Crystal structure of bis­­[μ-meth­­oxy(pyridin-2-yl)methano­lato-κ³N,O:O]bis­[chlorido­copper(II)]

The racemic title compound, [Cu₂(C₇H₈NO₂)₂Cl₂], is composed of dinuclear mol­ecules in which meth­oxy(pyridin-2-yl)methano­late ligands bridge two symmetry-related Cu^II ions. Each Cu^II ion is coordinated in a square-planar geometry by one Cl atom, the N and O atoms of the bidentate ligand and the bridging O atom of the centrosymmetrically related bidentate ligand. The separation between the two Cu^II atoms is 3.005 (1) Å. In the crystal, non-classical C—H⋯O hydrogen bonds, weak π–π stacking [centroid–centroid distance = 4.073 (1) Å] and weak electrostatic Cu⋯Cl inter­actions [3.023 (1) Å] link the dinuclear mol­ecules into chains running parallel to the b axis. These chains are further connected by weak C—H⋯Cl hydrogen bonds directed approximately along the a axis, forming a three-dimensional supra­molecular network.

1. Related literature

For related structures and applications of transition metal compounds with the meth­oxy-2-pyridyl­methano­late ligand, see: Pijper et al. (2010); Mondal et al. (2009); Drew et al. (2008); Wang et al. (2003); Guidote et al. (2001).

2. Experimental

2.1. Crystal data

• [Cu₂(C₇H₈NO₂)₂Cl₂]

• M_r = 474.29

• Monoclinic, P 2₁ /n

• a = 10.5568 (14) Å

• b = 4.0728 (6) Å

• c = 19.257 (3) Å

• β = 95.280 (3)°

• V = 824.5 (2) ų

• Z = 2

• Mo Kα radiation

• μ = 2.92 mm⁻¹

• T = 298 K

• 0.16 × 0.10 × 0.06 mm

2.2. Data collection

• Bruker D8 QUEST CMOS diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2014) T_min = 0.645, T_max = 0.745

• 7703 measured reflections

• 1485 independent reflections

• 1030 reflections with I > 2σ(I)

• R_int = 0.091

2.3. Refinement

• R[F² > 2σ(F²)] = 0.045

• wR(F²) = 0.108

• S = 1.04

• 1485 reflections

• 110 parameters

• H-atom parameters constrained

• Δρ_max = 0.52 e Å⁻³

• Δρ_min = −0.42 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯Cl1^i	0.93	2.90	3.756 (6)	154
C3—H3⋯O2^ii	0.93	2.65	3.517 (7)	156
C6—H6⋯O2^iii	0.98	2.59	3.548 (8)	165
Symmetry codes: (i) -x, -y, -z+1; (ii) ; (iii) x, y+1, z.

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2014); data reduction: SAINT; program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL97 (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010), enCIFer (Allen et al., 2004) and OLEX2 (Dolomanov et al., 2009).

Supporting information

S1. Synthesis and crystallization

The title compound was obtained unexpectedly from the reaction of copper(I) chloride and 4-iodo-N-(2-pyridyl­methyl­ene)aniline in a mixed solvent of aceto­nitrile and di­chloro­methane. Typically, a solution of 4-iodo-N-(2-pyridyl­methyl­ene)aniline (61.6 mg, 0.2 mmol) in dry di­chloro­methane (2 ml) was placed in a test tube. A mixture of aceto­nitrile and di­chloro­methane solution (6 ml, 1:1, v/v) was carefully added on the top. A solution of CuCl (19.8 mg, 0.2 mmol) in dry aceto­nitrile (2 ml) was then carefully layered on the top of the aceto­nitrile/di­chloro­methane mixed solution. After slow diffusion at room temperature for 2 days, pale-green plate shaped crystals of the title compound were obtained.

S2. Refinement

All H atoms were positioned geometrically and allowed to ride on their parent atoms, with d(C—H) = 0.93 Å for aromatic CH groups, 0.96 Å for non-aromatic CH groups and 0.98 Å for CH₃ groups. The U_iso were constrained to be 1.5U_eq of the carrier atom for methy H atoms and 1.2U_eq for the remaining H atoms.

Related literature

For related structures and applications of transition metal compounds with the methoxy-2-pyridylmethanolate ligand, see: Pijper et al. (2010); Mondal et al. (2009); Drew et al. (2008); Wang et al. (2003); Guidote et al. (2001).

Computing details

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL97 (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010), enCIFer (Allen et al., 2004) and OLEX2 (Dolomanov et al., 2009).

