Crystal structure of catena-poly[[(μ-6-{[bis­(pyridin-2-ylmeth­yl)amino]­meth­yl}pyridine-2-carboxyl­ato)copper(II)] perchlorate aceto­nitrile monosolvate]

Cioncoloni, G.; Wilson, C.; Roger, I.; Symes, M.D.

doi:10.1107/S2056989019006285

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 75| Part 6| June 2019| Pages 789-793

https://doi.org/10.1107/S2056989019006285

Open

access

Crystal structure of catena-poly[[(μ-6-{[bis(pyridin-2-ylmethyl)amino]methyl}pyridine-2-carboxylato)copper(II)] perchlorate acetonitrile monosolvate]

Giacomo Cioncoloni,^a Claire Wilson,^a Isolda Roger ^a and Mark D. Symes ^a ^*

^aWestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow, G12 8QQ, United Kingdom
^*Correspondence e-mail: Mark.Symes@glasgow.ac.uk

Edited by M. Zeller, Purdue University, USA (Received 8 April 2019; accepted 3 May 2019; online 14 May 2019)

The crystal structure of the title compound, {[Cu(C₁₉H₁₇N₄O₂)]ClO₄·C₂H₃N}_n, is reported and compared to similar structures in the literature. The compound crystallizes in the monoclinic space group P2₁. The unit cell contains one complex molecule in addition to perchlorate as the counter-ion and solvent (acetonitrile). The crystal packing evinces extended chains whereby the carboxylate moiety on the 6-carboxylato-2-(pyridylmethyl)bis(pyridin-2-ylmethyl)amine ligand bridges between two different copper centers in adjacent molecules. This packing arrangement for the title compound appears to be unique when compared to allied structures in the literature. The perchlorate anion showed signs of disorder and its oxygen atoms were modelled over two sets of partially occupied sites, the occupancy of which was competitively refined to 0.564 (12)/0.436 (12). The crystal studied was refined as a two-component inversion twin.

Keywords: crystal structure; coordination compound; nitrogen donor ligands.

CCDC reference: 1913833

1. Chemical context

A key part of the natural nitrogen cycle is the reduction of nitrite to nitric oxide by denitrifying bacteria. The copper-containing nitrite reductases are one of the classes of enzymes that undertake this reduction reaction (Maia & Moura, 2014 ). Previous studies have shown that the active site of these enzymes consists of a Cu center coordinated by three N-donor ligands, with the coordination environment being completed by either water or nitrite, depending on the progress of the catalytic cycle (Godden et al., 1991 ). This realization has spawned a large number of studies examining the use of copper centers held by multi-dentate N-donor ligands as mimics of the active sites of the copper-containing nitrite reductases (Wasser et al., 2002 ; Timmons & Symes, 2015 ). In this context, there has been interest from ourselves (Cioncoloni et al., 2018 ) and others (Komeda et al., 1995 ; Nagao et al., 1996 ; Orain et al., 2013 ) in employing copper complexes based on the tetradentate ligand tris(2-methylpyridyl)amine (TMPA) as electrocatalysts for the reduction of nitrite to nitric oxide, mimicking some of the activity of the copper nitrite reductases.

In the course of our previous study (Cioncoloni et al., 2018), we reported two TMPA-based copper complexes that were electrocatalysts for nitrite reduction to NO: [Cu(OH₂)(TMPA-CO₂)]⁺ [where one of the TMPA pyridines bears a carboxylate unit that can coordinate to the Cu center and in which the ligand can be named as 6-carboxylato-2-(pyridylmethyl)bis(pyridin-2-ylmethyl)amine] and the methylated analogue of this complex, [Cu(OH₂)(TMPA-CO₂Me)]²⁺. The acid-bearing complex was found to be the more active of the two electrocatalysts. However, although we were able to report the crystal structure of the methyl ester complex after recrystallization from acetonitrile solution, and also the structure of the acid-bearing complex when coordinated to nitrite ([Cu(NO₂)(TMPA-CO₂)]), we were not able to obtain similar data for [Cu(TMPA-CO₂)]⁺ when not bound to nitrite. This was a source of considerable frustration to us at the time, as the structure of the acid-bearing complex prior to nitrite addition constituted a `missing link' in our characterization of this suite of compounds.

Herein, we report that we have now indeed been able to obtain crystals of the acid-bearing complex in the absence of nitrite ([Cu(TMPA-CO₂)]⁺) by vapour diffusion of diethyl ether into an acetonitrile solution of [Cu(OH₂)(TMPA-CO₂)]⁺. In this manuscript, we report this crystal structure and compare it to the structures of [Cu(NO₂)(TMPA-CO₂)], [Cu(NCCH₃)(TMPA-CO₂Me)]²⁺, and other allied structures from the literature.

2. Structural commentary

The Cu ion in [Cu(TMPA-CO₂)]⁺ is in a hexa-coordinated environment where the two oxygen atoms of the carboxylate group are coordinated by two symmetry-related Cu centers, thus forming extended chains (see Figs. 1 and 2). This suggests that the carboxylate group is deprotonated. The presence of a perchlorate anion in the unit cell, coupled with the hexa-coordinate geometry, suggests that the copper is in the +2 oxidation state. The geometry around the Cu center is considerably distorted from octahedral, with all the vertices showing significant deviations from their positions in the platonic scenario as evinced by the following bond angles: N1—Cu1—O2 = 150.1 (2)°, O1ⁱ—Cu1—N2 = 161.0 (2)° and N4—Cu1—N3 = 158.7 (2)° [symmetry code: (i) −x + 1, y − $[1\over2]$ , −z].

