The asymmetric unit of the title compound, C
9H
9Br
3, is composed of a single molecule. Two bromo substituents are located on one side of the plane of the aromatic ring and the third is on the opposite side, with the molecular unit exhibiting an approximate noncrystallographic
Cs point group. The crystal structure is rich in Br
Br, CH
2Br and CH
![[pi]](/logos/entities/pi_rmgif.gif)
weak intermolecular contacts which mediate the crystal packing of individual molecules. These interactions promote a red-shift of a handful of vibrational modes (associated with the pendant -CH
2Br groups) compared with values from theoretical density functional theory (DFT) calculations.
Supporting information
CCDC reference: 833415
Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006); data reduction: SAINT-Plus (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
1,3,5-tris(Bromomethyl)benzene
top
Crystal data top
| C9H9Br3 | Z = 2 |
| Mr = 356.89 | F(000) = 336 |
| Triclinic, P1 | Dx = 2.168 Mg m−3 |
| Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
| a = 4.6061 (2) Å | Cell parameters from 4388 reflections |
| b = 8.2473 (2) Å | θ = 2.7–30.3° |
| c = 14.7545 (4) Å | µ = 11.02 mm−1 |
| α = 99.756 (2)° | T = 150 K |
| β = 93.909 (2)° | Block, colourless |
| γ = 96.506 (2)° | 0.12 × 0.04 × 0.03 mm |
| V = 546.64 (3) Å3 | |
Data collection top
Bruker X8 KappaCCD APEXII
diffractometer | 4130 independent reflections |
| Radiation source: fine-focus sealed tube | 2866 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.039 |
| ω and φ scans | θmax = 33.1°, θmin = 4.1° |
Absorption correction: multi-scan
(SADABS; Sheldrick, 1998) | h = −7→7 |
| Tmin = 0.352, Tmax = 0.734 | k = −12→12 |
| 13782 measured reflections | l = −22→22 |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.077 | H-atom parameters constrained |
| S = 1.01 | w = 1/[σ2(Fo2) + (0.0265P)2 + 0.4156P]
where P = (Fo2 + 2Fc2)/3 |
| 4130 reflections | (Δ/σ)max = 0.003 |
| 109 parameters | Δρmax = 1.48 e Å−3 |
| 0 restraints | Δρmin = −1.13 e Å−3 |
Special details top
Geometry. All s.u. (except the s.u. in the dihedral angle between two l.s. planes) are
estimated using the full covariance matrix. The cell s.u. are taken into
account individually in the estimation of s.u. in distances, angles and
torsion angles; correlations between s.u.s in cell parameters are only used when
they are defined by crystal symmetry. An approximate (isotropic) treatment of
cell s.u. is used for estimating s.u. 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 | 0.42572 (8) | 0.25156 (5) | 1.028285 (19) | 0.04581 (10) | |
| Br2 | 0.44135 (7) | 0.29983 (4) | 0.546414 (19) | 0.03728 (9) | |
| Br3 | 0.05600 (6) | −0.42568 (4) | 0.75227 (2) | 0.03895 (9) | |
| C1 | 0.2003 (6) | 0.1775 (3) | 0.83787 (17) | 0.0245 (5) | |
