2-Hydr-oxy-1,6,7,8-tetra-meth-oxy-3-methyl-anthraquinone.

The title compound, C(19)H(18)O(7), also known as chrysoobtusin, was isolated from Cassia tora L. (Leguminosae). The anthraquinone ring system is almost planar, the dihedral angle between the two benzene rings being 4.27 (4)°. The structure is stabilized by intra- and inter-molecular O-H⋯O and C-H⋯O hydrogen bonds, and by weak π-π stacking inter-actions along the b axis, with a centroid-centroid distance between related benzene rings of 3.800 (4) Å.

Related literature

For related literature, see: Boonnak et al. (2005 ▶); Hao et al. (1995 ▶); Jia et al. (2007 ▶); Ng et al. (2005 ▶); Patil et al. (2004 ▶); Wu & Yen (2004 ▶); Allen et al. (1987 ▶).

Experimental

Crystal data

C19H18O7

M = 358.33

Monoclinic,

a = 12.2960 (3) Å

b = 7.8545 (2) Å

c = 18.3361 (5) Å

β = 106.581 (2)°

V = 1697.24 (8) Å3

Z = 4

Mo Kα radiation

μ = 0.11 mm−1

T = 296 (2) K

0.30 × 0.28 × 0.26 mm

Data collection

Bruker APEXII area-detector diffractometer

Absorption correction: none

13295 measured reflections

3871 independent reflections

2527 reflections with I > 2σ(I)

R int = 0.032

Refinement

R[F 2 > 2σ(F 2)] = 0.046

wR(F 2) = 0.133

S = 1.02

3871 reflections

241 parameters

H-atom parameters constrained

Δρmax = 0.19 e Å−3

Δρmin = −0.21 e Å−3

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: SHELXTL (Bruker, 2004 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807067864/rz2185sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807067864/rz2185Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C19H18O7	F000 = 752
Mr = 358.33	Dx = 1.402 Mg m−3
Monoclinic, P21/n	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3645 reflections
a = 12.2960 (3) Å	θ = 1.4–28.0º
b = 7.8545 (2) Å	µ = 0.11 mm−1
c = 18.3361 (5) Å	T = 296 (2) K
β = 106.581 (2)º	Block, yellow
V = 1697.24 (8) Å3	0.30 × 0.28 × 0.26 mm
Z = 4

Bruker APEXII area-detector diffractometer	2527 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.032
Monochromator: graphite	θmax = 27.5º
T = 296(2) K	θmin = 1.8º
f and ω scans	h = −15→15
Absorption correction: none	k = −10→10
13295 measured reflections	l = −23→23
3871 independent reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.046	H-atom parameters constrained
wR(F2) = 0.133	w = 1/[σ2(Fo2) + (0.0598P)2 + 0.2883P] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max < 0.001
3871 reflections	Δρmax = 0.19 e Å−3
241 parameters	Δρmin = −0.21 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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.

