Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807035428/bq2032sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807035428/bq2032Isup2.hkl |
CCDC reference: 657824
Key indicators
- Single-crystal X-ray study
- T = 297 K
- Mean (C-C) = 0.005 Å
- R factor = 0.041
- wR factor = 0.112
- Data-to-parameter ratio = 11.6
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density .... 2.15 PLAT230_ALERT_2_C Hirshfeld Test Diff for N11 - C18 .. 6.04 su PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for Cl1 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for Cl2 PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ... 5 PLAT430_ALERT_2_C Short Inter D...A Contact O1 .. O12 .. 2.88 Ang. PLAT430_ALERT_2_C Short Inter D...A Contact O2 .. O11 .. 2.88 Ang.
Alert level G REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF. From the CIF: _diffrn_reflns_theta_max 25.00 From the CIF: _reflns_number_total 2923 Count of symmetry unique reflns 1566 Completeness (_total/calc) 186.65% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 1357 Fraction of Friedel pairs measured 0.867 Are heavy atom types Z>Si present yes PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 1
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 7 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 6 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
The title compound was prepared by reaction of stoichiometric amounts of benzimidazole and perchloric acid. The resulting solid was recrystallized from water at room temperature.
All H atoms were initially located in a difference Fourier map. Afterwards they were placed in geometrically idealized positions and constrained to ride on their parent atoms, with N—H and C—H distances of 0.86 and 0.97 Å, respectively, and Uiso(H) = 1.2Ueq(C,N).
The title compound, (I), was investigated as part of a structural study on hydrogen bonding in N-heterocyclic perchlorate salts (Sieroń, 2005a, b, 2007a, b, c). In (I), the asymmetric unit is composed of two benzimidazolium cations and two perchlorate anions (Fig. 1). The cations and anions are linked together by intermolecular N–H···O hydrogen bonds, forming fused 12-membered rings, described by the graph-set notations as R34(12) (Etter et al., 1990). The substructure based on these motif forms layers lying parallel to the (102) plane (Fig. 2). The distance between neighboring planes is ca 3.3 Å. One of the N-bonded H atoms of both benzotriazolium cations are engaged in a bifurcated unsymmetrical (strong and weak) hydrogen bonds. Each of these hydrogen bonds involve two perchlorate O atoms. A bifurcation is confirmed by the sums of angles about atoms H1 and H11, which are 355.5° and 357.9°, respectively (Jeffrey & Saenger, 1991). The crystal packing is stabilized by weak intermolecular C–H···O interactions to build up a three-dimensional network.
For related structures, see: Sieroń (2005a,b, 2007a,b,c). For related literature, see: Etter et al. (1990); Jeffrey & Saenger (1991).
Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL and Mercury (Macrae et al., 2006); software used to prepare material for publication: PLATON (Spek, 2003).
