supplementary materials


kq2008 scheme

Acta Cryst. (2013). E69, m536    [ doi:10.1107/S1600536813024549 ]

Dibromidobis(2-methyl-1H-benzimidazole-[kappa]N3)cadmium

B.-C. Liu, Y.-L. Jin and F.-Q. Liu

Abstract top

In the title compound, [CdBr2(C8H8N2)2], the CdII atom has a distorted tetrahedral coordination formed by the two imino N atoms of two 2-methylbenzimidazole ligands and two terminal bromide ligands. The CdII atom is slightly out of the benzimidazole planes by 0.320 (3) and 0.210 (3) Å. The dihedral angle between the benzimidazole planes is 71.6 (2)°. In the crystal, molecules are linked by N-H...Br hydrogen bonds into puckered layers parallel to (001).

Comment top

Benzimidazole and its derivatives have attracted interest because their biological activities as well as their abilities to bind different metal ions (Roderick et al., 1972). In this paper, we describe the synthesis and structure of dibromo-bis(2-methylbenzimidazole)-cadmium(II).

In the title compound, C16H16CdBr2N4, the cadmium atom has a distorted tetrahedral coordination formed by the two imino-nitrogen atoms of two 2-methyl-benzimidazole ligands and two terminal bromide ligands (Figure 1). The similar geometry was previously found in the related compounds – Cd(Cl)2(N-(5,6-dihydro-4H- 1,3-thiazin-2-yl)-2-aminobenzimidazole)2 (Barros-García et al., 2005), Cd(Cl)2(2-(2-furyl)-1-(2-furylmethyl)-1H-benzimidazole)2 (Wang et al., 2010), and Cd(I)2(2-(2-furyl)-1-(2-furylmethyl)- 1H-enzimidazole)2 (Yang et al., 2011). The cadmium atom is slightly out of the two benzimidazole planes by 0.320 (3) and 0.210 (3) Å, respectively. The dihedral angle between the two benzimidazole planes is 71.6 (2)°. The mean values of Cd—Br and Cd—N bond lengths are 2.562 (2) and 2.251 (3) Å, respectively. The N—Cd—Br bond angles range from 105.40 (10) to 117.76 (9)°.

In the crystal, the molecules of the title compound are linked by intermolecular N2—H2···Br1i and N4—H4···Br2ii hydrogen bonds (Table 1) into puckered layers parallel to (001) (Figure 2). Symmetry codes: (i) –x+1, y–1/2, –z+3/2; (ii) –x, y–1/2, –z+3/2.

Related literature top

For background to benzimidazole, see: Roderick et al. (1972). For related crystal structures, see: Barros-García et al. (2005); Wang et al. (2010); Yang et al. (2011).

Experimental top

The ligand 2-methyl-benzimidazole (0.02 mmol) in ethanol (10 mL) was added dropwise to a ethanol (10 mL) of CdBr2 (0.01 mmol). The resulting solution was allowed to stand at room temperature. After one week colorless crystals with good quality were obtained from the filtrate and dried in air. Analysis, calculated for C16H16Br2CdN4: C 35.82, H 3.01, N 10.44%; Found: C 35.68, H 3.02, N 10.47%.

Refinement top

All hydrogen atoms were placed in calculated positions with N—H = 0.86 Å and C—H = 0.93 (aryl-H) and 0.96 (methyl-H) Å and refined in the riding model with fixed isotropic displacement parameters [Uiso(H) = 1.2Ueq(N or C)].