Figures

	Fig. 1. A view of the dinuclear molecule of the title compound, showing the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Partial packing diagram of the title compound showing a molecular one-dimensional chain running parallel to the b axis assembled from dinuclear molecules linked together through non-classical C—H···O hydrogen bonds, weak π-π stacking and weak electrostatic Cu···Cl interactions (dashed lines). Hydrogen atoms not involved in the hydrogen bonding interactions are omitted for clarity.
	Fig. 3. A view of the weak C—H···Cl hydrogen bonding network between adjacent dinuclear molecules in the title compound which serve to connect the chains into a three-dimensional architecture.

Bis[µ-methoxy(pyridin-2-yl)methanolato-κ³N,O:O]bis[chloridocopper(II)]

Crystal data

[Cu2(C7H8NO2)2Cl2]	F(000) = 476
Mr = 474.29	Dx = 1.910 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.5568 (14) Å	Cell parameters from 546 reflections
b = 4.0728 (6) Å	θ = 3.6–25.4°
c = 19.257 (3) Å	µ = 2.92 mm^−1
β = 95.280 (3)°	T = 298 K
V = 824.5 (2) Å^3	Plate, pale-green
Z = 2	0.16 × 0.10 × 0.06 mm

Data collection

Bruker D8 QUEST CMOS diffractometer	1485 independent reflections
Radiation source: fine-focus sealed tube	1030 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.091
Detector resolution: 0 pixels mm^-1	θmax = 25.4°, θmin = 3.6°
ϕ and ω scans	h = −12→12
Absorption correction: multi-scan (SADABS; Bruker, 2014)	k = −4→4
Tmin = 0.645, Tmax = 0.745	l = −23→23
7703 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.108	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0544P)^2 + 0.5475P] where P = (Fo^2 + 2Fc^2)/3
1485 reflections	(Δ/σ)max = 0.001
110 parameters	Δρmax = 0.52 e Å^−3
0 restraints	Δρmin = −0.42 e Å^−3
0 constraints

Special details

Experimental. SADABS-2014/4 (Bruker,2014/4) was used for absorption correction. wR2(int) was 0.0681 before and 0.0535 after correction. The Ratio of minimum to maximum transmission is 0.8650. The λ/2 correction factor is 0.00150.

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

Refinement. Refinement of F² against all reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Cu1	0.36725 (5)	0.3633 (2)	0.49239 (3)	0.0376 (3)
Cl1	0.25368 (12)	−0.0100 (4)	0.42980 (7)	0.0431 (4)
O1	0.4853 (3)	0.5904 (12)	0.55882 (18)	0.0542 (13)
O2	0.4934 (3)	0.5112 (11)	0.6792 (2)	0.0491 (11)
N1	0.2501 (3)	0.4522 (11)	0.5649 (2)	0.0301 (11)
C1	0.1248 (4)	0.3804 (15)	0.5620 (3)	0.0371 (14)
H1	0.0886	0.2558	0.5248	0.044*
C2	0.0492 (5)	0.4839 (17)	0.6114 (3)	0.0486 (17)
H2	−0.0368	0.4299	0.6080	0.058*
C3	0.1015 (5)	0.6680 (17)	0.6662 (3)	0.0470 (16)
H3	0.0515	0.7428	0.7003	0.056*
C4	0.2300 (5)	0.7412 (15)	0.6700 (3)	0.0399 (14)
H4	0.2677	0.8658	0.7067	0.048*
C5	0.3014 (4)	0.6271 (14)	0.6186 (2)	0.0304 (12)
C6	0.4438 (4)	0.6921 (15)	0.6201 (3)	0.0336 (13)
H6	0.4613	0.9267	0.6272	0.040*
C7	0.6176 (5)	0.6071 (19)	0.7070 (3)	0.0587 (19)
H7A	0.6792	0.5237	0.6779	0.088*
H7B	0.6344	0.5200	0.7532	0.088*
H7C	0.6227	0.8424	0.7086	0.088*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0240 (3)	0.0552 (5)	0.0340 (4)	−0.0123 (3)	0.0041 (2)	−0.0096 (4)
Cl1	0.0392 (7)	0.0395 (9)	0.0504 (9)	−0.0114 (7)	0.0034 (6)	−0.0065 (7)
O1	0.0265 (18)	0.099 (4)	0.038 (2)	−0.020 (2)	0.0092 (16)	−0.025 (2)
O2	0.037 (2)	0.051 (3)	0.057 (3)	−0.0029 (19)	−0.0100 (18)	0.010 (2)
N1	0.026 (2)	0.032 (3)	0.032 (2)	−0.0024 (19)	0.0013 (18)	0.006 (2)
C1	0.025 (2)	0.044 (4)	0.041 (3)	−0.002 (3)	0.000 (2)	0.007 (3)
C2	0.024 (3)	0.060 (4)	0.063 (4)	−0.003 (3)	0.013 (3)	0.014 (4)
C3	0.042 (3)	0.050 (4)	0.052 (4)	0.013 (3)	0.020 (3)	0.008 (4)
C4	0.045 (3)	0.033 (4)	0.043 (3)	0.003 (3)	0.010 (3)	−0.001 (3)
C5	0.030 (2)	0.028 (3)	0.033 (3)	0.000 (2)	0.001 (2)	0.011 (3)
C6	0.028 (2)	0.038 (4)	0.034 (3)	−0.002 (2)	0.000 (2)	0.002 (3)
C7	0.042 (3)	0.073 (5)	0.058 (4)	−0.011 (3)	−0.009 (3)	0.013 (4)

