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Poly[bis­­(μ2-formato-κ2O:O′)(quinoxaline-κN)copper(II)]

aInstitute of General & Ecological Chemistry, Technical University of Łódź, Żeromskiego 116, 90-924 Łódź, Poland
*Correspondence e-mail: lsieron@p.lodz.pl

(Received 30 October 2007; accepted 24 November 2007; online 6 December 2007)

In the polymeric title copper(II) compound, [Cu(CHO2)2(C8H6N2)]n, both formato ligands are O-bidentate anions and act as bridging ligands, creating a planar polymeric arrangement. The slightly distorted square-pyramidal coordination around CuII comprises four O atoms from two different formate anions as the base and a quinoxaline mol­ecule in the apical position.

Related literature

For related literature, see: Addison et al. (1984[Addison, A. W., Rao, T. N., Reedijk, J., van Rijn, J. & Verschoor, G. C. (1984). J. Chem. Soc. Dalton Trans. pp. 1349-1356.]); Borthwick (1980[Borthwick, P. W. (1980). Acta Cryst. B36, 628-632.]); Sieroń (2003[Sieroń, L. (2003). Acta Cryst. E59, m803-m805.], 2007[Sieroń, L. (2007). Acta Cryst. C63, m199-m200.]).

[Scheme 1]

Experimental

Crystal data
  • [Cu(CHO2)2(C8H6N2)]

  • Mr = 283.73

  • Monoclinic, P 21 /n

  • a = 9.5648 (3) Å

  • b = 11.1913 (3) Å

  • c = 10.1910 (4) Å

  • β = 108.284 (3)°

  • V = 1035.80 (6) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 2.11 mm−1

  • T = 291 K

  • 0.30 × 0.30 × 0.08 mm

Data collection
  • KUMA KM4CCD diffractometer

  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Versions 1.171. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]) Tmin = 0.578, Tmax = 0.843

  • 12535 measured reflections

  • 2378 independent reflections

  • 2267 reflections with I > 2σ(I)

  • Rint = 0.017

Refinement
  • R[F2 > 2σ(F2)] = 0.027

  • wR(F2) = 0.070

  • S = 1.14

  • 2378 reflections

  • 155 parameters

  • H-atom parameters constrained

  • Δρmax = 0.35 e Å−3

  • Δρmin = −0.60 e Å−3

Table 1
Selected geometric parameters (Å, °)

Cu1—O1 1.9605 (11)
Cu1—O2 1.9564 (14)
Cu1—O3i 1.9598 (12)
Cu1—O4ii 1.9489 (13)
Cu1—N1 2.5150 (18)
O1—Cu1—O2 88.07 (5)
O1—Cu1—O3i 172.89 (6)
O1—Cu1—O4ii 90.52 (5)
O2—Cu1—O3i 88.43 (5)
O2—Cu1—O4ii 178.42 (5)
O3i—Cu1—O4ii 93.05 (5)
O1—Cu1—N1 89.62 (6)
O2—Cu1—N1 88.95 (6)
O3i—Cu1—N1 96.50 (5)
O4ii—Cu1—N1 90.32 (6)
Symmetry codes: (i) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [x-{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}].

Data collection: CrysAlis CCD (Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Versions 1.171. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]); cell refinement: CrysAlis RED (Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Versions 1.171. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXTL (Sheldrick, 2003[Sheldrick, G. M. (2003). SHELXTL. Version 6.14. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL (Sheldrick, 2003[Sheldrick, G. M. (2003). SHELXTL. Version 6.14. Bruker AXS Inc., Madison, Wisconsin, USA.]) and Mercury (Macrae et al., 2006[Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.]); software used to prepare material for publication: PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information


Comment top

The structure determination of the title compound was undertaken as a continuation of earlier studies of copper(II) complexes with formic acid (Sieroń, 2003; 2007). A fragment of the title compound structure is shown in Fig. 1.

