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Using 2-amino­methyl-1H-benz­imidazole as the ligand, a new thio­cyanate-bridged copper(II) complex, namely bis(2-aminomethyl-1H-benz­imidazole-[kappa]2N2,N3)­di­thio­cyanato­copper(II),[Cu(NCS)2(C8H9N3)], has been synthesized and structurally characterized. The Cu atom is five-coordinated and exhibits a distorted square-pyramidal geometry. The thio­cyanate ions (NCS-) act as either bridging or terminal ligands. The bridging NCS- ligands connect neighboring Cu atoms, constructing chains, while the terminal NCS- ligands form hydrogen bonds with amine H atoms, leading to a complicated network.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104009102/sq1155sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104009102/sq1155Isup2.hkl
Contains datablock I

CCDC reference: 243577

Comment top

2-Aminomethylbenzimidazole (Hambi) is a bidentate ligand that can coordinate to metal ions via two N atoms. The complex of cobalt(III) and ambi has been synthesized but has not been structurally characterized by X-ray diffraction analysis (Gable et al., 1996). However, the crystal structure of the mixed-ligand cobalt(III) complex with Hambi and acac has been reported (Cardwell et al., 1997), and the mixed-ligand copper(II) complex with Hambi and iminodiacetate (de la Cueva et al., 1998), and the nickel–Hambi/ambi (He et al., 2002) and copper–Hambi–dicyanamide (He, Kou, Wang & Li., 2003) complexes, have also been prepared and their structures determined.

Thiocyanate, NCS, is a common versatile pseudohalogen ligand for bridging metal ions. A considerable number of double thiocyanate-bridged copper(II) complexes have been reported (Julve et al., 1993; Liu et al., 2003); however, single thiocyanate-bridged complexes are comparatively rare (Moustarder et al., 2000; Cano et al., 2000; Karan et al., 2002).

A displacement ellipsoid drawing of the title complex is shown in Fig. 1, and selected bond lengths and angles are listed in Table 1. According to Brophy et al. (1999), the coordination geometry about the Cu atom is that of a slightly distorted square pyramid (τ = 0.126), with one N atom each from the pendant aminomethyl group and the imidazole ring, one N atom from the terminal thiocyanate ligand, and one N atom from the bridging thiocyanate ion defining the basal plane, and with one S atom from another bridging thiocyanate ligand occupying the apical position [Cu1—S2A = 2.942 (1) Å; (A) x, 0.5 − y, z − 0.5]. The Cu atom lies 0.0393 (4) Å above the basal plane, towards the apical S2A atom, suggesting of the presence of a weak Cu—S coordination interaction. As a result, an SCN-bridged chain-like structure is obtained. The chains are connected by interchain S···H—N hydrogen bonds, giving rise to a waved layer. As shown in Fig. 1, atom S1 of the terminal thiocyanate ligand interacts with the H atom of the pendant aminomethyl group of the neighboring chain, with an S···H distance of 2.644 (3) Å and an S···H—N angle of 136.6 (5)°. At the same time, atom S1 exhibits a hydrogen-bonding interaction with the intrachain primary amine H atom [S···H = 2.582 (3) Å and S···H—N = 175.3 (5)°]. Atom S2 atom of the bridging NCS ion is also involved in hydrogen bonding with the H atom attached to the benzimidazole N atom of the adjacent chain [S···H = 2.577 (3) Å and S···H—N = 150.4 (5)°].

The title complex is unlike the dicyanamide-bridged CuII analogue Cu(Hambi)(dca)2 (dca is the dicyanamide anion; Kou et al., 2003) in that no ππ contacts between conjugated benzimidazole cycles of the Hambi ligands are observed in (I). This difference which may be due to the existence of different interchain hydrogen bonding in two complexes.

Experimental top

A solution (5 ml) of CuCl2·4H2O (20.6 mg, 0.1 mmol) in water was added to an aqueous solution (5 ml) of Hambi·2HCl (22.1 mg, 0.1 mmol). Blue microcrystals were obtained by adding KSCN (19.6 mg, 0.2 mmol) dissolved in a minimum volume of water. Acetonitrile (~5 ml) was added until all of the precipitate dissolved. The mixture was filtered and the filtrate was evaporated slowly, generating blue–green needle-shaped single crystals suitable for X-ray diffraction analysis (yield 60%).

Refinement top

H atoms bound to C and N atoms were visible in difference maps and were placed using the HFIX commands in SHELXL97. All H atoms were allowed for as riding atoms (C—H = 0.97 Å and N—H = 0.86 Å).

