organic compounds
(E)-1,1′-Dibutyl-3,3′-biindolinylidene-2,2′-dione
aCollege of Science, Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, Shanxi Province, People's Republic of China, and bState Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong Province, People's Republic of China
*Correspondence e-mail: yuanms@nwsuaf.edu.cn
In the title molecule, C24H26N2O2, the two indol-2-one units, which are connected by a C=C double bond, are almost coplanar with an interplanar angle of 6.8 (1)°. On cooling from 293 to 120 K, the changes from P21/n to P21. Two intramolecular C—H⋯O hydrogen bonds occur.
Related literature
For uses of isoindigo derivatives as medicines, see: Sassatelli et al. (2004). For the room temperature (293 K) structure, see: Yuan et al. (2007).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2001); cell SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S160053681005066X/jh2237sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053681005066X/jh2237Isup2.hkl
1-Butyl-1H-indole-2,3-dione (1.5 g) and 1-butyl-1H -indole-2-one (1.5 g) were mixed with polyphosphoric acid (15 g), reacted at 333–338 K for 30 min. under N2, and then to 433–442 K with stirring. After 3 h, the mixture was poured into ice water and stirred for 1 h. The solution was extracted in chloroform and dried over Na2SO4. After removing the solvent, the crude product was purified by
on silica gel, eluting with petrol ether, affording the title compound (1.4 g, 47.1%). The compound was dissolved in THF and purple plate title crystals formed on slow evaporation at room temperature.All H atoms were positioned geometrically and allowed to ride on their attached atom. The C—H bond lengths for aromatic, methyl and methene groups were set to 0.95, 0.98 and 0.99 Å, respectively.
Isoindigo can be obtained from various natural sources. Its derivatives are usually known as useful medicine (Sassatelli et al., 2004). Recently we have synthesized the title isoindigo derivative and determined its structure at room temperature (293 K) (Yuan et al., 2007). To reduce the disorder of the two butyl groups of the molecule at room temperature, we redetermined the structure at low temperature (120 K). Unexpectedly, we found some changes of the crystal at different temperatures. Here we mainly report the correlation between structures at high and low temperatures.
The band features of the molecule at 120 K are very similar to those at 293 k. For example, the C3—C2═C22—C23 fragment is quite conjugated and exhibits an E configuration, in which the bond lengths are 1.479 (3), 1.373 (3), and 1.477 (3) for C3—C2, C2═C22, and C22—C23, respectively. There are a pair of intramolecular hydrogen bonds C4—H4···O2 and C24—H24···O1 (see Fig. 1).
The cell parameters of the compound at 293 K and 120 K are very close. The cell volumn 1005.32 (4) Å3 at 293 K slightly shrinks to 966.07 (7) Å3 at 120 K. The
on the molecule is significant that the severely disordered terminal C atoms of the two butyl groups at 293 K become completely ordered at 120 k and all the atomic displacement parameters are greatly reduced.At 293 K, the molecule is centrosymmetric and has a perfect planarity. At 120 K, however, the centrosymmetry is borken and a dihedral angle of 6.8 (1) ° between the two nine-membered indole planes are developed. Consequently, molecular
is produced, which brings the to the crystal. Meanwhile, the of the crystal changed from P21/n to P21.For uses of isoindigo derivatives as medicines, see: Sassatelli et al. (2004). For the room temperature (293 K) structure, see: Yuan et al. (2007).