C7H7N2+·ClO4− | F(000) = 896 |
Mr = 218.60 | Dx = 1.689 Mg m−3 |
Orthorhombic, Pca21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2c -2ac | Cell parameters from 11107 reflections |
a = 9.9885 (2) Å | θ = 3.0–29.0° |
b = 9.0509 (1) Å | µ = 0.43 mm−1 |
c = 19.0182 (3) Å | T = 297 K |
V = 1719.34 (5) Å3 | Plate, colourless |
Z = 8 | 0.60 × 0.30 × 0.06 mm |
Kuma KM4 CCD area-detector diffractometer | 2923 independent reflections |
Radiation source: CX-Mo12x0.4-S Seifert Mo tube | 2676 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.018 |
Detector resolution: 8.2356 pixels mm-1 | θmax = 25.0°, θmin = 3.0° |
ω scans | h = −11→11 |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006) | k = −10→10 |
Tmin = 0.781, Tmax = 0.974 | l = −22→22 |
16719 measured reflections |
Refinement on F2 | Hydrogen site location: difference Fourier map |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.041 | w = 1/[σ2(Fo2) + (0.0829P)2 + 0.431P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.112 | (Δ/σ)max = 0.001 |
S = 1.06 | Δρmax = 0.87 e Å−3 |
2923 reflections | Δρmin = −0.40 e Å−3 |
253 parameters | Absolute structure: Flack (1983), with 1462 Friedel pairs |
1 restraint | Absolute structure parameter: 0.04 (6) |
Primary atom site location: structure-invariant direct methods |
C7H7N2+·ClO4− | V = 1719.34 (5) Å3 |
Mr = 218.60 | Z = 8 |
Orthorhombic, Pca21 | Mo Kα radiation |
a = 9.9885 (2) Å | µ = 0.43 mm−1 |
b = 9.0509 (1) Å | T = 297 K |
c = 19.0182 (3) Å | 0.60 × 0.30 × 0.06 mm |
Kuma KM4 CCD area-detector diffractometer | 2923 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006) | 2676 reflections with I > 2σ(I) |
Tmin = 0.781, Tmax = 0.974 | Rint = 0.018 |
16719 measured reflections |
R[F2 > 2σ(F2)] = 0.041 | H-atom parameters constrained |
wR(F2) = 0.112 | Δρmax = 0.87 e Å−3 |
S = 1.06 | Δρmin = −0.40 e Å−3 |
2923 reflections | Absolute structure: Flack (1983), with 1462 Friedel pairs |
253 parameters | Absolute structure parameter: 0.04 (6) |
1 restraint |
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles |
Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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 | ||
N1 | 0.1711 (3) | 1.0228 (3) | 0.83955 (19) | 0.0372 (9) | |
N3 | 0.1090 (3) | 0.8084 (3) | 0.87538 (15) | 0.0407 (9) | |
C2 | 0.1928 (3) | 0.8817 (4) | 0.83387 (18) | 0.0429 (10) | |
C4 | −0.0706 (4) | 0.8899 (5) | 0.96160 (19) | 0.0443 (13) | |
C5 | −0.1273 (4) | 1.0173 (5) | 0.9862 (3) | 0.0467 (12) | |
C6 | −0.0876 (4) | 1.1586 (4) | 0.9630 (2) | 0.0432 (11) | |
