1,4-Dimethoxy­anthracene-9,10-dione

In the title compound, C₁₆H₁₂O₄, a 9,10-anthraquinone derivative, the crystal packing is stabilized by C—H...O non-classical hydrogen bonds with quinone O atoms as acceptors. There are no π–π stacking inter­actions in the crystal structure. The molecule lies across a crystallographic mirror plane.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C)= 0.002 Å
• R factor = 0.046
• wR factor = 0.122
• Data-to-parameter ratio = 15.4

checkCIF/PLATON results

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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: PLATON.

1,4-Dimethoxyanthracene-9,10-dione

Crystal data

C16H12O4	F(000) = 560
Mr = 268.26	Dx = 1.422 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 3257 reflections
a = 7.0520 (16) Å	θ = 2.2–26.1°
b = 14.662 (3) Å	µ = 0.10 mm^−1
c = 12.121 (3) Å	T = 298 K
V = 1253.2 (5) Å^3	Block, yellow
Z = 4	0.30 × 0.15 × 0.10 mm

Data collection

Bruker SMART 4K CCD area-detector diffractometer	1287 reflections with I > 2σ(I)
Radiation source: fine–focus sealed tube	Rint = 0.029
Graphite monochromator	θmax = 27.0°, θmin = 2.2°
φ and ω scans	h = −9→7
7938 measured reflections	k = −18→17
1420 independent 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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.122	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.06P)^2 + 0.3319P] where P = (Fo^2 + 2Fc^2)/3
1420 reflections	(Δ/σ)max = 0.001
92 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

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

	x	y	z	Uiso*/Ueq
C1	0.0338 (2)	0.34647 (10)	0.61793 (11)	0.0402 (4)
C2	−0.1242 (2)	0.29679 (11)	0.65202 (12)	0.0459 (4)
H2	−0.2320	0.3278	0.6753	0.055*
C3	0.1941 (2)	0.29832 (9)	0.58120 (11)	0.0353 (3)
C4	−0.1249 (2)	0.48880 (12)	0.64556 (15)	0.0564 (5)
H4A	−0.2276	0.4710	0.5982	0.085*
H4B	−0.1011	0.5529	0.6371	0.085*
H4C	−0.1579	0.4761	0.7209	0.085*
C5	0.36883 (19)	0.34702 (9)	0.54526 (11)	0.0369 (3)
C6	0.49592 (19)	0.29749 (9)	0.46779 (11)	0.0359 (3)
C7	0.6232 (2)	0.34514 (11)	0.40191 (12)	0.0447 (4)
H7	0.6270	0.4085	0.4040	0.054*
C8	0.7440 (2)	0.29740 (12)	0.33343 (14)	0.0541 (4)
H8	0.8260	0.3289	0.2869	0.065*
O1	0.04148 (16)	0.43872 (8)	0.61662 (10)	0.0546 (3)
O2	0.41099 (16)	0.42274 (7)	0.57774 (10)	0.0541 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0365 (8)	0.0486 (8)	0.0355 (7)	0.0065 (6)	−0.0010 (6)	−0.0002 (6)
C2	0.0343 (8)	0.0637 (9)	0.0396 (7)	0.0081 (6)	0.0044 (6)	−0.0014 (6)
C3	0.0316 (7)	0.0417 (8)	0.0326 (6)	0.0024 (5)	−0.0013 (5)	0.0005 (5)
C4	0.0502 (10)	0.0580 (10)	0.0611 (10)	0.0199 (8)	0.0049 (8)	−0.0051 (8)
C5	0.0341 (7)	0.0368 (7)	0.0397 (7)	0.0027 (6)	−0.0022 (6)	0.0018 (5)
C6	0.0303 (7)	0.0412 (7)	0.0361 (7)	0.0001 (5)	−0.0026 (5)	0.0015 (5)
C7	0.0429 (9)	0.0445 (8)	0.0466 (8)	−0.0025 (7)	0.0030 (6)	0.0043 (6)
C8	0.0470 (9)	0.0635 (10)	0.0518 (9)	−0.0061 (7)	0.0144 (7)	0.0070 (7)
O1	0.0450 (7)	0.0479 (7)	0.0708 (8)	0.0120 (5)	0.0106 (5)	−0.0013 (5)
O2	0.0501 (7)	0.0397 (6)	0.0726 (8)	−0.0050 (5)	0.0126 (6)	−0.0095 (5)

Geometric parameters (Å, º)

C1—O1	1.3538 (19)	C4—H4C	0.9600
C1—C2	1.394 (2)	C5—O2	1.2149 (17)
C1—C3	1.4046 (19)	C5—C6	1.4874 (19)
C2—C2^i	1.372 (3)	C6—C7	1.3899 (19)
C2—H2	0.9300	C6—C6^i	1.392 (3)
C3—C3^i	1.417 (3)	C7—C8	1.380 (2)
C3—C5	1.4895 (19)	C7—H7	0.9300
C4—O1	1.4280 (19)	C8—C8^i	1.390 (3)
C4—H4A	0.9600	C8—H8	0.9300
C4—H4B	0.9600
O1—C1—C2	123.88 (13)	H4B—C4—H4C	109.5
O1—C1—C3	117.80 (13)	O2—C5—C6	120.22 (13)
C2—C1—C3	118.32 (14)	O2—C5—C3	123.08 (13)
C2^i—C2—C1	121.50 (9)	C6—C5—C3	116.69 (12)
C2^i—C2—H2	119.2	C7—C6—C6^i	120.17 (9)
C1—C2—H2	119.2	C7—C6—C5	120.43 (13)
C1—C3—C3^i	120.17 (9)	C6^i—C6—C5	119.22 (7)
C1—C3—C5	121.15 (13)	C8—C7—C6	119.30 (15)
C3^i—C3—C5	118.64 (7)	C8—C7—H7	120.3
O1—C4—H4A	109.5	C6—C7—H7	120.3
O1—C4—H4B	109.5	C7—C8—C8^i	120.47 (9)
H4A—C4—H4B	109.5	C7—C8—H8	119.8
O1—C4—H4C	109.5	C8^i—C8—H8	119.8
H4A—C4—H4C	109.5	C1—O1—C4	118.56 (13)

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O2^ii	0.93	2.50	3.421 (2)	171

Symmetry code: (ii) −x+1, −y+1, −z+1.