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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 4| April 2012| Page o1012
doi:10.1107/S1600536812009415

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

Ming-Liang Liua*

aOrdered Matter Science Research Center, Southeast University, Nanjing 211189, People's Republic of China
*Correspondence e-mail: jgsdxlml@163.com

(Received 1 March 2012; accepted 3 March 2012; online 10 March 2012)

Ihe title salt, C8H6F3N2+·NO3−, the F atoms of the triflouromethyl group are disordered over two sets of sites in a 0.58 (2):0.42 (2) ratio. In the crystal, N—H⋯O hydrogen bonds link the cations and anions into chains running parallel to the b axis. There is π–π stacking between symmetry-related benzene rings with a centroid-centroid distance of 3.949 (3) Å. The crystal studied was a non-merohedral twin, with a 19% minor component.

Related literature

The title compound was synthesized as part of a search for potential ferroelectric compouns. For background to ferroelectric complexes, see: Fu et al. (2011[Fu, D. W., Zhang, W., Cai, H. L., Zhang, Y., Ge, J. Z., Xiong, R. G. & Huang, S. P. (2011). J. Am. Chem. Soc. 133, 12780-12786.]); Zhang et al. (2010[Zhang, W., Chen, L. Z., Gou, M., Li, Y. H., Fu, D. W. & Xiong, R. G. (2010). Cryst. Growth Des. 10, 1025-1027.]). For related structures, see: Liu (2011a[Liu, M.-L. (2011a). Acta Cryst. E67, o2821.],b[Liu, M.-L. (2011b). Acta Cryst. E67, o3473.], 2012[Liu, M.-L. (2012). Acta Cryst. E68, o342.]). For the separation of the non-merohedrally twinned diffraction data, see: Spek (2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

[Scheme 1]

Experimental

Crystal data

  • C8H6F3N2+·NO3−

  • Mr = 249.16

  • Triclinic, [P \overline 1]

  • a = 7.2745 (15) Å

  • b = 9.0962 (18) Å

  • c = 9.4502 (19) Å

  • α = 61.53 (3)°

  • β = 71.18 (3)°

  • γ = 82.41 (3)°

  • V = 520.1 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.16 mm−1

  • T = 293 K

  • 0.20 × 0.20 × 0.20 mm
Data collection

  • Rigaku SCXmini diffractometer

  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.969, Tmax = 0.969

  • 1828 measured reflections

  • 1828 independent reflections

  • 910 reflections with I > 2σ(I)
Refinement

  • R[F2 > 2σ(F2)] = 0.072

  • wR(F2) = 0.227

  • S = 1.01

  • 1828 reflections

  • 183 parameters

  • H-atom parameters constrained

  • Δρmax = 0.23 e Å−3

  • Δρmin = −0.27 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N2—H2A⋯O1 0.86 1.86 2.703 (5) 168
N3—H3A⋯O2i 0.86 1.84 2.682 (5) 165
Symmetry code: (i) x, y-1, z.

Data collection: CrystalClear (Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: PLATON (Spek, 2009)[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]; software used to prepare material for publication: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812009415/go2046sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812009415/go2046Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812009415/go2046Isup3.cml

checkCIF report


Comment top

Recently much attention has been devoted to crystals containing organic ions and inorganic ions due to the possibility of tuning their special structural features and their potential ferroelectrics properties (Fu et al., 2011; Zhang et al., 2010.). In our laboratory, the title compound (I) has been synthesized to investigate its potential ferroelectric propeties. However, it was found that the dielectric constant of the compound as a function of temperature indicated 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 range (below the melting point).

The asymmetric unit that consists of one 2-trifluoromethyl-1H-benzimidazole cation and nitrate anionwhich are linked by N2—H2A···O1 hydrogen bond. Figure 1. The N3—H3A···O2 hydrogen bond links the the asymmetric units together into chains which run parallel to the b-axis. (Fig 2). There is π···π stacking between the six-membered rings at (x,y,z) and (1-x,1-y,-z) with a centroid to centroid distance of 3.949 (3)Å, perpendicular distance between the planes of 3.514 (2)Å and a slippage of 1.802Å. The triflouromethyl group is disordered.

Related literature top

The title compound was synthesized as part of a search for potential ferroelectric compouns. For background to ferroelectric complexes, see: Fu et al. (2011); Zhang et al. (2010). For related structures, see: Liu (2011a,b, 2012).

Experimental top

0.144 g (1 mmol) of 2-trifluoromethyl-1H-benzimidazol was firstly dissolved in 30 ml of ethanol, to which 0.063 g (1 mmol) of nitric acid was added forming a solution at the ambient temperature. Single crystals suitable for X-ray structure analysis were obtained by the slow evaporation of the above solution after 3 days in air.

