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Acta Crystallogr Sect E Struct Rep Online. 2010 September 1; 66(Pt 9): m1124–m1125.
Published online 2010 August 18. doi:  10.1107/S1600536810031922
PMCID: PMC3008059

Bis(2,2′-bi-1H-imidazole-κ2 N 3,N 3′)bis­(dimethyl sulfoxide-κO)copper(II) bis­(tetra­fluoridoborate)

Abstract

In the title copper(II) salt, [Cu(C6H6N4)2(C2H6OS)2](BF4)2, the Jahn–Teller distorted octa­hedral coordination sphere of copper is formed from four 2,2′-bi-1H-imidazole N atoms and two dimethyl sulfoxide O atoms. The Cu atom lies on a center of inversion. N—H(...)O and N—H(...)F hydrogen bonds give rise to a one-dimensional structure. The BF4 anion is disordered over two sites in a 0.671 (10):0.329 (10) ratio.

Related literature

Supra­molecular complexes containing H2biim (H2biim = 2,2′-biimidazole) have been applied widely in mol­ecular catalysis, photoelectric conversion materials and mol­ecular recognition, see: Ding et al. (2005 [triangle]). For the effect of the coordination bonds, inter­molecular hydrogen bonds and π–π packing inter­actions on the mol­ecular arrangement, see: Burrows (2004 [triangle]); Dai et al. (2009 [triangle]). For related structures, see: Jin et al. (2010 [triangle]); Aminou et al. (2004 [triangle]); Gruia et al. (2007 [triangle]); Yang et al. (2008 [triangle]). For Cu—O coordination bond lengths, see: Tao et al. (2002 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-m1124-scheme1.jpg

Experimental

Crystal data

  • [Cu(C6H6N4)2(C2H6OS)2](BF4)2
  • M r = 661.71
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-m1124-efi1.jpg
  • a = 7.059 (1) Å
  • b = 10.0721 (13) Å
  • c = 10.3669 (15) Å
  • α = 113.436 (2)°
  • β = 96.860 (1)°
  • γ = 92.000 (1)°
  • V = 668.68 (16) Å3
  • Z = 1
  • Mo Kα radiation
  • μ = 1.06 mm−1
  • T = 298 K
  • 0.36 × 0.32 × 0.20 mm

Data collection

  • Bruker SMART CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2007 [triangle]) T min = 0.701, T max = 0.816
  • 3418 measured reflections
  • 2293 independent reflections
  • 1885 reflections with I > 2σ(I)
  • R int = 0.023

Refinement

  • R[F 2 > 2σ(F 2)] = 0.040
  • wR(F 2) = 0.111
  • S = 1.03
  • 2293 reflections
  • 209 parameters
  • H-atom parameters constrained
  • Δρmax = 0.34 e Å−3
  • Δρmin = −0.32 e Å−3

Data collection: SMART (Bruker, 2007 [triangle]); cell refinement: SAINT-Plus (Bruker, 2007 [triangle]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Selected bond lengths (Å)
Table 2
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810031922/ng5003sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810031922/ng5003Isup2.hkl

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

Acknowledgments

This work has been supported by the National Keystone Basic Research Program (973 Program) under grant No. 2007CB310408, No. 2006CB302901 and the Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality. It was also supported by the State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences.

supplementary crystallographic information

Comment

Supramolecular complexes containing H2biim have been applied widely in molecular catalysis, photoelectric conversion materials and molecular recognition (Ding et al., 2005) The ligand of H2biim has been widely studied and applied because of the diversity of their coordination and the strong ability to form hydrogen bonds as a multi-proton donor. The utilization of the coordination bonds of a transition metal ion, intermolecular hydrogen bonds and πi-πi packing interactions help to control the molecular arrangement (Burrows, 2004; Dai et al., 2009). We focus on the synthesis of the biimidazole-metal complexes. Here we report a new complex [Cu(H2biim)2(DMSO)2](BF4)2 (1). Similar complexes {[Cu(H2biim)2(H2O)](SiF6)}.H2O (2), [Cu(H2biim)2](ClO4)2.2DMSO (Jin et al.,2010) and [Cd(H2biim)3](SiF6)(BF4)2.6EtOH (Gruia et al.,2007) will be compared here.

