(E)-2-Meth-oxy-9-(2-meth-oxy-9H-xanthen-9-yl-idene)-9H-xanthene.

The title compound, C28H20O4, was synthesized by a bimolecular Zn-HCl reduction in glacial acetic acid using the meth-oxy-substituted xanthone as a starting material. The crystal structure shows that the 2,2'-meth-oxy-bixanthenyl-idene unit is an E-type conformation anti-folded conformer. The mol-ecule lies on an inversion center. The meth-oxy group is almost coplanar with the attached benzene ring, with a C-O-C-C torsion angle of 179.38 (14)°.

Related literature

For background to dixanthylidenes, see: Korenstein et al. (1976 ▶); Agranat & Tapuhi (1979 ▶); Mao et al. (2011 ▶). For related structures, see: Mills & Nyburg (1963 ▶); Shi et al. (2012 ▶).

Experimental

Crystal data

C28H20O4

M = 420.28

Monoclinic,

a = 8.5699 (7) Å

b = 7.5200 (6) Å

c = 16.6101 (18) Å

β = 102.682 (7)°

V = 1044.33 (16) Å3

Z = 2

Mo Kα radiation

μ = 0.09 mm−1

T = 291 K

0.42 × 0.40 × 0.32 mm

Data collection

Oxford Diffraction Gemini S Ultra diffractometer

Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007) ▶ T min = 0.964, T max = 0.972

6419 measured reflections

2205 independent reflections

1264 reflections with I > 2σ(I)

R int = 0.029

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.060

S = 1.00

2205 reflections

146 parameters

H-atom parameters constrained

Δρmax = 0.16 e Å−3

Δρmin = −0.17 e Å−3

Data collection: CrysAlis PRO (Oxford Diffraction, 2007 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813017297/zq2201sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813017297/zq2201Isup2.hkl

Click here for additional data file.

Supplementary material file. DOI: 10.1107/S1600536813017297/zq2201Isup3.cml

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

C28H20O4	F(000) = 440
Mr = 420.28	Dx = 1.337 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2041 reflections
a = 8.5699 (7) Å	θ = 2.7–29.1°
b = 7.5200 (6) Å	µ = 0.09 mm−1
c = 16.6101 (18) Å	T = 291 K
β = 102.682 (7)°	Block, colourless
V = 1044.33 (16) Å3	0.42 × 0.40 × 0.32 mm
Z = 2

Oxford Diffraction Gemini S Ultra diffractometer	2205 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1264 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
Detector resolution: 15.9149 pixels mm-1	θmax = 26.7°, θmin = 3.0°
ω scans	h = −10→7
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007)	k = −7→9
Tmin = 0.964, Tmax = 0.972	l = −21→21
6419 measured reflections

Refinement on F2	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.037	w = 1/[σ2(Fo2) + (0.0079P)2 + 0.150P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.060	(Δ/σ)max < 0.001
S = 1.00	Δρmax = 0.16 e Å−3
2205 reflections	Δρmin = −0.17 e Å−3
146 parameters

Experimental. CrysAlisPro, Oxford Diffraction Ltd., Version 1.171.33.34d (release 27-02-2009 CrysAlis171 .NET) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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
O1	0.37126 (14)	−0.03674 (16)	0.29797 (7)	0.0612 (4)
O2	0.15571 (11)	0.62217 (15)	0.36978 (6)	0.0464 (3)
C1	0.4953 (2)	−0.1274 (2)	0.35211 (12)	0.0720 (6)
H1A	0.5140	−0.2396	0.3283	0.108*
H1B	0.4654	−0.1471	0.4038	0.108*
H1C	0.5912	−0.0572	0.3611	0.108*
C2	0.32826 (18)	0.1287 (2)	0.32026 (10)	0.0419 (4)
C3	0.20616 (18)	0.2107 (2)	0.26345 (10)	0.0471 (4)
H3	0.1611	0.1537	0.2141	0.057*
C4	0.15201 (17)	0.3756 (2)	0.27995 (10)	0.0453 (4)
H4	0.0692	0.4298	0.2424	0.054*
C5	0.22169 (16)	0.4607 (2)	0.35303 (9)	0.0381 (4)
C6	0.34973 (16)	0.3863 (2)	0.40865 (9)	0.0335 (4)
C7	0.39884 (17)	0.2148 (2)	0.39259 (9)	0.0374 (4)
H7	0.4793	0.1586	0.4308	0.045*
C8	0.42069 (14)	0.49291 (19)	0.48303 (9)	0.0331 (4)
C9	0.29155 (16)	0.58847 (19)	0.51278 (9)	0.0340 (4)
C10	0.16438 (17)	0.6537 (2)	0.45337 (10)	0.0389 (4)
C11	0.04103 (17)	0.7507 (2)	0.47368 (11)	0.0484 (5)
H11	−0.0405	0.7970	0.4326	0.058*
C12	0.04121 (19)	0.7774 (2)	0.55581 (11)	0.0501 (5)
H12	−0.0398	0.8441	0.5704	0.060*
C13	0.16141 (18)	0.7056 (2)	0.61689 (11)	0.0466 (4)
H13	0.1593	0.7207	0.6722	0.056*
C14	0.28401 (16)	0.6117 (2)	0.59522 (10)	0.0397 (4)
H14	0.3635	0.5626	0.6365	0.048*

