Tetra-μ-acetato-κ⁸ O:O′-bis[(N ²,N ²-di­methyl­pyrazin-2-amine-κN ⁴)copper(II)]

Abstract

The title binuclear complex, [Cu₂(C₂H₃O₂)₄(C₆H₉N₃)₂], lies on an inversion center with four acetate ligands bridging two Cu^II ions and two monodentate N,N-dimethyl­pyrazine-2-amine ligands coordinating each Cu^II ion via N atoms, forming slightly distorted square-pyramidal environments.

Related literature

For related structures, see: Zhang et al. (2007 ▶); Li et al. (2003 ▶).

Experimental

Crystal data

• [Cu₂(C₂H₃O₂)₄(C₆H₉N₃)₂]

• M _r = 609.58

• Triclinic,

• a = 8.1052 (13) Å

• b = 8.1775 (13) Å

• c = 10.6534 (17) Å

• α = 67.826 (2)°

• β = 80.013 (2)°

• γ = 87.328 (2)°

• V = 643.84 (18) ų

• Z = 1

• Mo Kα radiation

• μ = 1.71 mm⁻¹

• T = 298 K

• 0.68 × 0.41 × 0.31 mm

Data collection

• Bruker SMART APEX CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.390, T _max = 0.620

• 3494 measured reflections

• 2465 independent reflections

• 2317 reflections with I > 2σ(I)

• R _int = 0.016

Refinement

• R[F ² > 2σ(F ²)] = 0.032

• wR(F ²) = 0.094

• S = 1.09

• 2465 reflections

• 167 parameters

• H-atom parameters constrained

• Δρ_max = 0.54 e Å⁻³

• Δρ_min = −0.44 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected geometric parameters (Å, °).

Cu1—O3	1.9649 (18)
Cu1—O1	1.9654 (19)
Cu1—O2	1.9738 (18)
Cu1—O4	1.9756 (18)
Cu1—N1	2.197 (2)

O3—Cu1—O1	168.16 (8)
O3—Cu1—O2	89.93 (9)
O1—Cu1—O2	90.44 (9)
O3—Cu1—O4	88.93 (8)
O1—Cu1—O4	88.32 (9)
O2—Cu1—O4	168.35 (7)
O3—Cu1—N1	94.74 (8)
O1—Cu1—N1	97.07 (8)
O2—Cu1—N1	92.23 (8)
O4—Cu1—N1	99.42 (8)

supplementary crystallographic information

Comment

Both acetate anions and pyrazine derivatives are useful ligands and a large number of multi-atom complexes have been synthesized with these as bridging ligands (Zhang et al., 2007; Li et al., 2003). We attempted to synthesize a mixed bridged multi-nuclear Cu^II complex by using acetate and N,N-dimethylpyrazine-2-amine as bridging ligands. The title complex was obtained and here we report its crystal structure, (I), Fig. 1.

The unique Cu^II ion is in a slightly distorted square-pyramidal coordination geometry with atom N1 lying at the apex. Four acetate ligands coordinate to two symmetry-related Cu^II atoms, with a Cu1···Cu1ⁱ separation of 2.6326 (6) Å and inversion centre lies at the middle of the Cu1···Cu1ⁱ vector (symmetry code, (i): -x + 1, -y + 1, -z + 2) resulting in the formation of a binuclear complex. The title complex is similar to a reported binuclear Cu^II complex (Zhang et al., 2007) except the title complex exhibits a slightly shorter Cu—N bond and a slightly longer Cu—Cu distance.

Experimental

N,N-dimethylpyrazine-2-amine (0.0954 g, 0.0696 mmol) was dissolved in 10 ml methanol and it was added into 10 ml water solution containing copper acetate (0.1390 g, 0.696 mmol), and the mixed solution was stirred for a few minutes. The blue single crystals were obtained after the solution had been allowed to stand at room temperature for five months.

Refinement

All H atoms were placed in calculated positions and refined as riding with C—H = 0.96 Å, U_iso = 1.5U_eq(C)for methyl group and C—H = 0.93 Å, U_iso = 1.2U_eq(C) for pyrazinyl H atoms.

Figures

Fig. 1.

The molecular structure of title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Primed atoms are related by the symmetry operator (-x + 1, -y + 1, -z + 2).