The CuII atom has a square-pyramidal environment. The four short equatorial Cu–O bonds, that range from 1.9489 (13) to 1.9605 (11) Å, are formed by the formate anions. The long Cu–N axial bond of 2.515 (2) Å to quinoxaline molecule completes the five coordination geometry around Cu. The degree of trigonality τ = 0.092 [τ is defined by Addison et al. (1984); for the regular square-pyramidal (SQP) structure, the trigonality parameter is 0, and for the trigonal-bipyramidal (TBP) structure, it increases to 1] indicates a slightly distorted SQP coordination of the Cu atom.

The O—C distances in both formate groups are approximately equal and range from 1.238 (2) to 1.250 (2) Å, indicating the distinct delocalization of their π electrons (Borthwick, 1980). All the formate anions coordinate in a bidentate anti-anti fashion, to result in a two-dimensional framework parralel to (101) plane (Fig. 2). The quinoxaline rings engage in π-π stacking interactions, with distances between ring centroids of 3.6704 (12) Å, and these serve to connect polymeric planes into three-dimensional network.

The closest Cu···Cu distance of 5.6164 (3) Å, corresponds aproximately to half the length of the b axis. The second-shortest Cu···Cu distance is 5.7924 (4) Å, which is half the length of the diagonal of the ac plane.

Related literature top

For related literature, see: Addison et al. (1984); Borthwick (1980); Sieroń (2003, 2007).

Experimental top

The title complex was prepared by dissolving cupric formate [2 mmol, Cu(HCOO)2.2H2O] in 50 ml of water with quinoxaline (2 mmol, C8H6N2). After heating to boiling, the formic acid was added dropwise to clear the solution. The solution was filtered and allowed to cool. After few days, green crystals were obtained.

Refinement top

All H atoms were initially located in a difference Fourier synthesis, but were positioned with idealized geometry, with C–H = 0.93 Å, and Uiso(H) = 1.2Ueq(C), and refined using a riding model.

Structure description top

The structure determination of the title compound was undertaken as a continuation of earlier studies of copper(II) complexes with formic acid (Sieroń, 2003; 2007). A fragment of the title compound structure is shown in Fig. 1.

The CuII atom has a square-pyramidal environment. The four short equatorial Cu–O bonds, that range from 1.9489 (13) to 1.9605 (11) Å, are formed by the formate anions. The long Cu–N axial bond of 2.515 (2) Å to quinoxaline molecule completes the five coordination geometry around Cu. The degree of trigonality τ = 0.092 [τ is defined by Addison et al. (1984); for the regular square-pyramidal (SQP) structure, the trigonality parameter is 0, and for the trigonal-bipyramidal (TBP) structure, it increases to 1] indicates a slightly distorted SQP coordination of the Cu atom.

The O—C distances in both formate groups are approximately equal and range from 1.238 (2) to 1.250 (2) Å, indicating the distinct delocalization of their π electrons (Borthwick, 1980). All the formate anions coordinate in a bidentate anti-anti fashion, to result in a two-dimensional framework parralel to (101) plane (Fig. 2). The quinoxaline rings engage in π-π stacking interactions, with distances between ring centroids of 3.6704 (12) Å, and these serve to connect polymeric planes into three-dimensional network.

The closest Cu···Cu distance of 5.6164 (3) Å, corresponds aproximately to half the length of the b axis. The second-shortest Cu···Cu distance is 5.7924 (4) Å, which is half the length of the diagonal of the ac plane.

