-(quinolin-8-yl)benzamidate transition metal chelates is scarce; the title compound is the first example of a mononuclear bis­[N-(quinolin-8-yl)benzamidate]–metal chelate. This ligand has been shown to form polynuclear structures when coordinated to yttrium(III) (Zhang et al., 2012) and silicon(II) (Wagler & Schwarz, 2014). In both cases, the ligands have acted as bidentate N-donor ligands to one metal centre, with the amide O atom coordinating a second metal ion, leading to tri- and binuclear chelates for yttrium(III) and silicon(II), respectively. The solid-state structure of a ruthenium(II) chelate, with N-(quinolin-8-yl)benzamidate acting as a bidentate ligand, has been studied as a suspected inter­mediate in the synthesis of iso­quinolines from 8-amino­quinoline (Allu & Swamy, 2014). A related ligand comprising two quinolyl­amide moieties bridged by a phenyl ring yielding a potentially tetra­dentate ligand has been coordinated to copper(II) (Begum et al., 2014). The resulting metal chelate is dinuclear with two independent ligands bridging two copper(II) centres. Derivatives of the free-base ligand with o-nitro (Lei et al., 2008a), m-nitro (Lei et al., 2008b) and p-nitro (Lei et al., 2008c) substitution have been studied by X-ray crystallography.

We report herein the solid-state structure of bis­[N-(quinolin-8-yl)benzamidato]copper(II), (1). The stability of the solid-state inter­actions and their influence on the conformation of the chelate are probed using molecular simulations. The limited solubility of the chelate in biological media precludes the complex from cytotoxicity and DNA binding studies.

The solid-state structure of the title compound, (1), shows that two independent bidentate N-(8-quinolinyl)benzamide ligands coordinated the copper(II) ion with concomitant deprotonation yielding a neutral metal chelate (Fig. 1). The bis­(bidentate) ligand conformation leads to a distorted tetra­hedral coordination geometry. Selected bond parameters describing the coordination sphere of the copper(II) ion are summarized in Table 2 and highlight nominally tetra­hedral coordination geometry. The N1—Cu1—N2 and N3—Cu1—N4 bond angles are significantly more acute than the ideal angle for a tetra­hedral geometry; this is the result of the limited bite of the ligand and the resulting five-membered chelate ring. The N1—Cu1—N4 and N2—Cu1—N3 bond angles [mean value = 102.6 (2)°], which are not restricted by ligand bite, are significantly closer to the ideal angle of 109.5° for a tetra­hedron.

The C10—O1 and C26—O2 bond lengths are 1.230 (3) and 1.239 (3) Å, respectively. This coupled with the O1—C10—C11 and O2—C26—C27 bond angles of 117.2 (2) and 117.8 (2)°, respectively, highlight the sp²-hybridized nature of the central amide C atom. Both ligands show a significant deviation from planarity. Considering the quinolyl ring as a reference point, the amide O atoms and phenyl rings both show an out-of-plane rotation. The deviation from planarity of the amide O atom is illustrated by the C7—C6···C10—O1 and C23—C22···C26—O2 pseudo-torsion angles of 20.3 (3) and −3.9 (3)°, respectively. The mean bond length between the amide C and phenyl C atoms is 1.505 (6) Å, indicating a formal single C—C bond. The free rotation afforded by this single bond allows for a significant out-of-plane rotation by the phenyl rings relative to the quinolyl ring, as shown by the C7—C6···C11—C16 [163.6 (3)°] and C23—C22···C27—C28 [144.7 (3)°] pseudo-torsion angles. Seemingly, this rotation of the phenyl rings is required to alleviate potential steric strain between the phenyl rings and quinolyl moieties.

In the absence of any classical hydrogen-bond donors, the solid-state structure of (1) does not have any hydrogen bonding. However, the structure does exhibit both inter­molecular and intra­molecular C—H···O inter­actions (Fig. 2). The intra­molecular inter­action is between amide atom O2 and the quinolyl C23—H23 group. This yields a six-membered ring. Complementary C—H···O inter­actions between amide atom O1 and the quinolyl C7—H7 group of an adjacent molecule leads to a dimeric supra­molecular structure with crystallographically imposed inversion symmetry. Although inter­action distances are not always a measure of the strength of an inter­action (Steiner, 1997) due to packing constraints in the lattice, these inter­action distances are significantly shorter (0.366 Å) than the sum of the van der Waals radii of the inter­acting atoms. This would suggest that the inter­actions are genuine. The geometrical parameters describing these inter­actions are summarized in Table 3.

