9,10-Dimethyl-9,10-per­oxy-9,10-dihydro­anthracene

The structure of the title compound, C₁₆H₁₄O₂, contains one half-mol­ecule in the asymmetric unit and the mol­ecule is located on a mirror plane. The dihedral angle between the two benzene ring planes is 53.07 (6)°. The crystal structure involves intermolecular C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.043
• wR factor = 0.107
• Data-to-parameter ratio = 7.4

checkCIF/PLATON results

No syntax errors found



Alert level C
REFNR01_ALERT_3_C  Ratio of reflections to parameters is < 8 for a
            non-centrosymmetric structure, where ZMAX < 18
            sine(theta)/lambda                0.6491
            Proportion of unique data used    0.8608
            Ratio reflections to parameters   7.4362
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       7.44
PLAT480_ALERT_4_C Long H...A H-Bond Reported H4     ..  O2      ..       2.64 Ang.

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           27.47
           From the CIF: _reflns_number_total                812
           Count of symmetry unique reflns          811
           Completeness (_total/calc)            100.12%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         1
           Fraction of Friedel pairs measured     0.001
           Are heavy atom types Z>Si present         no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 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
   2 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The Friedel–Crafts reaction of an alkyl halide with an aromatic hydrocarbon in the presence of aluminium chloride yields a substituted phenyl compound (Price, 1946). The reaction does not, however, stop at the stage of mono-substitution, an unpredictable compound was reported and determined by X-ray crystal structure analysis. The molecule of the title compound lie on a crystallographic mirror plane, which pass through atoms C1/O1/O2/C8/C9/C10 (Fig. 1). The geometrical parameters for (1) are similar to those of related 9,10-bridged anthracene derivatives (Simpson et al., 2004; Gable et al., 1996; Burrows et al., 1999). Atoms C1, C8 are almost coplanar with the benzene ring plane, and the deviating distance from the benzene ring are 0.0074 Å, -0.066 Å respectively. The dihedral angle between the plane of bridge atoms C1—O1—O2—C8 and the benzene ring plane is 63.45 (5)°. The benzene ring plane and its symmetry-related one form the dihedral angle of 53.07 (6)°, which is smaller than that of 9,10-bridged anthrancene systems, e.g. the corresponding dihedral angle in 11,12-bis(N,N-dimethyl-aminomethyl)-9,10-dihydro-9,10-ethanoanthrancene (Karolak-Wojciechowska et al., 1998) is 58.8 (2)°. The three six-membered rings of the bicycle core of (1) [C1—C2—C7—C8—C7ⁱ—C2ⁱ, C1—C2—C7—C8—O2—O1, C1—C2ⁱ—C7ⁱ—C8—O2—O1, symmetric code (i): 1 - x,y,z] are all forced into boat forms. Intermolecular weak interactions, C4—H4···O2ⁱⁱ [symmetric code (ii): 1/2 + x, 1/2 - y, -1/2 + z] and C6—H6···C4ⁱⁱⁱ [symmctric code (iii): x, 1 - y, 1/2 + z], link the molecules into circles (Fig. 2). The bridged O2 atom attached to H4 atom of neighbouring benzene ring may result in the longer distance O2—C8, compared with the bond length C1—O1 (Table 1).

Related literature

For related literature, see: Burrows et al. (1999); Gable et al. (1996); Karolak-Wojciechowska et al. (1998); Larson (1970); Price (1946); Simpson et al. (2004).

S2. Experimental

Ethyl 2-bromo-2-methylpropionate (3.84 g, 20 mmol) was added to a 50 ml flask equipped with a reflux condenser and large magnetic stirrer. Anhydrous benzene (20 ml) was added to the flask, followed by fresh anhydrous AlCl₃ (9.00 g, 67.5 mmol) in small portions. The solution was then slowly heated to the reflux temperature and at this time the exit of the reflux condenser was connected to a flowing-water HBr trap. The mixture was heated a total of 24 h without interruption. The reaction mixture was then cooled to 278k. and treated with 20 ml of 50/50 (by volume) conc. HCl/H₂O to decompose the catalyst complex. The benzene layer was then separated, washed once with ice-cold H₂O (12 ml) and twice with dilute aqueous sodium hydroxide. The organic phase was evaporate. After 6 days, a single-crystal suitable for X-ray analysis was obtained by recrystallization from ethanol.

S3. Refinement

All H atoms were placed in calculated positions with C—H = 0.93–0.96 Å and included in the refinement in riding model, with U_iso(H) = 1.2U_eq(carrier atom). In the absence of anomalous scatterers, no attempt was made to establish the absolute configuration of the title compound.

Computing details

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2004).

Figures

	Fig. 1. A view of (1). Displacement ellipsoids are drawn at 30% probability level and H atoms are shown as small circles of arbitary radii. Symmetry code (i): 1 - x, y, z
	Fig. 2. Packing arrangement for (1).