C7 | 0.0100 (3) | 1.1771 (4) | 0.9134 (2) | 0.0408 (11) | |
C8 | 0.0692 (4) | 1.0482 (4) | 0.88770 (18) | 0.0339 (11) | |
C9 | 0.0286 (3) | 0.9077 (3) | 0.91156 (19) | 0.0349 (10) | |
N11 | 0.0702 (3) | 0.4754 (4) | 0.69468 (19) | 0.0373 (9) | |
N13 | 0.1382 (3) | 0.6899 (3) | 0.66146 (16) | 0.0401 (9) | |
C12 | 0.0526 (3) | 0.6176 (4) | 0.70226 (18) | 0.0419 (10) | |
C14 | 0.3180 (4) | 0.6058 (4) | 0.57613 (19) | 0.0381 (11) | |
C15 | 0.3723 (4) | 0.4758 (5) | 0.5490 (2) | 0.0457 (14) | |
C16 | 0.3277 (4) | 0.3378 (5) | 0.5725 (2) | 0.0473 (12) | |
C17 | 0.2294 (4) | 0.3210 (4) | 0.62179 (18) | 0.0397 (10) | |
C18 | 0.1730 (4) | 0.4499 (4) | 0.64646 (18) | 0.0335 (11) | |
C19 | 0.2161 (3) | 0.5872 (4) | 0.62590 (17) | 0.0321 (10) | |
Cl1 | 0.44447 (8) | 0.96264 (9) | 0.68820 (4) | 0.0339 (3) | |
O1 | 0.3939 (3) | 1.0716 (3) | 0.73581 (17) | 0.0557 (10) | |
O2 | 0.4461 (3) | 0.8223 (3) | 0.72205 (16) | 0.0645 (10) | |
O3 | 0.5778 (3) | 1.0008 (3) | 0.6670 (2) | 0.0581 (15) | |
O4 | 0.3618 (3) | 0.9553 (4) | 0.6270 (2) | 0.0717 (12) | |
Cl2 | 0.29983 (8) | 0.46265 (9) | 0.84884 (4) | 0.0350 (3) | |
O11 | 0.3484 (3) | 0.5709 (3) | 0.79958 (17) | 0.0554 (9) | |
O12 | 0.2998 (4) | 0.3209 (3) | 0.81592 (16) | 0.0672 (11) | |
O13 | 0.1659 (3) | 0.4988 (3) | 0.8680 (2) | 0.0541 (13) | |
O14 | 0.3814 (3) | 0.4610 (4) | 0.9092 (2) | 0.0743 (12) | |
H1 | 0.21380 | 1.09040 | 0.81700 | 0.0450* | |
H2 | 0.25720 | 0.83860 | 0.80510 | 0.0520* | |
H3 | 0.10520 | 0.71380 | 0.87920 | 0.0490* | |
H4 | −0.09700 | 0.79720 | 0.97750 | 0.0530* | |
H5 | −0.19490 | 1.01040 | 1.01960 | 0.0560* | |
H6 | −0.12900 | 1.24150 | 0.98200 | 0.0520* | |
H7 | 0.03560 | 1.27020 | 0.89760 | 0.0490* | |
H11 | 0.02560 | 0.40790 | 0.71620 | 0.0450* | |
H12 | −0.01030 | 0.66140 | 0.73170 | 0.0500* | |
H13 | 0.14440 | 0.78440 | 0.65780 | 0.0480* | |
H14 | 0.34750 | 0.69870 | 0.56210 | 0.0460* | |
H15 | 0.43890 | 0.48090 | 0.51490 | 0.0550* | |
H16 | 0.36680 | 0.25340 | 0.55360 | 0.0570* | |
H17 | 0.20230 | 0.22860 | 0.63770 | 0.0480* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0363 (16) | 0.0406 (15) | 0.0346 (18) | −0.0029 (13) | 0.0032 (15) | 0.0083 (13) |
N3 | 0.0473 (17) | 0.0253 (14) | 0.0495 (16) | 0.0056 (12) | −0.0026 (14) | −0.0043 (12) |
C2 | 0.0382 (16) | 0.047 (2) | 0.0436 (17) | 0.0074 (17) | −0.0005 (15) | −0.0034 (16) |
C4 | 0.045 (2) | 0.054 (3) | 0.0339 (18) | −0.0130 (18) | 0.0038 (16) | 0.0057 (18) |
C5 | 0.038 (2) | 0.065 (2) | 0.037 (2) | −0.0036 (18) | 0.0033 (18) | −0.0060 (17) |
C6 | 0.0455 (19) | 0.039 (2) | 0.045 (2) | 0.0018 (16) | −0.0006 (16) | −0.0139 (17) |