Computing details top

Data collection: RAPID-AUTO (Rigaku, 2004); cell refinement: RAPID-AUTO (Rigaku, 2004); data reduction: RAPID-AUTO (Rigaku, 2004); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are shown at the 40% probability level. H atoms are presented as small spheres of arbitrary radius.
[Figure 2] Fig. 2. Crystal packing of the title compound along the b axis demonstrating the puckered layers parallel to (001). Dashed lines indicate the intermolecular hydrogen bonds.
Dibromidobis(2-methyl-1H-benzimidazole-κN3)cadmium top
Crystal data top
[CdBr2(C8H8N2)2]F(000) = 1032
Mr = 536.54Dx = 1.951 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3275 reflections
a = 10.007 (9) Åθ = 2.5–26.6°
b = 14.747 (12) ŵ = 5.57 mm1
c = 12.399 (11) ÅT = 296 K
β = 93.088 (14)°Block, colorless
V = 1827 (3) Å30.22 × 0.18 × 0.16 mm
Z = 4
Data collection top
Rigaku R-AXIS Spider
diffractometer
2748 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.032
Graphite monochromatorθmax = 26.0°, θmin = 2.0°
ω scansh = 1210
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
k = 1814
Tmin = 0.374, Tmax = 0.469l = 1514
9698 measured reflections13 standard reflections every 0 reflections
3585 independent reflections intensity decay: none
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)] = 0.033Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.077H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.0407P)2]
where P = (Fo2 + 2Fc2)/3
3585 reflections(Δ/σ)max = 0.001
210 parametersΔρmax = 0.39 e Å3
0 restraintsΔρmin = 1.02 e Å3
Crystal data top
[CdBr2(C8H8N2)2]V = 1827 (3) Å3
Mr = 536.54Z = 4
Monoclinic, P21/cMo Kα radiation
a = 10.007 (9) ŵ = 5.57 mm1
b = 14.747 (12) ÅT = 296 K
c = 12.399 (11) Å0.22 × 0.18 × 0.16 mm
β = 93.088 (14)°
Data collection top
Rigaku R-AXIS Spider
diffractometer
2748 reflections with I > 2σ(I)
Absorption correction: multi-scan
(ABSCOR; Higashi, 1995)
Rint = 0.032
Tmin = 0.374, Tmax = 0.469θmax = 26.0°
9698 measured reflections13 standard reflections every 0 reflections
3585 independent reflections intensity decay: none
Refinement top
R[F2 > 2σ(F2)] = 0.033H-atom parameters constrained
wR(F2) = 0.077Δρmax = 0.39 e Å3
S = 1.00Δρmin = 1.02 e Å3
3585 reflectionsAbsolute structure: ?
210 parametersAbsolute structure 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
N10.3592 (3)0.96335 (19)0.8577 (2)0.0362 (7)
N20.5028 (4)0.8661 (2)0.9341 (3)0.0485 (9)
