[2-(4-Methylbenzoyl)phenyl](4-methylphenyl)methanone

The asymmetric unit of the title compound, C₂₂H₁₈O₂, contains one half-mol­ecule, the complete mol­ecule being generated by the operation of a crystallographic twofold rotation axis. The carbonyl group and the two C atoms attached to it forms inter­planar angles of 23.67 (7)° with the methyl-substituted phenyl ring and 50.74 (8)° with the central ring. In the crystal, mol­ecules are linked into infinite chains along the b-axis direction by inter­molecular C—H⋯O inter­actions, generating R²₂(10) graph-set motifs.

Related literature

For the uses and biological importance of diketones, see: Bennett et al. (1999); Sato et al. (2008). For related structures, see: Muto et al. (2010); Khan et al. (2009); For asymmetry parameters, see: Nardelli (1983); Macrae et al. (2008). For graph-set notation: Bernstein et al. (1995).

Experimental

Crystal data

• C₂₂H₁₈O₂

• M_r = 314.36

• Monoclinic, C 2/c

• a = 20.7432 (13) Å

• b = 7.7564 (4) Å

• c = 11.3946 (6) Å

• β = 114.314 (5)°

• V = 1670.70 (17) ų

• Z = 4

• Mo Kα radiation

• μ = 0.08 mm⁻¹

• T = 295 K

• 0.30 × 0.25 × 0.20 mm

Data collection

• Bruker Kappa APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.977, T_max = 0.984

• 17689 measured reflections

• 2133 independent reflections

• 1729 reflections with I > 2σ(I)

• R_int = 0.076

Refinement

• R[F² > 2σ(F²)] = 0.050

• wR(F²) = 0.154

• S = 1.03

• 2133 reflections

• 110 parameters

• H-atom parameters constrained

• Δρ_max = 0.30 e Å⁻³

• Δρ_min = −0.28 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯O1^i	0.93	2.62	3.4305 (17)	145
Symmetry code: (i) x, y-1, z.

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009).

Supporting information

S1. Comment

Diketones are popular in organic synthesis, for their applications in biology and medicine. They are known to exhibit antioxidants, antitumour and antibacterial activities (Bennett et al., 1999). They are also key intermediates in the preparation of various heterocyclic compounds (Sato et al., 2008).

The title compound C₂₂H₁₈O₂, contains one half molecule in the asymmetric unit, the complete molecule being generated by twofold rotation, with direction [0 1 0], having symmetry code: (i) -x+1, y, -z+3/2. X-ray analysis confirms the molecular structure and atom connectivity of the compound as illustrated in (Fig. 1). The carbonyl group (C3/C4/C5/O1) forms an interplanar angle of 23.67 (7)° with the phenyl ring (C5/C6/C7/C8/C9/C10). The deviation of atom O1 from the phenyl ring (C5/C6/C7/C8/C9/C10) is -0.4719 (19)Å (Nardelli, 1983). The title compound exhibits structural similarities with the already reported related structures (Muto et al., 2010; Khan et al., 2009).

The central phenyl ring (C1/C2/C3/C1ⁱ/C2ⁱ/C3ⁱ) forms dihedral angles of 67.14 (17)° and 50.74 (8)° with the phenyl ring (C5/C6/C7/C8/C9/C10) and the mean plane of the carbonyl group (C3/C4/C5/O1), respectively. The dihedral angle between the phenyl rings (C5/C6/C7/C8/C9/C10) and (C5ⁱ/C6ⁱ/C7ⁱ/C8ⁱ/C9ⁱ/C10ⁱ) is 82.83 (2)° (Macrae et al., 2008), and thus they are almost orthogonal to each other.

The crystal packing is stabilized by C—H···O intermolecular interactions. The molecules are linked into infinite chains along the b axis via C1—H1···O1ⁱⁱ hydrogen bonds, generating the R²₂(10) graphset motifs (Bernstein et al., 1995). The symmetry code: (ii) x, -1+y, z (look Table 1). The packing view of the compound is shown in (Fig. 2).

Related literature

For the uses and biological importance of diketones, see: Bennett et al. (1999); Sato et al. (2008); For related structures, see: Muto et al. (2010); Khan et al. (2009); For asymmetry parameters, see: Nardelli (1983); Macrae et al. (2008). For graph-set notation: Bernstein et al. (1995).