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2002); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. A view of Cu(Hambi)(NCS)2, showing two hydrogen bonded chains. Displacement ellipsoids are drawn at the 30% probability level. Cu, S and N atoms are shown with octant shading. [Symmetry codes: (A) x, 0.5 − y, z − 0.5; (B) x, 0.5 − y, z + 0.5; (C) 1 − x, y − 0.5, 0.5 − z; (D) 1 − x, −y, 1 − z; (E) −x, 1 − y, −z.]
bis(2-aminomethyl-1H-benzimidazole-κ2N2,N3)dithiocyanatocopper(II) top
Crystal data top
[Cu(NCS)2(C8H9N3)]F(000) = 660
Mr = 326.88Dx = 1.691 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 1428 reflections
a = 9.522 (3) Åθ = 2.5–25°
b = 12.707 (4) ŵ = 2.01 mm1
c = 10.757 (3) ÅT = 293 K
β = 99.418 (6)°Prism, blue
V = 1284.0 (7) Å30.14 × 0.10 × 0.06 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
2257 independent reflections
Radiation source: fine-focus sealed tube1428 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.073
Detector resolution: 15×15 microns pixels mm-1θmax = 25.0°, θmin = 2.5°
ϕ and ω scansh = 1111
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
k = 1512
Tmin = 0.708, Tmax = 0.886l = 128
6534 measured reflections
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)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.085H-atom parameters constrained
S = 0.92 w = 1/[σ2(Fo2) + (0.029P)2]
where P = (Fo2 + 2Fc2)/3
2257 reflections(Δ/σ)max < 0.001
163 parametersΔρmax = 0.35 e Å3
0 restraintsΔρmin = 0.42 e Å3
Crystal data top
[Cu(NCS)2(C8H9N3)]V = 1284.0 (7) Å3
Mr = 326.88Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.522 (3) ŵ = 2.01 mm1
b = 12.707 (4) ÅT = 293 K
c = 10.757 (3) Å0.14 × 0.10 × 0.06 mm
β = 99.418 (6)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
2257 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
1428 reflections with I > 2σ(I)
Tmin = 0.708, Tmax = 0.886Rint = 0.073
6534 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.085H-atom parameters constrained
S = 0.92Δρmax = 0.35 e Å3
2257 reflectionsΔρmin = 0.42 e Å3
163 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cu10.34356 (6)0.29937 (5)0.24114 (5)0.03576 (19)
S20.60937 (13)0.20985 (11)0.63538 (11)0.0424 (3)
S10.25003 (16)0.03217 (11)0.05239 (13)0.0549 (4)
N50.2285 (4)0.3738 (3)0.0991 (3)0.0312 (9)
N10.2954 (4)0.1596 (3)0.1765 (4)0.0418 (11)
N20.4389 (5)0.2509 (3)0.4042 (4)0.0480 (12)
C50.1150 (5)0.4422 (4)0.0856 (4)0.0321 (12)
N40.2109 (4)0.5146 (3)0.0226 (4)0.0385 (10)
H4A0.22690.57690.04820.046*
N30.4007 (4)0.4486 (3)0.2917 (3)0.0440 (11)
H3A0.34550.47260.34600.053*
H3D0.49170.44930.33110.053*
C20.5113 (5)0.2341 (4)0.4995 (5)0.0367 (12)
C10.2756 (5)0.0804 (4)0.1242 (4)0.0361 (12)
C80.0487 (5)0.2705 (4)0.1558 (5)0.0475 (14)
H8A0.10550.21250.18170.057*
C30.3859 (5)0.5180 (4)0.1814 (4)0.0426 (13)
H3B0.47530.52280.14960.051*
H3C0.35770.58810.20320.051*
C60.0216 (5)0.4463 (4)0.1994 (4)0.0390 (13)
H6A0.01470.50570.25050.047*
C90.0428 (5)0.2656 (4)0.0431 (5)0.0443 (13)
H9A0.04810.20620.00800.053*
C40.2740 (5)0.4698 (4)0.0853 (4)0.0332 (12)
C100.1272 (5)0.3536 (4)0.0089 (4)0.0341 (12)
C70.0593 (5)0.3591 (4)0.2323 (5)0.0465 (14)
H7A0.12300.35890.30770.056*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0415 (4)0.0367 (4)0.0269 (3)0.0016 (3)0.0008 (2)0.0001 (3)
S20.0421 (8)0.0520 (9)0.0304 (7)0.0069 (7)0.0026 (6)0.0037 (6)
S10.0664 (10)0.0425 (9)0.0545 (10)0.0116 (8)0.0063 (7)0.0079 (7)
N50.032 (2)0.028 (2)0.032 (2)0.0020 (18)0.0000 (18)0.0003 (17)
N10.043 (3)0.038 (3)0.040 (3)0.006 (2)0.004 (2)0.005 (2)
N20.058 (3)0.059 (3)0.025 (3)0.004 (2)0.002 (2)0.003 (2)
C50.028 (3)0.037 (3)0.033 (3)0.002 (2)0.008 (2)0.004 (2)
N40.040 (3)0.029 (2)0.046 (3)0.002 (2)0.007 (2)0.0075 (19)
N30.041 (3)0.052 (3)0.037 (3)0.004 (2)0.0016 (19)0.012 (2)
C20.043 (3)0.034 (3)0.036 (3)0.005 (2)0.014 (2)0.005 (2)
C10.022 (3)0.051 (4)0.033 (3)0.008 (3)0.004 (2)0.014 (3)
C80.043 (3)0.045 (4)0.047 (3)0.007 (3)0.018 (3)0.005 (3)
C30.040 (3)0.038 (3)0.048 (3)0.006 (3)0.003 (2)0.008 (3)
C60.037 (3)0.050 (4)0.028 (3)0.010 (3)0.003 (2)0.014 (2)
C90.047 (3)0.035 (3)0.045 (3)0.005 (3)0.007 (3)0.006 (2)
C40.029 (3)0.033 (3)0.037 (3)0.004 (2)0.005 (2)0.004 (2)
C100.032 (3)0.038 (3)0.032 (3)0.000 (2)0.005 (2)0.001 (2)
C70.041 (3)0.056 (4)0.039 (3)0.003 (3)0.005 (3)0.002 (3)
Geometric parameters (Å, º) top
Cu1—N11.935 (4)N4—H4A0.8600
Cu1—N21.938 (4)N3—C31.466 (6)
Cu1—N51.970 (4)N3—H3A0.9000
Cu1—N32.022 (4)N3—H3D0.9000
Cu1—S2i2.942 (1)C8—C91.374 (6)
S2—C21.630 (5)C8—C71.388 (7)
S1—C11.625 (6)C8—H8A0.9300
N5—C41.311 (6)C3—C41.489 (6)
N5—C101.407 (5)C3—H3B0.9700
N1—C11.154 (6)C3—H3C0.9700
N2—C21.158 (5)C6—C71.363 (6)
C5—C101.390 (6)C6—H6A0.9300
C5—C61.390 (6)C9—C101.390 (6)
C5—N41.392 (5)C9—H9A0.9300
N4—C41.342 (5)C7—H7A0.9300
N1—Cu1—N294.68 (17)C9—C8—C7122.3 (5)
N1—Cu1—N595.35 (16)C9—C8—H8A118.9
N2—Cu1—N5166.60 (17)C7—C8—H8A118.9
N1—Cu1—N3174.14 (17)N3—C3—C4106.1 (4)
N2—Cu1—N389.38 (16)N3—C3—H3B110.5
N5—Cu1—N381.33 (16)C4—C3—H3B110.5
C4—N5—C10105.7 (4)N3—C3—H3C110.5
C4—N5—Cu1112.5 (3)C4—C3—H3C110.5
C10—N5—Cu1140.5 (3)H3B—C3—H3C108.7
C1—N1—Cu1170.5 (4)C7—C6—C5116.8 (4)
C2—N2—Cu1169.3 (4)C7—C6—H6A121.6
C10—C5—C6122.2 (5)C5—C6—H6A121.6
C10—C5—N4105.2 (4)C8—C9—C10116.9 (5)
C6—C5—N4132.7 (4)C8—C9—H9A121.6
C4—N4—C5107.8 (4)C10—C9—H9A121.6
C4—N4—H4A126.1N5—C4—N4112.5 (4)
C5—N4—H4A126.1N5—C4—C3121.0 (4)
C3—N3—Cu1111.1 (3)N4—C4—C3126.5 (4)
C3—N3—H3A109.4C5—C10—C9120.4 (4)
Cu1—N3—H3A109.4C5—C10—N5108.7 (4)
C3—N3—H3D109.4C9—C10—N5130.9 (4)
Cu1—N3—H3D109.4C6—C7—C8121.5 (5)
H3A—N3—H3D108.0C6—C7—H7A119.3
N2—C2—S2178.4 (5)C8—C7—H7A119.3
N1—C1—S1178.9 (5)
Symmetry code: (i) x, y+1/2, z1/2.

