metal-organic compounds
Bis(2,2′-bi-1H-imidazole-κ2N3,N3′)bis(dimethyl sulfoxide-κO)copper(II) bis(tetrafluoridoborate)
aDepartment of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China, and bBeijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Capital Normal University, Beijing 100048, People's Republic of China
*Correspondence e-mail: jinqh204@163.com
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). For the effect of the coordination bonds, intermolecular hydrogen bonds and π–π packing interactions on the molecular arrangement, see: Burrows (2004); Dai et al. (2009). For related structures, see: Jin et al. (2010); Aminou et al. (2004); Gruia et al. (2007); Yang et al. (2008). For Cu—O coordination bond lengths, see: Tao et al. (2002).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2007); cell SAINT-Plus (Bruker, 2007); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536810031922/ng5003sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810031922/ng5003Isup2.hkl
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.
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
in the riding model approximation with displacement parameters derived from the parent atoms to which they were bonded.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 SiF6 2-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).
Supramolecular complexes containing H2biim have been applied widely in molecular catalysis, photoelectric conversion materials and molecular recognition, see: Ding et al. (2005). For the effect of the coordination bonds, intermolecular hydrogen bonds and πi–πi packing interactions on the molecular arrangement, see: Burrows (2004); Dai et al. (2009). For related structures, see: Jin et al. (2010); Aminou et al. (2004); Gruia et al. (2007); Yang et al. (2008). or Cu—O coordination bond lengths, see: Tao et al. (2002).
Data collection: SMART (Bruker, 2007); cell
SAINT-Plus (Bruker, 2007); data reduction: SAINT-Plus (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).[Cu(C6H6N4)2(C2H6OS)2](BF4)2 | Z = 1 |
Mr = 661.71 | F(000) = 335 |
Triclinic, P1 | Dx = 1.643 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.059 (1) Å | Cell parameters from 2039 reflections |
b = 10.0721 (13) Å | θ = 2.2–27.1° |
c = 10.3669 (15) Å | µ = 1.06 mm−1 |
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 |
Bruker SMART CCD area-detector diffractometer | 2293 independent reflections |
Radiation source: fine-focus sealed tube | 1885 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.023 |