S2. Experimental

To a stirred suspension of benzo[c]furan, 1,3-bis(4-methylphenyl)-4,7-dihydro-2-benzofuran (3 g, 9.554 mmol) in dry THF (20 ml), lead tetra acetate (4.23 g, 9.5 mmol) was added and refluxed at 343 K for half an hour. The reaction mixture was then poured into water (200 ml) and extracted with ethyl acetate (2 x 20 ml), washed with brine solution and dried (Na₂SO₄). The removal of solvent in vacuo followed by crystallization from methanol afforded the title compound, (4-methylphenyl){2-[(4-methylphenyl)carbonyl]phenyl}methanone as a colourless solid.

S3. Refinement

The hydrogen atoms were placed in calculated positions with C—H = 0.93–0.96Å and refined in the riding model with fixed isotropic displacement parameters: U_iso(H) = 1.5U_eq(C) for methyl atoms and U_iso(H) = 1.2U_eq(C) for the aryl atoms.

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are shown at 30% probability level. The H atoms are presented as a small spheres of arbitrary radius. Related atoms have symmetry code: (i) -x+1, y, -z+3/2.
	Fig. 2. The crystal packing of the title compound, viewed down c axis, showing molecules linked along b axis. Intermolecular hydrogen bonds are shown in as dashed lines.

[2-(4-Methylbenzoyl)phenyl](4-methylphenyl)methanone

Crystal data

C22H18O2	F(000) = 664
Mr = 314.36	Dx = 1.250 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2133 reflections
a = 20.7432 (13) Å	θ = 2.2–28.6°
b = 7.7564 (4) Å	µ = 0.08 mm^−1
c = 11.3946 (6) Å	T = 295 K
β = 114.314 (5)°	Block, colourless
V = 1670.70 (17) Å^3	0.30 × 0.25 × 0.20 mm
Z = 4

Data collection

Bruker Kappa APEXII CCD diffractometer	2133 independent reflections
Radiation source: fine-focus sealed tube	1729 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.076
ω–scans	θmax = 28.6°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −27→27
Tmin = 0.977, Tmax = 0.984	k = −10→10
17689 measured reflections	l = −15→15

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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.154	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0914P)^2 + 0.4904P] where P = (Fo^2 + 2Fc^2)/3
2133 reflections	(Δ/σ)max = 0.005
110 parameters	Δρmax = 0.30 e Å^−3
0 restraints	Δρmin = −0.28 e Å^−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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	0.47990 (8)	−0.45596 (18)	0.68469 (16)	0.0577 (4)
H1	0.4669	−0.5598	0.6403	0.069*
C2	0.45881 (7)	−0.30216 (17)	0.61934 (13)	0.0493 (3)
H2	0.4310	−0.3030	0.5312	0.059*
C3	0.47868 (6)	−0.14603 (15)	0.68400 (11)	0.0375 (3)
C4	0.46029 (6)	0.01963 (15)	0.61000 (11)	0.0380 (3)
C5	0.38557 (6)	0.05007 (15)	0.52013 (11)	0.0384 (3)
C6	0.37060 (7)	0.16656 (18)	0.41976 (13)	0.0478 (3)
H6	0.4074	0.2221	0.4083	0.057*
C7	0.30152 (8)	0.2002 (2)	0.33701 (13)	0.0535 (4)
H7	0.2924	0.2766	0.2691	0.064*
C8	0.24545 (7)	0.12297 (18)	0.35264 (13)	0.0508 (4)
C9	0.26051 (7)	0.0089 (2)	0.45387 (14)	0.0529 (4)
H9	0.2236	−0.0433	0.4668	0.063*
C10	0.32965 (7)	−0.02856 (18)	0.53609 (13)	0.0474 (3)
H10	0.3387	−0.1072	0.6027	0.057*
C11	0.17032 (9)	0.1623 (3)	0.26113 (19)	0.0739 (5)
H11A	0.1696	0.2622	0.2109	0.111*
H11B	0.1425	0.1841	0.3093	0.111*
H11C	0.1509	0.0656	0.2050	0.111*
O1	0.50637 (5)	0.12345 (12)	0.62240 (9)	0.0503 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0579 (8)	0.0333 (6)	0.0742 (10)	−0.0053 (6)	0.0195 (7)	−0.0101 (6)
C2	0.0496 (7)	0.0405 (7)	0.0470 (7)	−0.0063 (5)	0.0091 (6)	−0.0084 (5)
C3	0.0360 (5)	0.0337 (6)	0.0368 (6)	−0.0015 (4)	0.0088 (5)	−0.0008 (4)
C4	0.0414 (6)	0.0359 (6)	0.0318 (6)	−0.0023 (4)	0.0100 (5)	−0.0016 (4)
C5	0.0405 (6)	0.0371 (6)	0.0324 (6)	0.0011 (4)	0.0097 (5)	−0.0003 (4)
C6	0.0487 (7)	0.0482 (7)	0.0442 (7)	0.0033 (5)	0.0167 (6)	0.0096 (5)
C7	0.0557 (8)	0.0531 (8)	0.0437 (7)	0.0116 (6)	0.0125 (6)	0.0121 (6)
C8	0.0450 (7)	0.0493 (7)	0.0471 (7)	0.0084 (6)	0.0079 (6)	−0.0061 (5)
C9	0.0418 (7)	0.0575 (8)	0.0566 (8)	−0.0040 (6)	0.0176 (6)	−0.0025 (6)
C10	0.0484 (7)	0.0482 (7)	0.0416 (7)	−0.0025 (5)	0.0143 (5)	0.0049 (5)
C11	0.0483 (8)	0.0751 (11)	0.0757 (11)	0.0150 (7)	0.0028 (8)	−0.0027 (9)
O1	0.0479 (5)	0.0442 (5)	0.0487 (5)	−0.0100 (4)	0.0098 (4)	0.0032 (4)