H20.57120.83110.94280.058*
N30.0723 (3)1.01679 (18)0.6820 (2)0.0339 (7)
N40.1049 (3)0.93220 (19)0.6357 (2)0.0417 (8)
H40.15540.88510.62900.050*
Br10.40130 (5)1.14156 (3)0.60773 (4)0.06071 (16)
Br20.20546 (5)1.20099 (3)0.88850 (4)0.06367 (17)
C10.4087 (4)0.8806 (2)1.0086 (3)0.0409 (9)
C20.3939 (5)0.8457 (3)1.1109 (3)0.0531 (12)
H2A0.45610.80601.14340.064*
C30.2816 (6)0.8730 (3)1.1622 (4)0.0626 (14)
H30.26810.85111.23110.075*
C40.1873 (6)0.9326 (3)1.1139 (4)0.0633 (13)
H4A0.11190.94821.15050.076*
C50.2045 (5)0.9687 (3)1.0127 (3)0.0535 (11)
H50.14321.00940.98120.064*
C60.3175 (4)0.9417 (2)0.9597 (3)0.0368 (9)
C70.4708 (4)0.9156 (2)0.8454 (3)0.0408 (9)
C80.5489 (5)0.9139 (3)0.7478 (4)0.0620 (13)
H8A0.49350.93380.68670.093*
H8B0.57930.85320.73550.093*
H8C0.62460.95360.75780.093*
C90.0236 (4)1.0707 (2)0.6250 (3)0.0332 (8)
C100.0180 (4)1.1618 (2)0.5961 (3)0.0420 (9)
H100.05711.19720.61310.050*
C110.1303 (5)1.1972 (3)0.5406 (3)0.0502 (11)
H110.12971.25750.51870.060*
C120.2441 (5)1.1449 (3)0.5168 (3)0.0531 (11)
H120.31841.17200.48200.064*
C130.2499 (4)1.0548 (3)0.5431 (3)0.0482 (10)
H130.32551.01990.52590.058*
C140.1372 (4)1.0184 (2)0.5966 (3)0.0364 (9)
C150.0180 (4)0.9343 (2)0.6856 (3)0.0386 (9)
C160.0818 (5)0.8531 (2)0.7384 (3)0.0577 (13)
H16A0.17490.85140.72330.087*
H16B0.03840.79920.71080.087*
H16C0.07330.85660.81500.087*
Cd10.26490 (3)1.074421 (18)0.75481 (2)0.03930 (11)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.039 (2)0.0255 (15)0.0436 (18)0.0043 (14)0.0033 (15)0.0002 (14)
N20.044 (2)0.0340 (18)0.066 (2)0.0133 (15)0.0060 (18)0.0078 (17)
N30.0365 (18)0.0242 (15)0.0410 (16)0.0068 (13)0.0015 (14)0.0021 (13)
N40.048 (2)0.0289 (17)0.0482 (19)0.0128 (14)0.0016 (16)0.0055 (14)
Br10.0653 (3)0.0460 (3)0.0713 (3)0.0150 (2)0.0077 (2)0.0149 (2)
Br20.0746 (4)0.0398 (3)0.0745 (3)0.0205 (2)0.0163 (3)0.0179 (2)
C10.044 (2)0.027 (2)0.050 (2)0.0007 (17)0.010 (2)0.0000 (18)
C20.066 (3)0.039 (2)0.053 (3)0.008 (2)0.017 (2)0.006 (2)
C30.089 (4)0.058 (3)0.041 (2)0.018 (3)0.003 (3)0.003 (2)
C40.082 (4)0.057 (3)0.052 (3)0.005 (3)0.016 (3)0.005 (2)
C50.058 (3)0.049 (3)0.053 (3)0.016 (2)0.002 (2)0.003 (2)
C60.043 (2)0.0256 (19)0.041 (2)0.0001 (16)0.0017 (18)0.0006 (16)
C70.039 (2)0.030 (2)0.053 (2)0.0008 (17)0.0057 (19)0.0037 (18)
C80.057 (3)0.050 (3)0.081 (3)0.006 (2)0.027 (3)0.005 (2)
C90.037 (2)0.030 (2)0.0328 (19)0.0039 (16)0.0046 (16)0.0025 (16)
