6,7-Dimeth­oxy-1,4-anthraquinone

Kitamura, C.; Akamatsu, N.; Yoneda, A.; Kawase, T.

doi:10.1107/S1600536808026500

organic compounds

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ISSN: 2056-9890

Volume 64| Part 9| September 2008| Page o1802

doi:10.1107/S1600536808026500

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6,7-Dimethoxy-1,4-anthraquinone

Chitoshi Kitamura,^a ^* Naoki Akamatsu,^a Akio Yoneda ^a and Takeshi Kawase ^a

^aDepartment of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
^*Correspondence e-mail: kitamura@eng.u-hyogo.ac.jp

(Received 16 August 2008; accepted 18 August 2008; online 23 August 2008)

The molecule of the title compound, C₁₆H₁₂O₄, is almost planar; the two methoxy groups are slightly out of the plane of the anthraquinone ring system, with C—C—O—C torsion angles of −6.25 (19) and −10.22 (19)°. In the crystal structure, the molecules adopt a herringbone arrangement and form face-to-face slipped antiparallel π–π stacking interactions along the b axis, with an interplanar distance of 3.278 (2) Å.

Related literature

For the synthesis of 1,4-anthraquinone, see: McOmie & Perry (1973 ). For related structures, see: Kitamura et al. (2006 ).

Experimental

Crystal data

C₁₆H₁₂O₄
M_r = 268.26
Monoclinic, P 2₁ /c
a = 7.478 (3) Å
b = 7.492 (3) Å
c = 22.949 (9) Å
β = 106.646 (10)°
V = 1231.8 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 223 K
0.5 × 0.1 × 0.1 mm

Data collection

Rigaku/MSC Mercury CCD area-detector diffractometer
Absorption correction: numerical (NUMABS; Higashi, 1999 ) T_min = 0.974, T_max = 0.991
5255 measured reflections
2705 independent reflections
2177 reflections with I > 2σ(I)
R_int = 0.018

Refinement

R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.147
S = 1.09
2705 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2001 ); cell refinement: CrystalClear; data reduction: WinGX (Farrugia, 1999 ); program(s) used to solve structure: SIR2004 (Burla et al., 2005 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808026500/is2326sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808026500/is2326Isup2.hkl

checkCIF report

Comment top

1,4-Anthraquinone has a weak dipole moment along the molecular long axis, whose value was estimated to be 2.54 debye by a B3LYP/6–31G(d) DFT calculation (Kitamura et al., 2006). The crystal structure exhibited a herring-bone packing with face-to-face slipped π-overlap along the stacking direction. In addition, the molecules were antiparallel with respect to one another. These charasteristics inspired us to study other 1,4-anthraquinone derivatives. The title compound (I), which was first prepared by McOmie & Perry (1973), has strong electron-donating methoxy groups, and therefore, has a larger dipole moment, compared with 1,4-anthraquinone, which was estimated to be 3.91 debye. This property should affect the intermolecular interactions in the crystal.

The molecular structure of (I) is shown in Fig. 1. The molecule is an almost coplanar conformation. The displacements of atoms O1, O2, O3, O4, C15, and C16 relative to the plane of the anthracene backbone are 0.159 (2), -0.004 (2), -0.039 (2), -0.003 (2), 0.168 (2), and -0.145 (2) Å, respectively. The torsion angles of the two methoxy groups are -6.25 (19)° for C11—C10—O4—C16 and -10.22 (19)° for C8—C9—O3—C15, indicating that the C_methyl—O bonds are directed along the molecular short axis. As shown in Fig. 2, the molecules adopt a herring-bone arrangement and form face-to-face slipped antiparallel π-π stacking along the direction of the b axis. The interplanar distance is 3.278 (2) Å, whose value is shorter than that (3.423 Å) of 1,4-anthraquinone (Kitamura et al., 2006) and is indicating the existence of strong intermolecular interactions.

Related literature top

For the synthesis of 1,4-anthraquinone, see: McOmie & Perry (1973). For related structures, see: Kitamura et al. (2006).