| C2 | 0.3936 (5) | 0.2199 (3) | 0.77418 (17) | 0.0226 (5) | |
| H2 | 0.5144 | 0.3238 | 0.7869 | 0.027* | |
| C3 | 0.4104 (5) | 0.1107 (3) | 0.69209 (16) | 0.0204 (5) | |
| C4 | 0.2333 (5) | −0.0415 (3) | 0.67394 (17) | 0.0228 (5) | |
| H4 | 0.2433 | −0.1159 | 0.6179 | 0.027* | |
| C5 | 0.0403 (5) | −0.0859 (3) | 0.73759 (18) | 0.0234 (5) | |
| C6 | 0.0269 (6) | 0.0241 (3) | 0.81938 (18) | 0.0260 (5) | |
| H6 | −0.1020 | −0.0058 | 0.8631 | 0.031* | |
| C7 | 0.1755 (7) | 0.2959 (4) | 0.9243 (2) | 0.0385 (7) | |
| H7A | −0.0312 | 0.2868 | 0.9393 | 0.046* | |
| H7B | 0.2333 | 0.4105 | 0.9145 | 0.046* | |
| C8 | 0.6170 (6) | 0.1585 (3) | 0.62449 (17) | 0.0253 (5) | |
| H8A | 0.6653 | 0.0573 | 0.5850 | 0.030* | |
| H8B | 0.8013 | 0.2191 | 0.6582 | 0.030* | |
| C9 | −0.1522 (6) | −0.2484 (3) | 0.7179 (2) | 0.0313 (6) | |
| H9A | −0.2193 | −0.2757 | 0.6513 | 0.038* | |
| H9B | −0.3275 | −0.2398 | 0.7528 | 0.038* | |
Atomic displacement parameters (Å2) top| | U11 | U22 | U33 | U12 | U13 | U23 |
| Br1 | 0.0576 (2) | 0.0520 (2) | 0.02446 (14) | −0.00972 (16) | 0.00629 (13) | 0.00734 (14) |
| Br2 | 0.0547 (2) | 0.03606 (17) | 0.02786 (13) | 0.01662 (14) | 0.00969 (12) | 0.01526 (12) |
| Br3 | 0.02925 (15) | 0.01889 (13) | 0.0684 (2) | 0.00009 (11) | −0.00106 (14) | 0.01098 (14) |
| C1 | 0.0247 (13) | 0.0232 (13) | 0.0266 (12) | 0.0043 (10) | 0.0039 (10) | 0.0056 (11) |
| C2 | 0.0214 (12) | 0.0182 (12) | 0.0286 (12) | 0.0026 (9) | 0.0020 (10) | 0.0056 (10) |
| C3 | 0.0189 (11) | 0.0198 (12) | 0.0245 (11) | 0.0041 (9) | 0.0010 (9) | 0.0086 (10) |
| C4 | 0.0239 (12) | 0.0203 (12) | 0.0239 (11) | 0.0050 (10) | −0.0022 (9) | 0.0034 (10) |
| C5 | 0.0180 (11) | 0.0208 (12) | 0.0316 (12) | −0.0001 (9) | −0.0038 (10) | 0.0097 (11) |
| C6 | 0.0219 (12) | 0.0269 (14) | 0.0314 (12) | 0.0023 (10) | 0.0053 (10) | 0.0111 (11) |
| C7 | 0.0419 (17) | 0.0383 (18) | 0.0345 (15) | 0.0070 (14) | 0.0094 (13) | 0.0006 (14) |
| C8 | 0.0262 (13) | 0.0247 (13) | 0.0273 (12) | 0.0046 (10) | 0.0048 (10) | 0.0095 (11) |
| C9 | 0.0253 (13) | 0.0262 (14) | 0.0421 (15) | −0.0040 (11) | −0.0079 (11) | 0.0140 (12) |
Geometric parameters (Å, º) top
| Br1—C7 | 1.965 (3) | C4—H4 | 0.9500 |
| Br2—C8 | 1.970 (2) | C5—C6 | 1.391 (4) |
| Br3—C9 | 1.954 (3) | C5—C9 | 1.494 (4) |
| C1—C6 | 1.392 (4) | C6—H6 | 0.9500 |
| C1—C2 | 1.397 (3) | C7—H7A | 0.9900 |
| C1—C7 | 1.488 (4) | C7—H7B | 0.9900 |
| C2—C3 | 1.394 (3) | C8—H8A | 0.9900 |
| C2—H2 | 0.9500 | C8—H8B | 0.9900 |
| C3—C4 | 1.391 (4) | C9—H9A | 0.9900 |
| C3—C8 | 1.494 (3) | C9—H9B | 0.9900 |
| C4—C5 | 1.401 (4) | | |
| | | |
| C6—C1—C2 | 119.5 (2) | C1—C7—Br1 | 111.5 (2) |
| C6—C1—C7 | 119.9 (2) | C1—C7—H7A | 109.3 |
| C2—C1—C7 | 120.5 (3) | Br1—C7—H7A | 109.3 |
| C3—C2—C1 | 120.4 (2) | C1—C7—H7B | 109.3 |