phi and ω scans | θmax = 25.0°, θmin = 2.2° |
Absorption correction: multi-scan SADABS | h = −8→8 |
Tmin = 0.701, Tmax = 0.816 | k = −11→11 |
3418 measured reflections | l = −12→11 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.040 | H-atom parameters constrained |
wR(F2) = 0.111 | w = 1/[σ2(Fo2) + (0.0545P)2 + 0.5099P] where P = (Fo2 + 2Fc2)/3 |
S = 1.03 | (Δ/σ)max = 0.001 |
2293 reflections | Δρmax = 0.34 e Å−3 |
209 parameters | Δρmin = −0.32 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.048 (5) |
[Cu(C6H6N4)2(C2H6OS)2](BF4)2 | γ = 92.000 (1)° |
Mr = 661.71 | V = 668.68 (16) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.059 (1) Å | Mo Kα radiation |
b = 10.0721 (13) Å | µ = 1.06 mm−1 |
c = 10.3669 (15) Å | T = 298 K |
α = 113.436 (2)° | 0.36 × 0.32 × 0.20 mm |
β = 96.860 (1)° |
Bruker SMART CCD area-detector diffractometer | 2293 independent reflections |
Absorption correction: multi-scan SADABS | 1885 reflections with I > 2σ(I) |
Tmin = 0.701, Tmax = 0.816 | Rint = 0.023 |
3418 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.111 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.34 e Å−3 |
2293 reflections | Δρmin = −0.32 e Å−3 |
209 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. |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Cu1 | 0.5000 | 0.5000 | 0.5000 | 0.0390 (2) | |
F1 | 0.7595 (5) | 0.2780 (3) | 0.7673 (4) | 0.1074 (11) | |
F2 | 0.7494 (11) | 0.2364 (7) | 0.9569 (6) | 0.133 (3) | 0.671 (10) |
F3 | 0.8593 (16) | 0.0735 (12) | 0.7739 (12) | 0.131 (5) | 0.671 (10) |
F4 | 0.5500 (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) |
N1 | 0.3310 (3) | 0.6573 (3) | 0.5939 (3) | 0.0400 (6) | |
N2 | 0.0728 (4) | 0.7101 (3) | 0.6960 (3) | 0.0487 (7) | |
H2 | −0.0297 | 0.7002 | 0.7297 | 0.058* | |
N3 | 0.3261 (3) | 0.3835 (3) | 0.5650 (3) | 0.0392 (6) | |
N4 | 0.0623 (4) | 0.3776 (3) | 0.6562 (3) | 0.0472 (7) | |
H4 | −0.0392 | 0.4047 | 0.6943 | 0.057* | |
O1 | 0.2552 (3) | 0.4077 (3) | 0.2573 (2) | 0.0501 (6) | |
S1 | 0.37073 (11) | 0.34825 (10) | 0.13515 (8) | 0.0454 (3) | |
B2 | 0.7268 (7) | 0.1654 (5) | 0.8039 (6) | 0.0657 (13) | |
C1 | 0.1883 (4) | 0.6060 (4) | 0.6387 (3) | 0.0378 (7) | |
C2 | 0.1466 (5) | 0.8336 (4) | 0.6911 (4) | 0.0585 (10) | |
H2A | 0.0972 | 0.9235 | 0.7252 | 0.070* | |
C3 | 0.3060 (5) | 0.8018 (4) | 0.6273 (4) | 0.0526 (9) | |
H3 | 0.3849 | 0.8663 | 0.6093 | 0.063* | |
C4 | 0.1839 (4) | 0.4588 (4) | 0.6222 (3) | 0.0377 (7) | |
C5 | 0.1283 (5) | 0.2444 (5) | 0.6198 (4) | 0.0579 (10) | |
H5 | 0.0720 | 0.1651 | 0.6303 | 0.069* | |