Figure 1
View showing the asymmetric unit and atom labelling. Displacement ellipsoids are drawn at 50% probability level. The minor disorder component of the perchlorate ion and H atoms are omitted for clarity. Colour scheme: C = grey, Cl = green, Cu = purple, N = blue, O = red.

Figure 2
View showing a chain running parallel to the b axis generated by the 2₁ screw axis. Colour scheme: C = grey, Cl = green, Cu = purple, N = blue, O = red.

In terms of bond lengths, the Cu—N1 bond length is long [2.296 (6) Å], consistent with N1 being a tertiary amine, rather than a pyridine nitrogen. The Cu—N_pyridyl lengths are all significantly shorter than this Cu—N_alkyl interaction, covering the range 2.000 (5)–2.076 (6) Å. There is an intriguing disparity in the lengths of the two Cu–oxygen interactions, with Cu—O1ⁱ being very short [1.965 (5) Å] in comparison to the Cu—O2 bond length [2.387 (5) Å]. Coupled with the long Cu—N1 bond, this implies that the N1—Cu1—O2 axis is displaying the Jahn–Teller elongation characteristic of many octahedral Cu^II complexes. Indeed, this Jahn–Teller effect manifests along the same axis as we observed previously for the related complex [Cu(NO₂)(TMPA-CO₂)] (Cioncoloni et al., 2018). Table 1 summarizes some selected geometric parameters for [Cu(TMPA-CO₂)]⁺.

Table 1
Selected geometric parameters (Å, °)

Cu1—O1ⁱ	1.965 (5)	Cu1—N2	2.076 (6)
Cu1—O2	2.387 (5)	Cu1—N3	2.026 (6)
Cu1—N1	2.296 (6)	Cu1—N4	2.000 (5)

O1ⁱ—Cu1—O2	88.33 (19)	N3—Cu1—O2	99.4 (2)
O1ⁱ—Cu1—N1	121.6 (2)	N3—Cu1—N1	79.3 (2)
O1ⁱ—Cu1—N2	161.0 (2)	N3—Cu1—N2	89.5 (2)
O1ⁱ—Cu1—N3	94.9 (2)	N4—Cu1—O2	101.0 (2)
O1ⁱ—Cu1—N4	91.7 (2)	N4—Cu1—N1	79.9 (2)
N1—Cu1—O2	150.1 (2)	N4—Cu1—N2	90.8 (2)
N2—Cu1—O2	72.76 (19)	N4—Cu1—N3	158.7 (2)
N2—Cu1—N1	77.3 (2)
Symmetry code: (i) $[-x+1, y-{\script{1\over 2}}, -z]$ .

3. Supramolecular features

The crystal structure shows that the carboxylate moiety on the modified TMPA ligand bridges between two different copper centers, with the result that extended chains of complexes form (see above for a discussion of these coordination bonds). Between the chains, there is some evidence for weak hydrogen bond-type interactions between the perchlorate oxygen atoms and the protons on the –CH₂– units in the TMPA ligands of complexes in neighbouring chains, and/or between the perchlorate anions and protons on the pyridine rings of some of the TMPA ligands (see Table 2). In this sense, the perchlorate ions can be considered as bridging between adjacent chains of complexes. Meanwhile, the acetonitrile molecule forms a hydrogen bond between its nitrogen and a C—H proton on one of the aromatic rings of the ligand, whilst simultaneously engaging in a hydrogen-bond-like interaction involving one of its methyl protons and the oxygen on a nearby perchlorate anion. However, there would appear to be no direct supramolecular interactions between adjacent chains.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2A⋯O5A	0.97	2.21	3.167 (19)	169
C3—H3A⋯O3ⁱⁱ	0.97	2.54	3.484 (16)	165
C3—H3B⋯O2ⁱ	0.97	2.44	3.149 (10)	130
C22—H22⋯N1Sⁱⁱ	0.93	2.53	3.393 (14)	154
C32—H32⋯O5ⁱⁱ	0.93	2.49	3.386 (17)	163
C32—H32⋯O3Aⁱⁱ	0.93	2.40	3.31 (2)	165
C34—H34⋯O3Aⁱⁱⁱ	0.93	2.41	3.23 (2)	148
C42—H42⋯O6^iv	0.93	2.61	3.43 (2)	147
C42—H42⋯O6A^iv	0.93	2.64	3.21 (2)	121
C3S—H3SC⋯O4^v	0.96	2.54	3.16 (2)	123
C3S—H3SC⋯O6	0.96	2.46	3.11 (2)	125
Symmetry codes: (i) $[-x+1, y-{\script{1\over 2}}, -z]$ ; (ii) $[-x+1, y-{\script{1\over 2}}, -z+1]$ ; (iii) x-1, y, z-1; (iv) $[-x+2, y-{\script{1\over 2}}, -z+1]$ ; (v) $[-x+2, y+{\script{1\over 2}}, -z+1]$ .

4. Comparison with related structures

Kojima and co-workers have previously reported complexes of this same (TMPA-CO₂)⁻ ligand with Ru^III and Cr^III (Kojima et al., 2010 ; Kotani et al., 2015 ). These complexes all display a distorted octahedral geometry in which the metals coordinate to the three pyridyl nitrogen atoms and the alkyl nitrogen in the TMPA backbone as well as to one of the carboxylate oxygen atoms. However, in these examples the sixth coordination site is occupied by either chloride or BF₄⁻ (which binds through an F atom) and so the complexes do not form extended chains in the solid state (the carboxylate does not bridge between adjacent metal centers). Likewise, Lonnon et al. (2003 ) have described a Co^III complex of this ligand in which the carboxylate coordinates to the metal center and where the sixth ligand is chloride. Again, the presence of this monodentate ligand means that these molecules exist as discrete complexes in the solid state. The metal–O_carboxylate distances in the Cr^III and Co^III complexes reported by Kojima and co-workers and Lonnon et al. are not dissimilar to the Cu1—O1 distance we observe [Cr—O = 1.959 Å and Co—O = 1.924 Å compared to Cu1—O1 = 1.965 (5) Å in our case].