	U11	U22	U33	U12	U13	U23
O1	0.0783 (9)	0.0499 (8)	0.0496 (8)	0.0048 (7)	0.0012 (6)	−0.0137 (7)
O2	0.0441 (7)	0.0518 (7)	0.0374 (7)	0.0114 (6)	−0.0043 (5)	0.0007 (6)
C1	0.0937 (16)	0.0533 (12)	0.0666 (14)	0.0160 (12)	0.0122 (12)	−0.0051 (12)
C2	0.0445 (10)	0.0415 (10)	0.0395 (11)	−0.0044 (8)	0.0088 (8)	−0.0064 (9)
C3	0.0441 (10)	0.0614 (12)	0.0319 (10)	−0.0077 (9)	−0.0003 (7)	−0.0105 (9)
C4	0.0365 (9)	0.0615 (12)	0.0336 (10)	0.0011 (9)	−0.0019 (7)	−0.0005 (9)
C5	0.0331 (9)	0.0438 (10)	0.0356 (10)	−0.0003 (8)	0.0032 (7)	−0.0019 (8)
C6	0.0263 (8)	0.0423 (10)	0.0295 (9)	−0.0025 (7)	0.0010 (6)	−0.0003 (8)
C7	0.0344 (9)	0.0429 (10)	0.0320 (9)	−0.0009 (8)	0.0012 (7)	−0.0002 (8)
C8	0.0326 (8)	0.0341 (9)	0.0299 (9)	0.0004 (7)	0.0007 (6)	0.0020 (7)
C9	0.0300 (9)	0.0343 (10)	0.0362 (10)	−0.0012 (7)	0.0039 (7)	0.0003 (8)
C10	0.0361 (9)	0.0398 (10)	0.0384 (11)	−0.0001 (8)	0.0027 (7)	−0.0014 (8)
C11	0.0351 (10)	0.0475 (11)	0.0581 (12)	0.0091 (8)	0.0003 (8)	0.0009 (10)
C12	0.0409 (10)	0.0473 (11)	0.0640 (14)	0.0060 (8)	0.0159 (9)	−0.0050 (10)
C13	0.0451 (11)	0.0496 (11)	0.0473 (11)	0.0002 (8)	0.0149 (9)	−0.0012 (9)
C14	0.0342 (9)	0.0430 (10)	0.0404 (11)	−0.0020 (8)	0.0047 (7)	0.0020 (9)