C6 | 0.2919 (5) | 0.2493 (4) | 0.5652 (4) | 0.0516 (9) | |
H6 | 0.3691 | 0.1732 | 0.5329 | 0.062* | |
C7 | 0.2567 (7) | 0.3869 (5) | −0.0058 (4) | 0.0692 (11) | |
H7A | 0.1224 | 0.3562 | −0.0226 | 0.104* | |
H7B | 0.3121 | 0.3360 | −0.0902 | 0.104* | |
H7C | 0.2735 | 0.4895 | 0.0189 | 0.104* | |
C8 | 0.3115 (7) | 0.1570 (5) | 0.0606 (5) | 0.0762 (13) | |
H8B | 0.3505 | 0.1193 | 0.1304 | 0.114* | |
H8C | 0.3765 | 0.1122 | −0.0202 | 0.114* | |
H8A | 0.1756 | 0.1363 | 0.0314 | 0.114* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0288 (3) | 0.0399 (4) | 0.0538 (4) | 0.0093 (2) | 0.0220 (2) | 0.0197 (3) |
F1 | 0.110 (2) | 0.0760 (19) | 0.165 (3) | 0.0132 (16) | 0.069 (2) | 0.066 (2) |
F2 | 0.163 (6) | 0.137 (5) | 0.080 (4) | −0.018 (4) | 0.039 (4) | 0.020 (3) |
F3 | 0.130 (10) | 0.099 (7) | 0.197 (12) | 0.083 (7) | 0.096 (10) | 0.067 (7) |
F4 | 0.084 (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) |
N1 | 0.0305 (13) | 0.0407 (15) | 0.0455 (15) | 0.0044 (11) | 0.0131 (11) | 0.0119 (12) |
N2 | 0.0365 (14) | 0.0599 (19) | 0.0431 (16) | 0.0132 (13) | 0.0190 (12) | 0.0095 (14) |
N3 | 0.0332 (13) | 0.0446 (15) | 0.0454 (15) | 0.0063 (11) | 0.0135 (11) | 0.0217 (12) |
N4 | 0.0333 (14) | 0.066 (2) | 0.0450 (16) | −0.0008 (13) | 0.0155 (12) | 0.0237 (14) |
O1 | 0.0525 (14) | 0.0504 (14) | 0.0450 (13) | 0.0066 (11) | 0.0263 (11) | 0.0113 (11) |
S1 | 0.0382 (5) | 0.0576 (6) | 0.0371 (5) | 0.0021 (4) | 0.0142 (3) | 0.0134 (4) |
B2 | 0.051 (3) | 0.052 (3) | 0.105 (4) | 0.009 (2) | 0.034 (3) | 0.037 (3) |
C1 | 0.0261 (14) | 0.0506 (19) | 0.0314 (15) | 0.0073 (13) | 0.0100 (12) | 0.0092 (14) |
C2 | 0.056 (2) | 0.048 (2) | 0.059 (2) | 0.0190 (18) | 0.0190 (18) | 0.0050 (18) |
C3 | 0.050 (2) | 0.042 (2) | 0.064 (2) | 0.0095 (15) | 0.0198 (17) | 0.0154 (17) |
C4 | 0.0261 (14) | 0.056 (2) | 0.0328 (16) | 0.0029 (13) | 0.0103 (12) | 0.0181 (14) |
C5 | 0.055 (2) | 0.065 (3) | 0.065 (2) | −0.0041 (19) | 0.0159 (18) | 0.037 (2) |
C6 | 0.050 (2) | 0.051 (2) | 0.063 (2) | 0.0090 (16) | 0.0183 (17) | 0.0298 (18) |
C7 | 0.089 (3) | 0.070 (3) | 0.053 (2) | 0.015 (2) | 0.015 (2) | 0.026 (2) |
C8 | 0.100 (3) | 0.054 (3) | 0.075 (3) | 0.020 (2) | 0.037 (3) | 0.018 (2) |
Cu1—N1 | 2.016 (2) | N4—H4 | 0.8600 |
Cu1—N1i | 2.016 (2) | N4—C4 | 1.335 (4) |
Cu1—N3i | 2.016 (2) | N4—C5 | 1.357 (5) |
Cu1—N3 | 2.016 (2) | O1—S1 | 1.519 (2) |
Cu1—O1 | 2.678 (2) | S1—C7 | 1.769 (4) |
F1—B2 | 1.351 (5) | S1—C8 | 1.779 (4) |
F2—B2 | 1.443 (8) | C1—C4 | 1.422 (5) |
F3—B2 | 1.316 (9) | C2—H2A | 0.9300 |
F4—B2 | 1.322 (8) | C2—C3 | 1.356 (5) |
F2'—B2 | 1.529 (14) | C3—H3 | 0.9300 |