9,10-Dimethyl-9,10-peroxy-9,10-dihydroanthracene

Crystal data

C16H14O2	F(000) = 504.00
Mr = 238.29	Dx = 1.244 Mg m^−3
Orthorhombic, Cmc21	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: C 2c -2	Cell parameters from 2234 reflections
a = 12.9873 (7) Å	θ = 2.4–27.3°
b = 11.0810 (8) Å	µ = 0.08 mm^−1
c = 8.8368 (8) Å	T = 296 K
V = 1271.72 (16) Å^3	Chunk, yellow
Z = 4	0.40 × 0.35 × 0.30 mm

Data collection

Rigaku R-AXIS RAPID diffractometer	585 reflections with F^2 > 2σ(F^2)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.083
ω scans	θmax = 27.5°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −16→16
Tmin = 0.958, Tmax = 0.976	k = −14→12
5690 measured reflections	l = −11→11
812 independent reflections

Refinement

Refinement on F^2	w = 1/[0.0011Fo^2 + σ(Fo^2)]/(4Fo^2)
R[F^2 > 2σ(F^2)] = 0.042	(Δ/σ)max < 0.001
wR(F^2) = 0.107	Δρmax = 0.23 e Å^−3
S = 1.00	Δρmin = −0.19 e Å^−3
699 reflections	Extinction correction: (Larson, 1970)
94 parameters	Extinction coefficient: 132 (34)
H-atom parameters constrained

Special details

Refinement. Refinement using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0σ(F²) is used only for calculating R-factor (gt).

Data collection(812 indenpent reflections but 699 in refinement): The author of the software, Dr Lee Daniels ([e-mail]) explain this problem (see following). The number of reflections used to refine the cell is taken from the diffractometer program, which uses all available reflections measured in different scans. Even though some reflections are used more than once, they measured at different psi angles and therefore represent independent observations for determination of the cell dimensions.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.5000	0.1212 (2)	0.7053 (3)	0.0584 (7)
O2	0.5000	0.1937 (2)	0.8453 (2)	0.0547 (6)
C1	0.5000	0.1992 (2)	0.5707 (4)	0.0488 (9)
C2	0.59500 (13)	0.27732 (18)	0.5847 (2)	0.0466 (6)
C3	0.67877 (17)	0.2829 (2)	0.4883 (3)	0.0631 (8)
C4	0.76037 (19)	0.3580 (2)	0.5212 (3)	0.0750 (10)
C5	0.75816 (19)	0.4289 (3)	0.6492 (3)	0.0769 (9)
C6	0.67600 (18)	0.4228 (2)	0.7475 (3)	0.0655 (8)
C7	0.59468 (14)	0.3466 (2)	0.7153 (2)	0.0482 (5)
C8	0.5000	0.3253 (3)	0.8122 (4)	0.0502 (9)
C9	0.500000 (10)	0.1104 (4)	0.4404 (5)	0.0734 (12)
C10	0.500000 (10)	0.3808 (4)	0.9660 (5)	0.0786 (13)
H3	0.6800	0.2359	0.4011	0.076*
H4	0.8170	0.3608	0.4569	0.090*
H5	0.8125	0.4811	0.6693	0.092*
H6	0.6753	0.4696	0.8349	0.079*
H101	0.5603	0.3555	1.0201	0.094*
H102	0.5000	0.4671	0.9567	0.094*
H901	0.5604	0.0606	0.4462	0.088*
H902	0.5000	0.1538	0.3464	0.088*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0637 (13)	0.0364 (11)	0.0750 (17)	0.0000	0.0000	0.0017 (13)
O2	0.0565 (13)	0.0537 (13)	0.0538 (15)	0.0000	0.0000	0.0087 (11)
C1	0.0523 (17)	0.0373 (15)	0.057 (2)	0.0000	0.0000	−0.0067 (16)
C2	0.0403 (12)	0.0385 (10)	0.0608 (15)	0.0054 (8)	0.0021 (10)	0.0028 (10)
C3	0.0594 (14)	0.0578 (15)	0.072 (2)	0.0127 (11)	0.0150 (14)	0.0089 (14)
C4	0.0450 (13)	0.081 (2)	0.099 (2)	0.0072 (13)	0.0146 (15)	0.032 (2)
C5	0.0440 (13)	0.0784 (19)	0.108 (2)	−0.0167 (13)	−0.0131 (16)	0.037 (2)
C6	0.0569 (14)	0.0614 (15)	0.078 (2)	−0.0120 (12)	−0.0224 (14)	0.0061 (14)
C7	0.0400 (10)	0.0440 (10)	0.0606 (14)	0.0016 (8)	−0.0061 (10)	0.0019 (12)
C8	0.0492 (16)	0.0492 (18)	0.052 (2)	0.0000	0.0000	−0.0027 (15)
C9	0.089 (2)	0.054 (2)	0.077 (2)	0.0000	0.0000	−0.019 (2)
C10	0.089 (2)	0.089 (2)	0.058 (2)	0.0000	0.0000	−0.017 (2)