Density functional theory (DFT) simulations were used to better understand the nature of the solid-state inter­actions and the influence they have on the conformation of the metal chelate. The DFT simulations were run at the PBE/6–311 G(dp) level of theory (Perdew et al., 1996, 1997; McLean & Chandler, 1980; Raghavachari et al., 1980; Wachters, 1970; Hay, 1977; Raghavachari & Trucks, 1989) using GAUSSIAN09W (Frisch et al., 2009). The monomeric and dimeric input structures for the simulations were generated from the X-ray coordinates. Diffuse and polarization functions (dp) were added to increase the accuracy of the simulations. Analysis of the frequency data shows no negative Eigen values and the optimized structures are therefore likely to be the true minima on the global potential energy surface.

The gas-phase structure of (1) was compared to the solid-state structure using a least-squares fit, as shown in Fig. 3. The similarity of the structures is highlighted by the r.m.s. deviation, which is 0.302 Å for all 39 non-H atoms. The similarity of the two structures would suggest that the level of theory applied for the simulations is appropriate. The key bond parameters describing the coordination spheres of both the simulated and experimental structures are summarized in Table 2. The most notable difference between the two structures is the point symmetry. The experimental structure of (1) shows C1 point symmetry, while the simulated structure (i.e. the lowest energy conformation) in the absence of packing constraints in the lattice exhibits C2 symmetry. The gas-phase structure with the higher point symmetry is 79.33 kJ mol⁻¹ lower in energy than the solid-state structure. Seemingly the lower symmetry conformation of the solid-state structure leads to more favourable packing and stabilizing solid-state inter­actions which can offset the energy difference.

Analysis of the natural bond orbitals (NBOs) offers a possible explanation for the origins of the C—H···O inter­actions. The NBO simulations show that the amide O atoms carry the largest partial negative charge, i.e. −0.601 e, the quinolyl C—H group correspondingly carries the largest partial positive charge, i.e. 0.258 e. If the inter­action is to be considered as electrostatic in nature, then the NBO charges show the origins of the inter­actions.

Optimization of the dimeric structure in the gas phase yields an inter­esting result. Although the NBO analysis shows that there is the potential for an electrostatic inter­action between the amide O atom and a quinolyl C—H group in the gas phase, the C—H···O inter­actions are not sufficient to stabilize the supra­molecular structure (Fig. 4). The gas-phase structure maintains inversion symmetry, but shows a lateral displacement of the adjacent molecules relative to the solid-state structure. This lateral displacement increases the H···O distance from 2.37 Å in the solid-state structure to 2.932 Å in the gas phase. The distance of the `inter­action' in the gas phase is therefore longer than the sum of the van der Waals radii of the inter­acting atoms. This displacement is seemingly required as the weak electrostatic attraction between the quinolyl C—H group and amide O atom is insufficient to offset the nonbonded repulsion between the inter­acting groups in the gas phase. This is in contrast to the stronger N—H···N and N—H···Cl inter­actions which have been shown to be stable in the gas phase (Akerman & Chiazzari, 2014; Nyamato et al., 2014). These data show that although the solid-state inter­actions are electrostatically favourable, without additional stabilization from various inter­actions within the crystal lattice, the dimeric structure is not favoured.

Synthesis and crystallization

8-Amino­quinoline (0.288 g, 2.00 mmol) and tri­ethyl­amine (0.222 g, 2.20 mmol) were dissolved in dry di­chloro­methane (10 ml) and stirred at room temperature for 30 min. The solution was then cooled to ca 277 K in an ice bath. Benzoyl chloride (0.281 g, 2.00 mmol) was added dropwise and the resulting solution stirred overnight at ambient temperature. The reaction mixture was diluted with ethyl acetate (20 ml) and washed with water (10 ml). The organic layer was separated and washed with 1 M NaOH (3 × 10 ml portions). The organic layer was dried over MgSO₄ and the solvent removed under reduced pressure yielding a brown viscous oil. The oil was purified by silica-gel column chromatography with 5:1 hexane–ethyl acetate eluent and recrystallized by slow evaporation from hexane/ethyl acetate to afford white needles (yield 0.26 g, 52%). ¹H NMR (400 MHz, CDCl₃): δ 10.77 (br, s, 1H, NH), 8.97 (dd, J = 1.4, 7.5 Hz, 1H, NCH), 8.88 (dd, J = 1.6, 4.2 Hz, 1H, NHCCH), 8.21 (dd, J = 1.6, 8.3 Hz, 1H, NCHCHCH), 8.11 (dd, 2H, COCCH), 7.65–7.54 (m, 4H), 7.49 (q, 2H, COCCHCH). IR (powder, cm⁻¹): 3349 (s, ν (N—H), stretch), 1668 [s, ν(C═O), stretch], 1525 [s, ν(C—C) aromatic, in-ring], 686 [s, ν(C—H) aromatic, wag].