Experimental top

The title compound was prepared according to the modified method described by McOmie & Perry (1973). A mixture of 4,5-bis(bromomethyl)-1,2-dimethoxybenezene (340 mg, 1.05 mmol), 1,4-benzoquinone (571 mg, 5.28 mmol) and sodium iodide (797 mg, 5.31 mmol) in DMF (6 ml) was heated at 110 °C for 16 h. After the reaction mixture was cooled to room temperature, the mixture was decolorized by addition of aqueous 5% Na₂SO₃ solution. The resulting yellow precipitate was filtered off, washed with acetone, and dried under vacuum to give the crude product of (I) (74 mg, 26%). Yellow single crystals suitable for X-ray analysis were obtained by standing of a hot DMF solution of the crude product at room temperature.

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2001); cell refinement: CrystalClear (Rigaku/MSC, 2001); data reduction: WinGX (Farrugia, 1999); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids for non-H atoms.
	Fig. 2. The packing diagram of (I). Hydrogen atoms are omitted for clarity.

6,7-Dimethoxy-1,4-anthraquinone top

Crystal data top

C₁₆H₁₂O₄	F(000) = 560
M_r = 268.26	D_x = 1.446 Mg m⁻³
Monoclinic, P2₁/c	Melting point: 547 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 7.478 (3) Å	Cell parameters from 3335 reflections
b = 7.492 (3) Å	θ = 3.2–27.5°
c = 22.949 (9) Å	µ = 0.10 mm⁻¹
β = 106.646 (10)°	T = 223 K
V = 1231.8 (8) Å³	Prism, yellow
Z = 4	0.5 × 0.1 × 0.1 mm

Data collection top

Rigaku/MSC Mercury CCD area-detector diffractometer	2705 independent reflections
Radiation source: rotating-anode X-ray tube	2177 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.018
Detector resolution: 14.7059 pixels mm^-1	θ_max = 27.5°, θ_min = 3.3°
ϕ and ω scans	h = −9→9
Absorption correction: numerical (NUMABS; Higashi, 1999)	k = −9→9
T_min = 0.974, T_max = 0.991	l = −29→9
5255 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.049	H-atom parameters constrained
wR(F²) = 0.147	w = 1/[σ²(F_o²) + (0.089P)² + 0.0212P] where P = (F_o² + 2F_c²)/3
S = 1.09	(Δ/σ)_max < 0.001
2705 reflections	Δρ_max = 0.28 e Å⁻³
181 parameters	Δρ_min = −0.17 e Å⁻³
0 restraints

Crystal data top

C₁₆H₁₂O₄	V = 1231.8 (8) Å³
M_r = 268.26	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.478 (3) Å	µ = 0.10 mm⁻¹
b = 7.492 (3) Å	T = 223 K
c = 22.949 (9) Å	0.5 × 0.1 × 0.1 mm
β = 106.646 (10)°