In the aforementioned Ru^III, Cr^III and Co^III examples, the metal–chloride and metal–BF₄⁻ interactions tend to be long, and the pyridine bearing the carboxylate unit is found to be trans to this chloride or BF₄⁻ ligand (and so it tends to display the shortest metal–N_pyridyl length in the complex). In our case, however, it is precisely this Cu—N_pyridyl bond between the Cu atom and the pyridine that bears the carboxylate substituent which is the longest of the three Cu—N_pyridyl bonds. A similar elongation of the Cu—N_pyridyl bond for pyridines bearing substituents adjacent to the N-donor has been observed previously by Tanaka and co-workers for the complex [CuCl(TMPA-Me)]⁺, where the TMPA pyridine bearing the methyl group exhibited a significantly longer Cu—N interaction than that found for the unsubstituted pyridines (2.337 vs. 1.99 Å; Nagao et al., 1996). We also noted an analogous elongation in our previously reported crystal structure of the complex [Cu(NCCH₃)(TMPA-CO₂Me)]²⁺ (Cioncoloni et al., 2018). One possible cause of this bond-elongation effect could be steric crowding brought about by the close proximity of the various substituents to the N-donor atom (Symes & Wilson, 2018 ). In support of this hypothesis, long Cu—N interactions of a similar nature also manifest in certain Cu^II–tris(2-methylpyridyl)amine complexes (where all the pyridines bear substituents next to the N-donors) reported by Reinaud and co-workers (Izzet et al., 2007 ).

Suzuki and co-workers have reported two related Cu^II complexes with carboxylate-substituted TMPA-like ligands where the carboxylate group binds to the Cu^II centre (Hayashi et al., 2002 ; Mizuno et al., 2006 ), but for both of these structures the metal is only five-coordinate. The same authors have also published the crystal structure of an allied six-coordinate Ni^II complex containing an Ni⋯O_carboxylate interaction (2.084 Å) and where the sixth ligand is water (Shiren et al., 2000 ). Again, these complexes appear to exist as discrete ions in the solid state and the formation of extended chains of complexes was not reported.

A number of structures in which Cu^II is supported by a TMPA-like ligand (which also bears a carboxylate group which coordinates to Cu), but where the linkage between the pyridine groups in the ligand is a bispidine have been described by Comba and co-workers (Comba et al., 2016 , 2018 ). In these structures, the metal center adopts a distorted octahedral geometry, with bonds to each of the three pyridines, two bonds to the amines in the bispidine backbone and a final bond to the carboxylate oxygen. Again, then, the carboxylate does not bridge between two Cu centers in neighbouring complexes and so extended chains are not observed.

5. Synthesis and crystallization

The synthesis and characterization of the complex [Cu(OH₂)(TMPA-CO₂)](ClO₄) have been reported previously (Cioncoloni et al., 2018). Crystals of [Cu(TMPA-CO₂)](ClO₄) were grown by vapor diffusion of diethyl ether into a 14 mL vial containing 2 mg of [Cu(OH₂)(TMPA-CO₂)](ClO₄) dissolved in 2 mL of acetonitrile. The 14 mL vial was sealed with a plastic cap, which was pierced by a needle, thus retarding the rate of mixing of the antisolvent into the acetonitrile solution. Crystals suitable for diffraction were obtained after 2–3 weeks.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3. The perchlorate anion showed signs of disorder and its oxygen atoms were modelled over two sets of partially occupied sites, the occupancy of which was competitively refined to 0.564 (12)/0.436 (12). Similarity distances restraints were applied to Cl—O bond lengths and O⋯O separations, as well as to the oxygen displacement parameters. Hydrogen atoms were placed in geometrically calculated positions (C—H = 0.93–0.97 Å) and refined as part of a riding model with U_iso(H) values set at 1.2U_eq of the parent carbon atoms, except the methyl hydrogen atoms of the acetonitrile which were refined as a rigid rotor with U_iso(H) set at 1.5U_eq of the methyl carbon atom. The crystal studied was refined as a two-component inversion twin.

Table 3
Experimental details

Crystal data
Chemical formula	[Cu(C₁₉H₁₇N₄O₂)]ClO₄·C₂H₃N
M_r	537.41
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	295
a, b, c (Å)	9.320 (3), 9.974 (3), 12.949 (5)
β (°)	109.710 (13)
V (Å³)	1133.1 (6)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	1.13
Crystal size (mm)	0.33 × 0.07 × 0.02

Data collection
Diffractometer	Bruker D8 VENTURE
Absorption correction	Multi-scan (SADABS; Bruker, 2016 )
T_min, T_max	0.647, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	15681, 5631, 4168
R_int	0.065
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.058, 0.147, 1.01
No. of reflections	5631
No. of parameters	346
No. of restraints	203
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.82, −0.36
Absolute structure	Refined as an inversion twin
Absolute structure parameter	0.01 (3)
Computer programs: APEX3 and, SAINT (Bruker, 2016), SHELXT2015 (Sheldrick, 2015a ), SHELXL2018 (Sheldrick, 2015b ) and OLEX2 (Dolomanov et al., 2009 ).

