2-(1-Naphthyl­meth­yl)-1H-benzo[d]imidazole

In the title compound, C₁₈H₁₄N₂, the benzimidazole and naphthalene ring systems are planar, making a dihedral angle of 78.71 (1)° with each other. The packing of the mol­ecules in the crystal structure is mainly due to an inter­molecular N—H...N hydrogen bond.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.044
• wR factor = 0.098
• Data-to-parameter ratio = 9.0

checkCIF/PLATON results

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Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C5     -   C6      ..       5.21 su
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

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           27.99
           From the CIF: _reflns_number_total               1651
           Count of symmetry unique reflns         1682
           Completeness (_total/calc)             98.16%
           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
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          2

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

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 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

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S1. Comment

Benzimidazoles are important heterocycles which exhibite good biological and pharmaceutical activities, such as antitumor activity (Matsuno et al., 2000). Many derivatives of benzimidazole have been prepared and their biological activities were studied (Garuti et al., 1999). In our work of preparing potentially active heterocycles, we obtained the title compound, (I). The benzimidazole ring is planar. The naphthalene ring C1—C10 is twisted with respect to this benzimidazole ring, with a dihedral angle of 78.71 (1)° (Fig. 1). In the crystal structure, intermolecular N—H···N hydrogen bonds form zigzag tapes running along the c axis (Fig. 2 and Table 1). There are no marked π-π interactions.

Related literature

Many derivatives of benzimidazole have been prepared and their biological and pharmaceutical activities have ben studied by Matsuno et al. (2000) and Garuti et al. (1999).

S2. Experimental

A solution of 1,2-benzenediamine (10.8 g, 0.1 mol) and 2-(1-naphthalenyl) acetic acid (18.6 g, 0.1 mol) in ethane-1,2-diol (30 ml) was refluxed for 8 h. After the reaction mixture was cooled to room temperature, it was poured into water (200 ml) and the precipitate was filtered and recrystallized from DMF/ethanol (1:8) to give the title compound, (I), in yield of 83% (m.p. 523 K). Suitable crystals were obtained by vapor diffusion of ethanol and dichloromethane at room temperature.

S3. Refinement

The N-bound H atom was refined isotropically, with U_iso(H) = 1.2U_eq(N). Other H atoms were treated as riding atoms, with C—H distances 0.93 Å (aromatic) and 0.97 Å (CH₂), and with U_iso(H) = 1.2U_eq(C). In the absence of significant anomalous scattering effects, Friedel pairs have been merged.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL (Sheldrick, 2001).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A crystal packing diagram, viewed along the b axis. Hydrogen bonds are indicated by dashed lines.

2-(1-Naphthylmethyl)-1H-benzo[d]imidazole

Crystal data

C18H14N2	F(000) = 272
Mr = 258.31	Dx = 1.231 Mg m^−3
Monoclinic, Pc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2yc	Cell parameters from 1373 reflections
a = 8.4578 (16) Å	θ = 2.3–21.6°
b = 9.0329 (17) Å	µ = 0.07 mm^−1
c = 9.6474 (18) Å	T = 298 K
β = 108.932 (3)°	Plate, colorless
V = 697.2 (2) Å^3	0.13 × 0.06 × 0.05 mm
Z = 2

Data collection

Bruker SMART 4K CCD area-detector diffractometer	1176 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.035
Graphite monochromator	θmax = 28.0°, θmin = 2.3°
φ and ω scans	h = −11→10
5884 measured reflections	k = −11→11
1651 independent reflections	l = −12→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.098	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0453P)^2] where P = (Fo^2 + 2Fc^2)/3
1651 reflections	(Δ/σ)max < 0.001
184 parameters	Δρmax = 0.12 e Å^−3
2 restraints	Δρmin = −0.10 e Å^−3

