Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270112040681/fn3112sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270112040681/fn3112Isup2.hkl | |
MDL mol file https://doi.org/10.1107/S0108270112040681/fn3112Isup3.mol | |
Chemical Markup Language (CML) file https://doi.org/10.1107/S0108270112040681/fn3112Isup4.cml |
CCDC reference: 887700
For related literature, see: Allen (2002); Erdtman & Högberg (1968, 1970); Högberg (1972); Karlsson et al. (1983); Nielsen et al. (2010); Pummerer et al. (1938, 1939); Rathore & Abdelwahed (2004).
The title compound was synthesized following a published procedure (Hogberg, 1972). A solution of aluminium chloride (3.50 g, 26.2 mmol) in freshly distilled nitrobenzene (100 ml) was added to a stirred solution of 1,4-naphthoquinone (3.00 g, 19.0 mmol) in nitrobenzene (150 ml) at 333 K. After stirring for 1 h at 333 K, the reaction mixture was poured into ethanol (1 l). The precipitate was filtered and washed successively with ethanol (400 ml), 2 M hydrochloric acid (400 ml), ethanol (400 ml), pyridine (200 ml) and finally ethanol (200 ml), to give the crude product as a yellowish powder (yield 1.8 g, 68%). A sample (50 mg) was purified by sublimation in a horizontal tube furnace (723 K, 170 µm Hg) to give 11 mg of (I) as a light-yellow crystals. Crystals of (I) suitable for single-crystal X-ray diffraction were selected directly from the sample as prepared.
The structure was solved using direct methods. This procedure yielded a number of the O and C atoms. Subsequent Fourier synthesis yielded the remaining atom positions. The H atoms were fixed in positions of ideal geometry and treated as riding, with C—H = 0.95 Å, and with Uiso(H) = 1.2Ueq(C). [Amended text OK?]
Data collection: APEX2 (Bruker 2007); cell refinement: SAINT (Bruker 2007); data reduction: SAINT (Bruker 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
C40H16O4 | F(000) = 576 |
Mr = 560.53 | Dx = 1.562 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 1241 reflections |
a = 15.592 (3) Å | θ = 2.7–25.4° |
b = 4.3936 (8) Å | µ = 0.10 mm−1 |
c = 17.713 (3) Å | T = 187 K |
β = 100.746 (3)° | Irregular, yellow |
V = 1192.1 (4) Å3 | 0.38 × 0.20 × 0.18 mm |
Z = 2 |
Bruker APEXII CCD area-detector diffractometer | 2117 independent reflections |
Radiation source: fine-focus sealed tube | 1466 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.054 |
ϕ and ω scans | θmax = 25.0°, θmin = 1.6° |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2001) | h = −18→18 |
Tmin = 0.963, Tmax = 0.982 | k = −5→5 |