The title complex is composed of [Cu(H2biim)2(DMSO)2]2+ and two free BF4- anions. Cu(II) atom is in the center of Jahn-Teller elongated octahedron. The equatorial positions are occupied by four nitrogen atoms of two bidentate H2biim molecules, while the axial positions are occupied by O atoms from two DMSO (Fig. 1). The [Cu(H2biim)2(DMSO)2]2+ unit stacks along the b axis to form a step-shaped infinite chain structure through πi-πi stacking and H-bonds(Fig.2).

The two identical distances Cu ··· O(DMSO) of 2.678 (2)Å are in the range of Cu—O coordination bond (from 2.522Å to 2.724 Å) (Tao et al., 2002). The two identical Cu—N distances of 2.016 (2)Å are slightly shorter than those in [Cu(H2biim)2](ClO4)2.2DMSO [2.021 (2)Å and 2.018 (2) Å]. In the title complex there exist two types of hydrogen bonds, one is N—H···O formed between N—H group of the H2biim and oxygen atom of DMSO, the other is N—H···F formed between N—H group of H2biim and fluorine atom of BF4-. The DMSO molecule and BF4- anion are located at both sides of the cation to form hydrogen bonds mentioned above. The face-to-face distance between the immidazole rings is 3.43Å with the dihedral angle of 3.718°, which suggests the existence of significant πi-πi interactions between them. There is a weak interaction Cu···SDMSO(3.458 Å) in complex (1).

The solvent plays an important role in the reaction of metal salt with 2,2'-bimidazole. Not only the configuration of the anions but also the coordination geometry of the cations are affected by the solvent. Complex 1 was prepared in the mixed solvent of ethanol and DMSO by the reaction of 2,2'- bimidazole with copper tetrafluoroborate with molar ratio 3:1. However, the ratio of ligand and metal in the cation [Cu(H2biim)2(DMSO)2]2+ of complex 1 is not consistent with the raw molar ratio, which may be related to the selectivity of solvent DMSO. Complex 2, {[Cu(H2biim)2(H2O)]SiF6}.H2O, was prepared by the similar method of preparing (1) except using solvent water (Jin et al.,2010). Due to the different solvents, both the cation and the anion in complex (1) and complex (2) are different. It is noted that in complex (1) the anion BF4- was coming from starting material Cu(BF4)2 while in complex (2) the anion SiF62- was not, but was formed by the reaction of BF4- with glass container in water. The complex [Cd(H2biim)3](SiF6)(BF4)2.6EtOH(Gruia et al.,2007) contains mixed cations SiF62-and BF4-, which is related to the mixed solvent water and enthanol used in the reaction system.

The title complex is also similar to the following complexes: [Cu(H2biim)2](ClO4)2 (Aminou et al.,2004), [Cu(H2biim)2]Br2(Yang et al.,2008) and [Cu(H2biim)2](ClO4)2.2DMSO (Jin et al.,2010).

Experimental

Cu(BF4)2.6H2O (0.1726 g, 1 mmol)dissolved in C2H5OH (5 ml) was added to a solution of H2biim (0.2010 g, 3 mmol) in C2H5OH (5 ml). The mixture was refluxed for 0.5 h, then 1 ml DMSO was added, stirring for another hour at room temperature, then filtered. Subsequent slow evaporation of the filtrate resulted in the formation of green crystals of the title complex after four weeks. Crystals suitable for single-crystal X-ray diffraction were selected directly from the sample as prepared. Analysis found(percentage): C 38.08, H 3.83, N 22.19; calculated:C 37.71, H 3.90, N 21.86.

Refinement

Metal atom centers were located from the E-maps and other non-hydrogen atoms were located in successive difference Fourier syntheses. The final refinements were performed by full matrix least-squares methods with anisotropic thermal parameters for non-hydrogen atoms on F2.

The final refinements were performed with isotropic thermal parameters. All hydrogen atoms were located in the calculated sites and included in the final refinement in the riding model approximation with displacement parameters derived from the parent atoms to which they were bonded.

Figures

Fig. 1.
Perspective view of a basic unit of the title complex. Hydrogen atoms are omitted for clarity. Atoms are displayed as elliposoids at the 50% probability level.
Fig. 2.
Step-like chain of [Cu(H2biim)2(DMSO)2]2+ (BF4)2 unit along b axis.