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	0.5318 (3)	0.5708 (3)	0.8424 (3)	0.0601 (8)
H1	0.5074	0.5024	0.9046	0.072*
C2	0.6502 (4)	0.5376 (4)	0.7806 (4)	0.0729 (9)
H2	0.7065	0.4477	0.8017	0.087*
C3	0.6881 (4)	0.6359 (5)	0.6866 (4)	0.0806 (10)
H3	0.7701	0.6124	0.6452	0.097*
C4	0.6063 (4)	0.7663 (4)	0.6546 (4)	0.0771 (10)
H4	0.6316	0.8311	0.5899	0.093*
C5	0.4828 (3)	0.8063 (4)	0.7175 (3)	0.0581 (7)
C6	0.4001 (5)	0.9432 (4)	0.6883 (4)	0.0820 (10)
H6	0.4275	1.0105	0.6268	0.098*
C7	0.2818 (5)	0.9784 (4)	0.7480 (5)	0.0912 (11)
H7	0.2274	1.0691	0.7268	0.109*
C8	0.2403 (4)	0.8782 (4)	0.8424 (4)	0.0763 (9)
H8	0.1569	0.9032	0.8816	0.092*
C9	0.3195 (3)	0.7456 (3)	0.8776 (3)	0.0535 (7)
C10	0.4441 (3)	0.7073 (3)	0.8147 (3)	0.0489 (7)
C11	0.2779 (4)	0.6426 (3)	0.9853 (3)	0.0632 (8)
H11A	0.3815	0.6068	1.0547	0.076*
H11B	0.2202	0.6990	1.0398	0.076*
C12	0.1730 (3)	0.5134 (3)	0.9175 (3)	0.0489 (7)
C13	0.0257 (3)	0.3107 (3)	0.9082 (3)	0.0479 (6)
C14	−0.0602 (4)	0.1883 (3)	0.9324 (3)	0.0638 (8)
H14	−0.0532	0.1591	1.0267	0.077*
C15	−0.1564 (4)	0.1118 (3)	0.8113 (4)	0.0731 (9)
H15	−0.2157	0.0290	0.8237	0.088*
C16	−0.1667 (4)	0.1559 (4)	0.6702 (4)	0.0717 (9)
H16	−0.2347	0.1030	0.5903	0.086*
C17	−0.0787 (4)	0.2758 (3)	0.6463 (3)	0.0581 (7)
H17	−0.0845	0.3037	0.5520	0.070*
C18	0.0192 (3)	0.3537 (3)	0.7677 (3)	0.0452 (6)
N1	0.1148 (3)	0.4813 (3)	0.7772 (2)	0.0509 (6)
N2	0.1247 (3)	0.4135 (3)	1.0011 (2)	0.0519 (6)
H2A	0.142 (4)	0.430 (3)	1.093 (3)	0.062*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0574 (17)	0.0615 (19)	0.0588 (18)	0.0032 (15)	0.0151 (14)	0.0005 (14)
C2	0.0534 (18)	0.077 (2)	0.088 (2)	0.0037 (16)	0.0223 (18)	−0.0165 (19)
C3	0.061 (2)	0.099 (3)	0.093 (3)	−0.012 (2)	0.0403 (19)	−0.023 (2)
C4	0.073 (2)	0.095 (3)	0.073 (2)	−0.021 (2)	0.0381 (18)	−0.0052 (19)
C5	0.0572 (18)	0.0603 (19)	0.0554 (17)	−0.0093 (14)	0.0163 (14)	0.0017 (13)
C6	0.081 (2)	0.078 (2)	0.085 (3)	−0.0061 (19)	0.024 (2)	0.0206 (19)
C7	0.089 (3)	0.059 (2)	0.117 (3)	0.019 (2)	0.021 (2)	0.019 (2)
C8	0.070 (2)	0.074 (2)	0.085 (2)	0.0127 (18)	0.0263 (18)	−0.0128 (19)
C9	0.0543 (17)	0.0585 (18)	0.0474 (15)	−0.0023 (14)	0.0160 (13)	−0.0078 (13)
C10	0.0478 (15)	0.0545 (17)	0.0416 (15)	−0.0067 (13)	0.0109 (12)	−0.0058 (12)
C11	0.0685 (19)	0.083 (2)	0.0419 (14)	−0.0090 (16)	0.0234 (13)	−0.0129 (14)
C12	0.0512 (15)	0.0670 (18)	0.0332 (14)	0.0059 (13)	0.0200 (11)	0.0005 (13)
C13	0.0496 (15)	0.0592 (17)	0.0390 (13)	0.0084 (13)	0.0201 (11)	0.0002 (12)
C14	0.078 (2)	0.063 (2)	0.0555 (17)	0.0067 (16)	0.0297 (15)	0.0087 (14)
C15	0.087 (2)	0.0592 (19)	0.080 (2)	−0.0094 (18)	0.0360 (18)	−0.0006 (17)
C16	0.078 (2)	0.071 (2)	0.066 (2)	−0.0070 (18)	0.0233 (16)	−0.0150 (18)
C17	0.0671 (18)	0.0673 (19)	0.0415 (15)	0.0035 (16)	0.0201 (14)	−0.0034 (13)
C18	0.0467 (14)	0.0549 (16)	0.0392 (14)	0.0094 (13)	0.0210 (11)	0.0011 (12)
N1	0.0556 (13)	0.0660 (15)	0.0346 (11)	0.0004 (11)	0.0196 (9)	−0.0011 (10)
N2	0.0606 (14)	0.0695 (15)	0.0291 (10)	0.0046 (12)	0.0193 (10)	0.0032 (11)

Geometric parameters (Å, º)