C100.046 (3)0.033 (2)0.048 (2)0.0044 (18)0.0004 (19)0.0034 (18)
C110.068 (3)0.029 (2)0.053 (2)0.013 (2)0.003 (2)0.0004 (19)
C120.051 (3)0.054 (3)0.053 (3)0.013 (2)0.010 (2)0.006 (2)
C130.041 (3)0.053 (3)0.050 (2)0.004 (2)0.005 (2)0.011 (2)
C140.041 (2)0.035 (2)0.0341 (19)0.0006 (17)0.0046 (17)0.0080 (16)
C150.051 (3)0.028 (2)0.038 (2)0.0037 (17)0.0054 (19)0.0007 (16)
C160.082 (4)0.030 (2)0.059 (3)0.008 (2)0.014 (2)0.011 (2)
Cd10.04113 (19)0.02686 (16)0.04918 (18)0.00061 (12)0.00430 (13)0.00266 (12)
Geometric parameters (Å, º) top
N1—C71.336 (5)C4—H4A0.9300
N1—C61.390 (5)C5—C61.396 (6)
N1—Cd12.252 (3)C5—H50.9300
N2—C71.345 (5)C7—C81.475 (6)
N2—C11.370 (5)C8—H8A0.9600
N2—H20.8600C8—H8B0.9600
N3—C151.334 (4)C8—H8C0.9600
N3—C91.407 (5)C9—C101.393 (5)
N3—Cd12.250 (3)C9—C141.403 (5)
N4—C151.347 (5)C10—C111.387 (6)
N4—C141.392 (5)C10—H100.9300
N4—H40.8600C11—C121.394 (6)
Br1—Cd12.5372 (15)C11—H110.9300
Br2—Cd12.5869 (15)C12—C131.370 (6)
C1—C21.385 (6)C12—H120.9300
C1—C61.398 (5)C13—C141.386 (6)
C2—C31.381 (7)C13—H130.9300
C2—H2A0.9300C15—C161.492 (5)
C3—C41.401 (7)C16—H16A0.9600
C3—H30.9300C16—H16B0.9600
C4—C51.381 (6)C16—H16C0.9600
C7—N1—C6106.1 (3)C7—C8—H8C109.5
C7—N1—Cd1130.2 (3)H8A—C8—H8C109.5
C6—N1—Cd1123.1 (2)H8B—C8—H8C109.5
C7—N2—C1109.0 (3)C10—C9—C14120.6 (4)
C7—N2—H2125.5C10—C9—N3129.7 (4)
C1—N2—H2125.5C14—C9—N3109.7 (3)
C15—N3—C9105.3 (3)C11—C10—C9116.6 (4)
C15—N3—Cd1132.3 (3)C11—C10—H10121.7
C9—N3—Cd1122.3 (2)C9—C10—H10121.7
C15—N4—C14109.1 (3)C10—C11—C12121.9 (4)
C15—N4—H4125.4C10—C11—H11119.1
C14—N4—H4125.4C12—C11—H11119.1
N2—C1—C2132.2 (4)C13—C12—C11122.1 (4)
N2—C1—C6105.3 (3)C13—C12—H12119.0
C2—C1—C6122.5 (4)C11—C12—H12119.0
C3—C2—C1116.3 (4)C12—C13—C14116.5 (4)
C3—C2—H2A121.8C12—C13—H13121.8
C1—C2—H2A121.8C14—C13—H13121.8
C2—C3—C4122.2 (4)C13—C14—N4133.4 (4)
C2—C3—H3118.9C13—C14—C9122.3 (4)
C4—C3—H3118.9N4—C14—C9104.2 (3)
C5—C4—C3121.0 (5)N3—C15—N4111.7 (3)
C5—C4—H4A119.5N3—C15—C16125.5 (4)
C3—C4—H4A119.5N4—C15—C16122.8 (3)
C4—C5—C6117.5 (4)C15—C16—H16A109.5
C4—C5—H5121.2C15—C16—H16B109.5
C6—C5—H5121.2H16A—C16—H16B109.5
N1—C6—C5130.8 (4)C15—C16—H16C109.5
N1—C6—C1108.8 (3)H16A—C16—H16C109.5
C5—C6—C1120.4 (4)H16B—C16—H16C109.5
N1—C7—N2110.8 (3)N3—Cd1—N1106.04 (12)
N1—C7—C8125.9 (4)N3—Cd1—Br1109.95 (9)
N2—C7—C8123.3 (4)N1—Cd1—Br1117.77 (9)
C7—C8—H8A109.5N3—Cd1—Br2107.95 (9)
C7—C8—H8B109.5N1—Cd1—Br2105.40 (9)
H8A—C8—H8B109.5Br1—Cd1—Br2109.28 (2)