Crystal data

[Cu2(C2H3O2)4(C6H9N3)2]	Z = 1
Mr = 609.58	F(000) = 314
Triclinic, P1	Dx = 1.572 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.1052 (13) Å	Cell parameters from 2730 reflections
b = 8.1775 (13) Å	θ = 2.7–28.2°
c = 10.6534 (17) Å	µ = 1.71 mm−1
α = 67.826 (2)°	T = 298 K
β = 80.013 (2)°	Block, blue
γ = 87.328 (2)°	0.68 × 0.41 × 0.31 mm
V = 643.84 (18) Å3

Data collection

Bruker SMART APEX CCD diffractometer	2465 independent reflections
Radiation source: fine-focus sealed tube	2317 reflections with I > 2σ(I)
graphite	Rint = 0.016
φ and ω scans	θmax = 26.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→8
Tmin = 0.390, Tmax = 0.620	k = −10→8
3494 measured reflections	l = −12→13

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.094	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.0576P)2 + 0.297P] where P = (Fo2 + 2Fc2)/3
2465 reflections	(Δ/σ)max = 0.020
167 parameters	Δρmax = 0.54 e Å−3
0 restraints	Δρmin = −0.44 e Å−3

Special details

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
C1	0.2373 (3)	0.6709 (3)	0.9386 (3)	0.0309 (5)
C2	0.0727 (3)	0.7590 (4)	0.9109 (3)	0.0471 (7)
H2A	0.0903	0.8578	0.8247	0.071*
H2B	0.0273	0.7995	0.9832	0.071*
H2C	−0.0043	0.6759	0.9072	0.071*
C3	0.6075 (3)	0.7439 (3)	1.0579 (3)	0.0362 (6)
C4	0.6713 (4)	0.8898 (4)	1.0918 (4)	0.0531 (8)
H4A	0.7270	0.9792	1.0090	0.080*
H4B	0.7487	0.8427	1.1548	0.080*
H4C	0.5788	0.9406	1.1330	0.080*
C5	0.6480 (4)	0.8180 (4)	0.5613 (3)	0.0480 (7)
H5	0.5351	0.8437	0.5768	0.058*
C6	0.7422 (4)	0.9016 (4)	0.4350 (3)	0.0577 (9)
H6	0.6911	0.9856	0.3675	0.069*
C7	0.8757 (3)	0.6637 (4)	0.6357 (3)	0.0367 (6)
H7	0.9256	0.5812	0.7048	0.044*
C8	0.9720 (3)	0.7479 (4)	0.5042 (3)	0.0413 (6)
C9	1.2305 (5)	0.8021 (6)	0.3383 (4)	0.0780 (12)
H9A	1.1700	0.7980	0.2696	0.117*
H9B	1.3370	0.7474	0.3294	0.117*
H9C	1.2478	0.9229	0.3261	0.117*
C10	1.2205 (4)	0.5823 (6)	0.5770 (4)	0.0647 (9)
H10A	1.2374	0.6312	0.6430	0.097*
H10B	1.3270	0.5564	0.5338	0.097*
H10C	1.1538	0.4757	0.6228	0.097*
Cu1	0.57009 (3)	0.57928 (4)	0.87055 (3)	0.02811 (13)
N1	0.7160 (3)	0.6997 (3)	0.6627 (2)	0.0350 (5)
N2	0.9033 (4)	0.8693 (4)	0.4033 (3)	0.0548 (7)
N3	1.1350 (3)	0.7085 (4)	0.4739 (3)	0.0577 (7)
O1	0.4726 (3)	0.3816 (3)	0.8439 (2)	0.0446 (5)
O2	0.7587 (2)	0.4311 (3)	0.94000 (19)	0.0408 (4)
O3	0.6383 (2)	0.7576 (3)	0.9348 (2)	0.0411 (4)
O4	0.3574 (2)	0.7044 (2)	0.83984 (19)	0.0379 (4)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0290 (12)	0.0292 (11)	0.0330 (13)	−0.0015 (9)	−0.0048 (10)	−0.0099 (10)
C2	0.0300 (13)	0.0478 (16)	0.0536 (18)	0.0026 (11)	−0.0087 (12)	−0.0076 (13)
C3	0.0276 (12)	0.0386 (14)	0.0479 (16)	0.0033 (10)	−0.0077 (11)	−0.0221 (12)
C4	0.0561 (18)	0.0498 (17)	0.063 (2)	−0.0056 (14)	−0.0098 (15)	−0.0309 (15)
C5	0.0421 (15)	0.0538 (17)	0.0360 (15)	0.0115 (13)	0.0022 (12)	−0.0083 (13)
C6	0.064 (2)	0.0578 (19)	0.0297 (15)	0.0184 (16)	0.0014 (14)	0.0023 (13)
C7	0.0354 (13)	0.0425 (14)	0.0271 (12)	−0.0005 (11)	0.0007 (10)	−0.0099 (11)
C8	0.0405 (14)	0.0440 (15)	0.0341 (14)	−0.0037 (11)	0.0065 (11)	−0.0139 (12)
C9	0.061 (2)	0.088 (3)	0.065 (2)	−0.010 (2)	0.0353 (19)	−0.024 (2)
C10	0.0394 (17)	0.088 (3)	0.072 (2)	0.0077 (16)	−0.0050 (16)	−0.039 (2)
Cu1	0.02545 (18)	0.03205 (19)	0.02278 (18)	−0.00127 (12)	0.00141 (12)	−0.00789 (13)
N1	0.0349 (11)	0.0380 (11)	0.0270 (11)	−0.0005 (9)	0.0026 (9)	−0.0096 (9)
N2	0.0591 (16)	0.0529 (15)	0.0328 (13)	0.0057 (12)	0.0109 (12)	−0.0028 (11)
N3	0.0402 (14)	0.0682 (18)	0.0511 (16)	0.0005 (12)	0.0134 (12)	−0.0163 (14)
O1	0.0521 (12)	0.0447 (11)	0.0411 (11)	−0.0074 (9)	−0.0005 (9)	−0.0228 (9)
O2	0.0323 (9)	0.0473 (11)	0.0312 (10)	0.0073 (8)	0.0004 (7)	−0.0048 (8)
O3	0.0438 (10)	0.0409 (10)	0.0390 (10)	−0.0095 (8)	−0.0003 (8)	−0.0169 (8)
O4	0.0307 (9)	0.0441 (10)	0.0313 (9)	0.0039 (7)	−0.0032 (7)	−0.0070 (8)

