Crystal structure of di-μ-chlorido-bis­[chlorido­bis­(1,2-dimethyl-5-nitro-1H-imidazole-κN3)copper(II)] acetonitrile disolvate

Quinlivan, P.J.; Upmacis, R.K.

doi:10.1107/S2056989016015413

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Volume 72| Part 11| November 2016| Pages 1633-1636

https://doi.org/10.1107/S2056989016015413

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Crystal structure of di-μ-chlorido-bis[chloridobis(1,2-dimethyl-5-nitro-1H-imidazole-κN³)copper(II)] acetonitrile disolvate

Patrick J. Quinlivan ^a and Rita K. Upmacis ^b ^*

^aDepartment of Chemistry, Columbia University, New York, NY 10027, USA, and ^bThe Haskins Laboratories, Department of Chemistry and Physical Sciences, Pace University, New York, NY 10038, USA
^*Correspondence e-mail: rupmacis@pace.edu

Edited by A. J. Lough, University of Toronto, Canada (Received 21 July 2016; accepted 1 October 2016; online 25 October 2016)

1,2-Dimethyl-5-nitroimidazole (dimetridazole, dimet) is a compound that belongs to a class of nitroimidazole drugs that are effective at inhibiting the activity of certain parasites and bacteria. However, there are few reports that describe structures of compounds that feature metals complexed by dimet. Therefore, we report here that dimet reacts with CuCl₂·H₂O to yield a chloride-bridged copper(II) dimer, [Cu₂Cl₄(C₅H₇N₃O₂)₄] or [Cu(μ-Cl)Cl(dimet)₂]₂. In this molecule, the Cu^II ions are coordinated in an approximately trigonal–bipyramidal manner, and the molecule lies across an inversion center. The dihedral angle between the imidazole rings in the asymmetric unit is 4.28 (7)°. Compared to metronidazole, dimetridazole lacks the hydroxyethyl group, and thus cannot form intermolecular O⋯H hydrogen-bonding interactions. Instead, [Cu(μ-Cl)Cl(dimet)₂]₂ exhibits weak intermolecular interactions between the hydrogen atoms of C—H groups and (i) oxygen in the nitro groups, and (ii) the terminal and bridging chloride ligands. The unit cell contains four disordered acetonitrile molecules. These were modeled as providing a diffuse contribution to the overall scattering by SQUEEZE [Spek (2015 ). Acta Cryst. C71, 9–18], which identified two voids, each with a volume of 163 Å³ and a count of 46 electrons, indicative of a total of four acetonitrile molecules. These acetonitrile molecules are included in the chemical formula to give the expected calculated density and F(000).

Keywords: crystal structure; copper(II); chloride-bridged dimer; dimetridazole; dimet.

CCDC reference: 1507712

1. Chemical context

1,2-Dimethyl-5-nitroimidazole, also known as dimetridazole (dimet), is structurally related to metronidazole [2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethanol, MET]. Thus, both compounds contain a 2-methyl-5-nitroimidazole core and are only differentiated according to whether one of the nitrogen atoms possesses a methyl substituent (as in dimet) or a hydroxyethyl substituent (as in MET), as illustrated in Fig. 1. Both MET and dimet are used to treat microbial infections, but dimet has specifically been used in animals for the treatment of, for instance, bovine trichomoniasis (McLoughlin, 1968 ), giardiasis in birds (Panigrahy et al., 1978 ) and swine dysentery (Messier et al., 1990 ). In order to control outbreaks of infection, a previous common practice was to incorporate dimet as a feed additive given, for example, to poultry and pigs (Buizer & Severijnen, 1975 ). However, concerns about the mutagenic properties displayed by this class of drug (Voogd et al., 1974 ), and the fact that trace amounts can be detected in certain animal products intended for human consumption (Arias et al., 2016 ), have led to a discontinuation of this practice (EC bans use of dimetridazole in food animals, 1995 ). Reports of structures of metal compounds involving the coordination by dimetridazole are scarce. Herein, we describe the structure of the copper compound [Cu(μ-Cl)Cl(dimet)₂]₂, which is obtained by the reaction of dimet with CuCl₂·H₂O (see Scheme).