F3'—B2 | 1.213 (13) | C5—H5 | 0.9300 |
F4'—B2 | 1.23 (2) | C5—C6 | 1.353 (5) |
N1—C1 | 1.328 (4) | C6—H6 | 0.9300 |
N1—C3 | 1.378 (4) | C7—H7A | 0.9600 |
N2—H2 | 0.8600 | C7—H7B | 0.9600 |
N2—C1 | 1.340 (4) | C7—H7C | 0.9600 |
N2—C2 | 1.353 (5) | C8—H8B | 0.9600 |
N3—C4 | 1.331 (4) | C8—H8C | 0.9600 |
N3—C6 | 1.365 (4) | C8—H8A | 0.9600 |
F1—B2—F2 | 102.1 (5) | N3—C6—H6 | 125.3 |
F1—B2—F2' | 92.2 (7) | N4—C4—C1 | 132.0 (3) |
F2—B2—F2' | 165.0 (7) | N4—C5—H5 | 126.6 |
F3—B2—F1 | 113.0 (7) | O1—S1—C7 | 107.35 (18) |
F3—B2—F2 | 106.0 (7) | O1—S1—C8 | 104.93 (18) |
F3—B2—F4 | 113.7 (8) | S1—O1—Cu1 | 107.75 (12) |
F3—B2—F2' | 71.8 (8) | S1—C7—H7A | 109.5 |
F4—B2—F1 | 115.9 (6) | S1—C7—H7B | 109.5 |
F4—B2—F2 | 104.4 (6) | S1—C7—H7C | 109.5 |
F4—B2—F2' | 64.6 (8) | S1—C8—H8B | 109.5 |
F3'—B2—F1 | 114.3 (9) | S1—C8—H8C | 109.5 |
F3'—B2—F2 | 67.7 (10) | S1—C8—H8A | 109.5 |
F3'—B2—F3 | 132.6 (11) | C1—N1—Cu1 | 111.0 (2) |
F3'—B2—F4 | 37.9 (7) | C1—N1—C3 | 106.2 (3) |
F3'—B2—F2' | 102.4 (11) | C1—N2—H2 | 126.1 |
F3'—B2—F4' | 123.6 (18) | C1—N2—C2 | 107.7 (3) |
F4'—B2—F1 | 114.2 (15) | C2—N2—H2 | 126.1 |
F4'—B2—F2 | 75.5 (12) | C2—C3—N1 | 108.3 (3) |
F4'—B2—F3 | 31.1 (11) | C2—C3—H3 | 125.9 |
F4'—B2—F4 | 128.6 (14) | C3—N1—Cu1 | 142.8 (2) |
F4'—B2—F2' | 102.9 (11) | C3—C2—H2A | 126.3 |
N1—Cu1—N1i | 180.00 (16) | C4—N3—Cu1 | 111.3 (2) |
N1i—Cu1—N3i | 82.24 (10) | C4—N3—C6 | 105.6 (3) |
N1i—Cu1—N3 | 97.76 (10) | C4—N4—H4 | 126.3 |
N1—Cu1—N3i | 97.76 (10) | C4—N4—C5 | 107.5 (3) |
N1—Cu1—N3 | 82.24 (10) | C5—N4—H4 | 126.3 |
N1—Cu1—O1 | 90.17 (9) | C5—C6—N3 | 109.4 (3) |
N1i—Cu1—O1 | 89.83 (9) | C5—C6—H6 | 125.3 |
N1—C1—N2 | 110.5 (3) | C6—N3—Cu1 | 143.0 (2) |
N1—C1—C4 | 118.0 (3) | C6—C5—N4 | 106.7 (3) |
N1—C3—H3 | 125.9 | C6—C5—H5 | 126.6 |
N2—C1—C4 | 131.6 (3) | C7—S1—C8 | 98.8 (2) |
N2—C2—H2A | 126.3 | H7A—C7—H7B | 109.5 |
N2—C2—C3 | 107.3 (3) | H7A—C7—H7C | 109.5 |
N3i—Cu1—N3 | 180.0 | H7B—C7—H7C | 109.5 |
N3—Cu1—O1 | 87.32 (9) | H8B—C8—H8C | 109.5 |
N3i—Cu1—O1 | 92.68 (9) | H8B—C8—H8A | 109.5 |
N3—C4—N4 | 110.9 (3) | H8C—C8—H8A | 109.5 |
N3—C4—C1 | 117.1 (3) | ||
Cu1—N1—C1—N2 | −177.6 (2) | N3—Cu1—N1—C3 | 176.9 (4) |
Cu1—N1—C1—C4 | 3.6 (3) | N3i—Cu1—N1—C3 | −3.1 (4) |
Cu1—N1—C3—C2 | 177.8 (3) | N3i—Cu1—N3—C4 | −68 (100) |
Cu1—N3—C4—N4 | 175.87 (19) | N3i—Cu1—N3—C6 | 107 (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—S1 | 50.07 (14) |
Cu1—O1—S1—C7 | −146.23 (18) | N4—C5—C6—N3 | −1.1 (4) |
Cu1—O1—S1—C8 | 109.39 (19) | O1—Cu1—N1—C1 | 82.3 (2) |
N1i—Cu1—N1—C1 | −142 (100) | O1—Cu1—N1—C3 | −95.8 (4) |