C7 | 0.0388 (19) | 0.0317 (17) | 0.052 (2) | −0.0025 (14) | −0.0051 (16) | −0.0034 (16) |
C8 | 0.0323 (18) | 0.037 (2) | 0.0324 (17) | −0.0023 (15) | −0.0012 (14) | 0.0060 (14) |
C9 | 0.0382 (18) | 0.0243 (16) | 0.0421 (18) | −0.0040 (14) | −0.0070 (15) | −0.0011 (15) |
N11 | 0.0297 (15) | 0.0434 (15) | 0.0388 (18) | 0.0000 (13) | 0.0066 (15) | −0.0014 (14) |
N13 | 0.0439 (16) | 0.0274 (14) | 0.0490 (15) | 0.0046 (12) | −0.0033 (13) | −0.0019 (12) |
C12 | 0.0366 (16) | 0.050 (2) | 0.0391 (16) | 0.0068 (16) | 0.0030 (15) | −0.0066 (15) |
C14 | 0.0400 (19) | 0.034 (2) | 0.0402 (19) | −0.0049 (15) | −0.0035 (15) | 0.0091 (16) |
C15 | 0.038 (2) | 0.068 (3) | 0.031 (2) | 0.0022 (18) | 0.0044 (18) | −0.0073 (19) |
C16 | 0.043 (2) | 0.050 (2) | 0.049 (2) | 0.0070 (18) | −0.0005 (17) | −0.0135 (18) |
C17 | 0.046 (2) | 0.0269 (16) | 0.0463 (18) | −0.0016 (14) | −0.0029 (16) | −0.0004 (14) |
C18 | 0.0352 (18) | 0.0297 (19) | 0.0356 (18) | −0.0004 (14) | −0.0069 (15) | −0.0008 (14) |
C19 | 0.0330 (18) | 0.0338 (18) | 0.0295 (15) | 0.0078 (14) | −0.0050 (13) | −0.0033 (14) |
Cl1 | 0.0330 (4) | 0.0262 (4) | 0.0425 (5) | −0.0005 (3) | 0.0064 (4) | −0.0017 (4) |
O1 | 0.0638 (18) | 0.0384 (16) | 0.0648 (18) | 0.0065 (13) | 0.0235 (15) | −0.0125 (13) |
O2 | 0.094 (2) | 0.0277 (15) | 0.0718 (19) | −0.0002 (12) | 0.0220 (16) | 0.0107 (13) |
O3 | 0.0322 (16) | 0.0402 (17) | 0.102 (4) | −0.0037 (11) | 0.0316 (18) | −0.0026 (14) |
O4 | 0.068 (2) | 0.077 (2) | 0.070 (2) | 0.0044 (19) | −0.0172 (18) | −0.0132 (19) |
Cl2 | 0.0340 (4) | 0.0273 (4) | 0.0436 (5) | 0.0016 (3) | 0.0077 (4) | 0.0039 (4) |
O11 | 0.0701 (18) | 0.0360 (15) | 0.0600 (16) | −0.0022 (13) | 0.0253 (15) | 0.0144 (13) |
O12 | 0.099 (2) | 0.0226 (14) | 0.080 (2) | −0.0070 (13) | 0.0311 (17) | −0.0102 (13) |
O13 | 0.0418 (17) | 0.0396 (17) | 0.081 (3) | 0.0061 (11) | 0.0095 (18) | 0.0030 (13) |
O14 | 0.068 (2) | 0.089 (2) | 0.066 (2) | −0.0168 (19) | −0.0248 (18) | 0.022 (2) |
Cl1—O1 | 1.431 (3) | C4—C9 | 1.383 (5) |
Cl1—O2 | 1.424 (3) | C5—C6 | 1.410 (6) |
Cl1—O3 | 1.434 (3) | C6—C7 | 1.367 (5) |
Cl1—O4 | 1.429 (4) | C7—C8 | 1.396 (5) |
Cl2—O11 | 1.440 (3) | C8—C9 | 1.410 (5) |
Cl2—O12 | 1.428 (3) | C2—H2 | 0.93 |
Cl2—O13 | 1.425 (3) | C4—H4 | 0.93 |
Cl2—O14 | 1.408 (4) | C5—H5 | 0.93 |
N1—C2 | 1.300 (5) | C6—H6 | 0.93 |
N1—C8 | 1.388 (5) | C7—H7 | 0.93 |
N3—C2 | 1.328 (4) | C14—C19 | 1.400 (5) |
N3—C9 | 1.388 (4) | C14—C15 | 1.395 (6) |
N1—H1 | 0.86 | C15—C16 | 1.399 (6) |
N3—H3 | 0.86 | C16—C17 | 1.366 (5) |
N11—C12 | 1.307 (5) | C17—C18 | 1.378 (5) |