CuCl₂·2H₂0 (0.200 g, 1.17 mmol) was dissolved in a minimum volume of methanol and added dropwise to two equivalents of N-(quinolin-8-yl)benzamide (0.582 g, 2.34 mmol) dissolved in methanol (30 ml). The resulting mixture was heated to reflux for 2 h. A green–grey precipitate formed and was collected by gravity filtration (yield 0.299 g, 46%). The complex was recrystallized by slow evaporation from a methanol solution. ESI–MS: 559.1323 m/z (M+1⁺). Analysis calculated for C₃₂H₂₂CuN₄O₂: C 68.87, H 3.97, N 10.04%; found: C 68.59, H 3.82, N 9.96%. IR (powder, cm⁻¹): 1596 [m, ν(C═O), stretch], 1554 [m, ν(C—C) aromatic, in-ring], 717 [s, ν(C—H) aromatic, wag].

Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 1. A l l H atoms were placed in geometrically calculated positions, with aromatic C—H distances of 0.93 Å and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: APEX2 (Bruker, 2012); cell refinement: SAINT-Plus (Bruker, 2012); data reduction: SAINT-Plus (Bruker, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: WinGX (Farrugia, 2012); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. Displacement ellipsoid plot (at the 50% probability level) showing the atom-numbering scheme of compound (1). H atoms are depicted with a common arbitrary radius.
	Fig. 2. The dimeric supramolecular structure of compound (1) in the solid state, stabilized by weak complementary C—H···O interactions between the amide O atom and a quinoline C—H group of an adjacent molecule. The intramolecular interaction is also depicted. [Symmetry code (i) −x, −y, −z.]
	Fig. 3. Least-squares fit of the experimental (blue) and DFT-simulated (yellow) structures. The root-mean-square deviation (RMSD) for the two structures is 0.302 Å for all 39 non-H atoms. This shows that the solid-state structure undergoes a relatively small conformational distortion from the true lowest energy structure.
	Fig. 4. Least-squares fit of a single monomer of the experimental and simulated dimeric structures of (1), showing the lateral displacement in the simulated (yellow) and experimental (blue) structures. The H···O hydrogen-bond distances of the experimental (2.37 Å) and simulated (2.931 Å) structures are indicated and highlight the conformational differences.

Bis[N-(quinolin-8-yl)benzamidato-κ²N,N']copper(II)

Crystal data

[Cu(C16H11N2O)2]	Z = 2
Mr = 558.07	F(000) = 574
Triclinic, P1	Dx = 1.510 Mg m^−3
a = 9.7987 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.3849 (5) Å	Cell parameters from 4843 reflections
c = 13.9923 (6) Å	θ = 1.6–26.1°
α = 79.948 (2)°	µ = 0.93 mm^−1
β = 69.724 (2)°	T = 100 K
γ = 66.911 (2)°	Needle, green
V = 1227.39 (10) Å^3	0.39 × 0.05 × 0.03 mm

Data collection

Bruker APEXII CCD diffractometer	4482 reflections with I > 2σ(I)
Radiation source: Incoatec microsource	Rint = 0.027
ω and φ–scans	θmax = 26.1°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2012)	h = −12→12
Tmin = 0.714, Tmax = 0.973	k = −12→5
18601 measured reflections	l = −17→17
4843 independent reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.037	H-atom parameters constrained
wR(F^2) = 0.103	w = 1/[σ^2(Fo^2) + (0.0426P)^2 + 2.9106P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max < 0.001
4843 reflections	Δρmax = 0.53 e Å^−3
352 parameters	Δρmin = −0.66 e Å^−3

Special details

Experimental. The X-ray data were recorded on a Bruker APEX DUO equipped with an Oxford Instruments Cryojet operating at 100 (2) K and an Incoatec microsource operating at 30 W power. Crystal and structure refinement data are given in Table 1. The data were collected with Mo Kα (λ = 0.71073 Å) radiation at a crystal-to-detector distance of 50 mm. The following conditions were used for the data collection: ω and φ scans with exposures taken at 30 W X-ray power and 0.50° frame widths using APEX2 (Bruker, 2012).