8923 measured reflections | l = −21→21 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.042 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 0.97 | w = 1/[σ2(Fo2) + (0.0461P)2 + 0.6737P] where P = (Fo2 + 2Fc2)/3 |
2117 reflections | (Δ/σ)max < 0.001 |
199 parameters | Δρmax = 0.20 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
C40H16O4 | V = 1192.1 (4) Å3 |
Mr = 560.53 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 15.592 (3) Å | µ = 0.10 mm−1 |
b = 4.3936 (8) Å | T = 187 K |
c = 17.713 (3) Å | 0.38 × 0.20 × 0.18 mm |
β = 100.746 (3)° |
Bruker APEXII CCD area-detector diffractometer | 2117 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2001) | 1466 reflections with I > 2σ(I) |
Tmin = 0.963, Tmax = 0.982 | Rint = 0.054 |
8923 measured reflections |
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 0.97 | Δρmax = 0.20 e Å−3 |
2117 reflections | Δρmin = −0.21 e Å−3 |
199 parameters |
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 | −0.10332 (9) | 0.4901 (4) | 0.18331 (8) | 0.0250 (4) | |
O2 | 0.17712 (9) | 1.0623 (3) | 0.09905 (8) | 0.0250 (4) | |
C1 | −0.13080 (14) | 0.3288 (5) | 0.11529 (12) | 0.0233 (5) | |
C2 | −0.07813 (14) | 0.3909 (5) | 0.06309 (12) | 0.0223 (5) | |
C3 | −0.01310 (14) | 0.5995 (5) | 0.09933 (12) | 0.0221 (5) | |
C4 | −0.03077 (14) | 0.6531 (5) | 0.17136 (13) | 0.0230 (5) | |
C5 | 0.01945 (14) | 0.8499 (5) | 0.22650 (13) | 0.0235 (5) | |
C6 | 0.00122 (15) | 0.9075 (5) | 0.30021 (13) | 0.0279 (6) | |
H6 | −0.0477 | 0.8139 | 0.3155 | 0.034* | |
C7 | 0.05408 (15) | 1.0987 (6) | 0.35000 (13) | 0.0307 (6) | |
H7 | 0.0410 | 1.1371 | 0.3994 | 0.037* | |
C8 | 0.12686 (15) | 1.2374 (6) | 0.32898 (14) | 0.0315 (6) | |
H8 | 0.1630 | 1.3665 | 0.3645 | 0.038* | |
C9 | 0.14660 (15) | 1.1888 (5) | 0.25737 (13) | 0.0279 (6) | |
H9 | 0.1958 | 1.2861 | 0.2434 | 0.033* | |
C10 | 0.09373 (14) | 0.9942 (5) | 0.20465 (12) | 0.0226 (5) | |
C11 | 0.10960 (14) | 0.9358 (5) | 0.12968 (13) | 0.0233 (5) | |
C12 | 0.05925 (14) | 0.7457 (5) | 0.07765 (12) | 0.0217 (5) | |
C13 | 0.09723 (14) | 0.7503 (5) | 0.00995 (12) | 0.0222 (5) | |
C14 | 0.16743 (14) | 0.9424 (5) | 0.02521 (12) | 0.0230 (5) | |
C15 | 0.22335 (14) | 1.0122 (5) | −0.02711 (12) | 0.0230 (5) | |
C16 | 0.20398 (14) | 0.8695 (5) | −0.10166 (12) | 0.0236 (5) | |
C17 | 0.25848 (15) | 0.9325 (5) | −0.15476 (13) | 0.0280 (6) | |
H17 | 0.2467 | 0.8399 | −0.2041 | 0.034* | |
C18 | 0.32821 (15) | 1.1252 (5) | −0.13629 (14) | 0.0302 (6) | |
H18 | 0.3642 | 1.1653 | −0.1729 | 0.036* | |
C19 | 0.34703 (15) | 1.2639 (6) | −0.06371 (14) | 0.0311 (6) | |
H19 | 0.3957 | 1.3966 | −0.0515 | 0.037* | |
C20 | 0.29571 (14) | 1.2093 (5) | −0.01050 (14) | 0.0281 (6) | |