Data collection top

Rigaku/MSC Mercury CCD area-detector diffractometer	2705 independent reflections
Absorption correction: numerical (NUMABS; Higashi, 1999)	2177 reflections with I > 2σ(I)
T_min = 0.974, T_max = 0.991	R_int = 0.018
5255 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	0 restraints
wR(F²) = 0.147	H-atom parameters constrained
S = 1.09	Δρ_max = 0.28 e Å⁻³
2705 reflections	Δρ_min = −0.17 e Å⁻³
181 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.2346 (2)	0.81897 (17)	0.17745 (6)	0.0348 (3)
C2	0.4192 (2)	0.7551 (2)	0.21515 (7)	0.0439 (4)
H2	0.4546	0.7773	0.2572	0.053*
C3	0.5361 (2)	0.66760 (19)	0.19142 (7)	0.0429 (4)
H3	0.6498	0.6269	0.2176	0.052*
C4	0.4950 (2)	0.63168 (17)	0.12589 (6)	0.0362 (3)
C5	0.30905 (19)	0.68684 (15)	0.08623 (6)	0.0286 (3)
C6	0.26003 (18)	0.65203 (15)	0.02483 (6)	0.0280 (3)
H6	0.3465	0.596	0.0081	0.034*
C7	0.08283 (18)	0.69868 (15)	−0.01340 (6)	0.0254 (3)
C8	0.03163 (18)	0.66243 (15)	−0.07661 (6)	0.0273 (3)
H8	0.1177	0.6074	−0.0937	0.033*
C9	−0.14174 (19)	0.70671 (16)	−0.11289 (6)	0.0285 (3)
C10	−0.27351 (18)	0.79192 (15)	−0.08715 (6)	0.0289 (3)
C11	−0.22806 (19)	0.82638 (16)	−0.02631 (6)	0.0285 (3)
H11	−0.3163	0.88	−0.0098	0.034*
C12	−0.04838 (18)	0.78199 (15)	0.01235 (6)	0.0263 (3)
C13	0.00577 (19)	0.81899 (16)	0.07530 (6)	0.0292 (3)
H13	−0.0794	0.8749	0.0926	0.035*
C14	0.18036 (19)	0.77496 (16)	0.11181 (6)	0.0289 (3)
C15	−0.0736 (2)	0.6124 (2)	−0.20281 (7)	0.0449 (4)
H15A	−0.1353	0.593	−0.2457	0.067*
H15B	−0.0186	0.5013	−0.1843	0.067*
H15C	0.0235	0.7014	−0.1984	0.067*
C16	−0.5822 (2)	0.9018 (2)	−0.10571 (7)	0.0413 (4)
H16A	−0.6925	0.9256	−0.1393	0.062*
H16B	−0.5399	1.0117	−0.0837	0.062*
H16C	−0.6123	0.8153	−0.0785	0.062*
O1	0.13258 (17)	0.90386 (15)	0.20045 (5)	0.0496 (3)
O2	0.61027 (17)	0.55939 (15)	0.10512 (5)	0.0524 (3)
O3	−0.20663 (14)	0.67321 (13)	−0.17341 (4)	0.0372 (3)
O4	−0.43858 (14)	0.83254 (13)	−0.12867 (4)	0.0375 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0407 (8)	0.0377 (7)	0.0246 (7)	−0.0091 (5)	0.0069 (6)	−0.0012 (5)
C2	0.0509 (9)	0.0481 (8)	0.0260 (7)	−0.0077 (7)	0.0000 (7)	0.0020 (6)
C3	0.0426 (9)	0.0416 (7)	0.0348 (8)	−0.0005 (6)	−0.0047 (7)	0.0043 (6)
C4	0.0348 (8)	0.0339 (7)	0.0344 (8)	−0.0014 (5)	0.0014 (6)	0.0030 (5)
C5	0.0301 (7)	0.0271 (6)	0.0263 (7)	−0.0030 (4)	0.0045 (5)	0.0022 (4)
C6	0.0276 (7)	0.0285 (6)	0.0280 (7)	−0.0012 (4)	0.0078 (5)	0.0011 (4)
C7	0.0279 (7)	0.0248 (6)	0.0237 (7)	−0.0032 (4)	0.0076 (5)	0.0012 (4)
C8	0.0283 (7)	0.0299 (6)	0.0248 (7)	−0.0030 (4)	0.0093 (5)	−0.0020 (4)
C9	0.0309 (7)	0.0327 (6)	0.0218 (6)	−0.0065 (5)	0.0073 (5)	−0.0014 (4)
C10	0.0243 (7)	0.0320 (6)	0.0283 (7)	−0.0032 (5)	0.0044 (5)	0.0026 (5)
C11	0.0276 (7)	0.0312 (6)	0.0274 (7)	−0.0003 (4)	0.0089 (5)	−0.0009 (5)
C12	0.0281 (7)	0.0265 (6)	0.0243 (6)	−0.0031 (4)	0.0073 (5)	0.0011 (4)
C13	0.0322 (7)	0.0305 (6)	0.0256 (7)	−0.0029 (5)	0.0094 (6)	−0.0017 (4)
C14	0.0333 (7)	0.0286 (6)	0.0240 (7)	−0.0065 (5)	0.0069 (5)	0.0005 (4)
C15	0.0452 (9)	0.0650 (9)	0.0254 (7)	−0.0003 (7)	0.0114 (6)	−0.0089 (6)
C16	0.0267 (7)	0.0530 (8)	0.0431 (9)	0.0020 (6)	0.0081 (6)	0.0042 (6)
O1	0.0507 (7)	0.0691 (7)	0.0311 (6)	−0.0053 (5)	0.0150 (5)	−0.0111 (5)
O2	0.0393 (7)	0.0647 (7)	0.0473 (7)	0.0151 (5)	0.0029 (5)	−0.0009 (5)
O3	0.0324 (6)	0.0543 (6)	0.0226 (5)	−0.0008 (4)	0.0041 (4)	−0.0040 (4)
O4	0.0275 (6)	0.0520 (6)	0.0292 (5)	0.0027 (4)	0.0021 (4)	0.0007 (4)