Supporting information

CCDC reference: 1913833

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989019006285/zl2754sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989019006285/zl2754Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989019006285/zl2754Isup3.cdx

checkCIF report

Computing details top

Data collection: APEX3 (Bruker, 2016); cell refinement: SAINT (Bruker, 2016); data reduction: APEX3 (Bruker, 2016); program(s) used to solve structure: SHELXT2015 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

catena-Poly[[(µ-6-{[bis(pyridin-2-ylmethyl)amino]methyl}pyridine-2-carboxylato)copper(II)] perchlorate acetonitrile monosolvate] top

Crystal data top

[Cu(C₁₉H₁₇N₄O₂)]ClO₄·C₂H₃N	F(000) = 550
M_r = 537.41	D_x = 1.575 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
a = 9.320 (3) Å	Cell parameters from 5520 reflections
b = 9.974 (3) Å	θ = 2.3–24.7°
c = 12.949 (5) Å	µ = 1.13 mm⁻¹
β = 109.710 (13)°	T = 295 K
V = 1133.1 (6) Å³	Lath, blue
Z = 2	0.33 × 0.07 × 0.02 mm

Data collection top

Bruker D8 VENTURE diffractometer	5631 independent reflections
Radiation source: microfocus sealed tube, INCOATEC Iµs 3.0	4168 reflections with I > 2σ(I)
Multilayer mirror optics monochromator	R_int = 0.065
Detector resolution: 7.4074 pixels mm^-1	θ_max = 28.4°, θ_min = 2.3°
φ and ω scans	h = −11→12
Absorption correction: multi-scan (SADABS; Bruker, 2016)	k = −13→13
T_min = 0.647, T_max = 0.746	l = −17→17
15681 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.058	H-atom parameters constrained
wR(F²) = 0.147	w = 1/[σ²(F_o²) + (0.0754P)²] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max = 0.001
5631 reflections	Δρ_max = 0.82 e Å⁻³
346 parameters	Δρ_min = −0.36 e Å⁻³
203 restraints	Absolute structure: Refined as an inversion twin
Primary atom site location: dual	Absolute structure parameter: 0.01 (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.