Figure 1
A comparison of the structures of (a) metronidazole (MET) and (b) dimetridazole (dimet).

2. Structural commentary

Crystals of composition [Cu(μ-Cl)Cl(dimet)₂]₂ were obtained by addition of dimet to CuCl₂·2H₂O in chloroform, followed by recrystallization of the blue precipitate from acetonitrile. The molecular structure, as illustrated in Fig. 2, shows a centrosymmetric chlorido-bridged dimer. The coordination geometry around each copper atom is a slightly distorted trigonal–bipyramidal with two axial dimet ligands, and three chlorine ligands in the equatorial plane, two of which bridge to the adjacent copper. This structure is analogous to a previously reported copper(II) dimer containing MET, instead of dimet, [Cu(MET)₂(μ–Cl)Cl]₂ (Barba-Behrens et al., 1991 ), and a comparison of the two structures is shown in Fig. 3. Other recent examples of metal compounds containing MET include: Cu(MET)₂Cl₂, [Ag(MET)₂](BF₄), and [H(MET)][AuCl₄] (Palmer et al., 2015 ; Palmer & Upmacis, 2015 ; Quinlivan et al., 2015 ).

Figure 2
The molecular structure of [Cu(μ-Cl)Cl(dimet)₂]₂, with displacement ellipsoids depicted at the 30% probability level. H atoms associated with methyl groups are not shown [symmetry code ('): −x, −y + 1, −z + 1].

Figure 3
A comparison of the structures of the dinuclear Cu complexes which are derived from (a) metronidazole (MET) and (b) dimetridazole (dimet).

Examination of the structure of the [Cu(μ-Cl)Cl(dimet)₂]₂ complex demonstrates that, interestingly, the chlorine atoms bridge in an asymmetric manner, with Cu—Cl_bridge bond lengths of 2.3811 (3) and 2.6024 (3) Å, both of which are longer than the terminal Cu—Cl bond length of 2.2822 (3) Å. Of note, these features are also observed for the MET analog, [Cu(MET)₂(μ–Cl)Cl]₂, which possesses bridging Cu—Cl distances of 2.418 (1) and 2.619 (1) Å, and a terminal bond length of 2.297 (2) Å (Barba-Behrens et al., 1991). Furthermore, the Cu—N bond lengths [2.0009 (10) and 1.9914 (9) Å] are also similar to the Cu—N bond lengths reported for the MET analog [2.002 (4) and 1.993 (4) Å]. In terms of the bond angles, the N—Cu—Cl_term and N—Cu—Cl_bridge angles are all close to 90° [ranging from 88.95 (3)° for N13—Cu—Cl1 to 91.85 (3)° for N23—Cu—Cl2], with the exception of N23—Cu—Cl2_bridge which is 85.42 (3) Å.

3. Supramolecular features

The crystal structure displays a number of weak intermolecular interactions between hydrogen atoms of CH groups and the more electronegative atoms on adjacent molecules, such as the oxygen atoms in the nitro groups of the dimet ligand and also the terminal and bridging chlorine atoms (see Table 1 and Fig. 4). In this regard, one of the oxygen atoms of the nitro group participates in intermolecular hydrogen-bonding interactions with CH₃ and CH groups of an adjacent molecule. For reference, intermolecular and intramolecular C—H⋯O hydrogen bonds involving an O atom from a nitro group (or other O-containing groups) have been reported (Desiraju, 1991 ; Sharma & Desiraju, 1994 ; Forlani, 2009 ). As an illustration, intermolecular C—H⋯O interactions (involving C—H motifs from an NMe₂ substituent and the O atoms of a nitro group) are reported at 2.71 (3) Å, with C⋯O distances of 3.658 (4) and 3.725 (4) Å (Sharma & Desiraju, 1994). The results of our structure analysis are also comparable to the average values that have been reported for hydrogen-bonding interactions of (N,C)Csp²—H (2.48 and 3.47 Å) and Csp³—CH₃ (2.63 and 3.61 Å) groups with a water O atom (Steiner, 2002 ). For comparison, intramolecular N—H⋯O interactions to an O atom of a nitro substituent form shorter contacts, e.g. 1.927 (15) Å for N-(2-nitrophenyl)benzamide (Saeed & Simpson, 2009 ) and 2.11 Å for 2-iodo-N-(2-nitrophenyl)benzamide (Wardell et al., 2005 ), which is in accord with the reports that C—H⋯O bonds are weaker than N—H⋯O bonds (Desiraju, 1991).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C25—H25C⋯O22ⁱ	0.98	2.39	3.2804 (17)	150
C15—H15B⋯Cl2ⁱ	0.98	2.73	3.6737 (13)	163
C12—H12A⋯O22ⁱⁱ	0.95	2.51	3.4029 (16)	156
C22—H22A⋯Cl2ⁱⁱ	0.95	2.75	3.6828 (12)	167
C24—H24C⋯Cl1ⁱⁱⁱ	0.98	2.84	3.7555 (13)	156
Symmetry codes: (i) x, y+1, z; (ii) -x+1, -y, -z+1; (iii) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Figure 4
Weak intermolecular hydrogen-bonding interactions (shown as dashed lines) for [Cu(μ-Cl)Cl(dimet)₂]₂.

