2-(1H-Benzimidazol-1-yl)-1-phenyl­ethanone oxime

In the mol­ecule of the title compound, C₁₅H₁₃N₃O, intra­molecular C—H...O hydrogen bonding causes the formation of a planar five-membered ring. The oxime unit has an E configuration. In this configuration, the oxime groups are involved as donors in inter­molecular O—H...N hydrogen bonds, linking the mol­ecules into chains elongated approximately parallel to the c axis and stacked along the b axis.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](Wave) = 0.000 Å
• R factor = 0.045
• wR factor = 0.128
• Data-to-parameter ratio = 6.6

checkCIF/PLATON results

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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           25.31
           From the CIF: _reflns_number_total               1252
           Count of symmetry unique reflns         1268
           Completeness (_total/calc)             98.74%
           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

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

   0 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

Oxime and dioxime derivatives are very important compounds in the chemical industry and medicine (Sevagapandian et al., 2000\bbr018). The oxime (–C=N—OH) moiety is potentially ambidentate, with possibilities of coordination through nitrogen and/or oxygen atoms. It is a functional group that has not been extensively explored in crystal engineering. In the solid state, oximes are usually associated via O—H···N hydrogen bonds of length 2.8 Å.

Oxime groups possess stronger hydrogen-bonding capabilities than alcohols, phenols, and carboxylic acids (Marsman et al., 1999\bbr015), in which intermolecular hydrogen bonding combines moderate strength and directionality (Karle et al., 1996\bbr014) in linking molecules to form supramolecular structures; this has received considerable attention with respect to directional noncovalent intermolecular interactions (Etter et al., 1990\bbr005).

The structures of oxime and dioxime derivatives have been the subject of much interest in our laboratory; examples are 2,3-dimethylquinoxaline-dimethyl- glyoxime (1/1), [(II) Hökelek, Batı et al., 2001\bbr009], 1-(2,6-dimethylphenyl- amino)propane-1,2-dione dioxime, [(III) (Hökelek, Zülfikaroğlu et al., 2001\bbr013), N-hydroxy-2-oxo-2,N'-diphenylacetamidine, [(IV) (Büyükgüngör et al., 2003\bbr002], N-(3,4-dichlorophenyl)-N'-hydroxy-2-oxo-2-phenylacetamidine, [(V) Hökelek et al., 2004\bbr012], N-hydroxy-N'-(1-naphthyl)-2-phenylacetamidin-2-one [(VI) Hökelek et al., 2004a\bbr010] and N-(3-chloro-4-methylphenyl)-N'-hydroxy-2 -oxo-2-phenylacetamidine [(VII) Hökelek et al., 2004b\bbr011]. The structure determination of the title molecule, (I) was carried out in order to investigate the strength of the hydrogen bonding capability of the oxime groups and to compare the geometry of the oxime moieties with the previously reported ones.

In the molecule of the title compound (Fig. 1) the bond lengths and angles are generally within normal ranges (Allen et al., 1987\bbr001). The intramolecular C—H···O hydrogen bond (Table 1) causes to the formation of a five-membered planar ring A (O/N3/C8/C9/H82). The benzimidazol B (N1/N2/C7/C1—C6) and phenyl C (C10—C15) rings are, of course, planar and the dihedral angles between the rings are A/B = 89.6 (3)°, A/C = 31.4 (3) and B/C = 74.9 (2)°.

Some significant changes in the geometry of the oxime moieties are evident when the bond lengths and angles are compared with the corresponding values in compounds (II)-(VII) (Table 2). The oxime moiety has an E configuration [C10—C9—N3—O 174.9 (5)°; Chertanova et al., 1994\bbr003]. In this configuration, the oxime groups are involved as donors in O—H···N intermolecular hydrogen bondings (Table 1).

In the crystal structure, the intermolecular O—H···N hydrogen bonds (Table 1) link the molecules into chains elongated approximately parallel to the c axis and stacked along the b axis (Fig. 2). The intra- and intermolecular hydrogen bonds seem to be effective in the stabilization of the crystal structure.

Related literature

For general background, see: Sevagapandian et al. (2000\bbr018); Marsman et al. (1999\bbr015); Karle et al. (1996\bbr014); Etter et al. (1990\bbr005); Chertanova et al. (1994\bbr003). For related structures, see: Özel Güven et al. (2007\bbr017); Hökelek, Batı et al. (2001\bbr009); Hökelek, Zülfikaroğlu et al. (2001\bbr013); Büyükgüngör et al. (2003\bbr002); Hökelek et al. (2004\bbr012); Hökelek et al. (2004a\bbr010,b\bbr011). For bond-length data, see: Allen et al. (1987\bbr001).