Refinement. Refined as a two-component inversion twin

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Cu1	0.51948 (8)	0.34337 (8)	0.09197 (6)	0.0371 (2)
O1	0.4445 (6)	0.7684 (4)	0.0375 (4)	0.0457 (12)
O2	0.4624 (7)	0.5529 (4)	−0.0021 (4)	0.0496 (12)
N1	0.5445 (7)	0.2152 (5)	0.2443 (5)	0.0422 (13)
N2	0.4717 (6)	0.4793 (5)	0.1974 (5)	0.0360 (12)
N3	0.3055 (7)	0.2687 (5)	0.0532 (5)	0.0417 (13)
N4	0.7432 (6)	0.3632 (6)	0.1717 (5)	0.0433 (14)
C2	0.5221 (11)	0.2979 (7)	0.3312 (7)	0.0521 (19)
H2A	0.616738	0.301036	0.392793	0.062*
H2B	0.445906	0.255813	0.356277	0.062*
C3	0.4263 (9)	0.1134 (8)	0.2015 (7)	0.0488 (19)
H3A	0.401161	0.073697	0.261660	0.059*
H3B	0.464204	0.042910	0.165958	0.059*
C4	0.7035 (9)	0.1691 (8)	0.2716 (7)	0.0542 (19)
H4A	0.707338	0.095062	0.223995	0.065*
H4B	0.740955	0.137309	0.346750	0.065*
C21	0.4725 (8)	0.4385 (7)	0.2957 (6)	0.0398 (15)
C22	0.4344 (9)	0.5259 (8)	0.3657 (7)	0.0501 (18)
H22	0.437609	0.497017	0.434733	0.060*
C23	0.3923 (10)	0.6543 (9)	0.3330 (7)	0.057 (2)
H23	0.363821	0.712700	0.378634	0.069*
C24	0.3925 (8)	0.6965 (7)	0.2317 (6)	0.0480 (17)
H24	0.364844	0.783833	0.208113	0.058*
C25	0.4344 (7)	0.6066 (6)	0.1658 (6)	0.0348 (15)
C26	0.4491 (7)	0.6439 (6)	0.0574 (6)	0.0376 (14)
C31	0.2860 (8)	0.1743 (6)	0.1209 (6)	0.0456 (16)
C32	0.1394 (9)	0.1350 (8)	0.1130 (7)	0.056 (2)
H32	0.125179	0.073406	0.162637	0.068*
C33	0.0161 (11)	0.1872 (10)	0.0321 (9)	0.073 (3)
H33	−0.082139	0.160005	0.025271	0.087*
C34	0.0397 (10)	0.2809 (9)	−0.0390 (8)	0.065 (2)
H34	−0.042082	0.316831	−0.095220	0.079*
C35	0.1858 (9)	0.3197 (7)	−0.0253 (6)	0.0526 (19)
H35	0.202007	0.383808	−0.072321	0.063*
C41	0.8035 (9)	0.2817 (7)	0.2577 (6)	0.0506 (18)
C42	0.9517 (10)	0.2992 (9)	0.3260 (7)	0.066 (2)
H42	0.991782	0.243111	0.386293	0.079*
C43	1.0397 (10)	0.3970 (10)	0.3066 (8)	0.072 (3)
H43	1.140019	0.407794	0.352611	0.087*
C44	0.9788 (10)	0.4811 (10)	0.2172 (8)	0.070 (3)
H44	1.036126	0.549964	0.202147	0.084*
C45	0.8316 (9)	0.4590 (7)	0.1523 (7)	0.0508 (18)
H45	0.790310	0.513541	0.091217	0.061*
Cl1	0.8713 (3)	0.4368 (3)	0.6178 (2)	0.0791 (8)
O3	0.7360 (14)	0.478 (2)	0.6156 (15)	0.122 (5)	0.564 (12)
O4	0.8583 (19)	0.2962 (13)	0.5808 (15)	0.105 (5)	0.564 (12)
O5	0.9871 (17)	0.4452 (18)	0.7185 (10)	0.113 (5)	0.564 (12)
O6	0.933 (2)	0.4989 (17)	0.5431 (13)	0.124 (5)	0.564 (12)
O3A	0.857 (3)	0.3871 (19)	0.7163 (13)	0.118 (6)	0.436 (12)
O4A	0.776 (2)	0.5562 (18)	0.5965 (18)	0.110 (6)	0.436 (12)
O5A	0.820 (3)	0.348 (2)	0.5358 (14)	0.119 (6)	0.436 (12)
O6A	1.0168 (17)	0.481 (2)	0.639 (2)	0.130 (7)	0.436 (12)
N1S	0.6734 (13)	0.8932 (11)	0.4305 (10)	0.103 (3)
C2S	0.7272 (12)	0.8141 (11)	0.3977 (8)	0.075 (3)
C3S	0.7983 (13)	0.7027 (12)	0.3537 (11)	0.097 (4)
H3SA	0.813619	0.731700	0.287459	0.145*
H3SB	0.732111	0.626035	0.338265	0.145*
H3SC	0.894629	0.679043	0.407121	0.145*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cu1	0.0469 (4)	0.0296 (3)	0.0357 (4)	−0.0019 (4)	0.0150 (3)	−0.0008 (4)
O1	0.069 (3)	0.028 (2)	0.044 (3)	0.009 (2)	0.024 (2)	0.008 (2)
O2	0.081 (4)	0.030 (2)	0.042 (3)	−0.001 (2)	0.026 (3)	0.000 (2)
N1	0.057 (3)	0.034 (3)	0.036 (3)	−0.002 (2)	0.016 (3)	0.005 (3)
N2	0.042 (3)	0.033 (3)	0.033 (3)	−0.005 (2)	0.012 (2)	0.001 (2)
N3	0.054 (3)	0.035 (3)	0.039 (3)	0.000 (2)	0.018 (3)	0.002 (2)
N4	0.048 (3)	0.041 (4)	0.043 (3)	−0.002 (3)	0.018 (2)	−0.002 (3)
C2	0.080 (5)	0.042 (4)	0.037 (4)	−0.003 (3)	0.024 (4)	0.006 (3)
C3	0.063 (4)	0.038 (4)	0.050 (5)	−0.006 (3)	0.026 (4)	0.004 (3)
C4	0.055 (4)	0.048 (4)	0.056 (5)	0.003 (3)	0.014 (4)	0.018 (4)
C21	0.045 (3)	0.040 (3)	0.032 (4)	−0.004 (3)	0.011 (3)	0.004 (3)
C22	0.057 (4)	0.061 (5)	0.039 (4)	−0.003 (4)	0.026 (3)	0.001 (4)
C23	0.070 (5)	0.064 (5)	0.049 (5)	0.007 (4)	0.035 (4)	−0.006 (4)
C24	0.052 (4)	0.043 (3)	0.054 (5)	0.009 (3)	0.024 (3)	0.000 (3)
C25	0.034 (3)	0.030 (3)	0.040 (4)	−0.001 (2)	0.012 (3)	−0.002 (3)
C26	0.034 (3)	0.035 (3)	0.041 (4)	0.003 (3)	0.010 (3)	0.002 (3)
C31	0.060 (4)	0.036 (3)	0.045 (4)	−0.009 (3)	0.024 (3)	−0.005 (3)
C32	0.062 (4)	0.047 (4)	0.063 (5)	−0.011 (3)	0.025 (4)	0.003 (4)
C33	0.058 (5)	0.075 (6)	0.090 (8)	−0.016 (4)	0.031 (5)	−0.010 (6)
C34	0.057 (5)	0.058 (4)	0.070 (6)	0.002 (4)	0.006 (4)	−0.007 (4)
C35	0.067 (4)	0.041 (5)	0.045 (4)	0.000 (3)	0.012 (3)	−0.002 (3)
C41	0.056 (4)	0.047 (4)	0.048 (5)	0.003 (3)	0.016 (3)	0.006 (3)
C42	0.056 (5)	0.079 (6)	0.053 (5)	0.005 (4)	0.006 (4)	0.016 (4)
C43	0.047 (4)	0.095 (7)	0.066 (6)	−0.012 (4)	0.006 (4)	0.013 (5)
C44	0.059 (5)	0.076 (6)	0.077 (7)	−0.008 (4)	0.026 (5)	0.013 (5)
C45	0.056 (4)	0.051 (4)	0.047 (4)	−0.004 (3)	0.021 (3)	0.011 (3)
Cl1	0.0638 (13)	0.102 (2)	0.0718 (17)	−0.0176 (13)	0.0237 (12)	−0.0053 (15)
O3	0.087 (9)	0.157 (12)	0.127 (11)	0.012 (9)	0.044 (8)	−0.032 (10)
O4	0.086 (9)	0.103 (10)	0.122 (12)	−0.029 (7)	0.028 (9)	−0.020 (9)
O5	0.114 (10)	0.149 (11)	0.061 (8)	0.027 (9)	0.010 (7)	−0.023 (8)
O6	0.153 (11)	0.136 (10)	0.093 (10)	−0.018 (10)	0.053 (9)	−0.003 (9)
O3A	0.148 (12)	0.125 (12)	0.084 (10)	−0.033 (10)	0.043 (9)	−0.001 (9)
O4A	0.078 (10)	0.135 (13)	0.116 (12)	0.004 (10)	0.033 (9)	0.029 (11)
O5A	0.117 (11)	0.162 (13)	0.067 (10)	−0.009 (12)	0.016 (9)	−0.031 (12)
O6A	0.090 (11)	0.115 (12)	0.167 (15)	−0.025 (10)	0.021 (11)	−0.005 (13)
N1S	0.115 (8)	0.105 (7)	0.099 (8)	−0.010 (6)	0.050 (6)	−0.033 (6)
C2S	0.077 (6)	0.084 (8)	0.061 (6)	−0.018 (5)	0.021 (5)	−0.019 (5)
C3S	0.088 (7)	0.093 (8)	0.112 (10)	−0.006 (6)	0.037 (7)	−0.034 (7)