H20 | 0.3090 | 1.3054 | 0.0383 | 0.034* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0276 (9) | 0.0265 (9) | 0.0216 (9) | −0.0025 (7) | 0.0059 (7) | −0.0028 (7) |
O2 | 0.0256 (8) | 0.0292 (9) | 0.0207 (9) | −0.0033 (7) | 0.0053 (6) | −0.0024 (7) |
C1 | 0.0270 (12) | 0.0220 (12) | 0.0199 (12) | 0.0001 (10) | 0.0022 (10) | −0.0001 (9) |
C2 | 0.0232 (12) | 0.0213 (12) | 0.0225 (13) | 0.0010 (10) | 0.0043 (9) | 0.0020 (10) |
C3 | 0.0230 (12) | 0.0226 (12) | 0.0207 (12) | 0.0023 (10) | 0.0039 (9) | 0.0009 (10) |
C4 | 0.0222 (12) | 0.0239 (12) | 0.0233 (13) | 0.0017 (10) | 0.0050 (10) | 0.0027 (10) |
C5 | 0.0238 (12) | 0.0250 (12) | 0.0216 (13) | 0.0042 (10) | 0.0038 (10) | 0.0006 (10) |
C6 | 0.0287 (13) | 0.0295 (14) | 0.0264 (13) | 0.0021 (11) | 0.0073 (10) | 0.0002 (11) |
C7 | 0.0323 (13) | 0.0384 (15) | 0.0218 (13) | 0.0044 (12) | 0.0057 (10) | −0.0050 (11) |
C8 | 0.0319 (13) | 0.0347 (15) | 0.0256 (14) | 0.0010 (12) | −0.0010 (10) | −0.0076 (11) |
C9 | 0.0267 (13) | 0.0306 (13) | 0.0254 (13) | 0.0011 (11) | 0.0025 (10) | −0.0018 (11) |
C10 | 0.0243 (12) | 0.0227 (12) | 0.0201 (12) | 0.0038 (10) | 0.0021 (9) | −0.0003 (9) |
C11 | 0.0230 (12) | 0.0242 (12) | 0.0230 (12) | 0.0006 (10) | 0.0051 (9) | 0.0017 (10) |
C12 | 0.0227 (12) | 0.0206 (12) | 0.0211 (12) | 0.0036 (10) | 0.0027 (9) | 0.0019 (9) |
C13 | 0.0236 (12) | 0.0218 (12) | 0.0208 (13) | 0.0014 (10) | 0.0031 (9) | 0.0025 (10) |
C14 | 0.0276 (12) | 0.0231 (12) | 0.0180 (12) | 0.0033 (10) | 0.0040 (9) | 0.0001 (10) |
C15 | 0.0230 (11) | 0.0217 (12) | 0.0234 (13) | 0.0026 (10) | 0.0022 (9) | 0.0036 (10) |
C16 | 0.0236 (12) | 0.0248 (13) | 0.0221 (12) | 0.0034 (10) | 0.0038 (10) | 0.0036 (10) |
C17 | 0.0296 (13) | 0.0297 (14) | 0.0249 (13) | 0.0019 (11) | 0.0056 (10) | 0.0021 (10) |
C18 | 0.0314 (13) | 0.0323 (14) | 0.0295 (14) | −0.0017 (11) | 0.0129 (11) | 0.0052 (11) |
C19 | 0.0282 (13) | 0.0310 (14) | 0.0346 (15) | −0.0069 (11) | 0.0069 (11) | 0.0021 (11) |
C20 | 0.0282 (13) | 0.0280 (13) | 0.0273 (14) | −0.0012 (11) | 0.0033 (10) | 0.0013 (10) |
O1—C4 | 1.388 (3) | C9—C10 | 1.413 (3) |
O1—C1 | 1.395 (3) | C9—H9 | 0.9500 |
O2—C11 | 1.387 (3) | C10—C11 | 1.419 (3) |
O2—C14 | 1.392 (3) | C11—C12 | 1.376 (3) |
C1—C2 | 1.374 (3) | C12—C13 | 1.433 (3) |
C1—C16i | 1.420 (3) | C13—C14 | 1.369 (3) |
C2—C13i | 1.416 (3) | C13—C2i | 1.416 (3) |
C2—C3 | 1.427 (3) | C14—C15 | 1.419 (3) |
C3—C4 | 1.375 (3) | C15—C20 | 1.409 (3) |
C3—C12 | 1.412 (3) | C15—C16 | 1.442 (3) |
C4—C5 | 1.425 (3) | C16—C17 | 1.407 (3) |
C5—C6 | 1.410 (3) | C16—C1i | 1.420 (3) |
C5—C10 | 1.435 (3) | C17—C18 | 1.369 (3) |
