The title compound, C
7H
4Br
2O, has mirror symmetry perpendicular to the tropone ring, and forms a head-to-head association of two nearly parallel molecules. Intermolecular π–π, halogen–halogen and C—H
O interactions are observed in the crystal structure.
Supporting information
CCDC reference: 282553
Key indicators
- Single-crystal X-ray study
- T = 123 K
- Mean (C-C) = 0.002 Å
- R factor = 0.019
- wR factor = 0.047
- Data-to-parameter ratio = 17.2
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT431_ALERT_2_C Short Inter HL..A Contact Br1 .. Br1 .. 3.41 Ang.
PLAT703_ALERT_1_C Torsion Calc 154.5(4), Rep 154.0(10), Dev.. 1.25 Sigma
BR1 -C2 -C1 -BR1 1.555 1.555 1.555 4.555
PLAT733_ALERT_1_C Torsion Calc 154.5(4), Rep 154.0(10) ...... 2.50 su-Rat
BR1 -C2 -C1 -BR1 1.555 1.555 1.555 4.555
PLAT734_ALERT_1_C Contact Calc 2.8068(11), Rep 2.8068(5) ...... 2.20 su-Rat
BR1 -C1 1.555 1.555
PLAT734_ALERT_1_C Contact Calc 2.8068(11), Rep 2.8068(5) ...... 2.20 su-Rat
C1 -BR1 1.555 4.555
PLAT734_ALERT_1_C Contact Calc 3.4115(12), Rep 3.4115(3) ...... 4.00 su-Rat
BR1 -BR1 1.555 3.557
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
6 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
5 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: CrystalClear (Rigaku, 1999); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC & Rigaku, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: program( reference)?; software used to prepare material for publication: CrystalStructure.
Crystal data top
C7H4Br2O | F(000) = 248.00 |
Mr = 263.92 | Dx = 2.416 Mg m−3 |
Monoclinic, P121/m1 | Mo Kα radiation, λ = 0.7107 Å |
Hall symbol: -P 2yb | Cell parameters from 1084 reflections |
a = 4.010 (1) Å | θ = 3.3–27.5° |
b = 14.829 (5) Å | µ = 11.12 mm−1 |
c = 6.111 (2) Å | T = 123 K |
β = 93.274 (2)° | Platelet, yellow |
V = 362.8 (2) Å3 | 0.13 × 0.03 × 0.02 mm |
Z = 2 | |
Data collection top
Rigaku Saturn diffractometer | 684 reflections with F2 > 2σ(F2) |
Detector resolution: 7.31 pixels mm-1 | Rint = 0.031 |
ω scans | θmax = 27.5° |
Absorption correction: multi-scan (Jacobson, 1998) | h = −5→5 |
Tmin = 0.606, Tmax = 0.801 | k = −19→19 |
4008 measured reflections | l = −7→7 |
859 independent reflections | |
Refinement top
Refinement on F2 | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.019 | w = 1/[σ2(Fo2) + (0.0297P)2 + 0.107P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.047 | (Δ/σ)max < 0.001 |
S = 1.04 | Δρmax = 0.64 e Å−3 |
859 reflections | Δρmin = −0.42 e Å−3 |
50 parameters | |
Special details top
Geometry. ENTER SPECIAL DETAILS OF THE MOLECULAR GEOMETRY |
Refinement. Refinement using reflections with F2 > 3.0 σ(F2). The
weighted R-factor(wR), goodness of fit (S) and
R-factor (gt) are based on F, with F set to zero for
negative 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 | 0.12126 (5) | 0.063640 (10) | 0.78602 (3) | 0.01954 (10) | |
O1 | −0.0639 (6) | 0.2500 | 0.8574 (4) | 0.0223 (5) | |
C1 | 0.1221 (7) | 0.2500 | 0.7057 (5) | 0.0145 (6) | |
C2 | 0.2383 (5) | 0.1645 (1) | 0.6136 (3) | 0.0142 (4) | |
C3 | 0.4002 (5) | 0.1454 (1) | 0.4314 (3) | 0.0156 (4) | |
C4 | 0.5244 (5) | 0.2044 (1) | 0.2710 (3) | 0.0167 (4) | |
H1 | 0.4363 | 0.0843 | 0.4069 | 0.019* | |
H2 | 0.6167 | 0.1769 | 0.1519 | 0.020* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Br1 | 0.0250 (1) | 0.0126 (1) | 0.0218 (1) | −0.00130 (8) | 0.00841 (9) | 0.00360 (7) |