Geometric parameters (Å, º) top

Cu1—O1ⁱ	1.965 (5)	C24—C25	1.382 (10)
Cu1—O2	2.387 (5)	C25—C26	1.502 (10)
Cu1—N1	2.296 (6)	C31—C32	1.392 (11)
Cu1—N2	2.076 (6)	C32—H32	0.9300
Cu1—N3	2.026 (6)	C32—C33	1.370 (13)
Cu1—N4	2.000 (5)	C33—H33	0.9300
O1—C26	1.265 (7)	C33—C34	1.381 (14)
O2—C26	1.224 (8)	C34—H34	0.9300
N1—C2	1.466 (9)	C34—C35	1.368 (11)
N1—C3	1.463 (9)	C35—H35	0.9300
N1—C4	1.475 (10)	C41—C42	1.377 (11)
N2—C21	1.334 (9)	C42—H42	0.9300
N2—C25	1.344 (8)	C42—C43	1.352 (12)
N3—C31	1.340 (9)	C43—H43	0.9300
N3—C35	1.330 (9)	C43—C44	1.386 (13)
N4—C41	1.340 (9)	C44—H44	0.9300
N4—C45	1.340 (9)	C44—C45	1.363 (12)
C2—H2A	0.9700	C45—H45	0.9300
C2—H2B	0.9700	Cl1—O3	1.317 (12)
C2—C21	1.499 (10)	Cl1—O4	1.473 (12)
C3—H3A	0.9700	Cl1—O5	1.386 (11)
C3—H3B	0.9700	Cl1—O6	1.422 (12)
C3—C31	1.500 (11)	Cl1—O3A	1.415 (14)
C4—H4A	0.9700	Cl1—O4A	1.456 (14)
C4—H4B	0.9700	Cl1—O5A	1.339 (14)
C4—C41	1.508 (11)	Cl1—O6A	1.362 (13)
C21—C22	1.387 (10)	N1S—C2S	1.095 (13)
C22—H22	0.9300	C2S—C3S	1.501 (16)
C22—C23	1.364 (12)	C3S—H3SA	0.9600
C23—H23	0.9300	C3S—H3SB	0.9600
C23—C24	1.379 (11)	C3S—H3SC	0.9600
C24—H24	0.9300