For related literature, see: Addison et al. (1984); Borthwick (1980); Sieroń (2003, 2007).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXTL (Sheldrick, 2003); program(s) used to refine structure: SHELXTL (Sheldrick, 2003); molecular graphics: SHELXTL (Sheldrick, 2003) and Mercury (Macrae et al., 2006); software used to prepare material for publication: PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. A view of a fragment of the title compound showing 50% probability displacement ellipsoids. H atoms are shown as spheres of arbitrary radius [symmetry codes: (i) -x + 3/2, y - 1/2, -z + 1/2; (ii) x - 1/2, -y + 3/2, z - 1/2].
[Figure 2] Fig. 2. The packing diagram showing two-dimensional polymeric framework parralel to (101) plane.
(I) top
Crystal data top
[Cu(CHO2)2(C8H6N2)]F(000) = 572
Mr = 283.73Dx = 1.819 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 7748 reflections
a = 9.5648 (3) Åθ = 2.8–32.3°
b = 11.1913 (3) ŵ = 2.11 mm1
c = 10.1910 (4) ÅT = 291 K
β = 108.284 (3)°Prism, green
V = 1035.80 (6) Å30.30 × 0.30 × 0.08 mm
Z = 4
Data collection top
KUMA KM4CCD
diffractometer
2378 independent reflections
Radiation source: CX-Mo12x0.4-S Seifert Mo tube2267 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.017
Detector resolution: 8.2356 pixels mm-1θmax = 27.5°, θmin = 3.1°
ω scansh = 1212
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction,2006)
k = 1414
Tmin = 0.578, Tmax = 0.843l = 1313
12535 measured reflections
Refinement top
Refinement on F2Secondary atom site location: structure-invariant direct methods
Least-squares matrix: fullHydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.027H-atom parameters constrained
wR(F2) = 0.070 w = 1/[σ2(Fo2) + (0.0359P)2 + 0.4837P]
where P = (Fo2 + 2Fc2)/3
S = 1.14(Δ/σ)max = 0.001
2378 reflectionsΔρmax = 0.35 e Å3
155 parametersΔρmin = 0.60 e Å3
0 restraintsExtinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0054 (8)
Crystal data top
[Cu(CHO2)2(C8H6N2)]V = 1035.80 (6) Å3
Mr = 283.73Z = 4
Monoclinic, P21/nMo Kα radiation
a = 9.5648 (3) ŵ = 2.11 mm1
b = 11.1913 (3) ÅT = 291 K
c = 10.1910 (4) Å0.30 × 0.30 × 0.08 mm
β = 108.284 (3)°
Data collection top
KUMA KM4CCD
diffractometer
2378 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction,2006)
2267 reflections with I > 2σ(I)
Tmin = 0.578, Tmax = 0.843Rint = 0.017
12535 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0270 restraints
wR(F2) = 0.070H-atom parameters constrained
S = 1.14Δρmax = 0.35 e Å3
2378 reflectionsΔρmin = 0.60 e Å3
155 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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 (Å2) top
xyzUiso*/Ueq
Cu10.72396 (2)0.74628 (2)0.24693 (2)0.0231 (1)
O10.75356 (15)0.89959 (10)0.34492 (12)0.0276 (4)
O20.88757 (15)0.68234 (11)0.39838 (14)0.0349 (4)
O30.78057 (14)1.09526 (10)0.35166 (12)0.0257 (3)
O41.05990 (14)0.68686 (11)0.59961 (12)0.0275 (3)
N10.55057 (18)0.68333 (15)0.37545 (17)0.0316 (5)
N20.3759 (2)0.66292 (17)0.55363 (17)0.0376 (6)
C10.75006 (19)0.99809 (14)0.28872 (19)0.0240 (5)
C20.9877 (2)0.73484 (16)0.48872 (18)0.0243 (5)