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
C1	−0.1992 (3)	0.4640 (3)	0.36121 (18)	0.0099 (5)
H1	−0.1491	0.4872	0.3975	0.012*
C2	−0.3584 (3)	0.5412 (3)	0.37509 (19)	0.0129 (5)
H2	−0.4120	0.6144	0.4195	0.015*
C3	−0.4336 (3)	0.5073 (3)	0.3225 (2)	0.0136 (5)
H3	−0.5390	0.5575	0.3311	0.016*
C4	−0.3509 (3)	0.3961 (3)	0.25516 (18)	0.0103 (5)
C5	−0.1903 (3)	0.3238 (2)	0.24473 (18)	0.0084 (5)
C6	−0.0991 (3)	0.2063 (3)	0.18159 (17)	0.0083 (5)
C7	−0.1738 (3)	0.1649 (3)	0.13106 (18)	0.0107 (5)
H7	−0.1184	0.0872	0.0908	0.013*
C8	−0.3323 (3)	0.2390 (3)	0.14011 (19)	0.0128 (5)
H8	−0.3788	0.2099	0.1045	0.015*
C9	−0.4206 (3)	0.3530 (3)	0.19972 (19)	0.0132 (5)
H9	−0.5248	0.4011	0.2035	0.016*
C10	0.1624 (3)	0.0480 (3)	0.10954 (18)	0.0101 (5)
C11	0.3198 (3)	−0.0368 (3)	0.12338 (18)	0.0104 (5)
C12	0.3761 (3)	−0.1801 (3)	0.10637 (19)	0.0141 (5)
H12	0.3155	−0.2172	0.0896	0.017*
C13	0.5214 (3)	−0.2669 (3)	0.1144 (2)	0.0196 (6)
H13	0.5576	−0.3620	0.1037	0.024*
C14	0.6129 (3)	−0.2112 (3)	0.1385 (2)	0.0209 (6)
H14	0.7104	−0.2693	0.1440	0.025*
C15	0.5592 (3)	−0.0696 (3)	0.1542 (2)	0.0181 (6)
H15	0.6212	−0.0326	0.1695	0.022*
C16	0.4125 (3)	0.0177 (3)	0.14720 (19)	0.0134 (5)
H16	0.3764	0.1127	0.1585	0.016*
C17	0.1557 (3)	−0.0863 (3)	0.37012 (18)	0.0109 (5)
H17	0.1142	−0.0987	0.3234	0.013*
C18	0.2064 (3)	−0.1994 (3)	0.43664 (19)	0.0127 (5)
H18	0.1998	−0.2855	0.4337	0.015*
C19	0.2657 (3)	−0.1795 (3)	0.50601 (19)	0.0128 (5)
H19	0.3029	−0.2539	0.5493	0.015*
C20	0.2713 (3)	−0.0479 (3)	0.51284 (18)	0.0105 (5)
C21	0.2222 (3)	0.0594 (2)	0.44123 (17)	0.0080 (5)
C22	0.2283 (3)	0.1951 (2)	0.43884 (18)	0.0086 (5)
C23	0.2819 (3)	0.2181 (3)	0.51146 (19)	0.0126 (5)
H23	0.2885	0.3049	0.5120	0.015*
C24	0.3268 (3)	0.1122 (3)	0.5847 (2)	0.0154 (5)
H24	0.3601	0.1319	0.6332	0.019*
C25	0.3228 (3)	−0.0182 (3)	0.58680 (19)	0.0136 (5)
H25	0.3533	−0.0862	0.6357	0.016*
C26	0.1786 (3)	0.4227 (3)	0.35029 (19)	0.0101 (5)
C27	0.1337 (3)	0.5095 (3)	0.26064 (19)	0.0108 (5)
C28	0.1744 (3)	0.4565 (3)	0.1657 (2)	0.0150 (5)
H28	0.2337	0.3621	0.1549	0.018*
C29	0.1266 (3)	0.5446 (3)	0.0869 (2)	0.0224 (6)
H29	0.1544	0.5088	0.0236	0.027*
C30	0.0379 (3)	0.6852 (3)	0.1023 (2)	0.0243 (7)
H30	0.0047	0.7431	0.0499	0.029*
C31	−0.0015 (3)	0.7395 (3)	0.1962 (2)	0.0224 (6)
H31	−0.0606	0.8339	0.2066	0.027*
C32	0.0474 (3)	0.6529 (3)	0.2742 (2)	0.0153 (5)
H32	0.0228	0.6901	0.3364	0.018*
N1	−0.1180 (2)	0.3597 (2)	0.29844 (15)	0.0079 (4)
N2	0.0566 (2)	0.1409 (2)	0.18210 (15)	0.0093 (4)
N3	0.1648 (2)	0.0374 (2)	0.37138 (15)	0.0084 (4)
N4	0.1792 (2)	0.2894 (2)	0.36126 (15)	0.0085 (4)
O1	0.1379 (2)	0.0250 (2)	0.03485 (14)	0.0166 (4)
O2	0.2107 (2)	0.47763 (19)	0.40734 (14)	0.0158 (4)
Cu1	0.09080 (3)	0.21120 (3)	0.28941 (2)	0.01109 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0106 (11)	0.0113 (11)	0.0099 (11)	−0.0060 (9)	−0.0028 (9)	−0.0017 (9)
C2	0.0124 (12)	0.0100 (12)	0.0151 (12)	−0.0030 (10)	−0.0017 (10)	−0.0057 (9)
