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Acta Cryst. (2009). E65, m1563    [ doi:10.1107/S1600536809046996 ]

Bis([mu]-2,2'-biimidazole-[kappa]2N3:N3')bis[aquacopper(I)] sulfate

X. Zhang, P. Wei, B. Hu, B. Li and C. Shi

Abstract top

In the structure of the title compound, [Cu2(C6H6N4)2(H2O)2]SO4, the asymmetric unit contains half each of two 2,2'-diimidazole ligands, one Cu+ cation, one water molecule and half of a sulfate anion (2 symmetry). The dinuclear complex is completed through a twofold rotation axis, leading to a twisted ten-membered ring molecule. The dihedral angle between the two symmetry-related 2,2'-diimidazole ligands is 23.6 (1)°. The copper centre is coordinated by two N atoms of two symmetry-related 2,2'-diimidazole ligands in an almost linear fashion. The water molecule exhibits a weak coordination to Cu+ with a more remote distance of 2.591 (2) Å. The distance between the two copper centres is 2.5956 (6) Å. O-H...O and N-H...O hydrogen bonds between the complex cation, the water molecule and the sulfate anion lead to the formation of a three-dimensional network.

Comment top

The design and synthesis of metal-organic frameworks (MOFs) has attracted continuous research interest not only because of their appealing structural and topological novelties, but also due to their optical, electronic, magnetic, and catalytic properties, as well as their potential medical applications (Lee et al. 2000). Here, we report the structure of the title compound.

As shown in Figure 1, the Cu+ cation is coordianted by two N atoms from two 2,2'-diimidazole molecules, showing an almost linear coordination to Cu(I), the Cu—N bond lengths being 1.8953 (18) and 1.9006 (18) Å, respectively. The separation between the two Cu+ cores is 2.5956 (6) Å. Moreover, the water molecule exhibits a weak coordination to Cu(I) with a more remote distance of 2.591 (2) Å. Each two Cu(I) ions and two 2,2'-diimidazole molecules form one ten-membered ring molecle via a twofold axis as symmetry element. The dihedral angle between two symmetry-related 2,2'-diimidazole molecules is 23.6 (1) °. In the voids of the packing, there is an intricate hydrogen bonding of the type O—H···O and N—H···O, as shown in Figure 2 and Table 2.

Related literature top

For background to metal organic framework structures, see: Lee et al. (2000).

Experimental top

A mixture of 2,2'-diimidazole (1 mmol, 0.14 g), oxalic acid (1 mmol, 0.09 g), copper(II) sulfate pentahydrate (1 mmol, 0.25 g), and 10 ml H2O was heated to 443 K for one day in an autoclave. Red crystals were obtained after cooling to room temperature with a yield of 82%. Elemental Analysis. Calc. for C12H16Cu2N8O6S: C 27.30, H 3.03, N 21.23%; Found: C 27.15, H 2.95, N 21.11%. Under the given hydrothermal conditions, Cu(II) was apparently reduced to Cu(I), leading to the formation of the title complex.