Data collection: SMART (Bruker, 2001); cell
SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 30% probability level. | |
Fig. 2. An a axis view of the molecular packing of (I) at 120 K. |
C24H26N2O2 | F(000) = 400 |
Mr = 374.47 | Dx = 1.287 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 3669 reflections |
a = 8.9224 (3) Å | θ = 2.7–30.0° |
b = 11.9605 (5) Å | µ = 0.08 mm−1 |
c = 9.6827 (4) Å | T = 120 K |
β = 110.782 (1)° | Plank, purple |
V = 966.07 (7) Å3 | 0.20 × 0.11 × 0.09 mm |
Z = 2 |
Bruker SMART 6K CCD area-detector diffractometer | 2926 independent reflections |
Radiation source: fine-focus sealed tube | 2477 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.041 |
Detector resolution: ω pixels mm-1 | θmax = 30.0°, θmin = 2.3° |
φ and ω scans | h = −12→12 |
Absorption correction: multi-scan (SADABS; Bruker, 2006) | k = −16→16 |
Tmin = 0.984, Tmax = 0.993 | l = −13→13 |
13014 measured reflections |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.121 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0708P)2 + 0.1553P] where P = (Fo2 + 2Fc2)/3 |
2926 reflections | (Δ/σ)max = 0.003 |
257 parameters | Δρmax = 0.38 e Å−3 |
1 restraint | Δρmin = −0.22 e Å−3 |
C24H26N2O2 | V = 966.07 (7) Å3 |
Mr = 374.47 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 8.9224 (3) Å | µ = 0.08 mm−1 |
b = 11.9605 (5) Å | T = 120 K |
c = 9.6827 (4) Å | 0.20 × 0.11 × 0.09 mm |
β = 110.782 (1)° |
Bruker SMART 6K CCD area-detector diffractometer | 2926 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2006) | 2477 reflections with I > 2σ(I) |
Tmin = 0.984, Tmax = 0.993 | Rint = 0.041 |
13014 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 1 restraint |
wR(F2) = 0.121 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.38 e Å−3 |
2926 reflections | Δρmin = −0.22 e Å−3 |
257 parameters |
Experimental. The data collection nominally covered full sphere of reciprocal space, by a combination of 3 runs of narrow-frame ω-scans (scan width 0.3° ω, 20 s exposure), every run at a different φ angle. Crystal to detector distance 4.83 cm. |
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. Methyl groups were refined as rigid bodies rotating around C—C bonds, with a common refined U for three H atoms. Other H atoms: riding model. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.5183 (2) | 0.40482 (16) | 0.3409 (2) | 0.0316 (4) | |
O2 | 0.9572 (2) | 0.57182 (16) | 0.1333 (2) | 0.0298 (4) | |
N1 | 0.7459 (2) | 0.30308 (16) | 0.4455 (2) | 0.0223 (4) | |
N2 | 0.7454 (2) | 0.69090 (16) | 0.0617 (2) | 0.0212 (4) | |
C1 | 0.6589 (3) | 0.3867 (2) | 0.3584 (2) | 0.0219 (4) | |
C2 | 0.7669 (2) | 0.44723 (18) | 0.2919 (2) | 0.0192 (4) | |
C3 | 0.9220 (2) | 0.38775 (19) | 0.3518 (2) | 0.0195 (4) | |
C4 | 1.0726 (3) | 0.3982 (2) | 0.3403 (3) | 0.0227 (4) | |
H4 | 1.0912 | 0.4548 | 0.2795 | 0.027* | |
C5 | 1.1959 (3) | 0.3257 (2) | 0.4182 (3) | 0.0266 (5) | |
