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In the title compound, C24H48Br2, the molecule is centrosymmetric and the molecular skeleton including both terminal Br atoms has an all-trans conformation. The molecules form layers with a thickness of c/2. These features are similar to the smectic CA phase of liquid crystals.
Supporting information
CCDC reference: 282519
Key indicators
- Single-crystal X-ray study
- T = 296 K
- Mean (C-C) = 0.007 Å
- R factor = 0.056
- wR factor = 0.108
- Data-to-parameter ratio = 16.2
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low ....... 0.96
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical . ?
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 8
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
3 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
0 ALERT type 2 Indicator that the structure model may be wrong or deficient
2 ALERT type 3 Indicator that the structure quality may be low
0 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation,
1992); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: CrystalStructure (Molecular Structure Corporation & Rigaku, 2001); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Watkin et al., 1996); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: CrystalStructure.
1,24-Dibromotetracosane
top
Crystal data top
C24H48Br2 | F(000) = 524.00 |
Mr = 496.45 | Dx = 1.276 Mg m−3 |
Monoclinic, P21/c | Cu Kα radiation, λ = 1.5418 Å |
Hall symbol: -P 2ybc | Cell parameters from 24 reflections |
a = 5.482 (3) Å | θ = 9.2–17.1° |
b = 5.381 (2) Å | µ = 3.99 mm−1 |
c = 43.859 (2) Å | T = 296 K |
β = 93.07 (2)° | Plate, colourless |
V = 1291.9 (9) Å3 | 0.51 × 0.41 × 0.01 mm |
Z = 2 | |
Data collection top
Rigaku AFC-5R diffractometer | Rint = 0.040 |
ω scans | θmax = 70.8° |
Absorption correction: numerical (ABSCOR; Higashi, 1999) | h = −1→6 |
Tmin = 0.175, Tmax = 0.961 | k = −1→6 |
4250 measured reflections | l = −53→53 |
2374 independent reflections | 3 standard reflections every 150 reflections |
1525 reflections with F2 > 2σ(F2) | intensity decay: 14.0% |
Refinement top
Refinement on F2 | w = 1/[0.0001Fo2 + 8.45σ2(Fo) + 0.525]/(4Fo2) |
R[F2 > 2σ(F2)] = 0.056 | (Δ/σ)max < 0.001 |
wR(F2) = 0.108 | Δρmax = 1.07 e Å−3 |
S = 1.00 | Δρmin = −1.26 e Å−3 |
2320 reflections | Extinction correction: Larson (1970) |
143 parameters | Extinction coefficient: 19.0 (2) |
All H-atom parameters refined | |
Special details top
Refinement. Refinement using reflections with F2 > -3.0 σ(F2). The
weighted R-factor (wR) and goodness of fit (S) are based
on F2. R-factor (gt) are based on F. The threshold
expression of F2 > 2.0 σ(F2) is used only for calculating
R-factor (gt). |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Br1 | 1.8638 (1) | −0.8002 (1) | 0.77362 (2) | 0.0798 (2) | |