Geometric parameters (Å, º)

Cu1—Cu1^i	3.0051 (12)	C1—C2	1.365 (7)
Cu1—Cl1	2.2215 (15)	C2—H2	0.9300
Cu1—O1^i	1.927 (3)	C2—C3	1.368 (8)
Cu1—O1	1.937 (4)	C3—H3	0.9300
Cu1—N1	1.982 (4)	C3—C4	1.385 (7)
O1—Cu1^i	1.927 (3)	C4—H4	0.9300
O1—C6	1.361 (6)	C4—C5	1.378 (7)
O2—C6	1.415 (6)	C5—C6	1.524 (6)
O2—C7	1.424 (6)	C6—H6	0.9800
N1—C1	1.351 (6)	C7—H7A	0.9600
N1—C5	1.330 (6)	C7—H7B	0.9600
C1—H1	0.9300	C7—H7C	0.9600
Cl1—Cu1—Cu1^i	139.33 (5)	C3—C2—H2	120.4
O1—Cu1—Cu1^i	38.82 (10)	C2—C3—H3	120.6
O1^i—Cu1—Cu1^i	39.07 (11)	C2—C3—C4	118.8 (5)
O1^i—Cu1—Cl1	102.14 (12)	C4—C3—H3	120.6
O1—Cu1—Cl1	165.33 (16)	C3—C4—H4	120.4
O1^i—Cu1—O1	77.89 (16)	C5—C4—C3	119.2 (5)
O1—Cu1—N1	81.54 (15)	C5—C4—H4	120.4
O1^i—Cu1—N1	158.20 (18)	N1—C5—C4	121.9 (5)
N1—Cu1—Cu1^i	120.03 (12)	N1—C5—C6	116.0 (4)
N1—Cu1—Cl1	99.59 (13)	C4—C5—C6	122.1 (5)
Cu1^i—O1—Cu1	102.11 (16)	O1—C6—O2	114.5 (5)
C6—O1—Cu1	118.6 (3)	O1—C6—C5	109.0 (4)
C6—O1—Cu1^i	138.9 (3)	O1—C6—H6	110.2
C6—O2—C7	114.8 (4)	O2—C6—C5	102.5 (4)
C1—N1—Cu1	127.1 (4)	O2—C6—H6	110.2
C5—N1—Cu1	114.2 (3)	C5—C6—H6	110.2
C5—N1—C1	118.4 (4)	O2—C7—H7A	109.5
N1—C1—H1	118.7	O2—C7—H7B	109.5
N1—C1—C2	122.5 (5)	O2—C7—H7C	109.5
C2—C1—H1	118.7	H7A—C7—H7B	109.5
C1—C2—H2	120.4	H7A—C7—H7C	109.5
C1—C2—C3	119.1 (5)	H7B—C7—H7C	109.5
Cu1—O1—C6—O2	108.4 (4)	C1—N1—C5—C6	178.4 (5)
Cu1^i—O1—C6—O2	−79.8 (7)	C1—C2—C3—C4	−0.6 (9)
Cu1—O1—C6—C5	−5.7 (6)	C2—C3—C4—C5	0.0 (9)
Cu1^i—O1—C6—C5	166.1 (4)	C3—C4—C5—N1	1.0 (8)
Cu1—N1—C1—C2	−172.6 (4)	C3—C4—C5—C6	−178.8 (5)
Cu1—N1—C5—C4	172.9 (4)	C4—C5—C6—O1	−171.8 (5)
Cu1—N1—C5—C6	−7.4 (6)	C4—C5—C6—O2	66.5 (7)
N1—C1—C2—C3	0.2 (9)	C5—N1—C1—C2	0.8 (8)
N1—C5—C6—O1	8.4 (7)	C7—O2—C6—O1	81.5 (6)
N1—C5—C6—O2	−113.2 (5)	C7—O2—C6—C5	−160.6 (5)
C1—N1—C5—C4	−1.4 (8)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···Cl1^ii	0.93	2.90	3.756 (6)	154
C3—H3···O2^iii	0.93	2.65	3.517 (7)	156
C6—H6···O2^iv	0.98	2.59	3.548 (8)	165

Symmetry codes: (ii) −x, −y, −z+1; (iii) −x+1/2, y+1/2, −z+3/2; (iv) x, y+1, z.