S2. Experimental

The title compound was prepared from a mixture of 2-(1H-benzimidazol-1-yl)-1-phenylethanone (Özel Güven et al., 2007\bbr017) (2.09 g, 8.84 mmol) in methanol (5 ml) and hydroxylaminehydrogensulfate (1.45 g, 8.84 mmol) in water (3 ml), which was stirred for 24 h at room temperature. Then, methanol was evaporated and extracted with ether and the organic layer was dried and evaporated to dryness. The crude residue was purified by chromatography and recrystallized from methanol solution to obtain colorless crystals (yield; 1.44 g, 65%).

S3. Refinement

Atoms H, H7, H81 and H82 were located in difference syntheses and refined isotropically [O—H = 0.87 (5) Å, U_iso(H) = 0.11 (3) Ų; C—H = 0.93 (6)–0.96 (6) Å, U_iso(H) = 0.053 (17)–0.062 (19) Ų]. The remaining H atoms were positioned geometrically, with C—H = 0.93 Å, and constrained to ride on their parent atom, with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994\bbr004); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995\bbr008); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997\bbr019); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997\bbr019); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997\bbr006); software used to prepare material for publication: WinGX (Farrugia, 1999\bbr007).

Figures

	Fig. 1. The molecular structure of the title molecule with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A packing diagram of (I). Hydrogen bonds are shown as dashed lines. H atoms not involved in hydrogen bonding have been omitted for clarity [symmetry codes: (') -x, -y, z + 1/2; ('') -x + 1/2, y + 1/2, z + 1/2; x + 1/2, -y + 1/2, z].

2-(1H-Benzimidazol-1-yl)-1-phenylethanone oxime

Crystal data

C15H13N3O	Dx = 1.258 Mg m^−3
Mr = 251.29	Melting point = 465–468 K
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 25 reflections
a = 9.3295 (1) Å	θ = 3.6–18.8°
b = 11.2863 (2) Å	µ = 0.08 mm^−1
c = 12.5962 (2) Å	T = 294 K
V = 1326.32 (3) Å^3	Block, colourless
Z = 4	0.35 × 0.25 × 0.20 mm
F(000) = 528

Data collection

Enraf–Nonius TurboCAD-4 diffractometer	714 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Graphite monochromator	θmax = 25.3°, θmin = 2.4°
non–profiled ω scans	h = −11→0
Absorption correction: ψ scan (North et al., 1968\bbr016)	k = 0→13
Tmin = 0.933, Tmax = 0.977	l = −15→0
1252 measured reflections	3 standard reflections every 120 min
1252 independent reflections	intensity decay: 1%

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)] = 0.045	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.128	w = 1/[σ^2(Fo^2) + (0.0654P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
1252 reflections	Δρmax = 0.16 e Å^−3
189 parameters	Δρmin = −0.13 e Å^−3
4 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997\bbr019), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.017 (5)

