2-Trifluoro­methyl-1H-benzimidazol-3-ium perchlorate

Liu, M.-L.

doi:10.1107/S1600536811039298

organic compounds

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Volume 67| Part 11| November 2011| Page o2821

doi:10.1107/S1600536811039298

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2-Trifluoromethyl-1H-benzimidazol-3-ium perchlorate

Ming-Liang Liu ^a ^*

^aCollege of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, People's Republic of China
^*Correspondence e-mail: jgsdxlml@163.com

(Received 14 September 2011; accepted 25 September 2011; online 5 October 2011)

In the title salt, C₈H₆F₃N₂⁺·ClO₄⁻, the atoms of the benzimidazole ring (including H atoms) are nearly coplanar (r.m.s. deviation of the fitted atoms = 0.0122 Å) and the triflouromethyl group lies out of this plane. The perchlorate anion adopts a distorted tetrahedral conformation with the Cl—O bond distances ranging from 1.412 (3) to 1.439 (2) Å. The benzimidazolium cations are linked to adjacent anions by intermolecular N—H⋯O hydrogen bonds, forming chains.

Related literature

For background to molecular–ionic compounds, see: Yu et al. (2004 ); Chen et al. (2009 ); Ge et al. (2007 ).

Experimental

Crystal data

C₈H₆F₃N₂⁺·ClO₄⁻
M_r = 286.60
Triclinic, $[P \overline 1]$
a = 7.6274 (15) Å
b = 9.0614 (18) Å
c = 9.3838 (19) Å
α = 61.80 (3)°
β = 81.98 (3)°
γ = 75.85 (3)°
V = 554.0 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.40 mm⁻¹
T = 293 K
0.36 × 0.32 × 0.28 mm

Data collection

Rigaku Mercury2 diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ) T_min = 0.963, T_max = 0.971
5756 measured reflections
2535 independent reflections
1980 reflections with I > 2σ(I)
R_int = 0.026

Refinement

R[F² > 2σ(F²)] = 0.051
wR(F²) = 0.140
S = 1.04
2535 reflections
163 parameters
H-atom parameters constrained
Δρ_max = 0.49 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O2	0.86	2.05	2.891 (3)	164
N1—H1A⋯O3	0.86	2.59	3.254 (4)	135
N2—H2A⋯O1ⁱ	0.86	1.98	2.822 (3)	167
Symmetry code: (i) x, y-1, z+1.

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811039298/go2027sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811039298/go2027Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811039298/go2027Isup3.cml

checkCIF report

Comment top

Some interesting physical properties of simple molecular–ionic crystals containing organic cations and anions have been discussed by several authors (Yu et al., 2004; Chen et al., 2009; Ge et al., 2007).

The asymmetric unit of the present compound , C₈H₆N₂H₆F₃⁺ ClO₄^- consists of one 2-trifluoromethyl-1H-benzimidazole cation and one perchlorate anion, Figure 1.

The atoms of the benzimidazole ring (including the H atoms) are nearly co-planar with a rms deviation of the fitted atoms of 0.0122Å. Atom C8 lies out of this plane. The perchlorate anion is a distorted tetrahedron, the average C—O bond distances range from 1.412 (3)Å to 1.439 (2)Å, the O—C—O angles range from 107.71 (17)° to 110.65 (15)°.

The 2-trifluoromethyl-1H-benzimidazole cations are linked to adjacent anions by intermolecular N-H···O hydrogen bonds to form chains, Table 1, Figure 2. The hydrogen bond involving N2-H2A is a three-centre contact to atoms O2 and O3 in which the H2A···O2, 2.05Å, is shorter than the H2A···O3, 2.59Å with the angles at H2A being 164° and 137° respectively. Centrosymmetrically related chains run through each unit cell and these are linked into ribbons by a π–π interaction between the phenyl rings, Cg1···Cg1(-x,1-y,1-z), 4.039 (2)Å, perpendicular distance between rings, 3.5948 (14)Å and slippage, 1.841Å. These ribbons run perpendicular to the a-axis.

Related literature top

For background to molecular–ionic compounds, see: Yu et al. (2004); Chen et al. (2009); Ge et al. (2007).