Refinement top

H atoms were placed in calculated positions (N—H = 0.89 Å; C—H = 0.93Å for Csp2 atoms and C—H = 0.96Å and 0.97Å for Csp3 atoms), assigned fixed Uiso values [Uiso = 1.2Ueq(Csp2) and 1.5Ueq(Csp3,N)] and allowed to ride. The trifluoromethyl group is modelled as being disordered over two sites with refined site occupancies of 0.58 and 0.42 respectively. The crystal was twinned. A .hkl file suitable for twin refinement was created using the TwinRotMat option in PLATON (Spek, 2009), and refined using the HKLF 5 option in SHELXL (Sheldrick,2008), giving a final BASF value of 0.19. Thus the ratio of the twin components was 0.81/0.19.

Structure description top

Recently much attention has been devoted to crystals containing organic ions and inorganic ions due to the possibility of tuning their special structural features and their potential ferroelectrics properties (Fu et al., 2011; Zhang et al., 2010.). In our laboratory, the title compound (I) has been synthesized to investigate its potential ferroelectric propeties. However, it was found that the dielectric constant of the compound as a function of temperature indicated 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 range (below the melting point).

The asymmetric unit that consists of one 2-trifluoromethyl-1H-benzimidazole cation and nitrate anionwhich are linked by N2—H2A···O1 hydrogen bond. Figure 1. The N3—H3A···O2 hydrogen bond links the the asymmetric units together into chains which run parallel to the b-axis. (Fig 2). There is π···π stacking between the six-membered rings at (x,y,z) and (1-x,1-y,-z) with a centroid to centroid distance of 3.949 (3)Å, perpendicular distance between the planes of 3.514 (2)Å and a slippage of 1.802Å. The triflouromethyl group is disordered.

The title compound was synthesized as part of a search for potential ferroelectric compouns. For background to ferroelectric complexes, see: Fu et al. (2011); Zhang et al. (2010). For related structures, see: Liu (2011a,b, 2012).