Geometric parameters (Å, º)

O1—O2	1.475 (3)	C7—C8	1.517 (3)
O1—C1	1.470 (4)	C8—C10	1.492 (6)
O2—C8	1.487 (4)	C3—H3	0.930
C1—C2	1.512 (2)	C4—H4	0.930
C1—C2^i	1.512 (2)	C5—H5	0.930
C1—C9	1.514 (5)	C6—H6	0.930
C2—C3	1.383 (3)	C9—H901	0.960
C2—C7	1.386 (3)	C9—H901^i	0.960
C3—C4	1.378 (3)	C9—H902	0.960
C4—C5	1.377 (4)	C10—H101	0.960
C5—C6	1.378 (3)	C10—H101^i	0.960
C6—C7	1.382 (3)	C10—H102	0.960
O2—O1—C1	111.0 (2)	C7—C8—C10	116.76 (19)
O1—O2—C8	111.6 (2)	C7^i—C8—C10	116.75 (19)
O1—C1—C2	105.68 (18)	C2—C3—H3	119.9
O1—C1—C2^i	105.68 (18)	C4—C3—H3	119.9
O1—C1—C9	103.5 (2)	C3—C4—H4	119.9
C2—C1—C2^i	109.3 (2)	C5—C4—H4	119.9
C2—C1—C9	115.72 (18)	C4—C5—H5	119.8
C2^i—C1—C9	115.72 (18)	C6—C5—H5	119.8
C1—C2—C3	128.1 (2)	C5—C6—H6	120.3
C1—C2—C7	112.5 (2)	C7—C6—H6	120.3
C3—C2—C7	119.37 (19)	C1—C9—H901	109.5
C2—C3—C4	120.1 (2)	C1—C9—H901^i	109.5
C3—C4—C5	120.1 (2)	C1—C9—H902	109.5
C4—C5—C6	120.4 (2)	H901—C9—H901^i	109.5
C5—C6—C7	119.4 (2)	H901—C9—H902	109.5
C2—C7—C6	120.5 (2)	H901^i—C9—H902	109.5
C2—C7—C8	112.7 (2)	C8—C10—H101	109.5
C6—C7—C8	126.7 (2)	C8—C10—H101^i	109.5
O2—C8—C7	105.30 (19)	C8—C10—H102	109.5
O2—C8—C7^i	105.30 (19)	H101—C10—H101^i	109.4
O2—C8—C10	103.0 (3)	H101—C10—H102	109.5
C7—C8—C7^i	108.3 (2)	H101^i—C10—H102	109.5
O2—O1—C1—C2	57.93 (16)	C1—C2—C7—C6	179.4 (2)
O2—O1—C1—C2^i	−57.93 (16)	C1—C2—C7—C8	0.8 (2)
O1—O2—C8—C7	−57.16 (18)	C3—C2—C7—C6	1.5 (3)
O1—O2—C8—C7^i	57.16 (18)	C3—C2—C7—C8	−177.1 (2)
O1—C1—C2—C3	118.2 (2)	C7—C2—C3—C4	−0.8 (3)
O1—C1—C2—C7	−59.5 (2)	C2—C3—C4—C5	−0.9 (4)
O1—C1—C2^i—C3^i	−118.2 (2)	C3—C4—C5—C6	1.9 (4)
O1—C1—C2^i—C7^i	59.5 (2)	C4—C5—C6—C7	−1.2 (4)
C2—C1—C2^i—C3^i	128.5 (2)	C5—C6—C7—C2	−0.5 (3)
C2—C1—C2^i—C7^i	−53.8 (3)	C5—C6—C7—C8	177.9 (2)
C2^i—C1—C2—C3	−128.5 (2)	C2—C7—C8—O2	57.3 (2)
C2^i—C1—C2—C7	53.8 (3)	C2—C7—C8—C10	170.8 (2)
C9—C1—C2—C3	4.3 (4)	C2—C7—C8—C7^i	−55.0 (3)
C9—C1—C2—C7	−173.3 (2)	C6—C7—C8—O2	−121.2 (2)
C9—C1—C2^i—C3^i	−4.3 (4)	C6—C7—C8—C10	−7.7 (4)
C9—C1—C2^i—C7^i	173.3 (2)	C6—C7—C8—C7^i	126.5 (2)
C1—C2—C3—C4	−178.4 (2)

Symmetry code: (i) −x+1, y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···O2^ii	0.93	2.64	3.526 (2)	159

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