C3	0.0082 (11)	0.0132 (12)	0.0178 (13)	−0.0018 (10)	−0.0036 (10)	−0.0026 (10)
C4	0.0098 (11)	0.0115 (12)	0.0106 (11)	−0.0045 (9)	−0.0040 (9)	0.0008 (9)
C5	0.0095 (11)	0.0095 (11)	0.0077 (11)	−0.0047 (9)	−0.0040 (9)	0.0017 (9)
C6	0.0090 (11)	0.0110 (11)	0.0060 (11)	−0.0040 (9)	−0.0036 (9)	0.0006 (9)
C7	0.0128 (11)	0.0122 (12)	0.0087 (11)	−0.0049 (10)	−0.0037 (9)	−0.0022 (9)
C8	0.0130 (12)	0.0186 (13)	0.0119 (12)	−0.0085 (10)	−0.0063 (10)	−0.0010 (10)
C9	0.0086 (11)	0.0182 (13)	0.0147 (12)	−0.0044 (10)	−0.0063 (10)	−0.0008 (10)
C10	0.0112 (11)	0.0104 (11)	0.0103 (11)	−0.0044 (9)	−0.0046 (9)	−0.0003 (9)
C11	0.0105 (11)	0.0138 (12)	0.0052 (11)	−0.0032 (10)	−0.0015 (9)	−0.0005 (9)
C12	0.0165 (12)	0.0133 (12)	0.0131 (12)	−0.0060 (10)	−0.0041 (10)	−0.0012 (10)
C13	0.0199 (13)	0.0109 (12)	0.0224 (14)	−0.0014 (11)	−0.0057 (11)	0.0013 (11)
C14	0.0111 (12)	0.0209 (14)	0.0247 (15)	−0.0007 (11)	−0.0071 (11)	0.0053 (11)
C15	0.0126 (12)	0.0236 (14)	0.0194 (14)	−0.0076 (11)	−0.0067 (10)	0.0020 (11)
C16	0.0128 (12)	0.0148 (12)	0.0122 (12)	−0.0047 (10)	−0.0038 (10)	−0.0005 (10)
C17	0.0120 (11)	0.0112 (12)	0.0100 (12)	−0.0048 (10)	−0.0021 (9)	−0.0027 (9)
C18	0.0120 (11)	0.0081 (11)	0.0152 (12)	−0.0041 (9)	0.0002 (10)	−0.0010 (9)
C19	0.0107 (11)	0.0117 (12)	0.0112 (12)	−0.0027 (10)	−0.0011 (9)	0.0038 (9)
C20	0.0072 (10)	0.0135 (12)	0.0076 (11)	−0.0023 (9)	−0.0004 (9)	0.0001 (9)
C21	0.0058 (10)	0.0103 (11)	0.0065 (11)	−0.0019 (9)	−0.0007 (8)	−0.0017 (9)
C22	0.0066 (10)	0.0089 (11)	0.0080 (11)	−0.0005 (9)	−0.0018 (9)	−0.0015 (9)
C23	0.0151 (12)	0.0118 (12)	0.0135 (12)	−0.0038 (10)	−0.0076 (10)	−0.0028 (10)
C24	0.0151 (12)	0.0205 (13)	0.0123 (12)	−0.0032 (10)	−0.0088 (10)	−0.0029 (10)
C25	0.0120 (11)	0.0175 (13)	0.0091 (12)	−0.0031 (10)	−0.0048 (9)	0.0025 (10)
C26	0.0069 (10)	0.0104 (11)	0.0121 (12)	−0.0017 (9)	−0.0027 (9)	−0.0022 (9)
C27	0.0073 (11)	0.0113 (12)	0.0160 (12)	−0.0059 (9)	−0.0051 (9)	0.0033 (10)
C28	0.0129 (12)	0.0160 (13)	0.0158 (13)	−0.0050 (10)	−0.0059 (10)	0.0027 (10)
C29	0.0164 (13)	0.0334 (17)	0.0137 (13)	−0.0077 (12)	−0.0050 (11)	0.0054 (12)
C30	0.0124 (12)	0.0298 (16)	0.0225 (15)	−0.0063 (12)	−0.0060 (11)	0.0167 (12)
C31	0.0122 (12)	0.0164 (14)	0.0315 (16)	−0.0036 (11)	−0.0048 (11)	0.0085 (12)
C32	0.0113 (11)	0.0124 (12)	0.0217 (14)	−0.0045 (10)	−0.0051 (10)	0.0010 (10)
N1	0.0084 (9)	0.0090 (10)	0.0076 (9)	−0.0044 (8)	−0.0030 (8)	0.0005 (7)
N2	0.0093 (9)	0.0110 (10)	0.0090 (10)	−0.0019 (8)	−0.0053 (8)	−0.0024 (8)
N3	0.0099 (9)	0.0080 (10)	0.0072 (9)	−0.0028 (8)	−0.0025 (8)	−0.0008 (7)
N4	0.0097 (9)	0.0088 (10)	0.0095 (10)	−0.0028 (8)	−0.0065 (8)	−0.0004 (8)
O1	0.0149 (9)	0.0208 (10)	0.0143 (9)	−0.0011 (8)	−0.0071 (7)	−0.0090 (7)
O2	0.0220 (9)	0.0119 (9)	0.0201 (10)	−0.0074 (8)	−0.0123 (8)	−0.0019 (7)
Cu1	0.01248 (16)	0.01028 (16)	0.01248 (17)	−0.00275 (12)	−0.00707 (12)	−0.00182 (11)