H5 | 1.2985 | 0.3338 | 0.4103 | 0.032* | |
C6 | 1.1715 (3) | 0.2420 (2) | 0.5069 (3) | 0.0265 (5) | |
H6A | 1.2570 | 0.1932 | 0.5587 | 0.032* | |
C7 | 1.0227 (3) | 0.2291 (2) | 0.5203 (3) | 0.0257 (5) | |
H7 | 1.0049 | 0.1719 | 0.5809 | 0.031* | |
C8 | 0.9016 (3) | 0.30130 (19) | 0.4437 (2) | 0.0210 (4) | |
C9 | 0.6854 (3) | 0.2281 (2) | 0.5331 (2) | 0.0259 (5) | |
H9A | 0.5909 | 0.2631 | 0.5466 | 0.031* | |
H9B | 0.7690 | 0.2188 | 0.6321 | 0.031* | |
C10 | 0.6377 (3) | 0.1131 (2) | 0.4634 (3) | 0.0289 (5) | |
H10A | 0.7291 | 0.0810 | 0.4414 | 0.035* | |
H10B | 0.6157 | 0.0633 | 0.5356 | 0.035* | |
C11 | 0.4915 (3) | 0.1152 (2) | 0.3223 (3) | 0.0330 (5) | |
H11A | 0.4000 | 0.1472 | 0.3440 | 0.040* | |
H11B | 0.5135 | 0.1646 | 0.2496 | 0.040* | |
C12 | 0.4457 (4) | 0.0003 (2) | 0.2548 (3) | 0.0424 (7) | |
H12A | 0.3545 | 0.0068 | 0.1617 | 0.049 (6)* | |
H12B | 0.4161 | −0.0474 | 0.3233 | 0.049 (6)* | |
H12C | 0.5370 | −0.0328 | 0.2358 | 0.049 (6)* | |
C21 | 0.8248 (2) | 0.59781 (19) | 0.1318 (2) | 0.0205 (4) | |
C22 | 0.7168 (2) | 0.53754 (18) | 0.1994 (2) | 0.0193 (4) | |
C23 | 0.5658 (2) | 0.60189 (19) | 0.1468 (2) | 0.0186 (4) | |
C24 | 0.4134 (2) | 0.5911 (2) | 0.1555 (2) | 0.0230 (4) | |
H24 | 0.3907 | 0.5296 | 0.2070 | 0.028* | |
C25 | 0.2947 (3) | 0.6699 (2) | 0.0894 (3) | 0.0243 (5) | |
H25 | 0.1908 | 0.6605 | 0.0940 | 0.029* | |
C26 | 0.3261 (3) | 0.7618 (2) | 0.0169 (2) | 0.0253 (5) | |
H26 | 0.2445 | 0.8158 | −0.0254 | 0.030* | |
C27 | 0.4764 (3) | 0.7760 (2) | 0.0054 (3) | 0.0245 (5) | |
H27 | 0.4993 | 0.8391 | −0.0432 | 0.029* | |
C28 | 0.5909 (2) | 0.69476 (18) | 0.0674 (2) | 0.0199 (4) | |
C29 | 0.8118 (3) | 0.7658 (2) | −0.0215 (2) | 0.0240 (4) | |
H29A | 0.7229 | 0.8062 | −0.0964 | 0.029* | |
H29B | 0.8676 | 0.7207 | −0.0742 | 0.029* | |
C30 | 0.9289 (3) | 0.8506 (2) | 0.0767 (3) | 0.0287 (5) | |
H30A | 1.0197 | 0.8098 | 0.1487 | 0.034* | |
H30B | 0.9724 | 0.8966 | 0.0146 | 0.034* | |
C31 | 0.8570 (3) | 0.9279 (2) | 0.1606 (3) | 0.0321 (5) | |
H31A | 0.8193 | 0.8831 | 0.2279 | 0.039* | |
H31B | 0.7631 | 0.9667 | 0.0898 | 0.039* | |
C32 | 0.9782 (4) | 1.0145 (3) | 0.2504 (3) | 0.0479 (8) | |
H32A | 1.0220 | 1.0551 | 0.1853 | 0.054 (6)* | |
H32B | 0.9249 | 1.0674 | 0.2953 | 0.054 (6)* | |
H32C | 1.0654 | 0.9769 | 0.3283 | 0.054 (6)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0265 (8) | 0.0276 (9) | 0.0468 (11) | 0.0064 (7) | 0.0204 (8) | 0.0120 (8) |
O2 | 0.0262 (8) | 0.0267 (9) | 0.0415 (9) | 0.0058 (7) | 0.0183 (7) | 0.0102 (7) |
N1 | 0.0218 (8) | 0.0200 (9) | 0.0262 (9) | −0.0022 (7) | 0.0100 (7) | 0.0037 (7) |
N2 | 0.0202 (8) | 0.0200 (9) | 0.0245 (9) | 0.0009 (7) | 0.0093 (7) | 0.0034 (7) |
C1 | 0.0236 (10) | 0.0197 (10) | 0.0245 (10) | −0.0014 (9) | 0.0112 (8) | −0.0011 (8) |
C2 | 0.0201 (9) | 0.0160 (9) | 0.0226 (10) | −0.0010 (8) | 0.0091 (7) | −0.0018 (7) |
C3 | 0.0207 (9) | 0.0173 (10) | 0.0195 (9) | −0.0012 (8) | 0.0060 (7) | −0.0011 (8) |