Geometric parameters (Å, °)

C1—O2i	1.252 (3)	C7—H7	0.9300
C1—O4	1.258 (3)	C8—N2	1.342 (4)
C1—C2	1.507 (3)	C8—N3	1.358 (4)
C2—H2A	0.9600	C9—N3	1.451 (4)
C2—H2B	0.9600	C9—H9A	0.9600
C2—H2C	0.9600	C9—H9B	0.9600
C3—O3	1.255 (3)	C9—H9C	0.9600
C3—O1i	1.259 (3)	C10—N3	1.447 (5)
C3—C4	1.506 (4)	C10—H10A	0.9600
C4—H4A	0.9600	C10—H10B	0.9600
C4—H4B	0.9600	C10—H10C	0.9600
C4—H4C	0.9600	Cu1—O3	1.9649 (18)
C5—N1	1.331 (4)	Cu1—O1	1.9654 (19)
C5—C6	1.363 (4)	Cu1—O2	1.9738 (18)
C5—H5	0.9300	Cu1—O4	1.9756 (18)
C6—N2	1.331 (4)	Cu1—N1	2.197 (2)
C6—H6	0.9300	Cu1—Cu1i	2.6326 (6)
C7—N1	1.321 (3)	O1—C3i	1.259 (3)
C7—C8	1.411 (4)	O2—C1i	1.252 (3)
O2i—C1—O4	125.7 (2)	H9A—C9—H9C	109.5
O2i—C1—C2	116.0 (2)	H9B—C9—H9C	109.5
O4—C1—C2	118.3 (2)	N3—C10—H10A	109.5
C1—C2—H2A	109.5	N3—C10—H10B	109.5
C1—C2—H2B	109.5	H10A—C10—H10B	109.5
H2A—C2—H2B	109.5	N3—C10—H10C	109.5
C1—C2—H2C	109.5	H10A—C10—H10C	109.5
H2A—C2—H2C	109.5	H10B—C10—H10C	109.5
H2B—C2—H2C	109.5	O3—Cu1—O1	168.16 (8)
O3—C3—O1i	125.6 (2)	O3—Cu1—O2	89.93 (9)
O3—C3—C4	117.4 (3)	O1—Cu1—O2	90.44 (9)
O1i—C3—C4	117.0 (2)	O3—Cu1—O4	88.93 (8)
C3—C4—H4A	109.5	O1—Cu1—O4	88.32 (9)
C3—C4—H4B	109.5	O2—Cu1—O4	168.35 (7)
H4A—C4—H4B	109.5	O3—Cu1—N1	94.74 (8)
C3—C4—H4C	109.5	O1—Cu1—N1	97.07 (8)
H4A—C4—H4C	109.5	O2—Cu1—N1	92.23 (8)
H4B—C4—H4C	109.5	O4—Cu1—N1	99.42 (8)
N1—C5—C6	120.7 (3)	O3—Cu1—Cu1i	83.66 (6)
N1—C5—H5	119.7	O1—Cu1—Cu1i	84.71 (6)
C6—C5—H5	119.7	O2—Cu1—Cu1i	81.05 (6)
N2—C6—C5	123.5 (3)	O4—Cu1—Cu1i	87.31 (5)
N2—C6—H6	118.3	N1—Cu1—Cu1i	173.08 (6)
C5—C6—H6	118.3	C7—N1—C5	117.8 (2)
