metal-organic compounds
Bis(2,2′-biimidazole-κ2N,N′)bis(2-bromofumarato-κO)copper(II)
aState Key Laboratory, Base of Novel Functional Materials and Preparation Science, Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
*Correspondence e-mail: lianghongze@nbu.edu.cn
In the title compound, [Cu(C4H2BrO4)2(C6H6N4)2], the central CuII atom lies on an inversion center and is six-coordinated in an octahedral geometry by four N atoms from two chelating biimidazole molecules in the equatorial plane and two O atoms from two 2-bromofumarate ligands in the axial positions. O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds lead to a three-dimensional network.
Related literature
For related literature, see: Atencio et al. (2005); Carraza et al. (2003); Öhrström et al. (2001); Sang & Xu (2006); Tadokoro et al. (1999). For the synthesis and of 2-bromofumaric acid, see: Fischer (2006).
Experimental
Crystal data
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Refinement
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Data collection: RAPID-AUTO (Rigaku, 1998); cell RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536807066585/hy2105sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807066585/hy2105Isup2.hkl
In a 50 ml two-neck bottle, the mixture of 2,2'-biimidazole (1.340 g, 10 mmol), 2-bromofumaric acid (0.195 g, 10 mmol) (Fischer, 2006), water (10 ml) and methanol (10 ml) was heated to 353 K, and then copper(II) chloride dihydrate (0.170 g, 10 mmol) was added. The suspension was stirred and kept at 353 K for 3 h. After cooling to room temperature, the solid was filtered off and the green solution was allowed to evaporate in air. After one day, block green crystals suitable for X-ray diffraction were formed.
H atoms on C and N atoms were positioned geometrically and refined as riding, with C—H = 0.93 Å, N—H = 0.86Å and Uiso(H) = 1.2Ueq(C,N). H atom attached to O atom was located in a difference Fourier map and fixed with Uiso(H) = 1.5Ueq(O).
Because of its various deprotonation modes (H2biim, Hbiim-, biim2-), the 2,2'-biimidazole ligand exhibits rich coordination patterns with various metals such as AgI (Sang & Xu, 2006), NiII (Tadokoro et al., 1999), CuII(Atencio et al., 2005; Carraza et al., 2003) and CoIIIÖhrström et al., 2001). We report here the
of a CuII complex with neutral 2,2'-biimidazole molecule and 2-bromofumarate anion as ligands.As illustrated in Fig. 1, the Cu atom shows a distorted octahedral coordination geometry, formed by four N atoms from two 2,2'-biimidazole molecules and two O atoms from carboxylate groups offered by two 2-bromofumarate ligands at the axial positions. The