N11—C18 | 1.396 (5) | C18—C19 | 1.372 (5) |
N13—C19 | 1.388 (4) | C12—H12 | 0.93 |
N13—C12 | 1.327 (4) | C14—H14 | 0.93 |
N11—H11 | 0.86 | C15—H15 | 0.93 |
N13—H13 | 0.86 | C16—H16 | 0.93 |
C4—C5 | 1.367 (6) | C17—H17 | 0.93 |
O1—Cl1—O2 | 109.43 (18) | N3—C9—C4 | 132.9 (3) |
O1—Cl1—O3 | 109.87 (18) | N3—C9—C8 | 105.0 (3) |
O1—Cl1—O4 | 110.09 (19) | N1—C2—H2 | 125 |
O2—Cl1—O3 | 109.35 (18) | N3—C2—H2 | 125 |
O2—Cl1—O4 | 109.5 (2) | C5—C4—H4 | 122 |
O3—Cl1—O4 | 108.6 (2) | C9—C4—H4 | 122 |
O11—Cl2—O12 | 109.04 (18) | C6—C5—H5 | 119 |
O11—Cl2—O13 | 109.06 (18) | C4—C5—H5 | 119 |
O11—Cl2—O14 | 110.05 (19) | C5—C6—H6 | 119 |
O12—Cl2—O13 | 108.6 (2) | C7—C6—H6 | 119 |
O12—Cl2—O14 | 110.4 (2) | C8—C7—H7 | 122 |
O13—Cl2—O14 | 109.7 (2) | C6—C7—H7 | 122 |
C2—N1—C8 | 109.9 (3) | N11—C12—N13 | 109.5 (3) |
C2—N3—C9 | 109.6 (3) | C15—C14—C19 | 115.6 (3) |
C2—N3—H3 | 125 | C14—C15—C16 | 120.7 (4) |
C2—N1—H1 | 125 | C15—C16—C17 | 123.2 (4) |
C8—N1—H1 | 125 | C16—C17—C18 | 115.7 (4) |
C9—N3—H3 | 125 | N11—C18—C17 | 131.6 (3) |
C12—N11—C18 | 109.5 (3) | C17—C18—C19 | 122.8 (3) |
C12—N13—C19 | 108.4 (3) | N11—C18—C19 | 105.6 (3) |
C12—N11—H11 | 125 | N13—C19—C18 | 107.0 (3) |
C18—N11—H11 | 125 | N13—C19—C14 | 131.0 (3) |
C12—N13—H13 | 126 | C14—C19—C18 | 122.0 (3) |
C19—N13—H13 | 126 | N11—C12—H12 | 125 |
N1—C2—N3 | 109.7 (3) | N13—C12—H12 | 125 |
C5—C4—C9 | 115.7 (4) | C15—C14—H14 | 122 |
C4—C5—C6 | 122.8 (4) | C19—C14—H14 | 122 |
C5—C6—C7 | 121.9 (4) | C14—C15—H15 | 120 |
C6—C7—C8 | 116.2 (3) | C16—C15—H15 | 120 |
N1—C8—C7 | 132.8 (3) | C15—C16—H16 | 118 |
C7—C8—C9 | 121.3 (3) | C17—C16—H16 | 118 |
N1—C8—C9 | 105.9 (3) | C18—C17—H17 | 122 |
C4—C9—C8 | 122.2 (3) | C16—C17—H17 | 122 |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.86 | 2.38 | 3.007 (5) | 130 |
N1—H1···O12i | 0.86 | 2.26 | 3.022 (4) | 148 |
N3—H3···O13 | 0.86 | 2.05 | 2.863 (4) | 157 |
N11—H11···O11ii | 0.86 | 2.38 | 3.011 (5) | 130 |
N11—H11···O2ii | 0.86 | 2.23 | 3.011 (4) | 151 |
N13—H13···O3iii | 0.86 | 2.06 | 2.866 (4) | 155 |
C2—H2···O2 | 0.93 | 2.47 | 3.349 (4) | 159 |
C2—H2···O11 | 0.93 | 2.59 | 3.279 (4) | 131 |
C7—H7···O13i | 0.93 | 2.51 | 3.413 (5) | 164 |
C12—H12···O12ii | 0.93 | 2.49 | 3.370 (5) | 158 |
C17—H17···O3ii | 0.93 | 2.48 | 3.393 (5) | 166 |
Symmetry codes: (i) x, y+1, z; (ii) x−1/2, −y+1, z; (iii) x−1/2, −y+2, z. |
Experimental details
Crystal data | |
Chemical formula | C7H7N2+·ClO4− |
Mr | 218.60 |
Crystal system, space group | Orthorhombic, Pca21 |
Temperature (K) | 297 |
a, b, c (Å) | 9.9885 (2), 9.0509 (1), 19.0182 (3) |