Refinement top

All hydrogen atoms bound to carbon were refined using a riding model with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C). The H atoms of the water molecule were located from difference density maps and were refined with distance restraints of d(H–H) = 1.38 (2) Å, d(O–H) = 0.88 (2) Å, and with a fixed Uiso of 0.80 Å2. The H atoms on nitrogen atoms were located from difference density maps and were refined with distance restraints of d(N–H) = 0.97 (2) Å.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); 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: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the title compound with the unique atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. [Symmetry code: #I -x,y,-z + 3/2]
[Figure 2] Fig. 2. A view of the packing diagram of the title compound. Displacement ellipsoids are drawn at the 30% probability level.
Bis(µ-2,2'-biimidazole-κ2N3:N3')bis[aquacopper(I)] sulfate top
Crystal data top
[Cu2(C6H6N4)2(H2O)2]SO4F(000) = 1064
Mr = 527.50Dx = 1.913 Mg m−3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 5587 reflections
a = 12.7597 (7) Åθ = 0.00–0.00°
b = 14.8594 (7) ŵ = 2.49 mm−1
c = 10.6375 (5) ÅT = 273 K
β = 114.777 (3)°Block, red
V = 1831.22 (16) Å30.12 × 0.10 × 0.08 mm
Z = 4
Data collection top
Bruker APEXII CCD
diffractometer		1630 independent reflections
Radiation source: fine-focus sealed tube1522 reflections with I > 2σ(I)
graphiteRint = 0.023
φ and ω scansθmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		h = −15→15
Tmin = 0.754, Tmax = 0.826k = −17→17
9619 measured reflectionsl = −12→12
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.025Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.073H atoms treated by a mixture of independent and constrained refinement
S = 1.00 w = 1/[σ2(Fo2) + (0.047P)2 + 2.1669P]
where P = (Fo2 + 2Fc2)/3
1630 reflections(Δ/σ)max = 0.008
148 parametersΔρmax = 0.30 e Å−3
0 restraintsΔρmin = −0.45 e Å−3
Crystal data top
[Cu2(C6H6N4)2(H2O)2]SO4V = 1831.22 (16) Å3
Mr = 527.50Z = 4
Monoclinic, C2/cMo Kα radiation
a = 12.7597 (7) ŵ = 2.49 mm−1
b = 14.8594 (7) ÅT = 273 K
c = 10.6375 (5) Å0.12 × 0.10 × 0.08 mm
β = 114.777 (3)°
Data collection top
Bruker APEXII CCD
diffractometer		1630 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		1522 reflections with I > 2σ(I)
Tmin = 0.754, Tmax = 0.826Rint = 0.023
9619 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.025H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.073Δρmax = 0.30 e Å−3
S = 1.00Δρmin = −0.45 e Å−3
1630 reflectionsAbsolute structure: ?
148 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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) top
xyzUiso*/Ueq
Cu10.01189 (3)0.265145 (18)0.63467 (3)0.04181 (14)
S11.00000.76744 (5)0.75000.0392 (2)
C10.03743 (17)0.45644 (13)0.7144 (2)0.0299 (4)
C20.14997 (19)0.50798 (15)0.6214 (2)0.0379 (5)
H20.19230.54640.59130.045*
C30.1405 (2)0.41751 (15)0.6049 (2)0.0400 (5)
H30.17660.38290.56160.048*
C4−0.1342 (2)0.12062 (16)0.4636 (2)0.0411 (5)
H4−0.16750.15630.38480.049*
C5−0.1485 (2)0.03051 (16)0.4682 (2)0.0410 (5)
H5−0.1917−0.00680.39440.049*
C6−0.03621 (17)0.07952 (13)0.6765 (2)0.0302 (4)
N1−0.08656 (15)0.00532 (12)0.6033 (2)0.0352 (4)
N2−0.06269 (16)0.15125 (12)0.59369 (19)0.0356 (4)
N30.08523 (15)0.53162 (11)0.69092 (19)0.0338 (4)
N40.06894 (16)0.38469 (12)0.66225 (19)0.0350 (4)
O10.9542 (2)0.71052 (14)0.8273 (3)0.0695 (6)
O20.90665 (16)0.82506 (12)0.6552 (2)0.0561 (5)
O1W0.1960 (2)0.18900 (17)0.6389 (3)0.0708 (6)
