1-[(S)-1-Phenyl­ethyl]-1H-benzimidazole

In the chiral title compound, C₁₅H₁₄N₂, the dihedral angle between the mean planes of the aromatic rings is 81.59 (4)°. An inter­molecular C—H...N inter­action (H...N = 2.50 Å) involving the chiral C atom results in [100] chains of mol­ecules in the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.032
• wR factor = 0.080
• Data-to-parameter ratio = 10.1

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?

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           27.54
           From the CIF: _reflns_number_total               1571
           Count of symmetry unique reflns         1581
           Completeness (_total/calc)             99.37%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C8     = .          S

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 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

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S1. Comment

The title compound (Fig. 1) was prepared as a possible component of a chiral catalyst. The same compound was recently reported by Rivas et al. (2002).

The geometrical parameters may be regarded as normal (Allen et al., 1987). The dihedral angle between the mean planes of the C1—C7/N1/N2 fused ring and C10—C15 ring is 81.59 (4)°. Atom C8 of the title molecule is chiral: S configuration was assigned to this atom based on the known chirality of the equivalent atom in the starting material.

The crystal packing is consolidated by a C8—H8···N2ⁱ interaction (Table 1), which links the molecules into [100] chains (Fig. 2) with a C(5) graph-set motif (Etter, 1990). There are no π-π stacking interactions, as the minimum separation of the centroids of the aromatic rings of nearby molecules is greater than 5 Å.

Related literature

The synthesis of the title compound was recently reported by Rivas et al. (2002).

For related literature, see: Allen et al. (1987); Etter (1990).

S2. Experimental

N-((S)-1-Phenyl-ethyl)-benzene-1,2-diamine (8.479 g, 39.9 mmol) was placed in a flask, and dissolved in HC(OEt)₃ (85 ml). p-Toluenesulphonic acid (0.340 g, 1.7 mmol, 5 mol%) was added, and the solution heated at 353 K for 24 h. Removal of volatiles in vacuo gave a yellow oil, which was partitioned between aqueous Na₂CO₃ solution (5% w/v, 200 ml) and DCM (3 τimes 200 ml). The combined organics were dried (MgSO₄), and solvent removed to yield pale yellow plates (3.323 g, 37%). Slow evaporation of a DCM solution produced colourless crystals of (I) suitable for diffraction; mp 418–420 K; [α]_D -9.3 (c = 1.73, DCM); C₁₅H₁₄N₂ requires C 81.05, H 6.35, N 12.60%; found C 81.21, H 6.38, N 12.64%.

S3. Refinement

Anomalous dispersion was negligible and Friedel pairs were merged before refinement. The S chirality at C8 was assigned based on the known chirality of the equivalent atom in the starting material. The hydrogen atoms were placed in calculated positions (C—H = 0.95–1.00 Å) and refined as riding with U_iso(H) = 1.2U_eq(C) or 1.5U_eq(methyl C). The –CH₃ group was allowed to rotate but not to tip, to best fit the electron density.

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997), and SORTAV (Blessing, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. View of the molecular structure showing 50% displacement ellipsoids (H atoms are drawn as small spheres of arbitrary radius).
	Fig. 2. Fragement of the crystal structure showing part of a [100] chain of molecules linked by C—H···N bonds (double dashed lines). All H atoms except H8 are omitted for clarity. Symmetry codes: (i) x - 1, y, z; (ii) x + 1, y, z.

1-[(S)-1-Phenylethyl]-1H-benzimidazole

Crystal data

C15H14N2	F(000) = 472
Mr = 222.28	Dx = 1.260 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1583 reflections
a = 6.3159 (3) Å	θ = 2.9–27.5°
b = 8.6989 (3) Å	µ = 0.08 mm^−1
c = 21.3277 (9) Å	T = 120 K
V = 1171.77 (8) Å^3	Shard, colourless
Z = 4	0.46 × 0.20 × 0.13 mm

Data collection

Nonius KappaCCD diffractometer	1571 independent reflections
Radiation source: fine-focus sealed tube	1463 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
ω and φ scans	θmax = 27.5°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −8→8
Tmin = 0.966, Tmax = 0.990	k = −9→11
8654 measured reflections	l = −27→27