The bridging chlorine atoms also form weak intermolecular interactions with CH₃ and CH groups of an adjacent molecule. In addition, the terminal chlorine atom participates in a hydrogen-bonding interaction with a CH₃ group of an adjacent molecule.

While C—H⋯O interactions are widely accepted (Desiraju, 1991), C—H⋯Cl interactions are considered more controversial, but a survey of the literature reveals that they also represent a common phenomenon (Aakeröy et al., 1999 ). For example, hydrogen-bonding interactions of sp² (N,C)C—H with Cl⁻ are reported at 2.64 Å (Kovacs & Varga, 2006 ). However, when Cl is bonded to a metal, the average C—H⋯Cl—M hydrogen-bonding distance is 2.974 Å (Thallapally & Nangia, 2001 ).

Fig. 4 illustrates some of these intermolecular interactions. An important difference between this structure and the MET analog is that the dimet compound lacks the hydroxyethyl group, which is involved in classical intermolecular hydrogen-bonding interactions for the MET derivative (Barba-Behrens et al., 1991).

4. Database survey

There is only one structurally characterized metal compound containing dimet listed in the Cambridge Database (CSD Version 5.37; Groom et al., 2016 ), namely, a mononuclear cobalt complex, [Co(dimet)₂Cl₂], in which the cobalt(II) atom is surrounded by two dimet and two chlorido ligands in a distorted tetrahedron (Rosu et al., 1997 ; Idešicová et al., 2012 ). The Co—N distances are reported to be 2.228 (2) and 2.035 (4) Å (Rosu et al., 1997).

5. Synthesis and crystallization

CuCl₂·H₂O (3 mg, 0.018 mmol) was added to a solution of dimet (6 mg, 0.043 mmol) in chloroform (0.7 mL), resulting in the precipitation of a blue solid over the course of 1 h at room temperature. The blue solid was isolated by decantation and crystals of [Cu(μ-Cl)Cl(dimet)₂]₂, suitable for X-ray diffraction, were obtained by slow evaporation from a solution in acetonitrile.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. Hydrogen atoms on carbon were placed in calculated positions (C—H = 0.95–1.00 Å) and included as riding contributions with isotropic displacement parameters U_iso(H) = 1.2U_eq(Csp²) or 1.5U_eq(Csp³). The unit cell contains four disordered acetonitrile molecules. In view of the disorder, the acetonitrile molecules were modeled as providing a diffuse contribution to the overall scattering by SQUEEZE (Spek, 2015), which identified two voids, each with a volume of 163 Å³ and a count of 46 electrons, indicative of a total of four acetonitrile molecules.