C4 | 0.0226 (9) | 0.0181 (10) | 0.0269 (10) | 0.0000 (9) | 0.0083 (8) | 0.0018 (8) |
C5 | 0.0216 (10) | 0.0267 (12) | 0.0308 (12) | −0.0002 (9) | 0.0084 (9) | 0.0022 (10) |
C6 | 0.0222 (10) | 0.0251 (11) | 0.0284 (11) | 0.0016 (9) | 0.0042 (8) | 0.0046 (9) |
C7 | 0.0252 (11) | 0.0226 (11) | 0.0263 (11) | −0.0017 (9) | 0.0054 (9) | 0.0036 (9) |
C8 | 0.0212 (9) | 0.0190 (10) | 0.0223 (10) | −0.0014 (8) | 0.0071 (7) | −0.0003 (8) |
C9 | 0.0282 (11) | 0.0263 (11) | 0.0243 (10) | −0.0022 (10) | 0.0107 (9) | 0.0059 (9) |
C10 | 0.0314 (11) | 0.0224 (11) | 0.0345 (12) | 0.0002 (10) | 0.0138 (9) | 0.0070 (9) |
C11 | 0.0379 (13) | 0.0232 (11) | 0.0337 (12) | −0.0016 (10) | 0.0077 (10) | 0.0016 (10) |
C12 | 0.0505 (17) | 0.0257 (13) | 0.0462 (16) | −0.0037 (12) | 0.0113 (13) | −0.0035 (11) |
C21 | 0.0221 (9) | 0.0174 (10) | 0.0228 (10) | −0.0009 (8) | 0.0091 (8) | 0.0011 (8) |
C22 | 0.0207 (9) | 0.0164 (9) | 0.0215 (10) | −0.0019 (8) | 0.0083 (7) | −0.0020 (7) |
C23 | 0.0180 (8) | 0.0163 (9) | 0.0200 (9) | 0.0012 (8) | 0.0051 (7) | −0.0016 (7) |
C24 | 0.0214 (10) | 0.0237 (11) | 0.0251 (10) | −0.0021 (9) | 0.0097 (8) | 0.0000 (8) |
C25 | 0.0208 (10) | 0.0249 (12) | 0.0276 (11) | −0.0008 (9) | 0.0091 (8) | −0.0003 (9) |
C26 | 0.0232 (10) | 0.0257 (11) | 0.0261 (10) | 0.0054 (9) | 0.0076 (8) | 0.0030 (9) |
C27 | 0.0232 (10) | 0.0225 (11) | 0.0274 (10) | 0.0025 (9) | 0.0083 (8) | 0.0047 (9) |
C28 | 0.0198 (9) | 0.0191 (10) | 0.0205 (9) | −0.0008 (8) | 0.0067 (7) | −0.0017 (8) |
C29 | 0.0255 (10) | 0.0215 (10) | 0.0269 (11) | −0.0010 (9) | 0.0117 (9) | 0.0048 (9) |
C30 | 0.0281 (11) | 0.0249 (11) | 0.0347 (12) | −0.0038 (9) | 0.0129 (9) | 0.0052 (9) |
C31 | 0.0365 (12) | 0.0227 (11) | 0.0361 (13) | −0.0028 (10) | 0.0114 (10) | 0.0009 (9) |
C32 | 0.064 (2) | 0.0330 (15) | 0.0429 (16) | −0.0158 (15) | 0.0146 (14) | −0.0077 (12) |
O1—C1 | 1.224 (3) | C11—H11B | 0.9900 |
O2—C21 | 1.217 (3) | C12—H12A | 0.9801 |
N1—C1 | 1.360 (3) | C12—H12B | 0.9801 |
N1—C8 | 1.396 (3) | C12—H12C | 0.9801 |
N1—C9 | 1.463 (3) | C21—C22 | 1.524 (3) |
N2—C21 | 1.364 (3) | C22—C23 | 1.477 (3) |
N2—C28 | 1.399 (3) | C23—C24 | 1.398 (3) |
N2—C29 | 1.464 (3) | C23—C28 | 1.413 (3) |
C1—C2 | 1.519 (3) | C24—C25 | 1.392 (3) |
C2—C22 | 1.373 (3) | C24—H24 | 0.9500 |
C2—C3 | 1.479 (3) | C25—C26 | 1.386 (3) |
C3—C4 | 1.393 (3) | C25—H25 | 0.9500 |
C3—C8 | 1.417 (3) | C26—C27 | 1.394 (3) |
C4—C5 | 1.394 (3) | C26—H26 | 0.9500 |
C4—H4 | 0.9500 | C27—C28 | 1.383 (3) |
C5—C6 | 1.386 (3) | C27—H27 | 0.9500 |
C5—H5 | 0.9500 | C29—C30 | 1.523 (3) |
C6—C7 | 1.388 (3) | C29—H29A | 0.9900 |
C6—H6A | 0.9500 | C29—H29B | 0.9900 |
C7—C8 | 1.376 (3) | C30—C31 | 1.514 (4) |
C7—H7 | 0.9500 | C30—H30A | 0.9900 |
C9—C10 | 1.525 (3) | C30—H30B | 0.9900 |
C9—H9A | 0.9900 | C31—C32 | 1.528 (4) |
C9—H9B | 0.9900 | C31—H31A | 0.9900 |
C10—C11 | 1.518 (3) | C31—H31B | 0.9900 |
C10—H10A | 0.9900 | C32—H32A | 0.9802 |