V (Å3) | 1719.34 (5) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.43 |
Crystal size (mm) | 0.60 × 0.30 × 0.06 |
Data collection | |
Diffractometer | Kuma KM4 CCD area-detector |
Absorption correction | Multi-scan (CrysAlis RED; Oxford Diffraction, 2006) |
Tmin, Tmax | 0.781, 0.974 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 16719, 2923, 2676 |
Rint | 0.018 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.112, 1.06 |
No. of reflections | 2923 |
No. of parameters | 253 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.87, −0.40 |
Absolute structure | Flack (1983), with 1462 Friedel pairs |
Absolute structure parameter | 0.04 (6) |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2006), CrysAlis RED (Oxford Diffraction, 2006), CrysAlis RED, SHELXTL (Sheldrick, 2001), SHELXTL and Mercury (Macrae et al., 2006), PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.86 | 2.38 | 3.007 (5) | 130 |
N1—H1···O12i | 0.86 | 2.26 | 3.022 (4) | 148 |
N3—H3···O13 | 0.86 | 2.05 | 2.863 (4) | 157 |
N11—H11···O11ii | 0.86 | 2.38 | 3.011 (5) | 130 |
N11—H11···O2ii | 0.86 | 2.23 | 3.011 (4) | 151 |
N13—H13···O3iii | 0.86 | 2.06 | 2.866 (4) | 155 |
C2—H2···O2 | 0.93 | 2.47 | 3.349 (4) | 159 |
C2—H2···O11 | 0.93 | 2.59 | 3.279 (4) | 131 |
C7—H7···O13i | 0.93 | 2.51 | 3.413 (5) | 164 |
C12—H12···O12ii | 0.93 | 2.49 | 3.370 (5) | 158 |
C17—H17···O3ii | 0.93 | 2.48 | 3.393 (5) | 166 |
Symmetry codes: (i) x, y+1, z; (ii) x−1/2, −y+1, z; (iii) x−1/2, −y+2, z. |
The title compound, (I), was investigated as part of a structural study on hydrogen bonding in N-heterocyclic perchlorate salts (Sieroń, 2005a, b, 2007a, b, c). In (I), the asymmetric unit is composed of two benzimidazolium cations and two perchlorate anions (Fig. 1). The cations and anions are linked together by intermolecular N–H···O hydrogen bonds, forming fused 12-membered rings, described by the graph-set notations as R34(12) (Etter et al., 1990). The substructure based on these motif forms layers lying parallel to the (102) plane (Fig. 2). The distance between neighboring planes is ca 3.3 Å. One of the N-bonded H atoms of both benzotriazolium cations are engaged in a bifurcated unsymmetrical (strong and weak) hydrogen bonds. Each of these hydrogen bonds involve two perchlorate O atoms. A bifurcation is confirmed by the sums of angles about atoms H1 and H11, which are 355.5° and 357.9°, respectively (Jeffrey & Saenger, 1991). The crystal packing is stabilized by weak intermolecular C–H···O interactions to build up a three-dimensional network.