O1—C2	1.3716 (18)	C6—C8	1.4865 (19)
O1—C1	1.4086 (19)	C7—H7	0.9300
O2—C5	1.3930 (17)	C8—C8i	1.357 (2)
O2—C10	1.3942 (17)	C8—C9	1.4918 (17)
C1—H1A	0.9600	C9—C10	1.3892 (19)
C1—H1B	0.9600	C9—C14	1.3960 (19)
C1—H1C	0.9600	C10—C11	1.3857 (19)
C2—C7	1.3816 (19)	C11—C12	1.379 (2)
C2—C3	1.390 (2)	C11—H11	0.9300
C3—C4	1.373 (2)	C12—C13	1.387 (2)
C3—H3	0.9300	C12—H12	0.9300
C4—C5	1.3861 (19)	C13—C14	1.3777 (18)
C4—H4	0.9300	C13—H13	0.9300
C5—C6	1.3878 (18)	C14—H14	0.9300
C6—C7	1.400 (2)
C2—O1—C1	118.46 (14)	C2—C7—H7	119.9
C5—O2—C10	114.32 (12)	C6—C7—H7	119.9
O1—C1—H1A	109.5	C8i—C8—C6	125.28 (16)
O1—C1—H1B	109.5	C8i—C8—C9	124.96 (17)
H1A—C1—H1B	109.5	C6—C8—C9	109.71 (11)
O1—C1—H1C	109.5	C10—C9—C14	117.04 (13)
H1A—C1—H1C	109.5	C10—C9—C8	117.27 (13)
H1B—C1—H1C	109.5	C14—C9—C8	125.63 (13)
O1—C2—C7	124.57 (15)	C11—C10—C9	122.30 (15)
O1—C2—C3	115.21 (15)	C11—C10—O2	117.08 (14)
C7—C2—C3	120.22 (15)	C9—C10—O2	120.62 (13)
C4—C3—C2	120.15 (15)	C12—C11—C10	118.85 (15)
C4—C3—H3	119.9	C12—C11—H11	120.6
C2—C3—H3	119.9	C10—C11—H11	120.6
C3—C4—C5	119.50 (15)	C11—C12—C13	120.42 (15)
C3—C4—H4	120.2	C11—C12—H12	119.8
C5—C4—H4	120.2	C13—C12—H12	119.8
C4—C5—C6	121.49 (15)	C14—C13—C12	119.68 (16)
C4—C5—O2	117.49 (14)	C14—C13—H13	120.2
C6—C5—O2	121.00 (14)	C12—C13—H13	120.2
C5—C6—C7	118.14 (14)	C13—C14—C9	121.50 (15)
C5—C6—C8	117.06 (13)	C13—C14—H14	119.3
C7—C6—C8	124.75 (13)	C9—C14—H14	119.3
C2—C7—C6	120.30 (15)
C1—O1—C2—C7	0.3 (2)	C5—C6—C8—C9	37.73 (17)
C1—O1—C2—C3	179.38 (14)	C7—C6—C8—C9	−139.75 (14)
O1—C2—C3—C4	179.07 (13)	C8i—C8—C9—C10	140.63 (19)
C7—C2—C3—C4	−1.8 (2)	C6—C8—C9—C10	−36.97 (18)
C2—C3—C4—C5	1.0 (2)	C8i—C8—C9—C14	−42.2 (3)
C3—C4—C5—C6	2.7 (2)	C6—C8—C9—C14	140.17 (15)
C3—C4—C5—O2	−175.69 (13)	C14—C9—C10—C11	5.3 (2)
C10—O2—C5—C4	147.12 (13)	C8—C9—C10—C11	−177.34 (14)
C10—O2—C5—C6	−31.24 (19)	C14—C9—C10—O2	−174.28 (13)
C4—C5—C6—C7	−5.4 (2)	C8—C9—C10—O2	3.1 (2)
O2—C5—C6—C7	172.91 (12)	C5—O2—C10—C11	−147.58 (13)
C4—C5—C6—C8	176.96 (12)	C5—O2—C10—C9	32.0 (2)
O2—C5—C6—C8	−4.7 (2)	C9—C10—C11—C12	−2.6 (2)
O1—C2—C7—C6	178.01 (13)	O2—C10—C11—C12	176.93 (15)
C3—C2—C7—C6	−1.0 (2)	C10—C11—C12—C13	−1.1 (2)
C5—C6—C7—C2	4.5 (2)	C11—C12—C13—C14	2.1 (2)
C8—C6—C7—C2	−178.03 (13)	C12—C13—C14—C9	0.8 (2)
C5—C6—C8—C8i	−139.87 (19)	C10—C9—C14—C13	−4.3 (2)
C7—C6—C8—C8i	42.7 (3)	C8—C9—C14—C13	178.55 (14)