Geometric parameters (Å, º) top

C1—O1	1.2233 (18)	C9—O3	1.3570 (16)
C1—C14	1.4806 (19)	C9—C10	1.4356 (19)
C1—C2	1.482 (2)	C10—O4	1.3603 (16)
C2—C3	1.328 (2)	C10—C11	1.3637 (19)
C2—H2	0.94	C11—C12	1.4213 (19)
C3—C4	1.471 (2)	C11—H11	0.94
C3—H3	0.94	C12—C13	1.4116 (19)
C4—O2	1.2248 (18)	C13—C14	1.374 (2)
C4—C5	1.4856 (19)	C13—H13	0.94
C5—C6	1.3755 (19)	C15—O3	1.4273 (18)
C5—C14	1.4249 (19)	C15—H15A	0.97
C6—C7	1.4078 (18)	C15—H15B	0.97
C6—H6	0.94	C15—H15C	0.97
C7—C8	1.4165 (18)	C16—O4	1.4231 (18)
C7—C12	1.4262 (19)	C16—H16A	0.97
C8—C9	1.3659 (19)	C16—H16B	0.97
C8—H8	0.94	C16—H16C	0.97

O1—C1—C14	122.12 (14)	O4—C10—C9	113.79 (12)
O1—C1—C2	120.49 (13)	C11—C10—C9	120.42 (12)
C14—C1—C2	117.39 (13)	C10—C11—C12	120.58 (12)
C3—C2—C1	122.14 (14)	C10—C11—H11	119.7
C3—C2—H2	118.9	C12—C11—H11	119.7
C1—C2—H2	118.9	C13—C12—C11	122.39 (12)
C2—C3—C4	122.70 (14)	C13—C12—C7	118.71 (12)
C2—C3—H3	118.7	C11—C12—C7	118.90 (12)
C4—C3—H3	118.7	C14—C13—C12	121.39 (13)
O2—C4—C3	120.97 (13)	C14—C13—H13	119.3
O2—C4—C5	121.61 (13)	C12—C13—H13	119.3
C3—C4—C5	117.42 (13)	C13—C14—C5	119.72 (12)
C6—C5—C14	119.78 (12)	C13—C14—C1	120.17 (13)
C6—C5—C4	120.19 (13)	C5—C14—C1	120.11 (12)
C14—C5—C4	120.03 (12)	O3—C15—H15A	109.5
C5—C6—C7	121.23 (12)	O3—C15—H15B	109.5
C5—C6—H6	119.4	H15A—C15—H15B	109.5
C7—C6—H6	119.4	O3—C15—H15C	109.5
C6—C7—C8	121.38 (12)	H15A—C15—H15C	109.5
C6—C7—C12	119.13 (11)	H15B—C15—H15C	109.5
C8—C7—C12	119.48 (12)	O4—C16—H16A	109.5
C9—C8—C7	120.57 (12)	O4—C16—H16B	109.5
C9—C8—H8	119.7	H16A—C16—H16B	109.5
C7—C8—H8	119.7	O4—C16—H16C	109.5
O3—C9—C8	125.28 (12)	H16A—C16—H16C	109.5
O3—C9—C10	114.65 (12)	H16B—C16—H16C	109.5
C8—C9—C10	120.05 (12)	C9—O3—C15	116.71 (11)
O4—C10—C11	125.79 (12)	C10—O4—C16	116.88 (11)