O1 | 0.0293 (12) | 0.0190 (11) | 0.0203 (11) | 0.0000 | 0.0150 (9) | 0.0000 |
C1 | 0.0147 (13) | 0.014 (1) | 0.0143 (13) | 0.0000 | 0.0014 (10) | 0.0000 |
C2 | 0.0129 (9) | 0.0136 (9) | 0.0159 (9) | −0.0034 (7) | 0.0003 (7) | 0.0014 (7) |
C3 | 0.0170 (10) | 0.0113 (9) | 0.0187 (10) | −0.0001 (8) | 0.0021 (8) | −0.0015 (8) |
C4 | 0.0180 (9) | 0.0198 (11) | 0.0127 (9) | 0.0010 (8) | 0.0044 (7) | −0.0021 (8) |
Geometric parameters (Å, º) top
Br1—C2 | 1.903 (2) | C3—C4 | 1.425 (3) |
O1—C1 | 1.223 (4) | C4—C4i | 1.352 (3) |
C1—C2 | 1.474 (3) | C3—H1 | 0.9300 |
C1—C2i | 1.474 (3) | C4—H2 | 0.9300 |
C2—C3 | 1.350 (3) | | |
| | | |
Br1···O1 | 2.9010 (7) | Br1···H1xi | 3.3020 |
Br1···C1 | 2.8068 (5) | Br1···H1xii | 3.0971 |
Br1···C3 | 2.774 (2) | Br1···H2iv | 3.5252 |
O1···Br1i | 2.9010 (7) | Br1···H2v | 3.3550 |
O1···C1ii | 3.342 (4) | O1···H2iv | 2.5132 |
O1···C2ii | 3.344 (3) | O1···H2v | 3.3616 |
O1···C2 | 2.346 (3) | O1···H2vi | 2.5132 |
O1···C2iii | 3.344 (3) | O1···H2vii | 3.3616 |
O1···C2i | 2.346 (3) | C1···H1 | 3.3492 |
O1···C4iv | 3.170 (3) | C1···H1i | 3.3492 |
O1···C4v | 3.425 (3) | C1···H2v | 3.4532 |
O1···C4vi | 3.170 (3) | C1···H2vii | 3.4532 |
O1···C4vii | 3.425 (3) | C2···H1ii | 3.5893 |
C1···Br1i | 2.8068 (5) | C2···H1 | 1.9367 |
C1···O1viii | 3.342 (4) | C2···H2 | 3.2842 |
C1···C3 | 2.583 (3) | C2···H2v | 3.5478 |
C1···C3i | 2.583 (3) | C3···H1xii | 3.5967 |
C1···C4ii | 3.540 (3) | C3···H2ii | 3.5207 |
C1···C4 | 3.256 (4) | C3···H2 | 2.0149 |
C1···C4iii | 3.540 (3) | C3···H2i | 3.2847 |
C1···C4i | 3.256 (4) | C4···H1 | 2.0043 |
C2···O1viii | 3.344 (3) | C4···H1i | 3.2649 |
C2···C2i | 2.537 (3) | C4···H2i | 1.9487 |
C2···C3ii | 3.490 (3) | H1···Br1viii | 3.5040 |
C2···C3i | 3.114 (3) | H1···Br1xi | 3.3020 |
C2···C4ii | 3.499 (3) | H1···Br1xii | 3.0971 |
C2···C4 | 2.515 (3) | H1···C2viii | 3.5893 |
C2···C4i | 3.123 (3) | H1···C3xii | 3.5967 |
C3···C2viii | 3.490 (3) | H1···C4i | 3.2649 |
C3···C2i | 3.114 (3) | H2···Br1ix | 3.3550 |
C3···C3i | 3.103 (3) | H2···Br1x | 3.5252 |
C3···C4i | 2.495 (3) | H2···O1ix | 3.3616 |
C4···O1ix | 3.425 (3) | H2···O1x | 2.5132 |
C4···O1x | 3.170 (3) | H2···C1ix | 3.4532 |
C4···C1viii | 3.540 (3) | H2···C2ix | 3.5478 |
C4···C2viii | 3.499 (3) | H2···C3viii | 3.5207 |
C4···C2i | 3.123 (3) | H2···C3i | 3.2847 |
C4···C3i | 2.495 (3) | H2···C4i | 1.9487 |
Br1···H1ii | 3.5040 | Br1···Br1xiii | 3.4115 (3) |
Br1···H1 | 2.7188 | | |
| | | |
Br1—C2—C1 | 111.8 (2) | C2—C3—C4 | 129.9 (2) |
Br1—C2—C3 | 115.9 (2) | C3—C4—C4i | 127.9 (2) |
O1—C1—C2 | 120.6 (1) | C4—C4i—C3i | 127.9 (2) |
O1—C1—C2i | 120.6 (1) | C2—C3—H1 | 115.0374 |
C1—C2—C3 | 132.2 (2) | H1—C3—C4 | 115.0391 |
C2i—C1—C2 | 118.8 (2) | C3—C4—H2 | 116.0533 |
C1—C2i—Br1i | 111.8 (2) | H2—C4—C4i | 116.0481 |
C1—C2i—C3i | 132.2 (2) | C4—C4i—H2i | 116.0481 |
| | | |
O1—C1—C2—Br1 | −9.0 (4) | C3—C2—C1—C2i | −11.8 (5) |
O1—C1—C2—C3 | 169.1 (3) | Br1—C2—C1—Br1i | 154 (1) |
Br1—C2—C3—C4 | −179.2 (2) | C2—C3—C4—C4i | 4.0 (4) |
C1—C2—C3—C4 | 2.8 (4) | | |
Symmetry codes: (i) x, −y+1/2, z; (ii) x−1, y, z; (iii) x−1, −y+1/2, z; (iv) x−1, y, z+1; (v) x, y, z+1; (vi) x−1, −y+1/2, z+1; (vii) x, −y+1/2, z+1; (viii) x+1, y, z; (ix) x, y, z−1; (x) x+1, y, z−1; (xi) −x, −y, −z+1; (xii) −x+1, −y, −z+1; (xiii) −x, −y, −z+2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H2···O1x | 0.93 | 2.51 | 3.170 (3) | 128 |
Symmetry code: (x) x+1, y, z−1. |