H1W0.169 (3)0.191 (4)0.5542 (3)0.13 (2)*
H2W0.2621 (13)0.208 (3)0.678 (3)0.082 (12)*
H3A0.069 (2)0.5926 (7)0.710 (3)0.061 (8)*
H1A−0.079 (2)−0.0551 (7)0.641 (3)0.060 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0621 (2)0.01984 (19)0.0446 (2)−0.00492 (11)0.02347 (16)−0.00188 (10)
S10.0481 (5)0.0179 (4)0.0512 (5)0.0000.0202 (4)0.000
C10.0328 (10)0.0188 (9)0.0321 (10)0.0000 (8)0.0075 (8)0.0009 (8)
C20.0378 (11)0.0326 (11)0.0440 (12)−0.0024 (9)0.0179 (10)0.0032 (9)
C30.0457 (12)0.0332 (12)0.0448 (13)0.0033 (10)0.0227 (10)0.0008 (10)
C40.0462 (12)0.0379 (12)0.0345 (11)−0.0033 (10)0.0122 (10)0.0019 (10)
C50.0424 (12)0.0387 (13)0.0383 (12)−0.0091 (10)0.0133 (10)−0.0073 (10)
C60.0317 (10)0.0214 (10)0.0384 (11)−0.0013 (8)0.0157 (8)−0.0008 (8)
N10.0373 (9)0.0235 (9)0.0432 (10)−0.0028 (7)0.0153 (8)−0.0024 (8)
N20.0438 (10)0.0245 (9)0.0368 (10)−0.0024 (7)0.0154 (8)0.0006 (7)
N30.0350 (9)0.0208 (9)0.0417 (10)−0.0009 (7)0.0124 (8)0.0009 (7)
N40.0436 (10)0.0221 (9)0.0391 (10)0.0003 (7)0.0173 (8)−0.0002 (7)
O10.1064 (17)0.0292 (9)0.0917 (16)−0.0109 (11)0.0600 (14)0.0037 (10)
O20.0531 (10)0.0340 (9)0.0671 (12)0.0030 (8)0.0113 (9)0.0031 (8)
O1W0.0653 (14)0.0608 (14)0.0795 (17)−0.0082 (11)0.0236 (12)−0.0130 (12)
Geometric parameters (Å, °) top
Cu1—N41.8953 (18)C3—H30.9300
Cu1—N21.9006 (18)C4—C51.355 (3)
Cu1—Cu1i2.5956 (6)C4—N21.377 (3)
S1—O11.462 (2)C4—H40.9300
S1—O1ii1.462 (2)C5—N11.370 (3)
S1—O2ii1.4704 (18)C5—H50.9300
S1—O21.4704 (18)C6—N21.333 (3)
C1—N41.339 (3)C6—N11.347 (3)
C1—N31.345 (3)C6—C6i1.446 (4)
C1—C1i1.447 (4)N1—H1A0.972 (15)
C2—C31.355 (3)N3—H3A0.970 (14)
C2—N31.366 (3)O1W—H1W0.819 (6)
C2—H20.9300O1W—H2W0.82 (3)
C3—N41.383 (3)
N4—Cu1—N2173.20 (8)N2—C4—H4125.3
N4—Cu1—Cu1i92.47 (6)C4—C5—N1106.3 (2)
N2—Cu1—Cu1i88.35 (6)C4—C5—H5126.9
O1—S1—O1ii109.29 (18)N1—C5—H5126.8
O1—S1—O2ii110.56 (13)N2—C6—N1110.22 (19)
O1ii—S1—O2ii108.83 (13)N2—C6—C6i125.81 (12)
O1—S1—O2108.83 (13)N1—C6—C6i123.98 (13)
O1ii—S1—O2110.56 (13)C6—N1—C5107.94 (18)
O2ii—S1—O2108.77 (15)C6—N1—H1A125.3 (18)
N4—C1—N3110.28 (19)C5—N1—H1A126.8 (18)
N4—C1—C1i126.55 (12)C6—N2—C4106.10 (18)
N3—C1—C1i123.17 (12)C6—N2—Cu1126.64 (15)
C3—C2—N3106.5 (2)C4—N2—Cu1125.59 (15)
C3—C2—H2126.7C1—N3—C2108.11 (18)
N3—C2—H2126.7C1—N3—H3A125.6 (17)
C2—C3—N4109.4 (2)C2—N3—H3A125.9 (17)
C2—C3—H3125.3C1—N4—C3105.68 (18)
N4—C3—H3125.3C1—N4—Cu1130.40 (15)
C5—C4—N2109.4 (2)C3—N4—Cu1122.96 (15)
C5—C4—H4125.3H1W—O1W—H2W115 (4)
Symmetry codes: (i) −x, y, −z+3/2; (ii) −x+2, y, −z+3/2.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1W—H1W···O2iii0.82 (1)2.04 (1)2.848 (3)170 (5)
O1W—H2W···O1iv0.82 (3)2.29 (1)3.072 (4)159 (4)
N3—H3A···O1v0.97 (1)1.79 (1)2.697 (3)153 (3)
N1—H1A···O2vi0.97 (2)1.80 (1)2.743 (3)162 (3)
Symmetry codes: (iii) −x+1, −y+1, −z+1; (iv) x−1/2, y−1/2, z; (v) −x+1, y, −z+3/2; (vi) x−1, y−1, z.
Table 1
Selected geometric parameters (Å, °) top
Cu1—N41.8953 (18)Cu1—N21.9006 (18)
N4—Cu1—N2173.20 (8)
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1W—H1W···O2i0.82 (1)2.04 (1)2.848 (3)170 (5)
O1W—H2W···O1ii0.82 (3)2.29 (1)3.072 (4)159 (4)
N3—H3A···O1iii0.97 (1)1.79 (1)2.697 (3)153 (3)
N1—H1A···O2iv0.97 (2)1.80 (1)2.743 (3)162 (3)
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x−1/2, y−1/2, z; (iii) −x+1, y, −z+3/2; (iv) x−1, y−1, z.
references
References top

Bruker (2001). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2004). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.

Lee, E., Heo, J. & Kim, K. (2000). Angew. Chem. Int. Ed. 112, 2811–2813.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.