O1ⁱ—Cu1—O2	88.33 (19)	C23—C24—H24	120.6
O1ⁱ—Cu1—N1	121.6 (2)	C23—C24—C25	118.7 (7)
O1ⁱ—Cu1—N2	161.0 (2)	C25—C24—H24	120.6
O1ⁱ—Cu1—N3	94.9 (2)	N2—C25—C24	121.5 (7)
O1ⁱ—Cu1—N4	91.7 (2)	N2—C25—C26	115.0 (6)
N1—Cu1—O2	150.1 (2)	C24—C25—C26	123.4 (6)
N2—Cu1—O2	72.76 (19)	O1—C26—C25	115.2 (6)
N2—Cu1—N1	77.3 (2)	O2—C26—O1	127.1 (7)
N3—Cu1—O2	99.4 (2)	O2—C26—C25	117.7 (6)
N3—Cu1—N1	79.3 (2)	N3—C31—C3	117.5 (7)
N3—Cu1—N2	89.5 (2)	N3—C31—C32	119.8 (7)
N4—Cu1—O2	101.0 (2)	C32—C31—C3	122.7 (7)
N4—Cu1—N1	79.9 (2)	C31—C32—H32	120.1
N4—Cu1—N2	90.8 (2)	C33—C32—C31	119.9 (8)
N4—Cu1—N3	158.7 (2)	C33—C32—H32	120.1
C26—O1—Cu1ⁱⁱ	122.9 (5)	C32—C33—H33	120.5
C26—O2—Cu1	112.4 (4)	C32—C33—C34	119.1 (8)
C2—N1—Cu1	110.3 (4)	C34—C33—H33	120.5
C2—N1—C4	112.6 (6)	C33—C34—H34	120.7
C3—N1—Cu1	102.5 (4)	C35—C34—C33	118.7 (8)
C3—N1—C2	113.4 (6)	C35—C34—H34	120.7
C3—N1—C4	116.2 (6)	N3—C35—C34	122.2 (8)
C4—N1—Cu1	100.5 (4)	N3—C35—H35	118.9
C21—N2—Cu1	119.7 (4)	C34—C35—H35	118.9
C21—N2—C25	119.8 (6)	N4—C41—C4	116.6 (7)
C25—N2—Cu1	120.5 (5)	N4—C41—C42	120.4 (7)
C31—N3—Cu1	115.8 (5)	C42—C41—C4	123.0 (7)
C35—N3—Cu1	123.4 (5)	C41—C42—H42	119.6
C35—N3—C31	120.2 (7)	C43—C42—C41	120.8 (8)
C41—N4—Cu1	116.2 (5)	C43—C42—H42	119.6
C45—N4—Cu1	125.0 (5)	C42—C43—H43	120.4
C45—N4—C41	118.4 (6)	C42—C43—C44	119.3 (8)
N1—C2—H2A	108.8	C44—C43—H43	120.4
N1—C2—H2B	108.8	C43—C44—H44	121.3
N1—C2—C21	113.6 (6)	C45—C44—C43	117.4 (8)
H2A—C2—H2B	107.7	C45—C44—H44	121.3
C21—C2—H2A	108.8	N4—C45—C44	123.7 (7)
C21—C2—H2B	108.8	N4—C45—H45	118.1
N1—C3—H3A	109.5	C44—C45—H45	118.1
N1—C3—H3B	109.5	O3—Cl1—O4	108.4 (9)
N1—C3—C31	110.5 (6)	O3—Cl1—O5	116.0 (9)
H3A—C3—H3B	108.1	O3—Cl1—O6	116.9 (11)
C31—C3—H3A	109.5	O5—Cl1—O4	108.4 (9)
C31—C3—H3B	109.5	O5—Cl1—O6	104.4 (9)
N1—C4—H4A	109.5	O6—Cl1—O4	101.6 (9)
N1—C4—H4B	109.5	O3A—Cl1—O4A	102.7 (10)
N1—C4—C41	110.5 (6)	O5A—Cl1—O3A	111.5 (12)
H4A—C4—H4B	108.1	O5A—Cl1—O4A	111.0 (11)
C41—C4—H4A	109.5	O5A—Cl1—O6A	115.6 (13)
C41—C4—H4B	109.5	O6A—Cl1—O3A	108.9 (12)
N2—C21—C2	118.7 (6)	O6A—Cl1—O4A	106.2 (11)
N2—C21—C22	120.8 (6)	N1S—C2S—C3S	178.3 (12)
C22—C21—C2	120.5 (6)	C2S—C3S—H3SA	109.5
C21—C22—H22	120.1	C2S—C3S—H3SB	109.5
C23—C22—C21	119.8 (7)	C2S—C3S—H3SC	109.5
C23—C22—H22	120.1	H3SA—C3S—H3SB	109.5
C22—C23—H23	120.3	H3SA—C3S—H3SC	109.5
C22—C23—C24	119.3 (7)	H3SB—C3S—H3SC	109.5
C24—C23—H23	120.3

Cu1ⁱⁱ—O1—C26—O2	−6.7 (10)	C2—C21—C22—C23	178.8 (8)
Cu1ⁱⁱ—O1—C26—C25	174.1 (4)	C3—N1—C2—C21	−108.0 (7)
Cu1—O2—C26—O1	167.3 (5)	C3—N1—C4—C41	150.8 (7)
Cu1—O2—C26—C25	−13.6 (7)	C3—C31—C32—C33	−175.1 (8)
Cu1—N1—C2—C21	6.3 (8)	C4—N1—C2—C21	117.6 (7)
Cu1—N1—C3—C31	−38.8 (7)	C4—N1—C3—C31	−147.3 (7)
Cu1—N1—C4—C41	41.2 (7)	C4—C41—C42—C43	176.1 (9)
Cu1—N2—C21—C2	5.6 (8)	C21—N2—C25—C24	−1.7 (9)
Cu1—N2—C21—C22	−177.1 (5)	C21—N2—C25—C26	175.5 (6)
Cu1—N2—C25—C24	175.7 (5)	C21—C22—C23—C24	−1.9 (12)
Cu1—N2—C25—C26	−7.0 (7)	C22—C23—C24—C25	0.5 (12)
Cu1—N3—C31—C3	−12.9 (8)	C23—C24—C25—N2	1.4 (11)
Cu1—N3—C31—C32	168.2 (6)	C23—C24—C25—C26	−175.7 (7)
Cu1—N3—C35—C34	−170.0 (6)	C24—C25—C26—O1	11.0 (9)
Cu1—N4—C41—C4	10.8 (9)	C24—C25—C26—O2	−168.3 (6)
Cu1—N4—C41—C42	−171.7 (7)	C25—N2—C21—C2	−177.0 (6)
Cu1—N4—C45—C44	170.9 (7)	C25—N2—C21—C22	0.3 (9)
N1—C2—C21—N2	−8.0 (10)	C31—N3—C35—C34	1.3 (11)
N1—C2—C21—C22	174.7 (7)	C31—C32—C33—C34	−1.5 (13)
N1—C3—C31—N3	38.2 (9)	C32—C33—C34—C35	−0.9 (13)
N1—C3—C31—C32	−143.0 (7)	C33—C34—C35—N3	1.0 (12)
N1—C4—C41—N4	−39.1 (10)	C35—N3—C31—C3	175.2 (7)
N1—C4—C41—C42	143.5 (8)	C35—N3—C31—C32	−3.7 (10)
N2—C21—C22—C23	1.5 (11)	C41—N4—C45—C44	−2.0 (12)
N2—C25—C26—O1	−166.3 (6)	C41—C42—C43—C44	0.6 (15)
N2—C25—C26—O2	14.5 (9)	C42—C43—C44—C45	−0.7 (15)
N3—C31—C32—C33	3.8 (12)	C43—C44—C45—N4	1.4 (14)
N4—C41—C42—C43	−1.2 (14)	C45—N4—C41—C4	−175.7 (7)
C2—N1—C3—C31	80.0 (8)	C45—N4—C41—C42	1.8 (11)
C2—N1—C4—C41	−76.1 (8)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2A···O5A	0.97	2.21	3.167 (19)	169
C3—H3A···O3ⁱⁱⁱ	0.97	2.54	3.484 (16)	165
C3—H3B···O2ⁱ	0.97	2.44	3.149 (10)	130
C22—H22···N1Sⁱⁱⁱ	0.93	2.53	3.393 (14)	154
C32—H32···O5ⁱⁱⁱ	0.93	2.49	3.386 (17)	163
C32—H32···O3Aⁱⁱⁱ	0.93	2.40	3.31 (2)	165
C34—H34···O3A^iv	0.93	2.41	3.23 (2)	148
C42—H42···O6^v	0.93	2.61	3.43 (2)	147
C42—H42···O6A^v	0.93	2.64	3.21 (2)	121
C3S—H3SC···O4^vi	0.96	2.54	3.16 (2)	123
C3S—H3SC···O6	0.96	2.46	3.11 (2)	125