Table 2
Experimental details

Crystal data
Chemical formula	[Cu₂Cl₄(C₅H₇N₃O₂)₄]·2C₂H₃N
M_r	915.53
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	130
a, b, c (Å)	13.9545 (8), 6.7004 (4), 19.5031 (11)
β (°)	96.424 (1)
V (Å³)	1812.10 (18)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	1.54
Crystal size (mm)	0.35 × 0.17 × 0.10

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2010 )
T_min, T_max	0.637, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	28822, 5564, 5034
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.716

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.024, 0.071, 1.26
No. of reflections	5564
No. of parameters	212
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.51, −0.51
Computer programs: APEX2 and SAINT (Bruker, 2010), SHELXS97 and SHELXTL (Sheldrick, 2008 ) and SHELXL2014 (Sheldrick, 2015 ).

Supporting information

CCDC reference: 1507712

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989016015413/lh5820sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989016015413/lh5820Isup2.hkl

checkCIF report

Computing details top

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

Di-µ-chlorido-bis[chloridobis(1,2-dimethyl-5-nitro-1H-imidazole-κN³)copper(II)] acetonitrile disolvate top

Crystal data top

[Cu₂Cl₄(C₅H₇N₃O₂)₄]·2C₂H₃N	F(000) = 932
M_r = 915.53	D_x = 1.678 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 13.9545 (8) Å	Cell parameters from 9452 reflections
b = 6.7004 (4) Å	θ = 2.9–30.6°
c = 19.5031 (11) Å	µ = 1.54 mm⁻¹
β = 96.424 (1)°	T = 130 K
V = 1812.10 (18) Å³	Block, blue
Z = 2	0.35 × 0.17 × 0.10 mm

Data collection top

Bruker APEXII CCD diffractometer	5034 reflections with I > 2σ(I)
φ and ω scans	R_int = 0.033
Absorption correction: multi-scan (SADABS; Bruker, 2010)	θ_max = 30.6°, θ_min = 1.5°
T_min = 0.637, T_max = 0.746	h = −19→19
28822 measured reflections	k = −9→9
5564 independent reflections	l = −27→27

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.024	H-atom parameters constrained
wR(F²) = 0.071	w = 1/[σ²(F_o²) + (0.0371P)²] where P = (F_o² + 2F_c²)/3
S = 1.26	(Δ/σ)_max = 0.033
5564 reflections	Δρ_max = 0.51 e Å⁻³
212 parameters	Δρ_min = −0.51 e Å⁻³