Experimental details

Crystal data
Chemical formula[Cu(NCS)2(C8H9N3)]
Mr326.88
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)9.522 (3), 12.707 (4), 10.757 (3)
β (°) 99.418 (6)
V3)1284.0 (7)
Z4
Radiation typeMo Kα
µ (mm1)2.01
Crystal size (mm)0.14 × 0.10 × 0.06
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2000)
Tmin, Tmax0.708, 0.886
No. of measured, independent and
observed [I > 2σ(I)] reflections
6534, 2257, 1428
Rint0.073
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.085, 0.92
No. of reflections2257
No. of parameters163
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.35, 0.42

Computer programs: SMART (Bruker, 2000), SMART, SAINT (Bruker, 2000), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2002), SHELXL97.

Selected geometric parameters (Å, º) top
Cu1—N11.935 (4)S2—C21.630 (5)
Cu1—N21.938 (4)S1—C11.625 (6)
Cu1—N51.970 (4)N1—C11.154 (6)
Cu1—N32.022 (4)N2—C21.158 (5)
Cu1—S2i2.942 (1)
N1—Cu1—N294.68 (17)N2—Cu1—N389.38 (16)
N1—Cu1—N595.35 (16)N5—Cu1—N381.33 (16)
N2—Cu1—N5166.60 (17)N2—C2—S2178.4 (5)
N1—Cu1—N3174.14 (17)N1—C1—S1178.9 (5)
Symmetry code: (i) x, y+1/2, z1/2.
 

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