C30.5850 (3)0.73576 (19)0.4970 (2)0.0376 (7)
C40.4972 (3)0.7260 (2)0.5847 (2)0.0411 (7)
C50.2092 (2)0.53257 (19)0.3880 (2)0.0357 (6)
C60.1703 (2)0.4739 (2)0.2637 (2)0.0404 (7)
C70.2566 (3)0.4848 (2)0.1746 (2)0.0400 (7)
C80.3807 (2)0.55395 (19)0.2109 (2)0.0340 (6)
C90.4245 (2)0.61503 (16)0.33862 (19)0.0280 (5)
C100.3373 (2)0.60485 (17)0.42837 (19)0.0292 (5)
H10.722800.999900.192700.0290*
H21.009500.813400.472500.0290*
H30.670600.781100.526200.0450*
H40.526800.766300.668700.0490*
H50.151400.524900.445900.0430*
H60.086300.426500.237900.0480*
H70.228700.444700.090400.0480*
H80.436500.560800.151200.0410*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0250 (2)0.0143 (1)0.0206 (1)0.0024 (1)0.0063 (1)0.0023 (1)
O10.0403 (8)0.0154 (5)0.0213 (6)0.0021 (5)0.0015 (5)0.0004 (4)
O20.0341 (7)0.0218 (6)0.0316 (7)0.0032 (5)0.0142 (6)0.0024 (5)
O30.0340 (7)0.0157 (5)0.0215 (6)0.0028 (5)0.0002 (5)0.0003 (4)
O40.0267 (6)0.0233 (6)0.0233 (6)0.0048 (5)0.0052 (5)0.0009 (5)
N10.0287 (8)0.0350 (9)0.0303 (8)0.0032 (7)0.0082 (7)0.0034 (7)
N20.0380 (10)0.0450 (10)0.0316 (9)0.0026 (8)0.0134 (7)0.0008 (7)
C10.0300 (9)0.0186 (8)0.0187 (7)0.0009 (7)0.0008 (6)0.0002 (6)
C20.0243 (9)0.0191 (8)0.0238 (9)0.0003 (6)0.0007 (7)0.0011 (6)
C30.0331 (11)0.0429 (12)0.0358 (11)0.0087 (9)0.0094 (9)0.0020 (8)
C40.0442 (13)0.0482 (12)0.0309 (10)0.0072 (10)0.0119 (9)0.0050 (9)
C50.0323 (10)0.0386 (10)0.0381 (11)0.0022 (8)0.0140 (8)0.0059 (9)
C60.0348 (11)0.0400 (11)0.0447 (12)0.0105 (9)0.0102 (9)0.0004 (9)
C70.0428 (12)0.0412 (11)0.0337 (11)0.0062 (9)0.0089 (9)0.0041 (9)
C80.0342 (10)0.0378 (10)0.0305 (9)0.0014 (8)0.0107 (8)0.0027 (8)
C90.0274 (9)0.0270 (9)0.0278 (9)0.0025 (7)0.0063 (7)0.0073 (7)
C100.0295 (10)0.0284 (9)0.0289 (9)0.0022 (7)0.0080 (7)0.0067 (7)
Geometric parameters (Å, º) top
Cu1—O11.9605 (11)C5—C61.371 (3)
Cu1—O21.9564 (14)C5—C101.417 (3)
Cu1—O3i1.9598 (12)C6—C71.411 (3)
Cu1—O4ii1.9489 (13)C7—C81.367 (3)
Cu1—N12.5150 (18)C8—C91.412 (3)
O1—C11.238 (2)C9—C101.423 (3)
O2—C21.248 (2)C1—H10.93
O3—C11.250 (2)C2—H20.93
O4—C21.246 (2)C3—H30.93
N1—C31.316 (3)C4—H40.93
N1—C91.377 (3)C5—H50.93
N2—C41.309 (3)C6—H60.93
N2—C101.376 (3)C7—H70.93
C3—C41.410 (4)C8—H80.93
O1—Cu1—O288.07 (5)C6—C7—C8120.55 (19)
O1—Cu1—O3i172.89 (6)C7—C8—C9120.31 (19)
O1—Cu1—O4ii90.52 (5)N1—C9—C8120.08 (18)
O2—Cu1—O3i88.43 (5)N1—C9—C10120.61 (17)
O2—Cu1—O4ii178.42 (5)C8—C9—C10119.31 (18)
O3i—Cu1—O4ii93.05 (5)N2—C10—C5119.66 (18)
O1—Cu1—N189.62 (6)N2—C10—C9121.20 (18)
O2—Cu1—N188.95 (6)C5—C10—C9119.14 (17)
O3i—Cu1—N196.50 (5)O1—C1—H1118
O4ii—Cu1—N190.32 (6)O3—C1—H1118
Cu1—O1—C1124.40 (11)O2—C2—H2118
Cu1—O2—C2130.44 (12)O4—C2—H2118
Cu1iii—O3—C1121.55 (11)N1—C3—H3119
Cu1iv—O4—C2128.06 (12)C4—C3—H3119
Cu1—N1—C3110.74 (15)N2—C4—H4118
Cu1—N1—C9132.68 (13)C3—C4—H4118
C3—N1—C9116.32 (19)C6—C5—H5120
C4—N2—C10116.02 (18)C10—C5—H5120
O1—C1—O3124.71 (17)C5—C6—H6120
O2—C2—O4123.02 (17)C7—C6—H6120
N1—C3—C4122.7 (2)C6—C7—H7120
N2—C4—C3123.19 (19)C8—C7—H7120
C6—C5—C10120.07 (18)C7—C8—H8120
C5—C6—C7120.6 (2)C9—C8—H8120
Symmetry codes: (i) x+3/2, y1/2, z+1/2; (ii) x1/2, y+3/2, z1/2; (iii) x+3/2, y+1/2, z+1/2; (iv) x+1/2, y+3/2, z+1/2.