C10—H10B | 0.9900 | C32—H32B | 0.9802 |
C11—C12 | 1.513 (4) | C32—H32C | 0.9802 |
C11—H11A | 0.9900 | ||
C1—N1—C8 | 110.82 (18) | C11—C12—H12C | 109.4 |
C1—N1—C9 | 124.27 (18) | H12A—C12—H12C | 109.5 |
C8—N1—C9 | 124.88 (19) | H12B—C12—H12C | 109.5 |
C21—N2—C28 | 110.65 (17) | O2—C21—N2 | 123.0 (2) |
C21—N2—C29 | 122.21 (18) | O2—C21—C22 | 129.3 (2) |
C28—N2—C29 | 126.74 (18) | N2—C21—C22 | 107.66 (17) |
O1—C1—N1 | 123.2 (2) | C2—C22—C23 | 132.94 (19) |
O1—C1—C2 | 129.1 (2) | C2—C22—C21 | 122.89 (18) |
N1—C1—C2 | 107.73 (17) | C23—C22—C21 | 104.12 (18) |
C22—C2—C3 | 132.62 (18) | C24—C23—C28 | 116.8 (2) |
C22—C2—C1 | 122.87 (17) | C24—C23—C22 | 136.0 (2) |
C3—C2—C1 | 104.50 (18) | C28—C23—C22 | 107.22 (18) |
C4—C3—C8 | 117.3 (2) | C25—C24—C23 | 120.5 (2) |
C4—C3—C2 | 136.1 (2) | C25—C24—H24 | 119.7 |
C8—C3—C2 | 106.67 (18) | C23—C24—H24 | 119.7 |
C3—C4—C5 | 120.0 (2) | C26—C25—C24 | 120.8 (2) |
C3—C4—H4 | 120.0 | C26—C25—H25 | 119.6 |
C5—C4—H4 | 120.0 | C24—C25—H25 | 119.6 |
C6—C5—C4 | 121.2 (2) | C25—C26—C27 | 120.7 (2) |
C6—C5—H5 | 119.4 | C25—C26—H26 | 119.7 |
C4—C5—H5 | 119.4 | C27—C26—H26 | 119.7 |
C5—C6—C7 | 120.3 (2) | C28—C27—C26 | 117.6 (2) |
C5—C6—H6A | 119.9 | C28—C27—H27 | 121.2 |
C7—C6—H6A | 119.9 | C26—C27—H27 | 121.2 |
C8—C7—C6 | 118.3 (2) | C27—C28—N2 | 126.3 (2) |
C8—C7—H7 | 120.9 | C27—C28—C23 | 123.57 (19) |
C6—C7—H7 | 120.9 | N2—C28—C23 | 110.10 (18) |
C7—C8—N1 | 126.7 (2) | N2—C29—C30 | 112.71 (18) |
C7—C8—C3 | 123.1 (2) | N2—C29—H29A | 109.0 |
N1—C8—C3 | 110.28 (19) | C30—C29—H29A | 109.0 |
N1—C9—C10 | 113.50 (19) | N2—C29—H29B | 109.0 |
N1—C9—H9A | 108.9 | C30—C29—H29B | 109.0 |
C10—C9—H9A | 108.9 | H29A—C29—H29B | 107.8 |
N1—C9—H9B | 108.9 | C31—C30—C29 | 114.5 (2) |
C10—C9—H9B | 108.9 | C31—C30—H30A | 108.6 |
H9A—C9—H9B | 107.7 | C29—C30—H30A | 108.6 |
C11—C10—C9 | 113.5 (2) | C31—C30—H30B | 108.6 |
C11—C10—H10A | 108.9 | C29—C30—H30B | 108.6 |
C9—C10—H10A | 108.9 | H30A—C30—H30B | 107.6 |
C11—C10—H10B | 108.9 | C30—C31—C32 | 111.7 (2) |
C9—C10—H10B | 108.9 | C30—C31—H31A | 109.3 |
H10A—C10—H10B | 107.7 | C32—C31—H31A | 109.3 |
C12—C11—C10 | 112.8 (2) | C30—C31—H31B | 109.3 |
C12—C11—H11A | 109.0 | C32—C31—H31B | 109.3 |
C10—C11—H11A | 109.0 | H31A—C31—H31B | 107.9 |
C12—C11—H11B | 109.0 | C31—C32—H32A | 109.5 |
C10—C11—H11B | 109.0 | C31—C32—H32B | 109.5 |
H11A—C11—H11B | 107.8 | H32A—C32—H32B | 109.5 |
C11—C12—H12A | 109.5 | C31—C32—H32C | 109.5 |
C11—C12—H12B | 109.5 | H32A—C32—H32C | 109.5 |
H12A—C12—H12B | 109.5 | H32B—C32—H32C | 109.5 |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O2 | 0.95 | 2.05 | 2.815 (3) | 137 |
C24—H24···O1 | 0.95 | 2.04 | 2.805 (3) | 136 |
Experimental details
Crystal data | |
Chemical formula | C24H26N2O2 |
Mr | 374.47 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 120 |
a, b, c (Å) | 8.9224 (3), 11.9605 (5), 9.6827 (4) |
β (°) | 110.782 (1) |
V (Å3) | 966.07 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.20 × 0.11 × 0.09 |