Experimental top

0.144 g(1 mmol) of 2-trifluoromethyl-1H-benzimidazole was firstly dissolved in 30 ml methanol, to which 0.1 g (1 mmol) of perchloric acid was added to give a solution without any precipitate while stirring at the ambient temperature. Single crystals suitable for X-ray structure analysis were obtained by the slow evaporation of the above solution after 2 days in air.

The dielectric constant of the compound as a function of temperature indicates that the permittivity is basically temperature-independent (ε = C/(T–T₀)), suggesting that this compound is not ferroelectric or there may be no distinct phase transition occurring within the measured temperature within the measured temperature (below the melting point).

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. A view of (I) with the numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A stereoview of part of the crystal structure of compound showing the π–π linked cation-anion hydrogen-bonded ribbons. Hydrogen atoms not involved in the motifs are not included.

2-Trifluoromethyl-1H-benzimidazol-3-ium perchlorate top

Crystal data top

C₈H₆F₃N₂⁺·ClO₄⁻	V = 554.0 (3) Å³
M_r = 286.60	Z = 2
Triclinic, P1	F(000) = 288
Hall symbol: -P 1	D_x = 1.718 Mg m⁻³
a = 7.6274 (15) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.0614 (18) Å	θ = 3.4–26°
c = 9.3838 (19) Å	µ = 0.40 mm⁻¹
α = 61.80 (3)°	T = 293 K
β = 81.98 (3)°	Block, colourless
γ = 75.85 (3)°	0.36 × 0.32 × 0.28 mm

Data collection top

Rigaku Mercury2 diffractometer	2535 independent reflections
Radiation source: fine-focus sealed tube	1980 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.026
CCD_Profile_fitting scans	θ_max = 27.5°, θ_min = 3.4°
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	h = −9→9
T_min = 0.963, T_max = 0.971	k = −11→11
5756 measured reflections	l = −12→12

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.140	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0636P)² + 0.384P] where P = (F_o² + 2F_c²)/3
2535 reflections	(Δ/σ)_max < 0.001
163 parameters	Δρ_max = 0.49 e Å⁻³
0 restraints	Δρ_min = −0.34 e Å⁻³

Crystal data top

C₈H₆F₃N₂⁺·ClO₄⁻	γ = 75.85 (3)°
M_r = 286.60	V = 554.0 (3) Å³
Triclinic, P1	Z = 2
a = 7.6274 (15) Å	Mo Kα radiation
b = 9.0614 (18) Å	µ = 0.40 mm⁻¹
c = 9.3838 (19) Å	T = 293 K
α = 61.80 (3)°	0.36 × 0.32 × 0.28 mm
β = 81.98 (3)°

Data collection top

Rigaku Mercury2 diffractometer	2535 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	1980 reflections with I > 2σ(I)
T_min = 0.963, T_max = 0.971	R_int = 0.026
5756 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.051	0 restraints
wR(F²) = 0.140	H-atom parameters constrained
S = 1.04	Δρ_max = 0.49 e Å⁻³
2535 reflections	Δρ_min = −0.34 e Å⁻³
163 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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