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
O	0.3005 (7)	1.2486 (4)	0.6439 (4)	0.0909 (16)
N1	0.2400 (7)	0.8842 (4)	0.9744 (4)	0.0668 (15)
N2	0.3004 (6)	1.0208 (4)	0.8558 (4)	0.0598 (14)
N3	0.3436 (6)	1.1408 (5)	0.6026 (5)	0.0700 (15)
C1	0.1192 (7)	0.9178 (5)	0.9184 (5)	0.0589 (16)
C2	−0.0212 (9)	0.8795 (6)	0.9275 (7)	0.080 (2)
C3	−0.1197 (9)	0.9278 (7)	0.8627 (7)	0.091 (2)
C4	−0.0845 (9)	1.0144 (8)	0.7884 (7)	0.095 (3)
C5	0.0541 (8)	1.0552 (6)	0.7774 (5)	0.074 (2)
C6	0.1554 (7)	1.0039 (5)	0.8440 (5)	0.0601 (17)
C7	0.3432 (10)	0.9469 (6)	0.9337 (5)	0.0697 (19)
C8	0.3909 (10)	1.1002 (7)	0.7907 (6)	0.070 (2)
C9	0.3845 (6)	1.0686 (5)	0.6770 (5)	0.0562 (16)
C10	0.4210 (7)	0.9465 (5)	0.6408 (5)	0.0613 (17)
C11	0.5217 (9)	0.8793 (7)	0.6923 (7)	0.091 (2)
C12	0.5529 (10)	0.7643 (9)	0.6562 (8)	0.119 (3)
C13	0.4857 (11)	0.7195 (8)	0.5701 (8)	0.111 (3)
C14	0.3855 (9)	0.7856 (7)	0.5190 (7)	0.091 (2)
C15	0.3517 (7)	0.8977 (6)	0.5544 (6)	0.074 (2)
H	0.261 (7)	1.288 (5)	0.592 (4)	0.11 (3)*
H2	−0.0466	0.8220	0.9769	0.096*
H3	−0.2144	0.9026	0.8677	0.109*
H4	−0.1561	1.0455	0.7451	0.114*
H5	0.0783	1.1135	0.7285	0.089*
H7	0.437 (7)	0.951 (5)	0.959 (5)	0.062 (18)*
H11	0.5694	0.9098	0.7511	0.109*
H12	0.6204	0.7187	0.6920	0.142*
H13	0.5079	0.6439	0.5459	0.134*
H14	0.3393	0.7550	0.4596	0.109*
H15	0.2812	0.9411	0.5196	0.089*
H81	0.484 (6)	1.088 (5)	0.817 (5)	0.053 (17)*
H82	0.361 (6)	1.180 (5)	0.806 (5)	0.062 (19)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O	0.151 (5)	0.060 (3)	0.062 (3)	−0.006 (3)	−0.015 (3)	0.017 (2)
N1	0.088 (4)	0.058 (3)	0.055 (3)	−0.005 (3)	0.001 (3)	0.018 (3)
N2	0.077 (4)	0.057 (3)	0.045 (3)	−0.010 (3)	−0.005 (3)	0.014 (3)
N3	0.086 (4)	0.055 (3)	0.069 (3)	−0.010 (3)	0.000 (3)	0.012 (3)
C1	0.073 (5)	0.053 (4)	0.050 (4)	0.001 (3)	0.010 (3)	0.007 (3)
C2	0.093 (6)	0.067 (4)	0.079 (5)	−0.004 (4)	0.016 (5)	0.016 (4)
C3	0.075 (5)	0.101 (5)	0.097 (6)	−0.001 (5)	0.015 (5)	0.012 (5)
C4	0.077 (6)	0.109 (6)	0.099 (6)	0.020 (5)	−0.008 (5)	0.017 (5)
C5	0.086 (6)	0.069 (4)	0.068 (5)	0.010 (4)	−0.007 (4)	0.015 (4)
C6	0.081 (5)	0.054 (3)	0.046 (4)	−0.002 (3)	−0.001 (4)	0.007 (3)
C7	0.091 (6)	0.069 (4)	0.049 (4)	−0.010 (4)	−0.021 (4)	0.020 (4)
C8	0.080 (5)	0.071 (5)	0.059 (4)	−0.025 (4)	−0.013 (4)	0.019 (4)
C9	0.066 (4)	0.057 (4)	0.046 (3)	−0.017 (3)	−0.008 (3)	0.019 (3)
C10	0.062 (4)	0.065 (4)	0.057 (4)	−0.009 (3)	0.010 (3)	0.019 (4)
C11	0.093 (5)	0.107 (6)	0.071 (5)	0.021 (5)	−0.005 (4)	0.015 (5)
C12	0.132 (8)	0.123 (8)	0.102 (7)	0.064 (6)	0.009 (6)	0.014 (6)
C13	0.130 (8)	0.092 (6)	0.112 (8)	0.019 (6)	0.036 (7)	0.002 (6)
C14	0.095 (6)	0.077 (5)	0.100 (6)	−0.007 (4)	0.007 (5)	−0.017 (4)
C15	0.066 (5)	0.067 (4)	0.091 (5)	−0.007 (3)	−0.005 (4)	0.004 (4)

Geometric parameters (Å, º)