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cu	0.41957 (2)	0.46806 (2)	0.42320 (2)	0.01249 (5)
Cl1	0.32308 (2)	0.45734 (5)	0.32075 (2)	0.02105 (7)
Cl2	0.46436 (2)	0.25939 (4)	0.52033 (2)	0.01295 (6)
O11	0.10021 (7)	0.39434 (18)	0.58607 (6)	0.0303 (2)
O12	0.02709 (7)	0.66914 (16)	0.55203 (5)	0.0280 (2)
O21	0.81805 (7)	0.13329 (16)	0.33794 (5)	0.0263 (2)
O22	0.72749 (7)	−0.08394 (15)	0.38274 (6)	0.0276 (2)
N11	0.09544 (8)	0.55179 (17)	0.55458 (6)	0.0209 (2)
N12	0.18478 (7)	0.77681 (16)	0.48250 (5)	0.01611 (19)
N13	0.30915 (7)	0.58276 (15)	0.46736 (5)	0.01353 (18)
N21	0.74156 (7)	0.07990 (16)	0.35776 (5)	0.0175 (2)
N22	0.65940 (7)	0.39673 (15)	0.31873 (5)	0.01363 (18)
N23	0.53211 (7)	0.37776 (14)	0.37688 (5)	0.01264 (18)
C11	0.17488 (8)	0.59978 (19)	0.51720 (6)	0.0164 (2)
C12	0.25207 (9)	0.48130 (18)	0.50794 (6)	0.0152 (2)
H12A	0.2639	0.3513	0.5264	0.018*
C13	0.26757 (8)	0.76046 (17)	0.45264 (6)	0.0146 (2)
C14	0.12067 (10)	0.9527 (2)	0.47787 (8)	0.0247 (3)
H14A	0.1480	1.0572	0.4508	0.037*
H14B	0.1145	1.0030	0.5244	0.037*
H14C	0.0569	0.9147	0.4554	0.037*
C15	0.30624 (9)	0.92050 (19)	0.41131 (7)	0.0189 (2)
H15A	0.3555	0.8650	0.3847	0.028*
H15B	0.3350	1.0252	0.4422	0.028*
H15C	0.2538	0.9774	0.3797	0.028*
C21	0.66334 (8)	0.21847 (17)	0.35462 (6)	0.0138 (2)
C22	0.58485 (8)	0.20765 (17)	0.39040 (6)	0.0135 (2)
H22A	0.5696	0.1011	0.4194	0.016*
C23	0.57767 (8)	0.48769 (17)	0.33275 (6)	0.0131 (2)
C24	0.72860 (10)	0.4744 (2)	0.27397 (7)	0.0218 (3)
H24A	0.7509	0.3653	0.2463	0.033*
H24B	0.7838	0.5330	0.3024	0.033*
H24C	0.6973	0.5768	0.2433	0.033*
C25	0.54213 (9)	0.68022 (18)	0.30190 (6)	0.0181 (2)
H25A	0.4740	0.6973	0.3085	0.027*
H25B	0.5491	0.6802	0.2525	0.027*
H25C	0.5798	0.7902	0.3244	0.027*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cu	0.01138 (8)	0.01446 (8)	0.01188 (8)	0.00362 (5)	0.00239 (5)	−0.00060 (5)
Cl1	0.01728 (14)	0.02815 (16)	0.01670 (14)	0.00367 (11)	−0.00253 (11)	−0.00714 (11)
Cl2	0.01421 (12)	0.01058 (12)	0.01442 (12)	0.00041 (9)	0.00312 (9)	0.00093 (9)
O11	0.0229 (5)	0.0378 (6)	0.0318 (6)	0.0017 (4)	0.0102 (4)	0.0092 (5)
O12	0.0167 (4)	0.0344 (6)	0.0343 (6)	0.0063 (4)	0.0090 (4)	−0.0021 (4)
O21	0.0165 (4)	0.0332 (5)	0.0304 (5)	0.0058 (4)	0.0078 (4)	0.0035 (4)
O22	0.0259 (5)	0.0198 (4)	0.0379 (6)	0.0084 (4)	0.0066 (4)	0.0071 (4)
N11	0.0131 (5)	0.0292 (6)	0.0208 (5)	0.0021 (4)	0.0034 (4)	−0.0032 (4)
N12	0.0126 (4)	0.0188 (5)	0.0171 (5)	0.0049 (4)	0.0020 (4)	−0.0022 (4)
N13	0.0116 (4)	0.0151 (4)	0.0140 (4)	0.0015 (3)	0.0020 (3)	−0.0017 (3)
N21	0.0157 (5)	0.0211 (5)	0.0157 (5)	0.0038 (4)	0.0018 (4)	−0.0016 (4)
N22	0.0139 (4)	0.0151 (4)	0.0122 (4)	0.0009 (4)	0.0029 (3)	0.0007 (3)
N23	0.0135 (4)	0.0125 (4)	0.0122 (4)	0.0023 (3)	0.0026 (3)	0.0003 (3)
C11	0.0131 (5)	0.0211 (6)	0.0155 (5)	0.0017 (4)	0.0035 (4)	−0.0016 (4)
C12	0.0132 (5)	0.0173 (5)	0.0153 (5)	0.0001 (4)	0.0022 (4)	−0.0009 (4)
C13	0.0116 (5)	0.0171 (5)	0.0148 (5)	0.0015 (4)	0.0001 (4)	−0.0034 (4)
C14	0.0214 (6)	0.0248 (7)	0.0287 (7)	0.0140 (5)	0.0061 (5)	0.0000 (5)
C15	0.0190 (6)	0.0162 (5)	0.0217 (6)	0.0024 (4)	0.0030 (5)	0.0019 (4)
C21	0.0139 (5)	0.0143 (5)	0.0135 (5)	0.0031 (4)	0.0020 (4)	−0.0008 (4)
C22	0.0154 (5)	0.0122 (5)	0.0130 (5)	0.0023 (4)	0.0025 (4)	0.0005 (4)
C23	0.0142 (5)	0.0133 (5)	0.0118 (5)	0.0007 (4)	0.0015 (4)	−0.0009 (4)
C24	0.0190 (6)	0.0278 (7)	0.0202 (6)	0.0008 (5)	0.0087 (5)	0.0068 (5)
C25	0.0207 (6)	0.0158 (5)	0.0186 (6)	0.0031 (4)	0.0049 (4)	0.0047 (4)