	x	y	z	Uiso*/Ueq
C1	0.12772 (16)	0.3847 (2)	−0.08053 (10)	0.0478 (4)
C2	0.23670 (15)	0.3514 (2)	−0.03234 (10)	0.0479 (4)
C3	0.25066 (14)	0.2624 (2)	0.03525 (9)	0.0417 (4)
C4	0.15663 (13)	0.2073 (2)	0.05800 (9)	0.0391 (4)
C5	0.04861 (13)	0.2443 (2)	0.00932 (9)	0.0394 (4)
C6	0.03506 (15)	0.3313 (2)	−0.05891 (9)	0.0452 (4)
H6	−0.0376	0.3536	−0.0902	0.054*
C7	−0.05610 (14)	0.1888 (2)	0.02762 (9)	0.0419 (4)
C8	−0.04420 (13)	0.10489 (19)	0.10100 (9)	0.0391 (4)
C9	0.06335 (13)	0.07377 (19)	0.15239 (9)	0.0385 (4)
C10	0.16909 (14)	0.1101 (2)	0.12996 (9)	0.0420 (4)
C11	0.06680 (13)	−0.0001 (2)	0.22235 (9)	0.0404 (4)
C12	−0.03346 (14)	−0.0496 (2)	0.23820 (9)	0.0447 (4)
C13	−0.14001 (14)	−0.0222 (2)	0.18680 (9)	0.0459 (4)
C14	−0.14247 (14)	0.0570 (2)	0.11918 (9)	0.0444 (4)
H14	−0.2124	0.0793	0.0844	0.053*
C15	0.01444 (17)	0.4980 (3)	−0.19883 (11)	0.0645 (5)
H15A	−0.0223	0.3913	−0.2157	0.097*
H15B	0.0236	0.5600	−0.2418	0.097*
H15C	−0.0311	0.5634	−0.1744	0.097*
C16	0.3571 (2)	0.5740 (3)	−0.04686 (16)	0.0795 (7)
H16A	0.2951	0.6370	−0.0794	0.119*
H16B	0.4246	0.5946	−0.0619	0.119*
H16C	0.3690	0.6098	0.0049	0.119*
C17	0.41092 (17)	0.0855 (3)	0.06199 (13)	0.0682 (6)
H17A	0.3652	−0.0108	0.0666	0.102*
H17B	0.4855	0.0729	0.0967	0.102*
H17C	0.4163	0.0920	0.0109	0.102*
C18	0.21311 (19)	0.1135 (3)	0.32189 (12)	0.0727 (6)
H18A	0.2443	0.1858	0.2907	0.109*
H18B	0.2723	0.0790	0.3660	0.109*
H18C	0.1559	0.1745	0.3375	0.109*
C19	−0.24641 (16)	−0.0758 (3)	0.20556 (12)	0.0666 (6)
H19A	−0.3114	−0.0311	0.1680	0.100*
H19B	−0.2450	−0.0327	0.2548	0.100*
H19C	−0.2507	−0.1978	0.2058	0.100*
O1	0.12327 (11)	0.46722 (18)	−0.14620 (7)	0.0641 (4)
O2	0.33123 (11)	0.39758 (17)	−0.05315 (8)	0.0617 (4)
O3	0.36000 (9)	0.23760 (15)	0.07962 (6)	0.0495 (3)
O4	0.26068 (10)	0.05769 (19)	0.16791 (7)	0.0642 (4)
O5	−0.14949 (10)	0.21417 (18)	−0.01744 (7)	0.0581 (4)
O6	0.16389 (10)	−0.03329 (16)	0.27947 (6)	0.0510 (3)
O7	−0.02886 (10)	−0.12633 (19)	0.30522 (7)	0.0599 (4)
H7	0.0376	−0.1434	0.3291	0.090*