N1—C7—C8	121.3 (3)	C7—N1—Cu1	121.20 (18)
N1—C7—H7	119.3	C5—N1—Cu1	120.88 (18)
C8—C7—H7	119.3	C6—N2—C8	116.2 (2)
N2—C8—N3	117.6 (3)	C8—N3—C10	121.5 (3)
N2—C8—C7	120.4 (3)	C8—N3—C9	120.0 (3)
N3—C8—C7	122.0 (3)	C10—N3—C9	118.4 (3)
N3—C9—H9A	109.5	C3i—O1—Cu1	122.29 (17)
N3—C9—H9B	109.5	C1i—O2—Cu1	126.74 (17)
H9A—C9—H9B	109.5	C3—O3—Cu1	123.65 (17)
N3—C9—H9C	109.5	C1—O4—Cu1	119.15 (16)
N1—C5—C6—N2	1.7 (6)	O3—Cu1—O1—C3i	−13.5 (5)
N1—C7—C8—N2	0.9 (4)	O2—Cu1—O1—C3i	78.2 (2)
N1—C7—C8—N3	−178.1 (3)	O4—Cu1—O1—C3i	−90.2 (2)
C8—C7—N1—C5	0.3 (4)	N1—Cu1—O1—C3i	170.5 (2)
C8—C7—N1—Cu1	−176.6 (2)	Cu1i—Cu1—O1—C3i	−2.7 (2)
C6—C5—N1—C7	−1.5 (5)	O3—Cu1—O2—C1i	81.6 (2)
C6—C5—N1—Cu1	175.3 (3)	O1—Cu1—O2—C1i	−86.6 (2)
O3—Cu1—N1—C7	85.5 (2)	O4—Cu1—O2—C1i	−2.8 (5)
O1—Cu1—N1—C7	−95.3 (2)	N1—Cu1—O2—C1i	176.3 (2)
O2—Cu1—N1—C7	−4.6 (2)	Cu1i—Cu1—O2—C1i	−2.0 (2)
O4—Cu1—N1—C7	175.2 (2)	O1i—C3—O3—Cu1	−1.4 (4)
Cu1i—Cu1—N1—C7	9.2 (6)	C4—C3—O3—Cu1	178.70 (18)
O3—Cu1—N1—C5	−91.3 (2)	O1—Cu1—O3—C3	13.4 (5)
O1—Cu1—N1—C5	87.9 (2)	O2—Cu1—O3—C3	−78.4 (2)
O2—Cu1—N1—C5	178.6 (2)	O4—Cu1—O3—C3	90.0 (2)
O4—Cu1—N1—C5	−1.6 (2)	N1—Cu1—O3—C3	−170.7 (2)
Cu1i—Cu1—N1—C5	−167.6 (4)	Cu1i—Cu1—O3—C3	2.6 (2)
C5—C6—N2—C8	−0.4 (5)	O2i—C1—O4—Cu1	3.5 (4)
N3—C8—N2—C6	178.2 (3)	C2—C1—O4—Cu1	−176.12 (18)
C7—C8—N2—C6	−0.8 (5)	O3—Cu1—O4—C1	−85.17 (19)
N2—C8—N3—C10	178.6 (3)	O1—Cu1—O4—C1	83.31 (19)
C7—C8—N3—C10	−2.4 (5)	O2—Cu1—O4—C1	−0.7 (5)
N2—C8—N3—C9	2.7 (5)	N1—Cu1—O4—C1	−179.80 (18)
C7—C8—N3—C9	−178.2 (3)	Cu1i—Cu1—O4—C1	−1.47 (18)

Symmetry codes: (i) −x+1, −y+1, −z+2.