Crystal data

[Cu(C6H6N4)2(C2H6OS)2](BF4)2Z = 1
Mr = 661.71F(000) = 335
Triclinic, P1Dx = 1.643 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.059 (1) ÅCell parameters from 2039 reflections
b = 10.0721 (13) Åθ = 2.2–27.1°
c = 10.3669 (15) ŵ = 1.06 mm1
α = 113.436 (2)°T = 298 K
β = 96.860 (1)°Block, green
γ = 92.000 (1)°0.36 × 0.32 × 0.20 mm
V = 668.68 (16) Å3

Data collection

Bruker SMART CCD area-detector diffractometer2293 independent reflections
Radiation source: fine-focus sealed tube1885 reflections with I > 2σ(I)
graphiteRint = 0.023
phi and ω scansθmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan SADABSh = −8→8
Tmin = 0.701, Tmax = 0.816k = −11→11
3418 measured reflectionsl = −12→11

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.040H-atom parameters constrained
wR(F2) = 0.111w = 1/[σ2(Fo2) + (0.0545P)2 + 0.5099P] where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max = 0.001
2293 reflectionsΔρmax = 0.34 e Å3
209 parametersΔρmin = −0.32 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.048 (5)

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 (Å2)

xyzUiso*/UeqOcc. (<1)
Cu10.50000.50000.50000.0390 (2)
F10.7595 (5)0.2780 (3)0.7673 (4)0.1074 (11)
F20.7494 (11)0.2364 (7)0.9569 (6)0.133 (3)0.671 (10)
F30.8593 (16)0.0735 (12)0.7739 (12)0.131 (5)0.671 (10)
F40.5500 (11)0.1020 (9)0.7667 (9)0.111 (3)0.671 (10)
F2'0.676 (3)0.0585 (13)0.6485 (15)0.153 (7)0.329 (10)
F3'0.577 (2)0.1641 (18)0.8495 (19)0.114 (7)0.329 (10)
F4'0.873 (3)0.121 (3)0.844 (3)0.137 (10)0.329 (10)
N10.3310 (3)0.6573 (3)0.5939 (3)0.0400 (6)
N20.0728 (4)0.7101 (3)0.6960 (3)0.0487 (7)
H2−0.02970.70020.72970.058*
N30.3261 (3)0.3835 (3)0.5650 (3)0.0392 (6)
N40.0623 (4)0.3776 (3)0.6562 (3)0.0472 (7)
H4−0.03920.40470.69430.057*
O10.2552 (3)0.4077 (3)0.2573 (2)0.0501 (6)
S10.37073 (11)0.34825 (10)0.13515 (8)0.0454 (3)
B20.7268 (7)0.1654 (5)0.8039 (6)0.0657 (13)
C10.1883 (4)0.6060 (4)0.6387 (3)0.0378 (7)
C20.1466 (5)0.8336 (4)0.6911 (4)0.0585 (10)
H2A0.09720.92350.72520.070*