contains an H2biim molecule and a 2-bromofumarate anion with a CuII atom lying on an inversion center. We can see that the lengths of Cu—N bonds [2.028 (5) and 2.001 (5) Å] are slightly asymmetric (Table 1). This behavior is similar to the reported Cu complex with H2biim [2.036 (2) and 2.010 (2) Å] (Atencio et al., 2005). Three types of strong hydrogen bonds are observed. The O—H···O hydrogen bonds are formed between two adjacent uncoordinated carboxylate groups. The N—H···O hydrogen bonds are formed between H2biim and the neighboring coordinated carboxylate group. Weak C—H···O hydrogen bonds also exist in the structure (Table 2). The complex molecules are assembled into two-dimensional layers via O—H···O and N—H···O hydrogen bonds. These layers are further assembled through C—H···O hydrogen bonds into a three-dimensional supramolecular structure.For related literature, see: Atencio et al. (2005); Carraza et al. (2003); Öhrström et al. (2001); Sang & Xu (2006); Tadokoro et al. (1999). For the synthesis and
of 2-bromofumaric acid, see: Fischer (2006).Data collection: RAPID-AUTO (Rigaku, 1998); cell
RAPID-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson,1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 45% probability level. [Symmetry code: (i) -x, -y, 2 - z.] |
[Cu(C4H2BrO4)2(C6H6N4)2] | Z = 1 |
Mr = 719.77 | F(000) = 355 |
Triclinic, P1 | Dx = 1.986 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.1650 (14) Å | Cell parameters from 2750 reflections |
b = 8.6458 (17) Å | θ = 3.0–27.5° |
c = 9.841 (2) Å | µ = 4.29 mm−1 |
α = 83.13 (1)° | T = 295 K |
β = 84.21 (3)° | Platelet, green |
γ = 87.56 (2)° | 0.12 × 0.1 × 0.09 mm |
V = 601.9 (2) Å3 |
Rigaku R-AXIS RAPID diffractometer | 2717 independent reflections |
Radiation source: fine-focus sealed tube | 1655 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.072 |
ω scans | θmax = 27.5°, θmin = 3.4° |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | h = −9→9 |
Tmin = 0.601, Tmax = 0.685 | k = −11→11 |
5942 measured reflections | l = −10→12 |
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)] = 0.068 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.196 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0963P)2 + 0.1925P] where P = (Fo2 + 2Fc2)/3 |
2717 reflections | (Δ/σ)max < 0.001 |
172 parameters | Δρmax = 1.01 e Å−3 |
1 restraint | Δρmin = −0.74 e Å−3 |
[Cu(C4H2BrO4)2(C6H6N4)2] | γ = 87.56 (2)° |
Mr = 719.77 | V = 601.9 (2) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.1650 (14) Å | Mo Kα radiation |
b = 8.6458 (17) Å | µ = 4.29 mm−1 |
c = 9.841 (2) Å | T = 295 K |
α = 83.13 (1)° | 0.12 × 0.1 × 0.09 mm |
β = 84.21 (3)° |
Rigaku R-AXIS RAPID diffractometer | 2717 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 1655 reflections with I > 2σ(I) |
Tmin = 0.601, Tmax = 0.685 | Rint = 0.072 |
5942 measured reflections |
R[F2 > 2σ(F2)] = 0.068 | 1 restraint |
wR(F2) = 0.196 | H-atom parameters constrained |
S = 1.06 | Δρmax = 1.01 e Å−3 |
2717 reflections | Δρmin = −0.74 e Å−3 |
172 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cu | 0.0000 | 0.0000 | 1.0000 | 0.0331 (3) | |
Br | −0.08553 (12) | 0.49244 (10) | 0.83673 (9) | 0.0604 (4) | |
N1 | 0.3926 (8) | −0.0593 (7) | 1.2738 (6) | 0.0444 (14) | |
H1 | 0.4976 | −0.1049 | 1.2915 | 0.053* | |
C1 | 0.2838 (12) | 0.0336 (10) | 1.3537 (8) | 0.053 (2) | |
H2 | 0.3108 | 0.0628 | 1.4369 | 0.064* | |
O1 | −0.3636 (9) | 0.4989 (7) | 0.6254 (6) | 0.0682 (18) | |