Experimental details

Crystal data
Chemical formula[Cu(CHO2)2(C8H6N2)]
Mr283.73
Crystal system, space groupMonoclinic, P21/n
Temperature (K)291
a, b, c (Å)9.5648 (3), 11.1913 (3), 10.1910 (4)
β (°) 108.284 (3)
V3)1035.80 (6)
Z4
Radiation typeMo Kα
µ (mm1)2.11
Crystal size (mm)0.30 × 0.30 × 0.08
Data collection
DiffractometerKUMA KM4CCD
diffractometer
Absorption correctionMulti-scan
(CrysAlis RED; Oxford Diffraction,2006)
Tmin, Tmax0.578, 0.843
No. of measured, independent and
observed [I > 2σ(I)] reflections
12535, 2378, 2267
Rint0.017
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.027, 0.070, 1.14
No. of reflections2378
No. of parameters155
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.35, 0.60

Computer programs: CrysAlis CCD (Oxford Diffraction, 2006), CrysAlis RED (Oxford Diffraction, 2006), SHELXTL (Sheldrick, 2003) and Mercury (Macrae et al., 2006), PLATON (Spek, 2003).

Selected geometric parameters (Å, º) top
Cu1—O11.9605 (11)Cu1—O4ii1.9489 (13)
Cu1—O21.9564 (14)Cu1—N12.5150 (18)
Cu1—O3i1.9598 (12)
O1—Cu1—O288.07 (5)O3i—Cu1—O4ii93.05 (5)
O1—Cu1—O3i172.89 (6)O1—Cu1—N189.62 (6)
O1—Cu1—O4ii90.52 (5)O2—Cu1—N188.95 (6)
O2—Cu1—O3i88.43 (5)O3i—Cu1—N196.50 (5)
O2—Cu1—O4ii178.42 (5)O4ii—Cu1—N190.32 (6)
Symmetry codes: (i) x+3/2, y1/2, z+1/2; (ii) x1/2, y+3/2, z1/2.
 

References

First citationAddison, A. W., Rao, T. N., Reedijk, J., van Rijn, J. & Verschoor, G. C. (1984). J. Chem. Soc. Dalton Trans. pp. 1349–1356.  CSD CrossRef Web of Science Google Scholar
First citationBorthwick, P. W. (1980). Acta Cryst. B36, 628–632.  CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationMacrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationOxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Versions 1.171. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.  Google Scholar
First citationSheldrick, G. M. (2003). SHELXTL. Version 6.14. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationSieroń, L. (2003). Acta Cryst. E59, m803–m805.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSieroń, L. (2007). Acta Cryst. C63, m199–m200.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSpek, A. L. (2003). J. Appl. Cryst. 36, 7–13.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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