C1 | 1.686 (1) | −0.510 (1) | 0.7854 (1) | 0.077 (2) | |
C2 | 1.536 (1) | −0.550 (1) | 0.8123 (1) | 0.066 (2) | |
C3 | 1.402 (1) | −0.319 (1) | 0.8212 (1) | 0.068 (2) | |
C4 | 1.249 (1) | −0.357 (1) | 0.8486 (1) | 0.066 (2) | |
C5 | 1.109 (1) | −0.130 (1) | 0.8580 (1) | 0.064 (2) | |
C6 | 0.956 (1) | −0.171 (1) | 0.8856 (1) | 0.065 (2) | |
C7 | 0.813 (1) | 0.056 (1) | 0.8947 (1) | 0.065 (2) | |
C8 | 0.663 (1) | 0.016 (1) | 0.9224 (1) | 0.066 (2) | |
C9 | 0.518 (1) | 0.243 (1) | 0.9313 (1) | 0.064 (2) | |
C10 | 0.368 (1) | 0.202 (1) | 0.9591 (1) | 0.066 (2) | |
C11 | 0.223 (1) | 0.427 (1) | 0.9678 (1) | 0.064 (2) | |
C12 | 0.073 (1) | 0.388 (1) | 0.9957 (1) | 0.064 (2) | |
H1 | 1.800 | −0.381 | 0.7903 | 0.094* | |
H2 | 1.580 | −0.460 | 0.7687 | 0.094* | |
H3 | 1.641 | −0.598 | 0.8292 | 0.080* | |
H4 | 1.422 | −0.680 | 0.8077 | 0.080* | |
H5 | 1.517 | −0.189 | 0.8252 | 0.082* | |
H6 | 1.295 | −0.274 | 0.8043 | 0.082* | |
H7 | 1.357 | −0.402 | 0.8654 | 0.080* | |
H8 | 1.135 | −0.488 | 0.8445 | 0.080* | |
H9 | 1.222 | 0.001 | 0.8624 | 0.077* | |
H10 | 1.002 | −0.083 | 0.8412 | 0.077* | |
H11 | 1.063 | −0.217 | 0.9024 | 0.078* | |
H12 | 0.843 | −0.302 | 0.8812 | 0.078* | |
H13 | 0.926 | 0.186 | 0.8991 | 0.079* | |
H14 | 0.706 | 0.102 | 0.8779 | 0.079* | |
H15 | 0.770 | −0.027 | 0.9393 | 0.079* | |
H16 | 0.552 | −0.117 | 0.9181 | 0.080* | |
H17 | 0.628 | 0.376 | 0.9355 | 0.078* | |
H18 | 0.410 | 0.285 | 0.9144 | 0.078* | |
H19 | 0.476 | 0.159 | 0.9759 | 0.080* | |
H20 | 0.257 | 0.068 | 0.9549 | 0.080* | |
H21 | 0.334 | 0.560 | 0.9718 | 0.078* | |
H22 | 0.115 | 0.469 | 0.9509 | 0.078* | |
H23 | 0.180 | 0.346 | 1.0126 | 0.077* | |
H24 | −0.039 | 0.256 | 0.9917 | 0.077* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Br1 | 0.0911 (5) | 0.0693 (4) | 0.0816 (4) | 0.0100 (5) | 0.0301 (4) | −0.0032 (4) |
C1 | 0.096 (5) | 0.066 (4) | 0.072 (4) | 0.012 (4) | 0.029 (4) | 0.005 (3) |
C2 | 0.078 (4) | 0.058 (4) | 0.063 (4) | 0.012 (3) | 0.016 (3) | −0.002 (3) |
C3 | 0.080 (4) | 0.066 (4) | 0.060 (3) | 0.006 (4) | 0.020 (3) | −0.004 (3) |
C4 | 0.072 (4) | 0.067 (4) | 0.061 (3) | 0.009 (3) | 0.024 (3) | −0.002 (3) |
C5 | 0.073 (4) | 0.065 (4) | 0.054 (3) | 0.007 (3) | 0.019 (3) | −0.003 (3) |
C6 | 0.074 (4) | 0.067 (4) | 0.055 (3) | 0.009 (3) | 0.021 (3) | 0.001 (3) |
C7 | 0.072 (4) | 0.067 (4) | 0.057 (3) | 0.014 (3) | 0.023 (3) | −0.001 (3) |
C8 | 0.081 (4) | 0.066 (4) | 0.052 (3) | 0.009 (3) | 0.016 (3) | −0.002 (3) |
C9 | 0.078 (4) | 0.060 (4) | 0.057 (3) | 0.015 (3) | 0.017 (3) | −0.005 (3) |
C10 | 0.079 (4) | 0.065 (3) | 0.057 (3) | 0.009 (4) | 0.021 (3) | −0.001 (3) |
C11 | 0.074 (4) | 0.061 (4) | 0.059 (3) | 0.015 (3) | 0.018 (3) | −0.003 (3) |