C7—N2—C1—C2178.9 (4)C9—C10—C11—C121.2 (6)
C7—N2—C1—C60.1 (4)C10—C11—C12—C132.5 (7)
N2—C1—C2—C3177.2 (4)C11—C12—C13—C141.1 (6)
C6—C1—C2—C31.3 (6)C12—C13—C14—N4179.9 (4)
C1—C2—C3—C40.1 (7)C12—C13—C14—C91.4 (6)
C2—C3—C4—C51.5 (7)C15—N4—C14—C13177.7 (4)
C3—C4—C5—C61.5 (7)C15—N4—C14—C91.2 (4)
C7—N1—C6—C5177.1 (4)C10—C9—C14—C132.7 (6)
Cd1—N1—C6—C511.3 (6)N3—C9—C14—C13177.7 (3)
C7—N1—C6—C10.9 (4)C10—C9—C14—N4178.3 (3)
Cd1—N1—C6—C1170.7 (2)N3—C9—C14—N41.4 (4)
C4—C5—C6—N1177.6 (4)C9—N3—C15—N40.2 (4)
C4—C5—C6—C10.2 (6)Cd1—N3—C15—N4175.6 (2)
N2—C1—C6—N10.6 (4)C9—N3—C15—C16179.7 (4)
C2—C1—C6—N1179.5 (3)Cd1—N3—C15—C163.9 (6)
N2—C1—C6—C5177.6 (4)C14—N4—C15—N30.6 (4)
C2—C1—C6—C51.3 (6)C14—N4—C15—C16178.9 (4)
C6—N1—C7—N20.9 (4)C15—N3—Cd1—N14.6 (3)
Cd1—N1—C7—N2169.9 (2)C9—N3—Cd1—N1170.6 (2)
C6—N1—C7—C8177.7 (4)C15—N3—Cd1—Br1123.7 (3)
Cd1—N1—C7—C811.5 (6)C9—N3—Cd1—Br161.0 (3)
C1—N2—C7—N10.5 (4)C15—N3—Cd1—Br2117.1 (3)
C1—N2—C7—C8178.1 (4)C9—N3—Cd1—Br258.1 (3)
C15—N3—C9—C10178.6 (4)C7—N1—Cd1—N3112.4 (3)
Cd1—N3—C9—C105.1 (5)C6—N1—Cd1—N378.2 (3)
C15—N3—C9—C141.0 (4)C7—N1—Cd1—Br111.1 (4)
Cd1—N3—C9—C14175.3 (2)C6—N1—Cd1—Br1158.3 (2)
C14—C9—C10—C111.3 (5)C7—N1—Cd1—Br2133.3 (3)
N3—C9—C10—C11179.1 (3)C6—N1—Cd1—Br236.2 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···Br1i0.862.883.495 (4)130
N4—H4···Br2ii0.862.773.563 (4)155
Symmetry codes: (i) x+1, y1/2, z+3/2; (ii) x, y1/2, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···Br1i0.862.883.495 (4)130
N4—H4···Br2ii0.862.773.563 (4)155
Symmetry codes: (i) x+1, y1/2, z+3/2; (ii) x, y1/2, z+3/2.
Acknowledgements top

This work was supported by the NSF of Shandong Province (No. 2009ZRA02071), the Scientific Development Plan of Universities in Shandong Province (No. J09LB53) and the Doctoral Science Foundation of QUST.

references
References top

Barros-García, F. J., Bermalte-García, A., Luna-Giles, F., Maldonado-Rogado, M. A. & Viñuelas-Zahínos, E. (2005). Polyhedron, 24, 1764–1772.

Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.

Rigaku (2004). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan.

Roderick, W. R., Nordeen, C. W., Von Esch, A. M. & Appell, R. N. J. (1972). J. Med. Chem. 15, 655–658.

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

Wang, X., Li, Y.-X., Liu, Y.-J., Yang, H.-X. & Zhang, C.-C. (2010). Acta Cryst. E66, m1207.

Yang, H.-X., Wang, X., Xie, C.-X., Li, X.-F. & Liu, Y.-J. (2011). Acta Cryst. E67, m1149.