C6—C7 | 1.375 (3) | C17—H17 | 0.9500 |
C6—H6 | 0.9500 | C18—C19 | 1.404 (3) |
C7—C8 | 1.398 (3) | C18—H18 | 0.9500 |
C7—H7 | 0.9500 | C19—C20 | 1.367 (3) |
C8—C9 | 1.376 (3) | C19—H19 | 0.9500 |
C8—H8 | 0.9500 | C20—H20 | 0.9500 |
C4—O1—C1 | 104.97 (16) | C11—C10—C5 | 117.55 (19) |
C11—O2—C14 | 104.99 (17) | C12—C11—O2 | 111.16 (19) |
C2—C1—O1 | 110.76 (19) | C12—C11—C10 | 124.0 (2) |
C2—C1—C16i | 124.7 (2) | O2—C11—C10 | 124.8 (2) |
O1—C1—C16i | 124.49 (19) | C11—C12—C3 | 118.6 (2) |
C1—C2—C13i | 118.5 (2) | C11—C12—C13 | 106.18 (19) |
C1—C2—C3 | 106.77 (19) | C3—C12—C13 | 135.2 (2) |
C13i—C2—C3 | 134.7 (2) | C14—C13—C2i | 118.4 (2) |
C4—C3—C12 | 118.9 (2) | C14—C13—C12 | 106.47 (19) |
C4—C3—C2 | 106.19 (19) | C2i—C13—C12 | 135.2 (2) |
C12—C3—C2 | 134.9 (2) | C13—C14—O2 | 111.20 (18) |
C3—C4—O1 | 111.29 (19) | C13—C14—C15 | 124.8 (2) |
C3—C4—C5 | 124.1 (2) | O2—C14—C15 | 124.0 (2) |
O1—C4—C5 | 124.61 (19) | C20—C15—C14 | 124.2 (2) |
C6—C5—C4 | 124.3 (2) | C20—C15—C16 | 118.8 (2) |
C6—C5—C10 | 118.8 (2) | C14—C15—C16 | 117.1 (2) |
C4—C5—C10 | 116.8 (2) | C17—C16—C1i | 125.0 (2) |
C7—C6—C5 | 120.2 (2) | C17—C16—C15 | 118.5 (2) |
C7—C6—H6 | 119.9 | C1i—C16—C15 | 116.54 (19) |
C5—C6—H6 | 119.9 | C18—C17—C16 | 120.9 (2) |
C6—C7—C8 | 121.0 (2) | C18—C17—H17 | 119.6 |
C6—C7—H7 | 119.5 | C16—C17—H17 | 119.6 |
C8—C7—H7 | 119.5 | C17—C18—C19 | 120.6 (2) |
C9—C8—C7 | 120.6 (2) | C17—C18—H18 | 119.7 |
C9—C8—H8 | 119.7 | C19—C18—H18 | 119.7 |
C7—C8—H8 | 119.7 | C20—C19—C18 | 120.4 (2) |
C8—C9—C10 | 120.0 (2) | C20—C19—H19 | 119.8 |
C8—C9—H9 | 120.0 | C18—C19—H19 | 119.8 |
C10—C9—H9 | 120.0 | C19—C20—C15 | 120.9 (2) |
C9—C10—C11 | 123.1 (2) | C19—C20—H20 | 119.6 |
C9—C10—C5 | 119.3 (2) | C15—C20—H20 | 119.6 |
Symmetry code: (i) −x, −y+1, −z. |
Experimental details
Crystal data | |
Chemical formula | C40H16O4 |
Mr | 560.53 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 187 |
a, b, c (Å) | 15.592 (3), 4.3936 (8), 17.713 (3) |
β (°) | 100.746 (3) |
V (Å3) | 1192.1 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.38 × 0.20 × 0.18 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Bruker, 2001) |
Tmin, Tmax | 0.963, 0.982 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8923, 2117, 1466 |
Rint | 0.054 |
(sin θ/λ)max (Å−1) | 0.596 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.106, 0.97 |
No. of reflections | 2117 |
No. of parameters | 199 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.20, −0.21 |
Computer programs: APEX2 (Bruker 2007), SAINT (Bruker 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999), SHELXTL (Sheldrick, 2008).