	x	y	z	U_iso*/U_eq
F1	0.3287 (4)	0.0295 (2)	0.1487 (2)	0.0793 (7)
F2	0.4027 (3)	0.2471 (3)	−0.0564 (2)	0.0697 (6)
F3	0.1269 (3)	0.2305 (3)	−0.0094 (3)	0.0791 (7)
N1	0.2447 (3)	0.4517 (3)	0.1052 (3)	0.0430 (5)
H1A	0.2375	0.5249	0.0045	0.052*
N2	0.2695 (3)	0.2099 (3)	0.3226 (2)	0.0379 (5)
H2A	0.2802	0.1020	0.3852	0.046*
C1	0.2548 (3)	0.3343 (3)	0.3721 (3)	0.0374 (5)
C2	0.2378 (4)	0.4892 (3)	0.2328 (3)	0.0395 (6)
C3	0.2214 (4)	0.6432 (4)	0.2384 (4)	0.0534 (7)
H3	0.2090	0.7476	0.1453	0.064*
C4	0.2248 (5)	0.6313 (4)	0.3883 (4)	0.0603 (8)
H4	0.2148	0.7308	0.3976	0.072*
C5	0.2429 (5)	0.4748 (4)	0.5284 (4)	0.0593 (8)
H5	0.2448	0.4737	0.6277	0.071*
C6	0.2577 (4)	0.3237 (4)	0.5248 (3)	0.0510 (7)
H6	0.2691	0.2199	0.6185	0.061*
C7	0.2639 (3)	0.2848 (3)	0.1636 (3)	0.0376 (5)
C8	0.2812 (4)	0.1957 (4)	0.0614 (3)	0.0483 (7)
Cl1	0.21788 (9)	0.83165 (8)	−0.28977 (7)	0.0426 (2)
O1	0.3244 (3)	0.8661 (3)	−0.4364 (2)	0.0571 (6)
O2	0.1589 (4)	0.6730 (3)	−0.2310 (3)	0.0692 (7)
O3	0.3197 (4)	0.8220 (5)	−0.1699 (3)	0.0965 (10)
O4	0.0612 (4)	0.9641 (3)	−0.3218 (3)	0.0806 (8)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
F1	0.131 (2)	0.0469 (11)	0.0617 (12)	−0.0124 (11)	−0.0017 (12)	−0.0287 (9)
F2	0.0740 (13)	0.0940 (15)	0.0507 (10)	−0.0281 (11)	0.0205 (9)	−0.0414 (10)
F3	0.0649 (12)	0.1233 (19)	0.0777 (14)	−0.0174 (12)	−0.0104 (10)	−0.0676 (14)
N1	0.0551 (13)	0.0378 (11)	0.0265 (10)	−0.0127 (10)	0.0002 (9)	−0.0058 (9)
N2	0.0466 (12)	0.0319 (10)	0.0273 (10)	−0.0068 (9)	−0.0029 (9)	−0.0071 (8)
C1	0.0396 (13)	0.0364 (13)	0.0318 (12)	−0.0081 (10)	−0.0015 (10)	−0.0118 (10)
C2	0.0442 (14)	0.0383 (13)	0.0316 (12)	−0.0115 (11)	−0.0005 (10)	−0.0112 (10)
C3	0.068 (2)	0.0385 (14)	0.0502 (17)	−0.0166 (14)	−0.0008 (14)	−0.0149 (13)
C4	0.076 (2)	0.0521 (18)	0.065 (2)	−0.0212 (16)	0.0012 (17)	−0.0337 (16)
C5	0.076 (2)	0.068 (2)	0.0453 (16)	−0.0156 (17)	−0.0024 (15)	−0.0339 (16)
C6	0.0646 (18)	0.0515 (16)	0.0323 (13)	−0.0109 (14)	−0.0049 (12)	−0.0149 (12)
C7	0.0389 (13)	0.0394 (13)	0.0291 (12)	−0.0098 (10)	0.0010 (10)	−0.0111 (10)
C8	0.0560 (17)	0.0536 (16)	0.0374 (14)	−0.0143 (13)	0.0025 (12)	−0.0219 (13)
Cl1	0.0500 (4)	0.0392 (3)	0.0302 (3)	−0.0106 (3)	−0.0028 (2)	−0.0079 (2)
O1	0.0636 (13)	0.0512 (12)	0.0351 (10)	−0.0059 (10)	0.0047 (9)	−0.0067 (9)
O2	0.0965 (18)	0.0503 (13)	0.0569 (14)	−0.0310 (12)	0.0130 (13)	−0.0178 (11)
O3	0.091 (2)	0.158 (3)	0.0524 (14)	−0.057 (2)	−0.0063 (14)	−0.0410 (17)
O4	0.0728 (16)	0.0586 (15)	0.0820 (18)	0.0036 (12)	0.0105 (14)	−0.0207 (13)

Geometric parameters (Å, º) top

F1—C8	1.312 (4)	C3—C4	1.363 (4)
F2—C8	1.317 (3)	C3—H3	0.9300
F3—C8	1.328 (4)	C4—C5	1.397 (5)
N1—C7	1.318 (3)	C4—H4	0.9300
N1—C2	1.382 (3)	C5—C6	1.362 (4)
N1—H1A	0.86	C5—H5	0.9300
N2—C7	1.318 (3)	C6—H6	0.9300
N2—C1	1.385 (3)	C7—C8	1.495 (4)
N2—H2A	0.86	Cl1—O3	1.412 (3)
C1—C2	1.385 (3)	Cl1—O4	1.420 (3)
C1—C6	1.393 (4)	Cl1—O1	1.434 (2)
C2—C3	1.395 (4)	Cl1—O2	1.439 (2)

