Buy article online - an online subscription or single-article purchase is required to access this article.
In the structure of 1,3-dibromoazulene, C10H6Br2, the planar molecule sits on a crystallographic mirror plane. The Br atoms are attached to the five-membered ring adjacent to the ring fusion. Head-to-tail charge-charge interactions due to partial positive charges on ring H atoms and partial negative charges within the aromatic ring system attract adjacent 1,3-dibromoazulene molecules together. This causes them to arrange themselves in a zigzag pattern that allows close packing of the oppositely charged groups.
Supporting information
CCDC reference: 270522
Key indicators
- Single-crystal X-ray study
- T = 100 K
- Mean (C-C) = 0.002 Å
- R factor = 0.016
- wR factor = 0.046
- Data-to-parameter ratio = 16.1
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT431_ALERT_2_C Short Inter HL..A Contact Br1 .. Br1 .. 3.55 Ang.
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
1 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 ALERT type 2 Indicator that the structure model may be wrong or deficient
0 ALERT type 3 Indicator that the structure quality may be low
0 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: SMART (Bruker, 1998); cell refinement: SMART (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 1998); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXTL.
Crystal data top
C10H6Br2 | Dx = 2.093 Mg m−3 |
Mr = 285.97 | Melting point: 76.5 K |
Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2n | Cell parameters from 4195 reflections |
a = 8.3575 (14) Å | θ = 2.7–26.0° |
b = 15.114 (2) Å | µ = 8.87 mm−1 |
c = 7.1840 (12) Å | T = 100 K |
V = 907.4 (2) Å3 | Block, blue |
Z = 4 | 0.28 × 0.20 × 0.20 mm |
F(000) = 544 | |
Data collection top
Bruker APEX diffractometer | 931 independent reflections |
Radiation source: fine-focus sealed tube | 870 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
ω scans | θmax = 26.0°, θmin = 2.7° |
Absorption correction: multi-scan (SADABS; Bruker, 2002) | h = −10→10 |
Tmin = 0.120, Tmax = 0.170 | k = −18→18 |
7311 measured reflections | l = −8→8 |
Refinement top
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)] = 0.016 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.046 | H-atom parameters constrained |
S = 0.96 | w = 1/[σ2(Fo2) + (0.03P)2 + 0.6P] where P = (Fo2 + 2Fc2)/3 |
931 reflections | (Δ/σ)max = 0.001 |
58 parameters | Δρmax = 0.48 e Å−3 |
0 restraints | Δρmin = −0.36 e Å−3 |
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 | x | y | z | Uiso*/Ueq | |
Br1 | 0.46263 (2) | 0.558729 (11) | 0.79056 (2) | 0.02160 (10) | |
C1 | 0.4714 (3) | 0.7500 | 0.8153 (3) | 0.0160 (5) | |
H1 | 0.5204 | 0.7500 | 0.9347 | 0.019* | |
C2 | 0.4286 (2) | 0.67563 (12) | 0.7108 (2) | 0.0157 (4) | |
C3 | 0.36081 (18) | 0.70040 (10) | 0.5410 (2) | 0.0147 (3) | |
C4 | 0.30704 (19) | 0.64441 (11) | 0.4015 (2) | 0.0169 (3) | |
H4 | 0.3153 | 0.5829 | 0.4272 | 0.020* | |
C5 | 0.2426 (2) | 0.66626 (12) | 0.2288 (2) | 0.0202 (4) | |
H5 | 0.2130 | 0.6177 | 0.1522 | 0.024* | |
C6 | 0.2156 (3) | 0.7500 | 0.1533 (3) | 0.0199 (5) | |
H6 | 0.1719 | 0.7500 | 0.0312 | 0.024* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Br1 | 0.02695 (14) | 0.01187 (13) | 0.02598 (15) | 0.00155 (6) | −0.00326 (7) | 0.00492 (6) |
C1 | 0.0167 (12) | 0.0139 (13) | 0.0175 (11) | 0.000 | 0.0004 (9) | 0.000 |
C2 | 0.0171 (8) | 0.0100 (8) | 0.0200 (9) | 0.0008 (7) | 0.0018 (6) | 0.0017 (6) |
C3 | 0.0133 (7) | 0.0109 (9) | 0.0198 (8) | 0.0012 (6) | 0.0023 (6) | 0.0008 (6) |
C4 | 0.0162 (8) | 0.0137 (8) | 0.0208 (8) | −0.0001 (6) | 0.0022 (7) | −0.0005 (6) |
C5 | 0.0181 (8) | 0.0201 (10) | 0.0223 (8) | −0.0016 (8) | −0.0012 (7) | −0.0066 (7) |
C6 | 0.0159 (11) | 0.0292 (14) | 0.0145 (11) | 0.000 | −0.0005 (10) | 0.000 |
Geometric parameters (Å, º) top
Br1—C2 | 1.879 (2) | C4—C5 | 1.392 (2) |
C1—C2 | 1.399 (2) | C4—H4 | 0.9500 |
C1—H1 | 0.9500 | C5—C6 | 1.395 (2) |
C2—C3 | 1.396 (2) | C5—H5 | 0.9500 |
C3—C4 | 1.386 (2) | C6—H6 | 0.9500 |
C3—C3i | 1.499 (2) | | |
| | | |
C2i—C1—C2 | 107.0 (2) | C3—C4—C5 | 128.65 (16) |
C2i—C1—H1 | 126.5 | C3—C4—H4 | 115.7 |
C2—C1—H1 | 126.5 | C5—C4—H4 | 115.7 |
C3—C2—C1 | 110.9 (2) | C4—C5—C6 | 128.62 (18) |
C3—C2—Br1 | 125.45 (13) | C4—C5—H5 | 115.7 |
C1—C2—Br1 | 123.59 (13) | C6—C5—H5 | 115.7 |
C4—C3—C2 | 126.81 (15) | C5i—C6—C5 | 130.2 (2) |
C4—C3—C3i | 127.6 (1) | C5i—C6—H6 | 114.9 |
C2—C3—C3i | 105.56 (10) | C5—C6—H6 | 114.9 |
| | | |
C2i—C1—C2—C3 | 0.6 (3) | Br1—C2—C3—C3i | −179.4 (1) |
C2i—C1—C2—Br1 | 179.63 (7) | C2—C3—C4—C5 | −178.26 (18) |
C1—C2—C3—C4 | 178.89 (17) | C3i—C3—C4—C5 | 0.9 (2) |
Br1—C2—C3—C4 | −0.1 (2) | C3—C4—C5—C6 | −0.2 (3) |
C1—C2—C3—C3i | −0.39 (16) | C4—C5—C6—C5i | −1.1 (5) |
Symmetry code: (i) x, −y+3/2, z. |
Subscribe to Acta Crystallographica Section E: Crystallographic Communications
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.