	U11	U22	U33	U12	U13	U23
C1	0.0551 (11)	0.0446 (9)	0.0446 (9)	0.0084 (8)	0.0161 (8)	0.0035 (8)
C2	0.0478 (10)	0.0460 (9)	0.0522 (10)	0.0032 (8)	0.0180 (8)	−0.0028 (8)
C3	0.0395 (9)	0.0421 (9)	0.0407 (9)	0.0039 (7)	0.0069 (7)	−0.0082 (7)
C4	0.0396 (9)	0.0387 (8)	0.0363 (8)	0.0037 (7)	0.0064 (7)	−0.0053 (7)
C5	0.0412 (9)	0.0371 (8)	0.0367 (8)	0.0034 (7)	0.0061 (7)	−0.0039 (7)
C6	0.0450 (9)	0.0420 (9)	0.0455 (9)	0.0075 (7)	0.0080 (7)	0.0007 (8)
C7	0.0409 (9)	0.0399 (9)	0.0401 (8)	0.0051 (7)	0.0038 (7)	−0.0022 (7)
C8	0.0399 (9)	0.0369 (8)	0.0368 (8)	0.0029 (7)	0.0047 (7)	−0.0036 (7)
C9	0.0396 (8)	0.0349 (8)	0.0376 (8)	0.0017 (7)	0.0056 (7)	−0.0034 (7)
C10	0.0388 (9)	0.0431 (9)	0.0392 (9)	0.0036 (7)	0.0032 (7)	−0.0049 (7)
C11	0.0386 (8)	0.0389 (8)	0.0379 (8)	0.0025 (7)	0.0017 (7)	−0.0031 (7)
C12	0.0474 (10)	0.0459 (9)	0.0379 (8)	0.0022 (8)	0.0078 (7)	0.0005 (7)
C13	0.0426 (9)	0.0484 (10)	0.0450 (9)	0.0006 (8)	0.0098 (7)	−0.0017 (8)
C14	0.0368 (8)	0.0475 (9)	0.0435 (9)	0.0043 (7)	0.0026 (7)	−0.0019 (8)
C15	0.0741 (14)	0.0684 (13)	0.0482 (10)	0.0172 (11)	0.0129 (10)	0.0118 (10)
C16	0.0717 (15)	0.0681 (14)	0.1065 (19)	−0.0097 (12)	0.0382 (14)	0.0046 (14)
C17	0.0536 (11)	0.0765 (14)	0.0700 (13)	0.0212 (10)	0.0104 (10)	−0.0125 (11)
C18	0.0665 (13)	0.0868 (16)	0.0526 (11)	−0.0165 (12)	−0.0026 (10)	−0.0160 (11)
C19	0.0477 (11)	0.0890 (15)	0.0636 (12)	−0.0002 (10)	0.0165 (9)	0.0115 (11)
O1	0.0621 (8)	0.0764 (9)	0.0543 (8)	0.0081 (7)	0.0177 (7)	0.0207 (7)
O2	0.0554 (8)	0.0657 (9)	0.0712 (9)	0.0024 (7)	0.0298 (7)	0.0041 (7)
O3	0.0375 (6)	0.0581 (7)	0.0487 (7)	0.0028 (5)	0.0056 (5)	−0.0093 (6)
O4	0.0424 (7)	0.0934 (11)	0.0526 (7)	0.0150 (7)	0.0069 (6)	0.0189 (7)
O5	0.0399 (7)	0.0773 (9)	0.0495 (7)	0.0038 (6)	0.0005 (6)	0.0141 (7)
O6	0.0447 (7)	0.0585 (7)	0.0411 (6)	−0.0002 (6)	−0.0016 (5)	0.0051 (6)
O7	0.0489 (7)	0.0822 (10)	0.0461 (7)	0.0018 (7)	0.0096 (6)	0.0156 (7)