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

Acknowledgements

MDS thanks the Royal Society for a University Research Fellowship.

Funding information

Funding for this research was provided by: Engineering and Physical Sciences Research Council (grant No. EP/L023652/1); Royal Society (award No. UF150104).

References

Bruker (2016). APEX3, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cioncoloni, G., Roger, I., Wheatley, P. S., Wilson, C., Morris, R. E., Sproules, S. & Symes, M. D. (2018). ACS Catal. 8, 5070–5084. Web of Science CSD CrossRef CAS Google Scholar
Comba, P., Grimm, L., Orvig, C., Rück, K. & Wadepohl, H. (2016). Inorg. Chem. 55, 12531–12543. Web of Science CSD CrossRef CAS PubMed Google Scholar
Comba, P., Jakob, M., Rück, K. & Wadepohl, H. (2018). Inorg. Chim. Acta, 481, 98-105. Web of Science CSD CrossRef CAS Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Godden, J. W., Turley, S., Teller, D. C., Adman, E. T., Liu, M. Y., Payne, W. J. & LeGall, J. (1991). Science, 253, 438–442. CrossRef PubMed CAS Web of Science Google Scholar
Hayashi, H., Uozumi, K., Fujinami, S., Nagatomo, S., Shiren, K., Furutachi, H., Suzuki, M., Uehara, A. & Kitagawa, T. (2002). Chem. Lett. 31, 416–417. Web of Science CSD CrossRef Google Scholar
Izzet, G., Zeng, X., Akdas, H., Marrot, J. & Reinaud, O. (2007). Chem. Commun. pp. 810–812. Web of Science CSD CrossRef Google Scholar
Kojima, T., Hirai, Y., Ishizuka, T., Shiota, Y., Yoshizawa, K., Ikemura, K., Ogura, T. & Fukuzumi, S. (2010). Angew. Chem. Int. Ed. 49, 8449–8453. Web of Science CSD CrossRef CAS Google Scholar
Komeda, N., Nagao, H., Kushi, Y., Adachi, G., Suzuki, M., Uehara, A. & Tanaka, K. (1995). Bull. Chem. Soc. Jpn, 68, 581–589. CSD CrossRef CAS Web of Science Google Scholar
Kotani, H., Kaida, S., Ishizuka, T., Sakaguchi, M., Ogura, T., Shiota, Y., Yoshizawa, K. & Kojima, T. (2015). Chem. Sci. 6, 945–955. Web of Science CSD CrossRef CAS PubMed Google Scholar
Lonnon, D. G., Craig, D. C. & Colbran, S. B. (2003). Inorg. Chem. Commun. 6, 1351–1353. Web of Science CSD CrossRef CAS Google Scholar
Maia, L. B. & Moura, J. J. G. (2014). Chem. Rev. 114, 5273–5357. Web of Science CrossRef CAS PubMed Google Scholar
Mizuno, M., Honda, K., Cho, J., Furutachi, H., Tosha, T., Matsumoto, T., Fujinami, S., Kitagawa, T. & Suzuki, M. (2006). Angew. Chem. Int. Ed. 45, 6911–6914. Web of Science CSD CrossRef CAS Google Scholar
Nagao, H., Komeda, N., Mukaida, M., Suzuki, M. & Tanaka, K. (1996). Inorg. Chem. 35, 6809–6815. CSD CrossRef PubMed CAS Web of Science Google Scholar
Orain, C., Porras-Gutiérrez, A. G., Evoung Evoung, F., Charles, C., Cosquer, N., Gomila, A., Conan, F., Le Mest, Y. & Le Poul, N. (2013). Electrochem. Commun. 34, 204–207. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Shiren, K., Ogo, S., Fujinami, S., Hayashi, H., Suzuki, M., Uehara, A., Watanabe, Y. & Moro-oka, Y. (2000). J. Am. Chem. Soc. 122, 254–262. Web of Science CSD CrossRef CAS Google Scholar
Symes, M. D. & Wilson, C. (2018). Supramol. Chem. 30, 742–750. Web of Science CSD CrossRef CAS Google Scholar
Timmons, A. J. & Symes, M. D. (2015). Chem. Soc. Rev. 44, 6708–6722. Web of Science CrossRef CAS PubMed Google Scholar
Wasser, I. M., de Vries, S., Moënne-Loccoz, P., Schröder, I. & Karlin, K. D. (2002). Chem. Rev. 102, 1201–1234. Web of Science CrossRef PubMed CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.