Geometric parameters (Å, º)

C1—N1	1.323 (3)	C17—H17	0.9300
C1—C2	1.406 (3)	C18—C19	1.371 (4)
C1—H1	0.9300	C18—H18	0.9300
C2—C3	1.371 (4)	C19—C20	1.410 (4)
C2—H2	0.9300	C19—H19	0.9300
C3—C4	1.413 (3)	C20—C21	1.414 (3)
C3—H3	0.9300	C20—C25	1.420 (3)
C4—C9	1.413 (3)	C21—N3	1.372 (3)
C4—C5	1.420 (3)	C21—C22	1.428 (3)
C5—N1	1.371 (3)	C22—C23	1.385 (3)
C5—C6	1.428 (3)	C22—N4	1.411 (3)
C6—C7	1.390 (3)	C23—C24	1.412 (4)
C6—N2	1.408 (3)	C23—H23	0.9300
C7—C8	1.408 (3)	C24—C25	1.364 (4)
C7—H7	0.9300	C24—H24	0.9300
C8—C9	1.373 (4)	C25—H25	0.9300
C8—H8	0.9300	C26—O2	1.239 (3)
C9—H9	0.9300	C26—N4	1.364 (3)
C10—O1	1.230 (3)	C26—C27	1.502 (3)
C10—N2	1.365 (3)	C27—C28	1.394 (4)
C10—C11	1.509 (3)	C27—C32	1.402 (4)
C11—C16	1.391 (4)	C28—C29	1.393 (4)
C11—C12	1.401 (4)	C28—H28	0.9300
C12—C13	1.386 (4)	C29—C30	1.385 (4)
C12—H12	0.9300	C29—H29	0.9300
C13—C14	1.391 (4)	C30—C31	1.389 (5)
C13—H13	0.9300	C30—H30	0.9300
C14—C15	1.383 (4)	C31—C32	1.383 (4)
C14—H14	0.9300	C31—H31	0.9300
C15—C16	1.394 (4)	C32—H32	0.9300
C15—H15	0.9300	N1—Cu1	1.999 (2)
C16—H16	0.9300	N2—Cu1	1.955 (2)
C17—N3	1.326 (3)	N3—Cu1	1.981 (2)
C17—C18	1.405 (4)	N4—Cu1	1.965 (2)
N1—C1—C2	122.4 (2)	C19—C20—C21	117.2 (2)
N1—C1—H1	118.8	C19—C20—C25	123.8 (2)
C2—C1—H1	118.8	C21—C20—C25	119.0 (2)
C3—C2—C1	119.3 (2)	N3—C21—C20	121.1 (2)
C3—C2—H2	120.4	N3—C21—C22	117.1 (2)
C1—C2—H2	120.4	C20—C21—C22	121.9 (2)
C2—C3—C4	119.9 (2)	C23—C22—N4	128.0 (2)
C2—C3—H3	120.1	C23—C22—C21	116.9 (2)
C4—C3—H3	120.1	N4—C22—C21	115.1 (2)
C3—C4—C9	123.3 (2)	C22—C23—C24	121.1 (2)
C3—C4—C5	117.5 (2)	C22—C23—H23	119.4
C9—C4—C5	119.1 (2)	C24—C23—H23	119.4
N1—C5—C4	121.3 (2)	C25—C24—C23	122.3 (2)
N1—C5—C6	117.2 (2)	C25—C24—H24	118.8
C4—C5—C6	121.3 (2)	C23—C24—H24	118.8
C7—C6—N2	127.2 (2)	C24—C25—C20	118.7 (2)
C7—C6—C5	117.5 (2)	C24—C25—H25	120.6
N2—C6—C5	115.2 (2)	C20—C25—H25	120.6
C6—C7—C8	120.8 (2)	O2—C26—N4	126.0 (2)
