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A new polymorph of 1,4-di­benzoyl­butane, C18H18O2, has been discovered. Until now only a monoclinic polymorph of the title compound was known. The newly found triclinic polymorph crystallizes in P\overline 1 with half a mol­ecule in the asymmetric unit. The two polymorphs differ slightly in the torsion angles of the central chain.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536804011390/ci6379sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536804011390/ci6379Isup2.hkl
Contains datablock I

CCDC reference: 242333

Key indicators

  • Single-crystal X-ray study
  • T = 173 K
  • Mean [sigma](C-C) = 0.002 Å
  • R factor = 0.036
  • wR factor = 0.096
  • Data-to-parameter ratio = 17.7

checkCIF/PLATON results

No syntax errors found


No errors found in this datablock

Computing details top

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 1990).

(I) top
Crystal data top
C18H18O2Z = 1
Mr = 266.32F(000) = 142
Triclinic, P1Dx = 1.274 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.7482 (12) ÅCell parameters from 4194 reflections
b = 7.6480 (16) Åθ = 3.8–27.7°
c = 8.2817 (15) ŵ = 0.08 mm1
α = 95.413 (16)°T = 173 K
β = 105.265 (15)°Block, colourless
γ = 95.206 (17)°0.52 × 0.29 × 0.27 mm
V = 347.13 (12) Å3
Data collection top
Stoe IPDS-II two-circle
diffractometer
1203 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.040
Graphite monochromatorθmax = 27.8°, θmin = 3.9°
ω scansh = 77
5151 measured reflectionsk = 99
1610 independent reflectionsl = 1010
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.096H-atom parameters constrained
S = 1.08 w = 1/[σ2(Fo2) + (0.0517P)2]
where P = (Fo2 + 2Fc2)/3
1610 reflections(Δ/σ)max < 0.001
91 parametersΔρmax = 0.29 e Å3
0 restraintsΔρmin = 0.17 e Å3
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
xyzUiso*/Ueq
O10.42467 (14)0.26727 (12)0.79614 (10)0.0371 (2)
C10.46452 (18)0.24376 (13)0.51876 (12)0.0251 (2)
C20.60358 (19)0.27709 (15)0.40828 (13)0.0311 (3)
H20.76120.34110.44990.037*
C30.5131 (2)0.21725 (16)0.23728 (14)0.0367 (3)
H30.60860.24080.16230.044*
C40.2847 (2)0.12377 (16)0.17644 (14)0.0354 (3)
H40.22390.08170.05980.042*
C50.1444 (2)0.09121 (15)0.28472 (13)0.0339 (3)
H50.01330.02760.24250.041*
C60.23372 (19)0.15142 (14)0.45531 (13)0.0292 (2)
H60.13620.12930.52930.035*
C70.55417 (18)0.30082 (14)0.70579 (12)0.0259 (2)
C80.80576 (17)0.39905 (14)0.77633 (12)0.0272 (2)
H8A0.81500.50940.72360.033*
H8B0.92450.32550.74580.033*
C90.87631 (18)0.44548 (15)0.96719 (12)0.0282 (2)
H9A0.75260.51290.99900.034*
H9B0.87870.33511.02080.034*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0326 (4)0.0489 (5)0.0288 (4)0.0058 (3)0.0122 (3)0.0016 (3)
C10.0260 (5)0.0240 (5)0.0248 (5)0.0039 (4)0.0059 (4)0.0028 (4)
C20.0263 (5)0.0364 (6)0.0307 (5)0.0010 (4)0.0093 (4)0.0035 (4)
C30.0388 (6)0.0452 (7)0.0297 (5)0.0065 (5)0.0150 (5)0.0059 (5)
C40.0421 (6)0.0379 (6)0.0233 (5)0.0059 (5)0.0049 (4)0.0002 (4)
C50.0321 (5)0.0327 (6)0.0317 (5)0.0018 (4)0.0028 (4)0.0015 (4)
C60.0292 (5)0.0292 (6)0.0290 (5)0.0001 (4)0.0089 (4)0.0037 (4)
C70.0257 (5)0.0263 (5)0.0259 (5)0.0030 (4)0.0076 (4)0.0022 (4)
C80.0239 (5)0.0299 (6)0.0259 (5)0.0003 (4)0.0054 (4)0.0014 (4)
C90.0260 (5)0.0321 (5)0.0251 (5)0.0003 (4)0.0055 (4)0.0032 (4)
Geometric parameters (Å, º) top
O1—C71.2144 (13)C5—C61.3870 (15)
C1—C61.3884 (15)C5—H50.95
C1—C21.3904 (15)C6—H60.95
C1—C71.5055 (14)C7—C81.5074 (14)
C2—C31.3901 (15)C8—C91.5229 (13)
C2—H20.95C8—H8A0.99
C3—C41.3790 (18)C8—H8B0.99
C3—H30.95C9—C9i1.518 (2)
C4—C51.3796 (17)C9—H9A0.99
C4—H40.95C9—H9B0.99
C6—C1—C2118.97 (9)C1—C6—H6119.7
C6—C1—C7118.05 (9)O1—C7—C1119.98 (9)
C2—C1—C7122.97 (9)O1—C7—C8121.52 (9)
C3—C2—C1120.33 (10)C1—C7—C8118.50 (9)
C3—C2—H2119.8C7—C8—C9113.26 (9)
C1—C2—H2119.8C7—C8—H8A108.9
C4—C3—C2120.04 (11)C9—C8—H8A108.9
C4—C3—H3120.0C7—C8—H8B108.9
C2—C3—H3120.0C9—C8—H8B108.9
C3—C4—C5120.12 (10)H8A—C8—H8B107.7
C3—C4—H4119.9C9i—C9—C8111.91 (11)
C5—C4—H4119.9C9i—C9—H9A109.2
C4—C5—C6119.99 (10)C8—C9—H9A109.2
C4—C5—H5120.0C9i—C9—H9B109.2
C6—C5—H5120.0C8—C9—H9B109.2
C5—C6—C1120.55 (10)H9A—C9—H9B107.9
C5—C6—H6119.7
C6—C1—C2—C30.57 (16)C6—C1—C7—O10.70 (15)
C7—C1—C2—C3178.41 (10)C2—C1—C7—O1179.69 (10)
C1—C2—C3—C40.24 (17)C6—C1—C7—C8179.20 (10)
C2—C3—C4—C50.77 (19)C2—C1—C7—C80.21 (14)
C3—C4—C5—C60.48 (18)O1—C7—C8—C91.19 (15)
C4—C5—C6—C10.35 (17)C1—C7—C8—C9178.72 (9)
C2—C1—C6—C50.87 (16)C7—C8—C9—C9i176.29 (11)
C7—C1—C6—C5178.17 (10)
Symmetry code: (i) x+2, y+1, z+2.
 

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