O1—C1—C2—C3	−177.80 (14)	C10—C11—C12—C13	178.54 (11)
C14—C1—C2—C3	2.5 (2)	C10—C11—C12—C7	−0.80 (18)
C1—C2—C3—C4	1.9 (2)	C6—C7—C12—C13	1.57 (17)
C2—C3—C4—O2	175.88 (15)	C8—C7—C12—C13	−179.27 (10)
C2—C3—C4—C5	−4.0 (2)	C6—C7—C12—C11	−179.07 (10)
O2—C4—C5—C6	2.1 (2)	C8—C7—C12—C11	0.09 (17)
C3—C4—C5—C6	−178.01 (11)	C11—C12—C13—C14	−179.95 (10)
O2—C4—C5—C14	−178.31 (13)	C7—C12—C13—C14	−0.61 (19)
C3—C4—C5—C14	1.54 (18)	C12—C13—C14—C5	−1.28 (19)
C14—C5—C6—C7	−1.29 (18)	C12—C13—C14—C1	178.67 (10)
C4—C5—C6—C7	178.27 (10)	C6—C5—C14—C13	2.25 (18)
C5—C6—C7—C8	−179.76 (10)	C4—C5—C14—C13	−177.31 (11)
C5—C6—C7—C12	−0.62 (18)	C6—C5—C14—C1	−177.71 (11)
C6—C7—C8—C9	179.20 (10)	C4—C5—C14—C1	2.73 (17)
C12—C7—C8—C9	0.06 (18)	O1—C1—C14—C13	−4.4 (2)
C7—C8—C9—O3	−177.93 (10)	C2—C1—C14—C13	175.27 (11)
C7—C8—C9—C10	0.46 (19)	O1—C1—C14—C5	175.55 (12)
O3—C9—C10—O4	−3.06 (16)	C2—C1—C14—C5	−4.77 (18)
C8—C9—C10—O4	178.39 (11)	C8—C9—O3—C15	−10.22 (19)
O3—C9—C10—C11	177.38 (11)	C10—C9—O3—C15	171.32 (11)
C8—C9—C10—C11	−1.16 (19)	C11—C10—O4—C16	−6.25 (19)
O4—C10—C11—C12	−178.17 (10)	C9—C10—O4—C16	174.23 (11)
C9—C10—C11—C12	1.33 (19)

Experimental details

Crystal data
Chemical formula	C₁₆H₁₂O₄
M_r	268.26
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	223
a, b, c (Å)	7.478 (3), 7.492 (3), 22.949 (9)
β (°)	106.646 (10)
V (Å³)	1231.8 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.5 × 0.1 × 0.1

Data collection
Diffractometer	Rigaku/MSC Mercury CCD area-detector diffractometer
Absorption correction	Numerical (NUMABS; Higashi, 1999)
T_min, T_max	0.974, 0.991
No. of measured, independent and observed [I > 2σ(I)] reflections	5255, 2705, 2177
R_int	0.018
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.049, 0.147, 1.09
No. of reflections	2705
No. of parameters	181
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.28, −0.17

Computer programs: CrystalClear (Rigaku/MSC, 2001), WinGX (Farrugia, 1999), SIR2004 (Burla et al., 2005), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997).

Acknowledgements

We thank the Instrument Center of the Institute for Molecular Science for the X-ray structural analysis. This work was supported by a Grant-in-Aid (No. 20550128) for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan.

References

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