N1i—Cu1—N1—C3 | 40 (100) | O1—Cu1—N3—C4 | −85.0 (2) |
N1i—Cu1—N3—C4 | −174.5 (2) | O1—Cu1—N3—C6 | 89.6 (4) |
N1—Cu1—N3—C4 | 5.5 (2) | C1—N1—C3—C2 | −0.4 (4) |
N1i—Cu1—N3—C6 | 0.1 (4) | C1—N2—C2—C3 | 1.3 (4) |
N1—Cu1—N3—C6 | −179.9 (4) | C2—N2—C1—N1 | −1.6 (4) |
N1—Cu1—O1—S1 | 147.85 (14) | C2—N2—C1—C4 | 177.0 (3) |
N1i—Cu1—O1—S1 | −32.15 (14) | C3—N1—C1—N2 | 1.2 (4) |
N1—C1—C4—N3 | 1.2 (4) | C3—N1—C1—C4 | −177.6 (3) |
N1—C1—C4—N4 | 179.7 (3) | C4—N3—C6—C5 | 1.2 (4) |
N2—C1—C4—N3 | −177.3 (3) | C4—N4—C5—C6 | 0.7 (4) |
N2—C1—C4—N4 | 1.3 (6) | C5—N4—C4—N3 | 0.0 (4) |
N2—C2—C3—N1 | −0.5 (4) | C5—N4—C4—C1 | −178.6 (3) |
N3i—Cu1—N1—C1 | 175.1 (2) | C6—N3—C4—N4 | −0.7 (4) |
N3—Cu1—N1—C1 | −4.9 (2) | C6—N3—C4—C1 | 178.1 (3) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1ii | 0.86 | 1.94 | 2.745 (4) | 155 |
N4—H4···F1iii | 0.86 | 2.26 | 2.874 (4) | 128 |
N4—H4···O1ii | 0.86 | 2.40 | 3.127 (4) | 142 |
Symmetry codes: (ii) −x, −y+1, −z+1; (iii) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C6H6N4)2(C2H6OS)2](BF4)2 |
Mr | 661.71 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 298 |
a, b, c (Å) | 7.059 (1), 10.0721 (13), 10.3669 (15) |
α, β, γ (°) | 113.436 (2), 96.860 (1), 92.000 (1) |
V (Å3) | 668.68 (16) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 1.06 |
Crystal size (mm) | 0.36 × 0.32 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan SADABS |
Tmin, Tmax | 0.701, 0.816 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3418, 2293, 1885 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.111, 1.03 |
No. of reflections | 2293 |
No. of parameters | 209 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.34, −0.32 |
Computer programs: SMART (Bruker, 2007), SAINT-Plus (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
Cu1—N1 | 2.016 (2) | Cu1—N3 | 2.016 (2) |
Cu1—N1i | 2.016 (2) | Cu1—O1 | 2.678 (2) |
Cu1—N3i | 2.016 (2) | ||
N1—Cu1—N1i | 180.00 (16) | N1—Cu1—N3 | 82.24 (10) |
N1i—Cu1—N3i | 82.24 (10) | N1—Cu1—O1 | 90.17 (9) |
N1i—Cu1—N3 | 97.76 (10) | N1i—Cu1—O1 | 89.83 (9) |
N1—Cu1—N3i | 97.76 (10) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1ii | 0.86 | 1.94 | 2.745 (4) | 154.5 |
N4—H4···F1iii | 0.86 | 2.26 | 2.874 (4) | 128.1 |
N4—H4···O1ii | 0.86 | 2.40 | 3.127 (4) | 142.2 |
Symmetry codes: (ii) −x, −y+1, −z+1; (iii) x−1, y, z. |
Acknowledgements
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.
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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 SiF6 2-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).