C6—C7—H7	119.6	O2—C26—C27	117.9 (2)
C8—C7—H7	119.6	N4—C26—C27	116.1 (2)
C9—C8—C7	122.2 (2)	C28—C27—C32	118.8 (2)
C9—C8—H8	118.9	C28—C27—C26	124.0 (2)
C7—C8—H8	118.9	C32—C27—C26	117.2 (2)
C8—C9—C4	119.0 (2)	C29—C28—C27	120.2 (3)
C8—C9—H9	120.5	C29—C28—H28	119.9
C4—C9—H9	120.5	C27—C28—H28	119.9
O1—C10—N2	125.0 (2)	C30—C29—C28	120.4 (3)
O1—C10—C11	117.2 (2)	C30—C29—H29	119.8
N2—C10—C11	117.8 (2)	C28—C29—H29	119.8
C16—C11—C12	119.2 (2)	C29—C30—C31	120.0 (3)
C16—C11—C10	125.0 (2)	C29—C30—H30	120.0
C12—C11—C10	115.8 (2)	C31—C30—H30	120.0
C13—C12—C11	120.5 (2)	C32—C31—C30	119.9 (3)
C13—C12—H12	119.7	C32—C31—H31	120.1
C11—C12—H12	119.7	C30—C31—H31	120.1
C12—C13—C14	119.8 (2)	C31—C32—C27	120.8 (3)
C12—C13—H13	120.1	C31—C32—H32	119.6
C14—C13—H13	120.1	C27—C32—H32	119.6
C15—C14—C13	120.1 (2)	C1—N1—C5	119.5 (2)
C15—C14—H14	119.9	C1—N1—Cu1	128.91 (16)
C13—C14—H14	119.9	C5—N1—Cu1	110.08 (15)
C14—C15—C16	120.2 (3)	C10—N2—C6	119.98 (19)
C14—C15—H15	119.9	C10—N2—Cu1	128.83 (16)
C16—C15—H15	119.9	C6—N2—Cu1	111.08 (15)
C11—C16—C15	120.2 (2)	C17—N3—C21	119.8 (2)
C11—C16—H16	119.9	C17—N3—Cu1	128.62 (17)
C15—C16—H16	119.9	C21—N3—Cu1	111.39 (16)
N3—C17—C18	122.6 (2)	C26—N4—C22	121.4 (2)
N3—C17—H17	118.7	C26—N4—Cu1	126.81 (16)
C18—C17—H17	118.7	C22—N4—Cu1	111.35 (16)
C19—C18—C17	118.2 (2)	N2—Cu1—N4	162.09 (9)
C19—C18—H18	120.9	N2—Cu1—N3	101.94 (8)
C17—C18—H18	120.9	N4—Cu1—N3	84.43 (8)
C18—C19—C20	121.0 (2)	N2—Cu1—N1	84.39 (8)
C18—C19—H19	119.5	N4—Cu1—N1	103.37 (8)
C20—C19—H19	119.5	N3—Cu1—N1	133.94 (8)
N1—C1—C2—C3	0.4 (4)	C22—C23—C24—C25	1.3 (4)
C1—C2—C3—C4	−0.1 (4)	C23—C24—C25—C20	−0.2 (4)
C2—C3—C4—C9	178.8 (2)	C19—C20—C25—C24	178.5 (2)
C2—C3—C4—C5	−0.3 (4)	C21—C20—C25—C24	−1.6 (3)
C3—C4—C5—N1	0.4 (4)	O2—C26—C27—C28	143.7 (2)
C9—C4—C5—N1	−178.6 (2)	N4—C26—C27—C28	−36.7 (3)
C3—C4—C5—C6	177.4 (2)	O2—C26—C27—C32	−35.4 (3)
C9—C4—C5—C6	−1.7 (4)	N4—C26—C27—C32	144.3 (2)