C30.3060 (5)0.8018 (4)0.6273 (4)0.0526 (9)
H30.38490.86630.60930.063*
C40.1839 (4)0.4588 (4)0.6222 (3)0.0377 (7)
C50.1283 (5)0.2444 (5)0.6198 (4)0.0579 (10)
H50.07200.16510.63030.069*
C60.2919 (5)0.2493 (4)0.5652 (4)0.0516 (9)
H60.36910.17320.53290.062*
C70.2567 (7)0.3869 (5)−0.0058 (4)0.0692 (11)
H7A0.12240.3562−0.02260.104*
H7B0.31210.3360−0.09020.104*
H7C0.27350.48950.01890.104*
C80.3115 (7)0.1570 (5)0.0606 (5)0.0762 (13)
H8B0.35050.11930.13040.114*
H8C0.37650.1122−0.02020.114*
H8A0.17560.13630.03140.114*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cu10.0288 (3)0.0399 (4)0.0538 (4)0.0093 (2)0.0220 (2)0.0197 (3)
F10.110 (2)0.0760 (19)0.165 (3)0.0132 (16)0.069 (2)0.066 (2)
F20.163 (6)0.137 (5)0.080 (4)−0.018 (4)0.039 (4)0.020 (3)
F30.130 (10)0.099 (7)0.197 (12)0.083 (7)0.096 (10)0.067 (7)
F40.084 (4)0.102 (6)0.142 (7)−0.037 (4)−0.005 (5)0.053 (5)
F2'0.180 (15)0.096 (9)0.129 (11)0.004 (8)0.030 (10)−0.013 (7)
F3'0.095 (13)0.124 (13)0.143 (16)0.020 (10)0.085 (13)0.056 (11)
F4'0.098 (13)0.120 (17)0.18 (2)0.012 (11)−0.044 (14)0.060 (15)
N10.0305 (13)0.0407 (15)0.0455 (15)0.0044 (11)0.0131 (11)0.0119 (12)
N20.0365 (14)0.0599 (19)0.0431 (16)0.0132 (13)0.0190 (12)0.0095 (14)
N30.0332 (13)0.0446 (15)0.0454 (15)0.0063 (11)0.0135 (11)0.0217 (12)
N40.0333 (14)0.066 (2)0.0450 (16)−0.0008 (13)0.0155 (12)0.0237 (14)
O10.0525 (14)0.0504 (14)0.0450 (13)0.0066 (11)0.0263 (11)0.0113 (11)
S10.0382 (5)0.0576 (6)0.0371 (5)0.0021 (4)0.0142 (3)0.0134 (4)
B20.051 (3)0.052 (3)0.105 (4)0.009 (2)0.034 (3)0.037 (3)
C10.0261 (14)0.0506 (19)0.0314 (15)0.0073 (13)0.0100 (12)0.0092 (14)
C20.056 (2)0.048 (2)0.059 (2)0.0190 (18)0.0190 (18)0.0050 (18)
C30.050 (2)0.042 (2)0.064 (2)0.0095 (15)0.0198 (17)0.0154 (17)
C40.0261 (14)0.056 (2)0.0328 (16)0.0029 (13)0.0103 (12)0.0181 (14)
C50.055 (2)0.065 (3)0.065 (2)−0.0041 (19)0.0159 (18)0.037 (2)
C60.050 (2)0.051 (2)0.063 (2)0.0090 (16)0.0183 (17)0.0298 (18)
C70.089 (3)0.070 (3)0.053 (2)0.015 (2)0.015 (2)0.026 (2)
C80.100 (3)0.054 (3)0.075 (3)0.020 (2)0.037 (3)0.018 (2)