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.032	H-atom parameters constrained
wR(F^2) = 0.081	w = 1/[σ^2(Fo^2) + (0.0349P)^2 + 0.2819P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
1571 reflections	Δρmax = 0.16 e Å^−3
156 parameters	Δρmin = −0.17 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.033 (6)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.2835 (3)	0.24132 (17)	0.13869 (7)	0.0194 (3)
C2	0.1813 (3)	0.21889 (19)	0.08162 (7)	0.0235 (4)
H2	0.0451	0.2607	0.0735	0.028*
C3	0.2884 (3)	0.13264 (19)	0.03749 (8)	0.0264 (4)
H3	0.2243	0.1150	−0.0022	0.032*
C4	0.4891 (3)	0.0703 (2)	0.04954 (8)	0.0270 (4)
H4	0.5580	0.0121	0.0179	0.032*
C5	0.5886 (3)	0.09180 (19)	0.10661 (8)	0.0251 (4)
H5	0.7241	0.0488	0.1148	0.030*
C6	0.4826 (3)	0.17917 (19)	0.15197 (7)	0.0213 (3)
C7	0.3886 (3)	0.3043 (2)	0.23324 (8)	0.0229 (4)
H7	0.3884	0.3491	0.2739	0.027*
C8	0.0229 (3)	0.40316 (18)	0.19948 (7)	0.0198 (3)
H8	−0.0933	0.3274	0.1918	0.024*
C9	−0.0023 (3)	0.4646 (2)	0.26587 (7)	0.0262 (4)
H9A	0.0136	0.3800	0.2959	0.039*
H9B	−0.1430	0.5107	0.2706	0.039*
H9C	0.1063	0.5426	0.2739	0.039*
C10	0.0007 (3)	0.53183 (18)	0.15155 (7)	0.0196 (3)
C11	0.1706 (3)	0.62418 (19)	0.13505 (8)	0.0250 (4)
H11	0.3061	0.6053	0.1528	0.030*
C12	0.1443 (3)	0.7442 (2)	0.09273 (8)	0.0285 (4)
H12	0.2619	0.8063	0.0813	0.034*
C13	−0.0541 (3)	0.7733 (2)	0.06721 (8)	0.0291 (4)
H13	−0.0726	0.8557	0.0385	0.035*
C14	−0.2241 (3)	0.6824 (2)	0.08370 (8)	0.0292 (4)
H14	−0.3599	0.7024	0.0663	0.035*
C15	−0.1974 (3)	0.5614 (2)	0.12572 (8)	0.0247 (4)
H15	−0.3149	0.4988	0.1368	0.030*
N1	0.2257 (2)	0.32261 (15)	0.19189 (6)	0.0193 (3)
N2	0.5455 (2)	0.21984 (17)	0.21242 (7)	0.0252 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0217 (8)	0.0153 (7)	0.0211 (7)	−0.0007 (7)	0.0028 (6)	0.0023 (6)
C2	0.0253 (8)	0.0219 (8)	0.0233 (8)	0.0021 (7)	−0.0003 (7)	0.0025 (6)
C3	0.0366 (10)	0.0225 (8)	0.0200 (8)	0.0003 (8)	0.0017 (7)	0.0004 (6)
C4	0.0348 (10)	0.0209 (8)	0.0252 (8)	0.0024 (9)	0.0092 (8)	−0.0010 (7)
C5	0.0232 (8)	0.0205 (8)	0.0316 (9)	0.0024 (7)	0.0054 (7)	0.0033 (7)
C6	0.0213 (8)	0.0187 (7)	0.0239 (7)	−0.0022 (7)	0.0019 (7)	0.0021 (6)
C7	0.0234 (8)	0.0221 (8)	0.0232 (8)	−0.0009 (7)	−0.0032 (7)	0.0001 (7)
C8	0.0177 (7)	0.0185 (7)	0.0233 (8)	0.0008 (7)	0.0023 (6)	0.0004 (6)
C9	0.0304 (9)	0.0251 (8)	0.0232 (8)	0.0040 (9)	0.0052 (9)	−0.0001 (7)
C10	0.0223 (8)	0.0190 (7)	0.0177 (7)	0.0017 (7)	0.0011 (7)	−0.0020 (6)
C11	0.0232 (9)	0.0232 (8)	0.0285 (9)	0.0030 (7)	0.0012 (7)	0.0025 (7)
C12	0.0330 (10)	0.0234 (9)	0.0290 (9)	0.0020 (8)	0.0093 (8)	0.0040 (7)
C13	0.0410 (11)	0.0255 (9)	0.0207 (7)	0.0108 (9)	0.0049 (7)	0.0027 (7)
C14	0.0294 (9)	0.0317 (9)	0.0264 (8)	0.0090 (9)	−0.0047 (8)	−0.0018 (7)
C15	0.0231 (8)	0.0253 (8)	0.0257 (8)	0.0007 (8)	−0.0004 (7)	−0.0010 (7)
N1	0.0204 (7)	0.0186 (6)	0.0189 (6)	0.0005 (6)	0.0000 (5)	−0.0001 (5)
N2	0.0234 (7)	0.0254 (7)	0.0267 (7)	0.0013 (6)	−0.0028 (6)	−0.0004 (6)

Geometric parameters (Å, º)