Geometric parameters (Å, º)

C1—C1^i	1.374 (3)	C6—H6	0.9300
C1—C2	1.379 (2)	C7—C8	1.383 (2)
C1—H1	0.9300	C7—H7	0.9300
C2—C3	1.3890 (16)	C8—C9	1.384 (2)
C2—H2	0.9300	C8—C11	1.507 (2)
C3—C3^i	1.396 (2)	C9—C10	1.383 (2)
C3—C4	1.4975 (16)	C9—H9	0.9300
C4—O1	1.2128 (15)	C10—H10	0.9300
C4—C5	1.4832 (16)	C11—H11A	0.9600
C5—C10	1.3872 (18)	C11—H11B	0.9600
C5—C6	1.3887 (17)	C11—H11C	0.9600
C6—C7	1.3778 (19)
C1^i—C1—C2	120.07 (8)	C6—C7—C8	121.50 (13)
C1^i—C1—H1	120.0	C6—C7—H7	119.2
C2—C1—H1	120.0	C8—C7—H7	119.2
C1—C2—C3	120.60 (12)	C7—C8—C9	118.11 (12)
C1—C2—H2	119.7	C7—C8—C11	120.53 (14)
C3—C2—H2	119.7	C9—C8—C11	121.36 (15)
C2—C3—C3^i	119.31 (7)	C10—C9—C8	120.95 (13)
C2—C3—C4	119.89 (10)	C10—C9—H9	119.5
C3^i—C3—C4	120.54 (6)	C8—C9—H9	119.5
O1—C4—C5	121.61 (11)	C9—C10—C5	120.58 (12)
O1—C4—C3	119.89 (10)	C9—C10—H10	119.7
C5—C4—C3	118.48 (10)	C5—C10—H10	119.7
C10—C5—C6	118.59 (11)	C8—C11—H11A	109.5
C10—C5—C4	122.14 (11)	C8—C11—H11B	109.5
C6—C5—C4	119.21 (11)	H11A—C11—H11B	109.5
C7—C6—C5	120.25 (13)	C8—C11—H11C	109.5
C7—C6—H6	119.9	H11A—C11—H11C	109.5
C5—C6—H6	119.9	H11B—C11—H11C	109.5
C1^i—C1—C2—C3	1.0 (3)	C10—C5—C6—C7	−1.1 (2)
C1—C2—C3—C3^i	1.0 (2)	C4—C5—C6—C7	−178.36 (12)
C1—C2—C3—C4	175.06 (13)	C5—C6—C7—C8	1.4 (2)
C2—C3—C4—O1	−125.83 (13)	C6—C7—C8—C9	−0.5 (2)
C3^i—C3—C4—O1	48.2 (2)	C6—C7—C8—C11	179.79 (14)
C2—C3—C4—C5	52.62 (16)	C7—C8—C9—C10	−0.8 (2)
C3^i—C3—C4—C5	−133.37 (15)	C11—C8—C9—C10	178.91 (14)
O1—C4—C5—C10	−156.10 (13)	C8—C9—C10—C5	1.2 (2)
C3—C4—C5—C10	25.47 (17)	C6—C5—C10—C9	−0.2 (2)
O1—C4—C5—C6	21.08 (18)	C4—C5—C10—C9	177.00 (12)
C3—C4—C5—C6	−157.35 (12)

Symmetry code: (i) −x+1, y, −z+3/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···O1^ii	0.93	2.62	3.4305 (17)	145

Symmetry code: (ii) x, y−1, z.