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: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing the atomic numbering scheme with 30% probability displacement ellipsoids.
[Figure 2] Fig. 2. View of the cation/anion chain running parallel to the b axis. Minor component F atoms and H atoms not involved in the hydrogen bonding are omitted for clarity. Atoms labelled with a *(star) are at (x,-1+y,z) and those labelled with a #(hash) are at (x,1+y,z).
2-Trifluoromethyl-1H-benzimidazol-3-ium nitrate top
Crystal data top
C8H6F3N2+·NO3−V = 520.1 (3) Å3
Mr = 249.16Z = 2
Triclinic, P1F(000) = 252
Hall symbol: -P 1Dx = 1.591 Mg m−3
a = 7.2745 (15) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.0962 (18) Åθ = 3.3–25.0°
c = 9.4502 (19) ŵ = 0.16 mm−1
α = 61.53 (3)°T = 293 K
β = 71.18 (3)°Block, colourless
γ = 82.41 (3)°0.20 × 0.20 × 0.20 mm
Data collection top
Rigaku SCXmini
diffractometer		1828 independent reflections
Radiation source: fine-focus sealed tube910 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.000
CCD_Profile_fitting scansθmax = 25.0°, θmin = 3.3°
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)		h = −8→8
Tmin = 0.969, Tmax = 0.969k = −10→10
1828 measured reflectionsl = −9→11
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)] = 0.072Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.227H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.1061P)2]
where P = (Fo2 + 2Fc2)/3
1828 reflections(Δ/σ)max < 0.001
183 parametersΔρmax = 0.23 e Å−3
0 restraintsΔρmin = −0.27 e Å−3
Crystal data top
C8H6F3N2+·NO3−γ = 82.41 (3)°
Mr = 249.16V = 520.1 (3) Å3
Triclinic, P1Z = 2
a = 7.2745 (15) ÅMo Kα radiation
b = 9.0962 (18) ŵ = 0.16 mm−1
c = 9.4502 (19) ÅT = 293 K
α = 61.53 (3)°0.20 × 0.20 × 0.20 mm
β = 71.18 (3)°
Data collection top
Rigaku SCXmini
diffractometer		1828 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)		910 reflections with I > 2σ(I)
Tmin = 0.969, Tmax = 0.969Rint = 0.000
1828 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0720 restraints
wR(F2) = 0.227H-atom parameters constrained
S = 1.01Δρmax = 0.23 e Å−3
1828 reflectionsΔρmin = −0.27 e Å−3
183 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 > 2sigma(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*/UeqOcc. (<1)
N20.2477 (5)0.3645 (4)0.4631 (4)0.0551 (10)
H2A0.24790.43610.49810.066*
O20.2968 (6)0.7956 (4)0.5882 (4)0.0824 (12)
O10.2843 (6)0.5588 (4)0.5979 (5)0.0849 (12)
N30.2467 (5)0.1269 (4)0.4602 (4)0.0541 (10)
H3A0.24700.02090.49320.065*
N10.2547 (6)0.7095 (5)0.5303 (5)0.0586 (11)
O30.1883 (5)0.7778 (5)0.4106 (5)0.0839 (12)
F10.343 (3)−0.0238 (12)0.7647 (14)0.104 (7)0.58 (2)
F20.331 (4)0.1984 (11)0.7662 (17)0.108 (7)0.58 (2)
F30.0708 (17)0.077 (4)0.8311 (11)0.166 (11)0.58 (2)
F1'0.396 (2)0.077 (7)0.7605 (16)0.187 (17)0.42 (2)
F2'0.144 (5)0.1946 (18)0.8128 (15)0.110 (8)0.42 (2)
F3'0.132 (4)−0.0270 (19)0.8115 (17)0.107 (8)0.42 (2)
C20.2467 (6)0.2011 (5)0.5524 (6)0.0531 (12)
C30.2462 (7)0.2518 (5)0.3017 (5)0.0523 (12)
C80.2483 (6)0.4019 (5)0.3024 (5)0.0520 (12)
C70.2462 (7)0.5527 (6)0.1610 (6)0.0681 (14)
H70.24620.65450.16190.082*
C50.2441 (8)0.3936 (8)0.0199 (6)0.0781 (16)
H50.24470.3947−0.07910.094*
C60.2442 (8)0.5454 (7)0.0225 (7)0.0778 (16)
H60.24280.6445−0.07410.093*
C10.2396 (12)0.1092 (7)0.7352 (7)0.0659 (14)
C40.2431 (8)0.2420 (7)0.1588 (6)0.0698 (15)
H40.24050.14050.15800.084*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N20.073 (3)0.041 (2)0.063 (2)0.0001 (18)−0.026 (2)−0.029 (2)
O20.130 (3)0.050 (2)0.090 (3)0.009 (2)−0.050 (2)−0.041 (2)
O10.140 (3)0.042 (2)0.093 (3)0.010 (2)−0.050 (2)−0.0389 (19)
N30.071 (3)0.038 (2)0.060 (2)−0.0001 (17)−0.019 (2)−0.0276 (19)
N10.071 (3)0.051 (3)0.060 (3)−0.005 (2)−0.015 (2)−0.031 (2)
O30.097 (3)0.085 (3)0.081 (3)0.003 (2)−0.045 (2)−0.036 (2)
F10.20 (2)0.049 (5)0.082 (5)0.045 (7)−0.079 (9)−0.028 (4)
F20.21 (2)0.068 (5)0.084 (6)−0.002 (6)−0.088 (10)−0.037 (4)