| C3—C2—H2 | 119.8 | Br1—C7—H7B | 109.3 |
| C1—C2—H2 | 119.8 | H7A—C7—H7B | 108.0 |
| C4—C3—C2 | 119.5 (2) | C3—C8—Br2 | 110.77 (17) |
| C4—C3—C8 | 120.8 (2) | C3—C8—H8A | 109.5 |
| C2—C3—C8 | 119.7 (2) | Br2—C8—H8A | 109.5 |
| C3—C4—C5 | 120.6 (2) | C3—C8—H8B | 109.5 |
| C3—C4—H4 | 119.7 | Br2—C8—H8B | 109.5 |
| C5—C4—H4 | 119.7 | H8A—C8—H8B | 108.1 |
| C6—C5—C4 | 119.3 (2) | C5—C9—Br3 | 111.15 (18) |
| C6—C5—C9 | 120.0 (2) | C5—C9—H9A | 109.4 |
| C4—C5—C9 | 120.7 (2) | Br3—C9—H9A | 109.4 |
| C5—C6—C1 | 120.7 (2) | C5—C9—H9B | 109.4 |
| C5—C6—H6 | 119.6 | Br3—C9—H9B | 109.4 |
| C1—C6—H6 | 119.6 | H9A—C9—H9B | 108.0 |
| | | |
| C6—C1—C2—C3 | 0.9 (4) | C9—C5—C6—C1 | −178.6 (2) |
| C7—C1—C2—C3 | −178.2 (2) | C2—C1—C6—C5 | −1.2 (4) |
| C1—C2—C3—C4 | −0.1 (3) | C7—C1—C6—C5 | 177.9 (2) |
| C1—C2—C3—C8 | 179.6 (2) | C6—C1—C7—Br1 | 85.5 (3) |
| C2—C3—C4—C5 | −0.4 (3) | C2—C1—C7—Br1 | −95.4 (3) |
| C8—C3—C4—C5 | 179.9 (2) | C4—C3—C8—Br2 | 97.1 (2) |
| C3—C4—C5—C6 | 0.1 (4) | C2—C3—C8—Br2 | −82.5 (3) |
| C3—C4—C5—C9 | 179.4 (2) | C6—C5—C9—Br3 | −96.5 (3) |
| C4—C5—C6—C1 | 0.6 (4) | C4—C5—C9—Br3 | 84.3 (3) |
Selected short interactions (Å, °) top| A—B···C | A—B | B···C | A···C | A—B···C | Type of interaction |
| C8—H8B···Cgi | 0.99 | 2.84 | 3.493 (3) | 124 | C—H···π* |
| | | | | |
| C7—H7A···Br1ii | 0.99 | 2.91 | 3.878 (3) | 166 | Weak hydrogen bond |
| C7—H7B···Br1iii | 0.99 | 3.00 | 3.896 (3) | 152 | Short distance |
| C7—H7B···Br3iv | 0.99 | 3.05 | 3.754 (3) | 129 | Short distance |
| C9—H9···Br2v | 0.99 | 2.99 | 3.971 (3) | 171 | Short distance |
| | | | | |
| C7—Br1···Br3vi | 1.954 (3) | 3.8520 (5) | | 148.14 (10) | Undefined Br···Br |
| C9—Br3···Br1vi | 1.965 (3) | 3.8520 (5) | | 109.04 (8) | Undefined Br···Br |
| C8—Br2···Br2vii | 1.970 (2) | 3.7813 (5) | | 144.99 (8) | Type I Br···Br |
| Symmetry codes: (i) x + 1, y, z;
(ii) x - 1, y, z;
(iii) -x + 1, -y + 1, -z + 2;
(iv) x, y + 1, z;
(v) -x, -y, -z + 1;
(vi) -x + 1, -y, -z + 2;
(vii) -x + 1, 1y + 1, -z + 1.
Note: (*) The C—H···(ring plane) angle is 36°. |
Vibrational spectrum and assignment top| Wavenumber (cm-1) | Intensity | Assignment | Wavenumber (cm-1) | Intensity | Assignment |
| 3024 | w | νas(CH2) | 980 | w | δ(Ph) |
| 2972 | w | ν(CH) | 894 | m | γ(CH) |
| 2856 | w | νsym(CH2) | 857 | m | ρ(CH) |
| 1605 | m | ν(Ph) | 704 | s | γ(CH) |
| 1455 | m | a | 663 | m | γ(CH) |
| 1435 | m | a | 634 | m | γ(CH) |
| 1401 | m | a | 582 | s | δ(Ph) |
| 1385 | s | a | 554 | m | b |
| 1213 | m | ω(CH2) | 530 | m | b |
| 1167 | m | δ(CH) | 477 | w | γ(Ph—C) |
| 1120 | m | τ(CH2) | | | |
| Notes: (a) δ(CH2) or [ρ(CH2) + ν(Ph)] (four very close theoretical
vibrational modes); (b) δ(Ph—C) and γ(Ph—C) [two very close theoretical
vibrational modes below δ(Ph)]. |
journal menu
organic compounds