N2 | 0.1405 (7) | 0.0166 (6) | 1.1664 (6) | 0.0344 (12) | |
C2 | 0.1300 (11) | 0.0765 (10) | 1.2905 (8) | 0.0497 (19) | |
H3 | 0.0302 | 0.1382 | 1.3246 | 0.060* | |
O2 | −0.3039 (8) | 0.3652 (7) | 0.4506 (6) | 0.0654 (17) | |
H8 | −0.4087 | 0.4102 | 0.4343 | 0.098* | |
N3 | 0.4932 (8) | −0.2414 (7) | 1.0080 (7) | 0.0445 (15) | |
H4 | 0.5900 | −0.2626 | 1.0522 | 0.053* | |
C3 | 0.3013 (9) | −0.0657 (7) | 1.1606 (7) | 0.0344 (14) | |
O3 | 0.2811 (8) | 0.2094 (7) | 0.6488 (6) | 0.0643 (16) | |
N4 | 0.2205 (7) | −0.1400 (6) | 0.9522 (6) | 0.0334 (12) | |
C4 | 0.3456 (8) | −0.1495 (7) | 1.0427 (7) | 0.0336 (14) | |
O4 | 0.1940 (7) | 0.2317 (7) | 0.8670 (6) | 0.0568 (12) | |
C5 | 0.4601 (10) | −0.2935 (9) | 0.8885 (8) | 0.0493 (19) | |
H5 | 0.5373 | −0.3610 | 0.8399 | 0.059* | |
C6 | 0.2919 (10) | −0.2312 (9) | 0.8536 (8) | 0.0441 (18) | |
H6 | 0.2352 | −0.2467 | 0.7755 | 0.053* | |
C7 | −0.2662 (11) | 0.4104 (9) | 0.5622 (8) | 0.0477 (18) | |
C8 | −0.0839 (11) | 0.3384 (9) | 0.6025 (8) | 0.0514 (19) | |
H7 | −0.0230 | 0.2741 | 0.5416 | 0.062* | |
C9 | 0.0024 (10) | 0.3520 (8) | 0.7107 (8) | 0.0459 (17) | |
C10 | 0.1763 (10) | 0.2592 (10) | 0.7433 (10) | 0.0568 (12) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu | 0.0202 (6) | 0.0442 (6) | 0.0367 (6) | 0.0114 (4) | −0.0126 (5) | −0.0077 (5) |
Br | 0.0523 (6) | 0.0680 (6) | 0.0663 (6) | 0.0119 (4) | −0.0203 (5) | −0.0224 (5) |
N1 | 0.032 (3) | 0.058 (4) | 0.046 (3) | 0.006 (3) | −0.017 (3) | −0.005 (3) |
C1 | 0.042 (5) | 0.077 (5) | 0.044 (4) | 0.005 (4) | −0.021 (4) | −0.011 (4) |
O1 | 0.058 (4) | 0.093 (4) | 0.060 (4) | 0.020 (3) | −0.040 (3) | −0.015 (3) |
N2 | 0.021 (3) | 0.043 (3) | 0.040 (3) | 0.008 (2) | −0.006 (2) | −0.008 (3) |
C2 | 0.045 (5) | 0.067 (5) | 0.042 (4) | 0.002 (4) | −0.004 (4) | −0.025 (4) |
O2 | 0.050 (4) | 0.084 (4) | 0.066 (4) | 0.028 (3) | −0.018 (3) | −0.023 (3) |
N3 | 0.023 (3) | 0.051 (3) | 0.059 (4) | 0.010 (3) | −0.010 (3) | −0.003 (3) |
C3 | 0.017 (3) | 0.046 (3) | 0.040 (4) | −0.001 (3) | −0.008 (3) | 0.004 (3) |
O3 | 0.044 (3) | 0.082 (4) | 0.068 (4) | 0.020 (3) | −0.020 (3) | −0.007 (3) |
N4 | 0.017 (3) | 0.041 (3) | 0.042 (3) | 0.008 (2) | −0.007 (2) | −0.005 (2) |
C4 | 0.017 (3) | 0.040 (3) | 0.045 (4) | 0.002 (2) | −0.006 (3) | −0.003 (3) |
O4 | 0.032 (2) | 0.070 (3) | 0.068 (3) | 0.007 (2) | −0.022 (2) | 0.004 (3) |
C5 | 0.032 (4) | 0.058 (4) | 0.060 (5) | 0.015 (3) | −0.006 (4) | −0.023 (4) |
C6 | 0.030 (4) | 0.056 (4) | 0.048 (4) | 0.013 (3) | −0.009 (3) | −0.013 (4) |
C7 | 0.033 (4) | 0.055 (4) | 0.052 (5) | 0.006 (3) | −0.009 (4) | 0.008 (4) |
C8 | 0.043 (5) | 0.061 (5) | 0.051 (5) | 0.002 (4) | −0.011 (4) | −0.005 (4) |
C9 | 0.036 (4) | 0.049 (4) | 0.053 (4) | −0.002 (3) | −0.010 (4) | 0.000 (4) |
C10 | 0.032 (2) | 0.070 (3) | 0.068 (3) | 0.007 (2) | −0.022 (2) | 0.004 (3) |
Cu—N4 | 2.001 (5) | O2—H8 | 0.8512 |
Cu—N4i | 2.001 (5) | N3—C4 | 1.337 (8) |
Cu—N2 | 2.028 (5) | N3—C5 | 1.354 (9) |
Cu—N2i | 2.028 (5) | N3—H4 | 0.8600 |
Cu—O4 | 2.627 (6) | C3—C4 | 1.441 (9) |
Cu—O4i | 2.627 (6) | O3—C10 | 1.242 (10) |