C1—N1	1.3858 (19)	C8—C10	1.522 (2)
C1—C2	1.391 (2)	C8—H8	1.0000
C1—C6	1.398 (2)	C9—H9A	0.9800
C2—C3	1.381 (2)	C9—H9B	0.9800
C2—H2	0.9500	C9—H9C	0.9800
C3—C4	1.402 (3)	C10—C11	1.386 (2)
C3—H3	0.9500	C10—C15	1.391 (2)
C4—C5	1.383 (3)	C11—C12	1.390 (2)
C4—H4	0.9500	C11—H11	0.9500
C5—C6	1.401 (2)	C12—C13	1.389 (3)
C5—H5	0.9500	C12—H12	0.9500
C6—N2	1.395 (2)	C13—C14	1.379 (3)
C7—N2	1.311 (2)	C13—H13	0.9500
C7—N1	1.364 (2)	C14—C15	1.393 (2)
C7—H7	0.9500	C14—H14	0.9500
C8—N1	1.469 (2)	C15—H15	0.9500
C8—C9	1.522 (2)
N1—C1—C2	131.74 (16)	C8—C9—H9B	109.5
N1—C1—C6	105.56 (14)	H9A—C9—H9B	109.5
C2—C1—C6	122.70 (15)	C8—C9—H9C	109.5
C3—C2—C1	116.44 (16)	H9A—C9—H9C	109.5
C3—C2—H2	121.8	H9B—C9—H9C	109.5
C1—C2—H2	121.8	C11—C10—C15	119.24 (15)
C2—C3—C4	121.88 (16)	C11—C10—C8	121.71 (15)
C2—C3—H3	119.1	C15—C10—C8	118.99 (15)
C4—C3—H3	119.1	C10—C11—C12	120.53 (17)
C5—C4—C3	121.31 (16)	C10—C11—H11	119.7
C5—C4—H4	119.3	C12—C11—H11	119.7
C3—C4—H4	119.3	C13—C12—C11	119.92 (17)
C4—C5—C6	117.67 (17)	C13—C12—H12	120.0
C4—C5—H5	121.2	C11—C12—H12	120.0
C6—C5—H5	121.2	C14—C13—C12	119.86 (16)
N2—C6—C1	110.21 (14)	C14—C13—H13	120.1
N2—C6—C5	129.79 (16)	C12—C13—H13	120.1
C1—C6—C5	119.99 (16)	C13—C14—C15	120.20 (17)
N2—C7—N1	114.61 (15)	C13—C14—H14	119.9
N2—C7—H7	122.7	C15—C14—H14	119.9
N1—C7—H7	122.7	C10—C15—C14	120.25 (17)
N1—C8—C9	111.16 (14)	C10—C15—H15	119.9
N1—C8—C10	110.91 (13)	C14—C15—H15	119.9
C9—C8—C10	110.92 (13)	C7—N1—C1	105.73 (13)
N1—C8—H8	107.9	C7—N1—C8	129.94 (13)
C9—C8—H8	107.9	C1—N1—C8	124.27 (13)
C10—C8—H8	107.9	C7—N2—C6	103.88 (14)
C8—C9—H9A	109.5
N1—C1—C2—C3	178.50 (16)	C11—C12—C13—C14	−0.4 (3)
C6—C1—C2—C3	−0.9 (2)	C12—C13—C14—C15	−0.1 (3)
C1—C2—C3—C4	0.3 (2)	C11—C10—C15—C14	0.1 (2)
C2—C3—C4—C5	0.4 (3)	C8—C10—C15—C14	177.38 (14)
C3—C4—C5—C6	−0.5 (2)	C13—C14—C15—C10	0.3 (3)
N1—C1—C6—N2	0.65 (17)	N2—C7—N1—C1	0.02 (19)
C2—C1—C6—N2	−179.85 (15)	N2—C7—N1—C8	177.34 (14)
N1—C1—C6—C5	−178.71 (14)	C2—C1—N1—C7	−179.84 (17)
C2—C1—C6—C5	0.8 (2)	C6—C1—N1—C7	−0.40 (16)
C4—C5—C6—N2	−179.32 (16)	C2—C1—N1—C8	2.6 (3)
C4—C5—C6—C1	−0.1 (2)	C6—C1—N1—C8	−177.92 (13)
N1—C8—C10—C11	−39.39 (19)	C9—C8—N1—C7	−3.7 (2)
C9—C8—C10—C11	84.65 (19)	C10—C8—N1—C7	120.19 (17)
N1—C8—C10—C15	143.39 (15)	C9—C8—N1—C1	173.17 (14)
C9—C8—C10—C15	−92.57 (18)	C10—C8—N1—C1	−62.93 (18)
C15—C10—C11—C12	−0.6 (2)	N1—C7—N2—C6	0.38 (19)
C8—C10—C11—C12	−177.81 (15)	C1—C6—N2—C7	−0.63 (17)
C10—C11—C12—C13	0.7 (3)	C5—C6—N2—C7	178.64 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8···N2^i	1.00	2.50	3.422 (2)	152

Symmetry code: (i) x−1, y, z.