N1—C5—C6—C7	176.7 (2)	C32—C27—C28—C29	−1.5 (4)
C4—C5—C6—C7	−0.4 (3)	C26—C27—C28—C29	179.5 (2)
N1—C5—C6—N2	−0.1 (3)	C27—C28—C29—C30	−0.2 (4)
C4—C5—C6—N2	−177.2 (2)	C28—C29—C30—C31	1.2 (4)
N2—C6—C7—C8	178.1 (2)	C29—C30—C31—C32	−0.3 (4)
C5—C6—C7—C8	1.7 (4)	C30—C31—C32—C27	−1.4 (4)
C6—C7—C8—C9	−1.1 (4)	C28—C27—C32—C31	2.3 (4)
C7—C8—C9—C4	−1.0 (4)	C26—C27—C32—C31	−178.6 (2)
C3—C4—C9—C8	−176.7 (2)	C2—C1—N1—C5	−0.3 (4)
C5—C4—C9—C8	2.3 (4)	C2—C1—N1—Cu1	−165.04 (19)
O1—C10—C11—C16	133.9 (3)	C4—C5—N1—C1	−0.2 (3)
N2—C10—C11—C16	−48.0 (3)	C6—C5—N1—C1	−177.2 (2)
O1—C10—C11—C12	−43.4 (3)	C4—C5—N1—Cu1	167.25 (18)
N2—C10—C11—C12	134.7 (2)	C6—C5—N1—Cu1	−9.8 (3)
C16—C11—C12—C13	0.8 (4)	O1—C10—N2—C6	7.8 (4)
C10—C11—C12—C13	178.3 (2)	C11—C10—N2—C6	−170.1 (2)
C11—C12—C13—C14	−0.7 (4)	O1—C10—N2—Cu1	−167.9 (2)
C12—C13—C14—C15	−0.1 (4)	C11—C10—N2—Cu1	14.1 (3)
C13—C14—C15—C16	0.8 (4)	C7—C6—N2—C10	17.3 (4)
C12—C11—C16—C15	−0.2 (4)	C5—C6—N2—C10	−166.2 (2)
C10—C11—C16—C15	−177.4 (2)	C7—C6—N2—Cu1	−166.2 (2)
C14—C15—C16—C11	−0.6 (4)	C5—C6—N2—Cu1	10.3 (3)
N3—C17—C18—C19	0.8 (4)	C18—C17—N3—C21	−1.6 (3)
C17—C18—C19—C20	2.0 (4)	C18—C17—N3—Cu1	−176.64 (17)
C18—C19—C20—C21	−3.8 (3)	C20—C21—N3—C17	−0.4 (3)
C18—C19—C20—C25	176.2 (2)	C22—C21—N3—C17	−179.7 (2)
C19—C20—C21—N3	3.0 (3)	C20—C21—N3—Cu1	175.49 (17)
C25—C20—C21—N3	−177.0 (2)	C22—C21—N3—Cu1	−3.9 (2)
C19—C20—C21—C22	−177.7 (2)	O2—C26—N4—C22	−4.2 (4)
C25—C20—C21—C22	2.3 (3)	C27—C26—N4—C22	176.2 (2)
N3—C21—C22—C23	178.1 (2)	O2—C26—N4—Cu1	167.10 (19)
C20—C21—C22—C23	−1.2 (3)	C27—C26—N4—Cu1	−12.6 (3)
N3—C21—C22—N4	−2.3 (3)	C23—C22—N4—C26	−0.7 (4)
C20—C21—C22—N4	178.4 (2)	C21—C22—N4—C26	179.8 (2)
N4—C22—C23—C24	179.9 (2)	C23—C22—N4—Cu1	−173.2 (2)
C21—C22—C23—C24	−0.6 (3)	C21—C22—N4—Cu1	7.3 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O1^i	0.93	2.37	3.145 (3)	141
C23—H23···O2	0.93	2.17	2.781 (3)	122

Symmetry code: (i) −x, −y, −z.