Data collection | |
Diffractometer | Bruker SMART 6K CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2006) |
Tmin, Tmax | 0.984, 0.993 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 13014, 2926, 2477 |
Rint | 0.041 |
(sin θ/λ)max (Å−1) | 0.703 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.121, 1.04 |
No. of reflections | 2926 |
No. of parameters | 257 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.38, −0.22 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O2 | 0.95 | 2.05 | 2.815 (3) | 137 |
C24—H24···O1 | 0.95 | 2.04 | 2.805 (3) | 136 |
Acknowledgements
This work is supported by the National Natural Science Foundation of China (grant Nos. 50673054 and 20972089).
References
Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2006). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Sassatelli, M., Saab, E., Anizon, F., Prudhomme, M. & Moreau, P. (2004). Tetrahedron Lett. 45, 4827–4830. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yuan, M.-S., Fang, Q., Ji, L. & Yu, W.-T. (2007). Acta Cryst. E63, o4342. Web of Science CSD CrossRef IUCr Journals Google Scholar
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Isoindigo can be obtained from various natural sources. Its derivatives are usually known as useful medicine (Sassatelli et al., 2004). Recently we have synthesized the title isoindigo derivative and determined its structure at room temperature (293 K) (Yuan et al., 2007). To reduce the disorder of the two butyl groups of the molecule at room temperature, we redetermined the structure at low temperature (120 K). Unexpectedly, we found some changes of the crystal at different temperatures. Here we mainly report the correlation between structures at high and low temperatures.
The band features of the molecule at 120 K are very similar to those at 293 k. For example, the C3—C2═C22—C23 fragment is quite conjugated and exhibits an E configuration, in which the bond lengths are 1.479 (3), 1.373 (3), and 1.477 (3) for C3—C2, C2═C22, and C22—C23, respectively. There are a pair of intramolecular hydrogen bonds C4—H4···O2 and C24—H24···O1 (see Fig. 1).
The cell parameters of the compound at 293 K and 120 K are very close. The cell volumn 1005.32 (4) Å3 at 293 K slightly shrinks to 966.07 (7) Å3 at 120 K. The temperature effect on the molecule is significant that the severely disordered terminal C atoms of the two butyl groups at 293 K become completely ordered at 120 k and all the atomic displacement parameters are greatly reduced.
At 293 K, the molecule is centrosymmetric and has a perfect planarity. At 120 K, however, the centrosymmetry is borken and a dihedral angle of 6.8 (1) ° between the two nine-membered indole planes are developed. Consequently, molecular chirality is produced, which brings the chirality to the crystal. Meanwhile, the space group of the crystal changed from P21/n to P21.