Geometric parameters (Å, º) top

Cu—N23	1.9914 (9)	N22—C24	1.4678 (16)
Cu—N13	2.0009 (10)	N23—C23	1.3455 (15)
Cu—Cl1	2.2822 (3)	N23—C22	1.3663 (14)
Cu—Cl2	2.3811 (3)	C11—C12	1.3662 (16)
Cu—Cl2ⁱ	2.6024 (3)	C12—H12A	0.9500
Cl2—Cuⁱ	2.6024 (3)	C13—C15	1.4792 (17)
O11—N11	1.2188 (16)	C14—H14A	0.9800
O12—N11	1.2329 (14)	C14—H14B	0.9800
O12—N11ⁱⁱ	2.9399 (15)	C14—H14C	0.9800
O21—N21	1.2285 (14)	C15—H15A	0.9800
O22—N21	1.2258 (15)	C15—H15B	0.9800
N11—C11	1.4299 (16)	C15—H15C	0.9800
N11—O12ⁱⁱ	2.9399 (15)	C21—C22	1.3649 (16)
N12—C13	1.3552 (15)	C22—H22A	0.9500
N12—C11	1.3802 (16)	C23—C25	1.4850 (16)
N12—C14	1.4764 (15)	C24—H24A	0.9800
N13—C13	1.3414 (15)	C24—H24B	0.9800
N13—C12	1.3653 (15)	C24—H24C	0.9800
N21—C21	1.4291 (15)	C25—H25A	0.9800
N22—C23	1.3478 (15)	C25—H25B	0.9800
N22—C21	1.3823 (15)	C25—H25C	0.9800

N23—Cu—N13	175.06 (4)	N13—C12—H12A	126.1
N23—Cu—Cl1	90.65 (3)	N13—C13—N12	110.42 (11)
N13—Cu—Cl1	88.95 (3)	N13—C13—C15	125.78 (11)
N23—Cu—Cl2	91.85 (3)	N12—C13—C15	123.78 (11)
N13—Cu—Cl2	91.68 (3)	N12—C14—H14A	109.5
Cl1—Cu—Cl2	139.002 (12)	N12—C14—H14B	109.5
N23—Cu—Cl2ⁱ	85.42 (3)	H14A—C14—H14B	109.5
N13—Cu—Cl2ⁱ	91.21 (3)	N12—C14—H14C	109.5
Cl1—Cu—Cl2ⁱ	132.139 (12)	H14A—C14—H14C	109.5
Cl2—Cu—Cl2ⁱ	88.842 (10)	H14B—C14—H14C	109.5
Cu—Cl2—Cuⁱ	91.158 (10)	C13—C15—H15A	109.5
N11—O12—N11ⁱⁱ	95.37 (8)	C13—C15—H15B	109.5
O11—N11—O12	124.80 (11)	H15A—C15—H15B	109.5
O11—N11—C11	116.73 (10)	C13—C15—H15C	109.5
O12—N11—C11	118.46 (11)	H15A—C15—H15C	109.5
O11—N11—O12ⁱⁱ	85.14 (8)	H15B—C15—H15C	109.5
O12—N11—O12ⁱⁱ	84.63 (8)	C22—C21—N22	108.42 (10)
C11—N11—O12ⁱⁱ	100.10 (7)	C22—C21—N21	126.61 (11)
C13—N12—C11	106.15 (10)	N22—C21—N21	124.75 (10)
C13—N12—C14	125.32 (11)	C21—C22—N23	107.62 (10)
C11—N12—C14	128.53 (10)	C21—C22—H22A	126.2
C13—N13—C12	107.43 (10)	N23—C22—H22A	126.2
C13—N13—Cu	125.75 (8)	N23—C23—N22	110.69 (10)
C12—N13—Cu	125.84 (8)	N23—C23—C25	125.06 (10)
O21—N21—O22	124.71 (11)	N22—C23—C25	124.23 (11)
O21—N21—C21	118.93 (11)	N22—C24—H24A	109.5
O22—N21—C21	116.32 (10)	N22—C24—H24B	109.5
C23—N22—C21	105.94 (9)	H24A—C24—H24B	109.5
C23—N22—C24	126.03 (10)	N22—C24—H24C	109.5
C21—N22—C24	128.03 (10)	H24A—C24—H24C	109.5
C23—N23—C22	107.29 (9)	H24B—C24—H24C	109.5
C23—N23—Cu	125.24 (8)	C23—C25—H25A	109.5
C22—N23—Cu	126.94 (8)	C23—C25—H25B	109.5
C12—C11—N12	108.11 (10)	H25A—C25—H25B	109.5
C12—C11—N11	127.19 (12)	C23—C25—H25C	109.5
N12—C11—N11	124.69 (10)	H25A—C25—H25C	109.5
C11—C12—N13	107.88 (11)	H25B—C25—H25C	109.5
C11—C12—H12A	126.1