C12 | 0.071 (4) | 0.065 (4) | 0.056 (3) | 0.011 (3) | 0.024 (3) | −0.000 (3) |
Geometric parameters (Å, º) top
Br1—C1 | 1.926 (5) | C4—H7 | 0.95 |
C1—C2 | 1.493 (6) | C4—H8 | 0.950 |
C2—C3 | 1.506 (7) | C5—H9 | 0.950 |
C3—C4 | 1.520 (6) | C5—H10 | 0.95 |
C4—C5 | 1.514 (6) | C6—H11 | 0.95 |
C5—C6 | 1.526 (6) | C6—H12 | 0.950 |
C6—C7 | 1.516 (6) | C7—H13 | 0.950 |
C7—C8 | 1.520 (6) | C7—H14 | 0.95 |
C8—C9 | 1.518 (6) | C8—H15 | 0.95 |
C9—C10 | 1.521 (6) | C8—H16 | 0.950 |
C10—C11 | 1.509 (6) | C9—H17 | 0.950 |
C11—C12 | 1.526 (6) | C9—H18 | 0.95 |
C12—C12i | 1.506 (8) | C10—H19 | 0.95 |
C1—H1 | 0.950 | C10—H20 | 0.950 |
C1—H2 | 0.95 | C11—H21 | 0.950 |
C2—H3 | 0.95 | C11—H22 | 0.95 |
C2—H4 | 0.950 | C12—H23 | 0.95 |
C3—H5 | 0.950 | C12—H24 | 0.950 |
C3—H6 | 0.95 | | |
| | | |
Br1···Br1ii | 3.754 (2) | Br1···Br1iii | 3.754 (2) |
| | | |
Br1—C1—C2 | 113.8 (4) | C6—C5—H10 | 108.1 |
C1—C2—C3 | 112.4 (5) | H9—C5—H10 | 109.5 |
C2—C3—C4 | 112.9 (5) | C5—C6—H11 | 108.1 |
C3—C4—C5 | 114.6 (4) | C7—C6—H11 | 108.3 |
C4—C5—C6 | 113.9 (4) | C5—C6—H12 | 109.1 |
C5—C6—C7 | 113.8 (4) | C7—C6—H12 | 108.0 |
C6—C7—C8 | 114.0 (5) | H11—C6—H12 | 109.5 |
C7—C8—C9 | 114.0 (5) | C6—C7—H13 | 108.0 |
C8—C9—C10 | 113.7 (4) | C8—C7—H13 | 108.3 |
C9—C10—C11 | 113.6 (5) | C6—C7—H14 | 108.3 |
C10—C11—C12 | 114.0 (4) | C8—C7—H14 | 108.7 |
C11—C12—C12i | 114.1 (4) | H13—C7—H14 | 109.4 |
Br1—C1—H1 | 108.7 | C7—C8—H15 | 108.7 |
C2—C1—H1 | 108.0 | C9—C8—H15 | 107.8 |
Br1—C1—H2 | 108.8 | C7—C8—H16 | 108.3 |
C2—C1—H2 | 108.0 | C9—C8—H16 | 108.6 |
H1—C1—H2 | 109.5 | H15—C8—H16 | 109.5 |
C1—C2—H3 | 108.6 | C8—C9—H17 | 108.5 |
C3—C2—H3 | 108.0 | C10—C9—H17 | 108.8 |
C1—C2—H4 | 108.6 | C8—C9—H18 | 107.8 |
C3—C2—H4 | 109.8 | C10—C9—H18 | 108.5 |
H3—C2—H4 | 109.4 | H17—C9—H18 | 109.5 |
C2—C3—H5 | 109.2 | C9—C10—H19 | 108.4 |
C4—C3—H5 | 109.9 | C11—C10—H19 | 108.0 |
C2—C3—H6 | 107.4 | C9—C10—H20 | 108.8 |
C4—C3—H6 | 107.9 | C11—C10—H20 | 108.5 |
C4—C5—H9 | 108.5 | H19—C10—H20 | 109.5 |
H5—C3—H6 | 109.5 | C10—C11—H21 | 108.4 |
C3—C4—H7 | 107.5 | C12—C11—H21 | 108.7 |
C5—C4—H7 | 107.5 | C10—C11—H22 | 107.9 |
C3—C4—H8 | 109.5 | C12—C11—H22 | 108.3 |
C5—C4—H8 | 108.2 | H21—C11—H22 | 109.5 |
H7—C4—H8 | 109.5 | C11—C12—H23 | 108.7 |
C6—C5—H9 | 109.1 | C11—C12—H24 | 109.2 |
C4—C5—H10 | 107.7 | H23—C12—H24 | 109.5 |
| | | |
Br1—C1—C2—C3 | 179.3 (3) | C6—C7—C8—C9 | −179.5 (4) |
C1—C2—C3—C4 | −179.9 (5) | C7—C8—C9—C10 | 180.0 (4) |
C2—C3—C4—C5 | −179.2 (4) | C8—C9—C10—C11 | −179.8 (4) |
C3—C4—C5—C6 | 180.0 (4) | C9—C10—C11—C12 | −179.8 (4) |
C4—C5—C6—C7 | −179.2 (4) | C10—C11—C12—C12i | −179.7 (4) |
C5—C6—C7—C8 | −179.3 (4) | C11—C12—C12i—C11i | 180.0 (4) |
Symmetry codes: (i) −x, −y+1, −z+2; (ii) −x+4, y−1/2, −z+3/2; (iii) −x+4, y+1/2, −z+3/2. |
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