Br—C9 | 1.883 (7) | N4—C4 | 1.319 (8) |
N1—C3 | 1.355 (8) | N4—C6 | 1.369 (8) |
N1—C1 | 1.358 (10) | O4—C10 | 1.230 (10) |
N1—H1 | 0.8600 | C5—C6 | 1.358 (10) |
C1—C2 | 1.337 (11) | C5—H5 | 0.9300 |
C1—H2 | 0.9300 | C6—H6 | 0.9300 |
O1—C7 | 1.200 (9) | C7—C8 | 1.492 (10) |
N2—C3 | 1.329 (7) | C8—C9 | 1.304 (10) |
N2—C2 | 1.377 (8) | C8—H7 | 0.9300 |
C2—H3 | 0.9300 | C9—C10 | 1.494 (7) |
O2—C7 | 1.266 (9) | ||
N4—Cu—N4i | 180.000 (1) | C5—N3—H4 | 126.8 |
N4—Cu—N2 | 81.9 (2) | N2—C3—N1 | 111.6 (6) |
N4i—Cu—N2 | 98.1 (2) | N2—C3—C4 | 117.0 (6) |
N4—Cu—N2i | 98.1 (2) | N1—C3—C4 | 131.3 (6) |
N4i—Cu—N2i | 81.9 (2) | C4—N4—C6 | 105.7 (5) |
N2—Cu—N2i | 180.000 (1) | C4—N4—Cu | 112.8 (4) |
N4—Cu—O4 | 87.3 (2) | C6—N4—Cu | 141.5 (5) |
N4i—Cu—O4 | 92.7 (2) | N4—C4—N3 | 111.9 (6) |
N2—Cu—O4 | 88.9 (2) | N4—C4—C3 | 116.9 (5) |
N2i—Cu—O4 | 91.1 (2) | N3—C4—C3 | 131.2 (6) |
N4—Cu—O4i | 92.7 (2) | C10—O4—Cu | 115.9 (5) |
N4i—Cu—O4i | 87.3 (2) | N3—C5—C6 | 107.7 (6) |
N2—Cu—O4i | 91.1 (2) | N3—C5—H5 | 126.2 |
N2i—Cu—O4i | 88.9 (2) | C6—C5—H5 | 126.1 |
O4—Cu—O4i | 180.00 (17) | C5—C6—N4 | 108.3 (6) |
C3—N1—C1 | 106.0 (6) | C5—C6—H6 | 126.0 |
C3—N1—H1 | 127.0 | N4—C6—H6 | 125.7 |
C1—N1—H1 | 127.0 | O1—C7—O2 | 124.4 (7) |
C2—C1—N1 | 107.8 (6) | O1—C7—C8 | 125.4 (7) |
C2—C1—H2 | 125.7 | O2—C7—C8 | 110.2 (7) |
N1—C1—H2 | 126.5 | C9—C8—C7 | 129.5 (8) |
C3—N2—C2 | 104.6 (6) | C9—C8—H7 | 115.2 |
C3—N2—Cu | 111.4 (4) | C7—C8—H7 | 115.3 |
C2—N2—Cu | 143.8 (5) | C8—C9—C10 | 122.9 (7) |
C1—C2—N2 | 109.9 (6) | C8—C9—Br | 121.5 (6) |
C1—C2—H3 | 125.5 | C10—C9—Br | 115.5 (6) |
N2—C2—H3 | 124.6 | O4—C10—O3 | 126.1 (7) |
C7—O2—H8 | 105.0 | O4—C10—C9 | 114.2 (8) |
C4—N3—C5 | 106.3 (6) | O3—C10—C9 | 119.5 (8) |
C4—N3—H4 | 126.9 |
Symmetry code: (i) −x, −y, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3ii | 0.86 | 1.90 | 2.756 (8) | 174 |
N3—H4···O4ii | 0.86 | 1.85 | 2.672 (8) | 159 |
O2—H8···O1iii | 0.85 | 1.90 | 2.743 (9) | 172 |
C1—H2···O3iv | 0.93 | 2.55 | 3.433 (10) | 159 |
C5—H5···O1v | 0.93 | 2.58 | 3.432 (10) | 153 |
C6—H6···O2vi | 0.93 | 2.56 | 3.329 (10) | 141 |
Symmetry codes: (ii) −x+1, −y, −z+2; (iii) −x−1, −y+1, −z+1; (iv) x, y, z+1; (v) x+1, y−1, z; (vi) −x, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C4H2BrO4)2(C6H6N4)2] |
Mr | 719.77 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 295 |
a, b, c (Å) | 7.1650 (14), 8.6458 (17), 9.841 (2) |
α, β, γ (°) | 83.13 (1), 84.21 (3), 87.56 (2) |
V (Å3) | 601.9 (2) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 4.29 |
Crystal size (mm) | 0.12 × 0.1 × 0.09 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.601, 0.685 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5942, 2717, 1655 |
Rint | 0.072 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.068, 0.196, 1.06 |
No. of reflections | 2717 |
No. of parameters | 172 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.01, −0.74 |
Computer programs: RAPID-AUTO (Rigaku, 1998), CrystalStructure (Rigaku/MSC, 2002), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson,1976).