N11ⁱⁱ—O12—N11—O11	−80.27 (13)	C11—N12—C13—C15	−178.76 (11)
N11ⁱⁱ—O12—N11—C11	98.59 (11)	C14—N12—C13—C15	0.78 (19)
N11ⁱⁱ—O12—N11—O12ⁱⁱ	0.0	C23—N22—C21—C22	−1.06 (13)
C13—N12—C11—C12	0.40 (13)	C24—N22—C21—C22	179.19 (11)
C14—N12—C11—C12	−179.12 (12)	C23—N22—C21—N21	−175.98 (11)
C13—N12—C11—N11	−178.29 (11)	C24—N22—C21—N21	4.28 (19)
C14—N12—C11—N11	2.2 (2)	O21—N21—C21—C22	−160.72 (12)
O11—N11—C11—C12	6.01 (19)	O22—N21—C21—C22	16.86 (18)
O12—N11—C11—C12	−172.94 (12)	O21—N21—C21—N22	13.27 (17)
O12ⁱⁱ—N11—C11—C12	−83.60 (13)	O22—N21—C21—N22	−169.15 (11)
O11—N11—C11—N12	−175.55 (12)	N22—C21—C22—N23	0.11 (13)
O12—N11—C11—N12	5.50 (18)	N21—C21—C22—N23	174.90 (11)
O12ⁱⁱ—N11—C11—N12	94.84 (12)	C23—N23—C22—C21	0.90 (13)
N12—C11—C12—N13	−0.50 (13)	Cu—N23—C22—C21	−171.07 (8)
N11—C11—C12—N13	178.15 (11)	C22—N23—C23—N22	−1.62 (13)
C13—N13—C12—C11	0.40 (13)	Cu—N23—C23—N22	170.52 (7)
Cu—N13—C12—C11	−168.81 (8)	C22—N23—C23—C25	176.82 (11)
C12—N13—C13—N12	−0.15 (13)	Cu—N23—C23—C25	−11.04 (16)
Cu—N13—C13—N12	169.07 (8)	C21—N22—C23—N23	1.66 (13)
C12—N13—C13—C15	178.42 (11)	C24—N22—C23—N23	−178.59 (11)
Cu—N13—C13—C15	−12.36 (17)	C21—N22—C23—C25	−176.79 (11)
C11—N12—C13—N13	−0.16 (13)	C24—N22—C23—C25	2.96 (19)
C14—N12—C13—N13	179.38 (11)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C25—H25C···O22ⁱⁱⁱ	0.98	2.39	3.2804 (17)	150
C15—H15B···Cl2ⁱⁱⁱ	0.98	2.73	3.6737 (13)	163
C12—H12A···O22^iv	0.95	2.51	3.4029 (16)	156
C22—H22A···Cl2^iv	0.95	2.75	3.6828 (12)	167
C24—H24C···Cl1^v	0.98	2.84	3.7555 (13)	156

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

Acknowledgements

RKU would like to thank Pace University for research support. Gerard Parkin (Columbia University) is thanked for helpful discussions.

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