C1—O1	1.355 (2)	C13—C14	1.380 (2)
C1—C6	1.374 (2)	C13—C19	1.505 (2)
C1—C2	1.403 (2)	C14—H14	0.9300
C2—O2	1.372 (2)	C15—O1	1.429 (2)
C2—C3	1.390 (2)	C15—H15A	0.9600
C3—O3	1.3723 (19)	C15—H15B	0.9600
C3—C4	1.405 (2)	C15—H15C	0.9600
C4—C5	1.403 (2)	C16—O2	1.419 (2)
C4—C10	1.494 (2)	C16—H16A	0.9600
C5—C6	1.393 (2)	C16—H16B	0.9600
C5—C7	1.485 (2)	C16—H16C	0.9600
C6—H6	0.9300	C17—O3	1.428 (2)
C7—O5	1.2245 (19)	C17—H17A	0.9600
C7—C8	1.468 (2)	C17—H17B	0.9600
C8—C14	1.394 (2)	C17—H17C	0.9600
C8—C9	1.409 (2)	C18—O6	1.425 (2)
C9—C11	1.397 (2)	C18—H18A	0.9600
C9—C10	1.499 (2)	C18—H18B	0.9600
C10—O4	1.2144 (19)	C18—H18C	0.9600
C11—O6	1.3699 (18)	C19—H19A	0.9600
C11—C12	1.400 (2)	C19—H19B	0.9600
C12—O7	1.355 (2)	C19—H19C	0.9600
C12—C13	1.395 (2)	O7—H7	0.8200
O1—C1—C6	125.14 (16)	C13—C14—C8	122.57 (15)
O1—C1—C2	115.97 (16)	C13—C14—H14	118.7
C6—C1—C2	118.88 (16)	C8—C14—H14	118.7
O2—C2—C3	118.82 (16)	O1—C15—H15A	109.5
O2—C2—C1	120.56 (16)	O1—C15—H15B	109.5
C3—C2—C1	120.52 (16)	H15A—C15—H15B	109.5
O3—C3—C2	116.80 (15)	O1—C15—H15C	109.5
O3—C3—C4	122.02 (15)	H15A—C15—H15C	109.5
C2—C3—C4	121.13 (15)	H15B—C15—H15C	109.5
C5—C4—C3	117.20 (15)	O2—C16—H16A	109.5
C5—C4—C10	120.50 (14)	O2—C16—H16B	109.5
C3—C4—C10	122.29 (14)	H16A—C16—H16B	109.5
C6—C5—C4	121.45 (15)	O2—C16—H16C	109.5
C6—C5—C7	117.22 (14)	H16A—C16—H16C	109.5
C4—C5—C7	121.32 (15)	H16B—C16—H16C	109.5
C1—C6—C5	120.80 (16)	O3—C17—H17A	109.5
C1—C6—H6	119.6	O3—C17—H17B	109.5
C5—C6—H6	119.6	H17A—C17—H17B	109.5
O5—C7—C8	121.37 (16)	O3—C17—H17C	109.5
O5—C7—C5	120.42 (15)	H17A—C17—H17C	109.5
C8—C7—C5	118.21 (14)	H17B—C17—H17C	109.5
C14—C8—C9	120.37 (15)	O6—C18—H18A	109.5
C14—C8—C7	118.30 (14)	O6—C18—H18B	109.5
C9—C8—C7	121.33 (15)	H18A—C18—H18B	109.5
C11—C9—C8	117.57 (15)	O6—C18—H18C	109.5
C11—C9—C10	121.97 (14)	H18A—C18—H18C	109.5
C8—C9—C10	120.37 (14)	H18B—C18—H18C	109.5
O4—C10—C4	121.60 (15)	C13—C19—H19A	109.5
O4—C10—C9	120.89 (15)	C13—C19—H19B	109.5
C4—C10—C9	117.48 (13)	H19A—C19—H19B	109.5
O6—C11—C9	124.92 (15)	C13—C19—H19C	109.5
O6—C11—C12	114.54 (14)	H19A—C19—H19C	109.5
C9—C11—C12	120.53 (14)	H19B—C19—H19C	109.5
O7—C12—C13	118.00 (15)	C1—O1—C15	118.27 (15)
O7—C12—C11	120.03 (14)	C2—O2—C16	115.05 (15)
C13—C12—C11	121.98 (15)	C3—O3—C17	113.79 (13)
C14—C13—C12	116.89 (15)	C11—O6—C18	113.88 (14)
C14—C13—C19	122.28 (16)	C12—O7—H7	109.5
C12—C13—C19	120.83 (16)

D—H···A	D—H	H···A	D···A	D—H···A
C18—H18A···O4	0.96	2.53	3.074 (3)	116
C17—H17A···O4	0.96	2.60	3.046 (3)	109
C16—H16A···O1	0.96	2.50	3.049 (3)	116
O7—H7···O6	0.82	2.19	2.6482 (17)	116
O7—H7···O3i	0.82	2.02	2.7221 (16)	144

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C18—H18A⋯O4	0.96	2.53	3.074 (3)	116
C17—H17A⋯O4	0.96	2.60	3.046 (3)	109
C16—H16A⋯O1	0.96	2.50	3.049 (3)	116
O7—H7⋯O6	0.82	2.19	2.6482 (17)	116
O7—H7⋯O3i	0.82	2.02	2.7221 (16)	144

Symmetry code: (i) .