Geometric parameters (Å, °)

Cu1—N12.016 (2)N4—H40.8600
Cu1—N1i2.016 (2)N4—C41.335 (4)
Cu1—N3i2.016 (2)N4—C51.357 (5)
Cu1—N32.016 (2)O1—S11.519 (2)
Cu1—O12.678 (2)S1—C71.769 (4)
F1—B21.351 (5)S1—C81.779 (4)
F2—B21.443 (8)C1—C41.422 (5)
F3—B21.316 (9)C2—H2A0.9300
F4—B21.322 (8)C2—C31.356 (5)
F2'—B21.529 (14)C3—H30.9300
F3'—B21.213 (13)C5—H50.9300
F4'—B21.23 (2)C5—C61.353 (5)
N1—C11.328 (4)C6—H60.9300
N1—C31.378 (4)C7—H7A0.9600
N2—H20.8600C7—H7B0.9600
N2—C11.340 (4)C7—H7C0.9600
N2—C21.353 (5)C8—H8B0.9600
N3—C41.331 (4)C8—H8C0.9600
N3—C61.365 (4)C8—H8A0.9600
F1—B2—F2102.1 (5)N3—C6—H6125.3
F1—B2—F2'92.2 (7)N4—C4—C1132.0 (3)
F2—B2—F2'165.0 (7)N4—C5—H5126.6
F3—B2—F1113.0 (7)O1—S1—C7107.35 (18)
F3—B2—F2106.0 (7)O1—S1—C8104.93 (18)
F3—B2—F4113.7 (8)S1—O1—Cu1107.75 (12)
F3—B2—F2'71.8 (8)S1—C7—H7A109.5
F4—B2—F1115.9 (6)S1—C7—H7B109.5
F4—B2—F2104.4 (6)S1—C7—H7C109.5
F4—B2—F2'64.6 (8)S1—C8—H8B109.5
F3'—B2—F1114.3 (9)S1—C8—H8C109.5
F3'—B2—F267.7 (10)S1—C8—H8A109.5
F3'—B2—F3132.6 (11)C1—N1—Cu1111.0 (2)
F3'—B2—F437.9 (7)C1—N1—C3106.2 (3)
F3'—B2—F2'102.4 (11)C1—N2—H2126.1
F3'—B2—F4'123.6 (18)C1—N2—C2107.7 (3)
F4'—B2—F1114.2 (15)C2—N2—H2126.1
F4'—B2—F275.5 (12)C2—C3—N1108.3 (3)
F4'—B2—F331.1 (11)C2—C3—H3125.9
F4'—B2—F4128.6 (14)C3—N1—Cu1142.8 (2)
F4'—B2—F2'102.9 (11)C3—C2—H2A126.3
N1—Cu1—N1i180.00 (16)C4—N3—Cu1111.3 (2)
N1i—Cu1—N3i82.24 (10)C4—N3—C6105.6 (3)
N1i—Cu1—N397.76 (10)C4—N4—H4126.3
N1—Cu1—N3i97.76 (10)C4—N4—C5107.5 (3)
N1—Cu1—N382.24 (10)C5—N4—H4126.3
N1—Cu1—O190.17 (9)C5—C6—N3109.4 (3)
N1i—Cu1—O189.83 (9)C5—C6—H6125.3
N1—C1—N2110.5 (3)C6—N3—Cu1143.0 (2)
N1—C1—C4118.0 (3)C6—C5—N4106.7 (3)
N1—C3—H3125.9C6—C5—H5126.6
N2—C1—C4131.6 (3)C7—S1—C898.8 (2)
N2—C2—H2A126.3H7A—C7—H7B109.5
N2—C2—C3107.3 (3)H7A—C7—H7C109.5
N3i—Cu1—N3180.0H7B—C7—H7C109.5
N3—Cu1—O187.32 (9)H8B—C8—H8C109.5
N3i—Cu1—O192.68 (9)H8B—C8—H8A109.5
N3—C4—N4110.9 (3)H8C—C8—H8A109.5
N3—C4—C1117.1 (3)
Cu1—N1—C1—N2−177.6 (2)N3—Cu1—N1—C3176.9 (4)
Cu1—N1—C1—C43.6 (3)N3i—Cu1—N1—C3−3.1 (4)
Cu1—N1—C3—C2177.8 (3)N3i—Cu1—N3—C4−68 (100)
Cu1—N3—C4—N4175.87 (19)N3i—Cu1—N3—C6107 (100)
Cu1—N3—C4—C1−5.3 (3)N3—Cu1—O1—S1−129.93 (14)
Cu1—N3—C6—C5−173.6 (3)N3i—Cu1—O1—S150.07 (14)
Cu1—O1—S1—C7−146.23 (18)N4—C5—C6—N3−1.1 (4)
Cu1—O1—S1—C8109.39 (19)O1—Cu1—N1—C182.3 (2)
N1i—Cu1—N1—C1−142 (100)O1—Cu1—N1—C3−95.8 (4)
N1i—Cu1—N1—C340 (100)O1—Cu1—N3—C4−85.0 (2)
N1i—Cu1—N3—C4−174.5 (2)O1—Cu1—N3—C689.6 (4)
N1—Cu1—N3—C45.5 (2)C1—N1—C3—C2−0.4 (4)
N1i—Cu1—N3—C60.1 (4)C1—N2—C2—C31.3 (4)
N1—Cu1—N3—C6−179.9 (4)C2—N2—C1—N1−1.6 (4)
N1—Cu1—O1—S1147.85 (14)C2—N2—C1—C4177.0 (3)
N1i—Cu1—O1—S1−32.15 (14)C3—N1—C1—N21.2 (4)
N1—C1—C4—N31.2 (4)C3—N1—C1—C4−177.6 (3)
N1—C1—C4—N4179.7 (3)C4—N3—C6—C51.2 (4)
N2—C1—C4—N3−177.3 (3)C4—N4—C5—C60.7 (4)
N2—C1—C4—N41.3 (6)C5—N4—C4—N30.0 (4)
N2—C2—C3—N1−0.5 (4)C5—N4—C4—C1−178.6 (3)
N3i—Cu1—N1—C1175.1 (2)C6—N3—C4—N4−0.7 (4)
N3—Cu1—N1—C1−4.9 (2)C6—N3—C4—C1178.1 (3)

Symmetry codes: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N2—H2···O1ii0.861.942.745 (4)155.
N4—H4···F1iii0.862.262.874 (4)128.
N4—H4···O1ii0.862.403.127 (4)142.

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: NG5003).

References

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