C7—N1—C2	108.6 (2)	C4—C5—H5	118.8
C7—N1—H1A	125.7	C5—C6—C1	115.8 (3)
C2—N1—H1A	125.8	C5—C6—H6	122.1
C7—N2—C1	108.5 (2)	C1—C6—H6	122.1
C7—N2—H2A	125.8	N2—C7—N1	110.3 (2)
C1—N2—H2A	125.7	N2—C7—C8	125.6 (2)
N2—C1—C2	106.3 (2)	N1—C7—C8	124.1 (2)
N2—C1—C6	131.7 (2)	F1—C8—F2	108.7 (3)
C2—C1—C6	121.9 (3)	F1—C8—F3	108.6 (3)
N1—C2—C1	106.3 (2)	F2—C8—F3	106.2 (2)
N1—C2—C3	132.0 (2)	F1—C8—C7	110.7 (2)
C1—C2—C3	121.6 (3)	F2—C8—C7	111.0 (2)
C4—C3—C2	116.0 (3)	F3—C8—C7	111.4 (2)
C4—C3—H3	122.0	O3—Cl1—O4	110.0 (2)
C2—C3—H3	122.0	O3—Cl1—O1	110.25 (16)
C3—C4—C5	122.2 (3)	O4—Cl1—O1	109.06 (15)
C3—C4—H4	118.9	O3—Cl1—O2	109.08 (18)
C5—C4—H4	118.9	O4—Cl1—O2	107.71 (17)
C6—C5—C4	122.4 (3)	O1—Cl1—O2	110.65 (15)
C6—C5—H5	118.8

C7—N2—C1—C2	0.7 (3)	N2—C1—C6—C5	178.7 (3)
C7—N2—C1—C6	−178.2 (3)	C2—C1—C6—C5	0.0 (4)
C7—N1—C2—C1	0.2 (3)	C1—N2—C7—N1	−0.6 (3)
C7—N1—C2—C3	179.0 (3)	C1—N2—C7—C8	178.0 (2)
N2—C1—C2—N1	−0.5 (3)	C2—N1—C7—N2	0.2 (3)
C6—C1—C2—N1	178.5 (3)	C2—N1—C7—C8	−178.4 (2)
N2—C1—C2—C3	−179.4 (2)	N2—C7—C8—F1	−9.0 (4)
C6—C1—C2—C3	−0.5 (4)	N1—C7—C8—F1	169.4 (3)
N1—C2—C3—C4	−178.0 (3)	N2—C7—C8—F2	−129.8 (3)
C1—C2—C3—C4	0.6 (4)	N1—C7—C8—F2	48.6 (4)
C2—C3—C4—C5	−0.2 (5)	N2—C7—C8—F3	112.1 (3)
C3—C4—C5—C6	−0.2 (6)	N1—C7—C8—F3	−69.5 (3)
C4—C5—C6—C1	0.3 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2	0.86	2.05	2.891 (3)	164
N1—H1A···O3	0.86	2.59	3.254 (4)	135
N2—H2A···O1ⁱ	0.86	1.98	2.822 (3)	167

Symmetry code: (i) x, y−1, z+1.

Experimental details

Crystal data
Chemical formula	C₈H₆F₃N₂⁺·ClO₄⁻
M_r	286.60
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	7.6274 (15), 9.0614 (18), 9.3838 (19)
α, β, γ (°)	61.80 (3), 81.98 (3), 75.85 (3)
V (Å³)	554.0 (3)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.40
Crystal size (mm)	0.36 × 0.32 × 0.28

Data collection
Diffractometer	Rigaku Mercury2 diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2005)
T_min, T_max	0.963, 0.971
No. of measured, independent and observed [I > 2σ(I)] reflections	5756, 2535, 1980
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.051, 0.140, 1.04
No. of reflections	2535
No. of parameters	163
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.49, −0.34

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2	0.86	2.05	2.891 (3)	164
N1—H1A···O3	0.86	2.59	3.254 (4)	135
N2—H2A···O1ⁱ	0.86	1.98	2.822 (3)	167

Symmetry code: (i) x, y−1, z+1.

Acknowledgements

The author thanks an anonymous referee from the Ordered Matter Science Research Centre, Southeast University, for great help in the revision of this paper.

References

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