F30.094 (7)0.26 (3)0.055 (5)−0.013 (14)0.003 (5)−0.021 (12)
F1'0.094 (11)0.33 (4)0.063 (7)0.00 (2)−0.033 (7)−0.02 (2)
F2'0.19 (3)0.076 (8)0.065 (7)0.019 (9)−0.025 (10)−0.044 (6)
F3'0.18 (2)0.066 (7)0.063 (7)−0.045 (9)−0.021 (9)−0.015 (5)
C20.063 (3)0.041 (3)0.060 (3)0.003 (2)−0.022 (2)−0.025 (2)
C30.065 (3)0.043 (3)0.054 (3)0.003 (2)−0.024 (2)−0.023 (2)
C80.058 (3)0.048 (3)0.055 (3)0.001 (2)−0.022 (2)−0.025 (2)
C70.079 (4)0.052 (3)0.071 (3)0.000 (2)−0.025 (3)−0.024 (3)
C50.087 (4)0.093 (4)0.051 (3)0.005 (3)−0.026 (3)−0.028 (3)
C60.104 (5)0.059 (3)0.066 (3)0.000 (3)−0.040 (3)−0.016 (3)
C10.093 (5)0.053 (4)0.059 (4)0.003 (3)−0.028 (4)−0.029 (3)
C40.082 (4)0.075 (4)0.068 (3)0.002 (3)−0.025 (3)−0.044 (3)
Geometric parameters (Å, º) top
N2—C21.314 (5)F2'—C11.303 (13)
N2—C81.388 (5)F3'—C11.309 (15)
N2—H2A0.8600C2—C11.504 (6)
O2—N11.260 (4)C3—C81.371 (6)
O1—N11.228 (5)C3—C41.402 (6)
N3—C21.333 (5)C8—C71.388 (6)
N3—C31.384 (5)C7—C61.346 (7)
N3—H3A0.8600C7—H70.9300
N1—O31.226 (5)C5—C41.377 (7)
F1—C11.295 (12)C5—C61.393 (8)
F2—C11.297 (12)C5—H50.9300
F3—C11.240 (10)C6—H60.9300
F1'—C11.206 (14)C4—H40.9300
C2—N2—C8108.3 (3)C5—C6—H6119.1
C2—N2—H2A125.9F1'—C1—F3132.5 (9)
C8—N2—H2A125.9F1'—C1—F148 (2)
C2—N3—C3107.4 (3)F3—C1—F1112.0 (13)
C2—N3—H3A126.3F1'—C1—F255 (2)
C3—N3—H3A126.3F3—C1—F2110.2 (11)
O3—N1—O1123.2 (4)F1—C1—F2102.3 (10)
O3—N1—O2119.6 (4)F1'—C1—F2'108.7 (16)
O1—N1—O2117.2 (4)F3—C1—F2'54.6 (9)
N2—C2—N3110.6 (4)F1—C1—F2'139.1 (9)
N2—C2—C1125.0 (4)F2—C1—F2'59.5 (9)
N3—C2—C1124.3 (4)F1'—C1—F3'110.3 (19)
C8—C3—N3107.3 (4)F3—C1—F3'49.3 (11)
C8—C3—C4122.1 (4)F1—C1—F3'67.9 (9)
N3—C3—C4130.6 (4)F2—C1—F3'141.3 (8)
C3—C8—N2106.5 (4)F2'—C1—F3'102.4 (12)
C3—C8—C7121.4 (4)F1'—C1—C2115.1 (8)
N2—C8—C7132.1 (4)F3—C1—C2112.3 (7)
C6—C7—C8117.2 (5)F1—C1—C2110.6 (6)
C6—C7—H7121.4F2—C1—C2108.9 (6)
C8—C7—H7121.4F2'—C1—C2110.0 (7)
C4—C5—C6122.3 (5)F3'—C1—C2109.6 (7)
C4—C5—H5118.9C5—C4—C3115.1 (5)
C6—C5—H5118.9C5—C4—H4122.4
C7—C6—C5121.8 (5)C3—C4—H4122.4
C7—C6—H6119.1
C8—N2—C2—N30.0 (5)N2—C2—C1—F1'−92 (3)
C8—N2—C2—C1−178.0 (5)N3—C2—C1—F1'90 (3)
C3—N3—C2—N2−0.5 (5)N2—C2—C1—F390 (2)
C3—N3—C2—C1177.6 (5)N3—C2—C1—F3−88 (2)
C2—N3—C3—C80.7 (5)N2—C2—C1—F1−144.3 (11)
C2—N3—C3—C4−178.9 (5)N3—C2—C1—F138.0 (13)
N3—C3—C8—N2−0.7 (5)N2—C2—C1—F2−32.6 (16)
C4—C3—C8—N2179.0 (4)N3—C2—C1—F2149.7 (13)
N3—C3—C8—C7−179.3 (4)N2—C2—C1—F2'31 (2)
C4—C3—C8—C70.4 (7)N3—C2—C1—F2'−146.9 (18)
C2—N2—C8—C30.4 (5)N2—C2—C1—F3'142.8 (16)
C2—N2—C8—C7178.8 (5)N3—C2—C1—F3'−35.0 (17)
C3—C8—C7—C6−0.7 (8)C6—C5—C4—C3−1.2 (8)
N2—C8—C7—C6−178.8 (5)C8—C3—C4—C50.5 (7)
C8—C7—C6—C50.0 (8)N3—C3—C4—C5−179.8 (5)
C4—C5—C6—C71.0 (9)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O10.861.862.703 (5)168
N3—H3A···O2i0.861.842.682 (5)165
Symmetry code: (i) x, y−1, z.

Experimental details

Crystal data
Chemical formulaC8H6F3N2+·NO3−
Mr249.16
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)7.2745 (15), 9.0962 (18), 9.4502 (19)
α, β, γ (°)61.53 (3), 71.18 (3), 82.41 (3)
V (Å3)520.1 (3)
Z2
Radiation typeMo Kα
µ (mm−1)0.16
Crystal size (mm)0.20 × 0.20 × 0.20
Data collection
DiffractometerRigaku SCXmini
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.969, 0.969
No. of measured, independent and
observed [I > 2σ(I)] reflections		1828, 1828, 910
Rint0.000
(sin θ/λ)max (Å−1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.072, 0.227, 1.01
No. of reflections1828
No. of parameters183
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.23, −0.27

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

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O10.861.862.703 (5)168
N3—H3A···O2i0.861.842.682 (5)165
Symmetry code: (i) x, y−1, z.
 

Acknowledgements

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

References

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Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 68| Part 4| April 2012| Page o1012
doi:10.1107/S1600536812009415
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