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It has been known for a long time that the treatment of quinones with acid produces oligomeric products (Pummerer et al., 1938; Pummerer et al. 1939). These reactions, especially those producing interesting cyclooligomers, were studied in some detail by the group of Erdtman and Högberg (Erdtman & Högberg, 1968, 1970; Högberg, 1972). More recently, these highly conjugated and planar tetrameric cyclooligomers (derivatives of tetraoxa[8]circulene, including those with substituents about the periphery) have been promoted as substrates for electrooptic applications (Rathore & Abdelwahed, 2004; Nielsen et al., 2010).
Surprisingly, in spite of the growing interest in this family of compounds in electrooptic materials, little is known about their solid-state structures. In an effort to generate additional candidates for materials applications, the synthesis of the title tetrameric cyclooligomer, [C10H4O]4, (I), was undertaken. Compound (I) was isolated as yellow crystals by sublimation in a horizontal tube furnace (723 K, 170 µm Hg). The subsequent solid-state structural characterization is presented here.
The molecular structure of (I) is depicted in Fig. 1. It possesses a crystallographic inversion center at the center of the eight-membered ring. Interatomic distances within (I) are in agreement with literature values [Reference?]. The molecule of (I) is essentially planar, with an r.m.s. deviation of 0.0023 Å for the central C8 ring. This prohibits (I) from having a boat or saddle form.
Crystals of (I) are composed of relatively closely spaced continuous stacks of planar molecules, each slipped relative to neighbors by (0,1,0) with respect to the monoclinic axes. The distance between nearest-neighbor planes is 3.38 (2) Å. The only van der Waals close contacts are between O and H atoms in neighboring stacks, which form a network of molecules, as seen in Fig. 2. More pertinent, perhaps, for electronic applications of (I) are the closest C—C intra-stack contacts of 3.41 (6) Å (slightly larger than twice the van der Waals radius; Standard reference?). There are two such interactions per nearest-neighbor pair within a stack, between the 2- and 5-positions of the two furan rings lying on a line orthogonal to the slip direction (Fig. 3). There are numerous other close C—C contacts between neighbors within a stack (e.g. 26 interactions of less than 3.5 Å). Also of note are several C—O close contacts, the shortest being 3.40 (7) Å (interestingly, even shorter C—O interactions occur between stacks). The relatively short C—C and C—O contacts, along with the favorable π-stacking geometry, make (I) a potentially interesting candidate as an organic semiconductor.
It is interesting to compare the crystal structure of (I) with that of the analogous compound tetraphenyleno[1,16-bcd:4,5-b'c'd':8,9-b''c''d'':12,13-b'''c'''d''']tetrafuran, [C6H20]4, (II), which lacks the four annulated phenyl groups [Cambridge Structural Database (Allen, 2002) refcode TPTFUR20; Karlsson et al., 1983]. Both (I) and (II) crystallize in the monoclinic space group P21/n and possess stacks of molecules, with almost identical π-stacking distances [distance between molecular planes = 3.41 (8) Å in (II) versus 3.38 (2) Å in (I)], close contacts [smallest C—C distances = 3.41 (6) Å in (II) versus 3.41 (3) Å in (I)] and degree of slip stacking (Fig. 4). One difference between the two structures is that, while in (I) the minimum C—C intra-stack distance is between the α and α positions on furan groups, it is between the α and β positions in (II). Overall, however, the internal nature of the stacks themselves in the two structures is extremely similar.
On the other hand, the organization of the stacks relative to each other is quite different for the two compounds (Figs. 2 and 4). In (II) there are elements of four stacks in a conventional unit cell, with the molecular planes of adjacent stacks tilted about 20° relative to each other. In contrast, in (I) there are parts of five stacks in a unit cell, with the central stack at 79.3 (4)° (see Fig. 2). Given the similarity in the intra-stack geometry and the differences in the inter-stack geometry, it is reasonable to conclude that the π-stacking is controlled by the shared core of the two compounds, while the need to accommodate groups external to this component will result in a rearrangement of the stacks relative to each other. Investigation of other compounds with the same core structure will clarify this issue and demonstrate whether materials with (II) as a core generically demonstrate enhanced π-stacking.