Cu—N4 | 2.001 (5) | Cu—O4 | 2.627 (6) |
Cu—N2 | 2.028 (5) | ||
N4—Cu—N2 | 81.9 (2) | N4i—Cu—O4 | 92.7 (2) |
N4i—Cu—N2 | 98.1 (2) | N2—Cu—O4 | 88.9 (2) |
N4—Cu—O4 | 87.3 (2) | N2—Cu—O4i | 91.1 (2) |
Symmetry code: (i) −x, −y, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3ii | 0.86 | 1.90 | 2.756 (8) | 174 |
N3—H4···O4ii | 0.86 | 1.85 | 2.672 (8) | 159 |
O2—H8···O1iii | 0.85 | 1.90 | 2.743 (9) | 172 |
C1—H2···O3iv | 0.93 | 2.55 | 3.433 (10) | 159 |
C5—H5···O1v | 0.93 | 2.58 | 3.432 (10) | 153 |
C6—H6···O2vi | 0.93 | 2.56 | 3.329 (10) | 141 |
Symmetry codes: (ii) −x+1, −y, −z+2; (iii) −x−1, −y+1, −z+1; (iv) x, y, z+1; (v) x+1, y−1, z; (vi) −x, −y, −z+1. |
Acknowledgements
This project was sponsored by the Scientific Research Foundation of the State Education Ministry for Returned Overseas Chinese Scholars (grant No. 2006331), the Educational Committee of Zhejiang Province (grant No. 20061696), the Starting Foundation of Zhejiang Province for Returned Overseas Chinese Scholars (grant No. 2005545), the Natural Science Foundation of Ningbo City (grant No. 2007A610021) and Ningbo University (grant No. 2005062). We thank Dr K.-W. Lei for structural discussions and Mrs W. Xu and D.-Y. Cheng for collecting the diffraction data.
References
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Because of its various deprotonation modes (H2biim, Hbiim-, biim2-), the 2,2'-biimidazole ligand exhibits rich coordination patterns with various metals such as AgI (Sang & Xu, 2006), NiII (Tadokoro et al., 1999), CuII(Atencio et al., 2005; Carraza et al., 2003) and CoIIIÖhrström et al., 2001). We report here the crystal structure of a CuII complex with neutral 2,2'-biimidazole molecule and 2-bromofumarate anion as ligands.
As illustrated in Fig. 1, the Cu atom shows a distorted octahedral coordination geometry, formed by four N atoms from two 2,2'-biimidazole molecules and two O atoms from carboxylate groups offered by two 2-bromofumarate ligands at the axial positions. The asymmetric unit contains an H2biim molecule and a 2-bromofumarate anion with a CuII atom lying on an inversion center. We can see that the lengths of Cu—N bonds [2.028 (5) and 2.001 (5) Å] are slightly asymmetric (Table 1). This behavior is similar to the reported Cu complex with H2biim [2.036 (2) and 2.010 (2) Å] (Atencio et al., 2005). Three types of strong hydrogen bonds are observed. The O—H···O hydrogen bonds are formed between two adjacent uncoordinated carboxylate groups. The N—H···O hydrogen bonds are formed between H2biim and the neighboring coordinated carboxylate group. Weak C—H···O hydrogen bonds also exist in the structure (Table 2). The complex molecules are assembled into two-dimensional layers via O—H···O and N—H···O hydrogen bonds. These layers are further assembled through C—H···O hydrogen bonds into a three-dimensional supramolecular structure.