O—N3	1.383 (7)	C5—C6	1.389 (9)
O—H	0.87 (5)	C7—H7	0.93 (6)
N1—C7	1.300 (9)	C8—H81	0.94 (6)
N2—C6	1.375 (8)	C8—H82	0.96 (6)
N2—C7	1.348 (8)	C9—C8	1.478 (10)
N2—C8	1.479 (8)	C10—C9	1.491 (8)
N3—C9	1.300 (7)	C10—C11	1.370 (10)
C1—N1	1.383 (8)	C10—C15	1.381 (9)
C1—C2	1.384 (10)	C11—H11	0.9300
C1—C6	1.392 (8)	C11—C12	1.405 (11)
C2—C3	1.345 (11)	C12—H12	0.9300
C2—H2	0.9300	C12—C13	1.351 (13)
C3—H3	0.9300	C13—H13	0.9300
C3—C4	1.393 (11)	C14—C13	1.358 (12)
C4—H4	0.9300	C14—H14	0.9300
C5—C4	1.379 (9)	C15—C14	1.378 (9)
C5—H5	0.9300	C15—H15	0.9300
N3—O—H	107 (4)	N2—C8—H81	104 (3)
N1—C1—C2	130.1 (6)	N2—C8—H82	107 (4)
N1—C1—C6	109.7 (6)	C9—C8—N2	111.5 (5)
C7—N1—C1	104.7 (5)	C9—C8—H81	110 (4)
C6—N2—C8	125.9 (5)	C9—C8—H82	114 (4)
C7—N2—C6	106.5 (6)	H81—C8—H82	110 (5)
C7—N2—C8	127.5 (6)	N3—C9—C8	124.0 (6)
C9—N3—O	111.4 (5)	N3—C9—C10	115.3 (5)
C2—C1—C6	120.2 (6)	C8—C9—C10	120.7 (6)
C1—C2—H2	121.0	C11—C10—C15	118.2 (6)
C3—C2—C1	118.1 (7)	C11—C10—C9	121.6 (7)
C3—C2—H2	121.0	C15—C10—C9	120.2 (6)
C2—C3—C4	122.1 (8)	C10—C11—C12	120.0 (8)
C2—C3—H3	119.0	C10—C11—H11	120.0
C4—C3—H3	119.0	C12—C11—H11	120.0
C3—C4—H4	119.3	C11—C12—H12	119.7
C5—C4—C3	121.5 (8)	C13—C12—C11	120.6 (9)
C5—C4—H4	119.3	C13—C12—H12	119.7
C4—C5—C6	116.0 (7)	C12—C13—C14	119.6 (9)
C4—C5—H5	122.0	C12—C13—H13	120.2
C6—C5—H5	122.0	C14—C13—H13	120.2
N2—C6—C5	132.6 (6)	C13—C14—C15	120.5 (8)
N2—C6—C1	105.2 (5)	C13—C14—H14	119.7
C5—C6—C1	122.2 (7)	C15—C14—H14	119.7
N1—C7—N2	113.9 (7)	C10—C15—H15	119.5
N1—C7—H7	126 (4)	C14—C15—C10	121.0 (7)
N2—C7—H7	120 (4)	C14—C15—H15	119.5
C1—N1—C7—N2	0.8 (7)	C1—C2—C3—C4	−0.3 (12)
C7—N2—C6—C5	179.4 (7)	C2—C3—C4—C5	0.0 (13)
C8—N2—C6—C5	−3.6 (11)	C6—C5—C4—C3	0.6 (12)
C7—N2—C6—C1	0.0 (6)	C4—C5—C6—N2	179.8 (7)
C8—N2—C6—C1	177.0 (6)	C4—C5—C6—C1	−0.9 (10)
C6—N2—C7—N1	−0.5 (7)	N3—C9—C8—N2	121.9 (7)
C8—N2—C7—N1	−177.5 (6)	C10—C9—C8—N2	−55.9 (10)
C7—N2—C8—C9	117.9 (8)	C11—C10—C9—N3	149.8 (6)
C6—N2—C8—C9	−58.5 (10)	C11—C10—C9—C8	−32.2 (9)
O—N3—C9—C8	−3.0 (9)	C15—C10—C9—N3	−31.0 (8)
O—N3—C9—C10	174.9 (5)	C15—C10—C9—C8	147.0 (7)
C2—C1—N1—C7	179.6 (7)	C15—C10—C11—C12	0.5 (11)
C6—C1—N1—C7	−0.8 (6)	C9—C10—C11—C12	179.7 (7)
N1—C1—C2—C3	179.6 (7)	C9—C10—C15—C14	179.1 (6)
C6—C1—C2—C3	0.0 (10)	C11—C10—C15—C14	−1.7 (10)
N1—C1—C6—N2	0.5 (6)	C10—C11—C12—C13	0.9 (13)
C2—C1—C6—N2	−179.9 (6)	C11—C12—C13—C14	−1.0 (14)
N1—C1—C6—C5	−179.0 (6)	C15—C14—C13—C12	−0.1 (13)
C2—C1—C6—C5	0.6 (9)	C10—C15—C14—C13	1.6 (11)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O—H···N1^i	0.87 (6)	1.84 (5)	2.654 (7)	155 (6)
C8—H82···O	0.96 (6)	2.26 (6)	2.634 (9)	102 (4)

Symmetry code: (i) −x+1/2, y+1/2, z−1/2.