C1—C2	1.356 (4)	C11—C12	1.484 (4)
C1—C10	1.419 (4)	C11—H11A	0.9700
C1—H1	0.9300	C11—H11B	0.9700
C2—C3	1.379 (5)	C12—N1	1.314 (3)
C2—H2	0.9300	C12—N2	1.358 (3)
C3—C4	1.350 (5)	C13—N2	1.371 (3)
C3—H3	0.9300	C13—C14	1.383 (4)
C4—C5	1.414 (4)	C13—C18	1.394 (3)
C4—H4	0.9300	C14—C15	1.374 (4)
C5—C6	1.403 (5)	C14—H14	0.9300
C5—C10	1.409 (4)	C15—C16	1.393 (4)
C6—C7	1.344 (5)	C15—H15	0.9300
C6—H6	0.9300	C16—C17	1.375 (4)
C7—C8	1.407 (5)	C16—H16	0.9300
C7—H7	0.9300	C17—C18	1.387 (4)
C8—C9	1.361 (4)	C17—H17	0.9300
C8—H8	0.9300	C18—N1	1.394 (3)
C9—C10	1.418 (4)	N2—H2A	0.87 (3)
C9—C11	1.519 (4)
C2—C1—C10	121.7 (3)	C12—C11—H11A	108.6
C2—C1—H1	119.2	C9—C11—H11A	108.6
C10—C1—H1	119.2	C12—C11—H11B	108.6
C1—C2—C3	120.6 (3)	C9—C11—H11B	108.6
C1—C2—H2	119.7	H11A—C11—H11B	107.6
C3—C2—H2	119.7	N1—C12—N2	112.4 (2)
C4—C3—C2	120.1 (3)	N1—C12—C11	126.7 (2)
C4—C3—H3	120.0	N2—C12—C11	120.9 (2)
C2—C3—H3	120.0	N2—C13—C14	132.4 (2)
C3—C4—C5	121.3 (3)	N2—C13—C18	105.6 (2)
C3—C4—H4	119.3	C14—C13—C18	122.0 (3)
C5—C4—H4	119.3	C15—C14—C13	117.2 (3)
C6—C5—C10	119.0 (3)	C15—C14—H14	121.4
C6—C5—C4	121.9 (3)	C13—C14—H14	121.4
C10—C5—C4	119.1 (3)	C14—C15—C16	121.3 (3)
C7—C6—C5	120.9 (3)	C14—C15—H15	119.3
C7—C6—H6	119.5	C16—C15—H15	119.3
C5—C6—H6	119.5	C17—C16—C15	121.5 (3)
C6—C7—C8	120.1 (3)	C17—C16—H16	119.3
C6—C7—H7	119.9	C15—C16—H16	119.3
C8—C7—H7	119.9	C16—C17—C18	117.7 (3)
C9—C8—C7	121.4 (3)	C16—C17—H17	121.1
C9—C8—H8	119.3	C18—C17—H17	121.1
C7—C8—H8	119.3	C17—C18—C13	120.3 (2)
C8—C9—C10	118.8 (3)	C17—C18—N1	130.5 (2)
C8—C9—C11	120.3 (3)	C13—C18—N1	109.2 (2)
C10—C9—C11	120.8 (2)	C12—N1—C18	105.4 (2)
C5—C10—C9	119.7 (2)	C12—N2—C13	107.4 (2)
C5—C10—C1	117.2 (3)	C12—N2—H2A	120.6 (18)
C9—C10—C1	123.1 (2)	C13—N2—H2A	130.8 (19)
C12—C11—C9	114.8 (2)
C10—C1—C2—C3	−0.7 (5)	C10—C9—C11—C12	−77.1 (3)
C1—C2—C3—C4	−0.4 (5)	C9—C11—C12—N1	−0.1 (4)
C2—C3—C4—C5	1.0 (5)	C9—C11—C12—N2	−179.1 (2)
C3—C4—C5—C6	178.2 (3)	N2—C13—C14—C15	176.7 (3)
C3—C4—C5—C10	−0.4 (5)	C18—C13—C14—C15	−1.5 (4)
C10—C5—C6—C7	−2.1 (5)	C13—C14—C15—C16	0.0 (4)
C4—C5—C6—C7	179.3 (3)	C14—C15—C16—C17	1.3 (5)
C5—C6—C7—C8	0.6 (6)	C15—C16—C17—C18	−1.1 (4)
C6—C7—C8—C9	1.1 (5)	C16—C17—C18—C13	−0.3 (4)
C7—C8—C9—C10	−1.3 (4)	C16—C17—C18—N1	−176.9 (2)
C7—C8—C9—C11	177.2 (3)	N2—C13—C18—C17	−176.9 (2)
C6—C5—C10—C9	1.9 (4)	C14—C13—C18—C17	1.7 (4)
C4—C5—C10—C9	−179.5 (3)	N2—C13—C18—N1	0.3 (3)
C6—C5—C10—C1	−179.4 (3)	C14—C13—C18—N1	178.9 (2)
C4—C5—C10—C1	−0.7 (4)	N2—C12—N1—C18	1.2 (3)
C8—C9—C10—C5	−0.2 (4)	C11—C12—N1—C18	−177.8 (3)
C11—C9—C10—C5	−178.7 (2)	C17—C18—N1—C12	175.9 (3)
C8—C9—C10—C1	−178.9 (3)	C13—C18—N1—C12	−0.9 (2)
C11—C9—C10—C1	2.6 (4)	N1—C12—N2—C13	−1.1 (3)
C2—C1—C10—C5	1.3 (4)	C11—C12—N2—C13	178.1 (2)
C2—C1—C10—C9	180.0 (3)	C14—C13—N2—C12	−178.0 (3)
C8—C9—C11—C12	104.5 (3)	C18—C13—N2—C12	0.4 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···N1^i	0.87 (3)	2.03 (3)	2.855 (3)	160 (3)

Symmetry code: (i) x, −y+1, z+1/2.