2,7-Dibromo-9,9-dimethyl-9H-fluorene.

The title mol-ecule, C(15)H(15)Br(2), has crystallographic m2m site symmetry. As a result, all atoms, except for those of the methyl groups, are exactly coplanar. In the crystal structure, there are weak π-π inter-actions with a centroid-centroid distance of 3.8409 (15) Å between symmetry-related mol-ecules, which stack along the c axis.

Related literature

For applications of fluorene derivatives, see: Holder et al. (2005 ▶); Kulkarni et al. (2004 ▶); Padmaperuma et al. (2006 ▶); Seneclauze et al. (2007 ▶); Tsuboyama et al. (2003 ▶). For the properties of fluorene-based mol­ecules, see: Scherf & List (2002 ▶). For the synthesis of the title compound, see: Belfield et al. (2000 ▶).

Experimental

Crystal data

C15H12Br2

M = 352.07

Orthorhombic,

a = 17.097 (4) Å

b = 11.161 (3) Å

c = 6.9120 (17) Å

V = 1319.0 (6) Å3

Z = 4

Mo Kα radiation

μ = 6.12 mm−1

T = 296 K

0.38 × 0.36 × 0.32 mm

Data collection

Bruker SMART CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.083, T max = 1.000

3295 measured reflections

662 independent reflections

499 reflections with I > 2σ(I)

R int = 0.047

Refinement

R[F 2 > 2σ(F 2)] = 0.032

wR(F 2) = 0.085

S = 1.05

662 reflections

54 parameters

H-atom parameters constrained

Δρmax = 0.42 e Å−3

Δρmin = −0.38 e Å−3

Data collection: SMART-NT (Bruker, 1998 ▶); cell refinement: SAINT-NT (Bruker, 1998 ▶); data reduction: SAINT-NT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Berndt, 1999 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810012171/lh5021sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810012171/lh5021Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C15H12Br2	F(000) = 688
Mr = 352.07	Dx = 1.773 Mg m−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2c 2	Cell parameters from 958 reflections
a = 17.097 (4) Å	θ = 2.4–24.1°
b = 11.161 (3) Å	µ = 6.12 mm−1
c = 6.9120 (17) Å	T = 296 K
V = 1319.0 (6) Å3	Block, colourless
Z = 4	0.38 × 0.36 × 0.32 mm

Bruker SMART CCD diffractometer	662 independent reflections
Radiation source: fine-focus sealed tube	499 reflections with I > 2σ(I)
graphite	Rint = 0.047
φ and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −18→20
Tmin = 0.083, Tmax = 1.000	k = −13→11
3295 measured reflections	l = −7→8

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.032	H-atom parameters constrained
wR(F2) = 0.085	w = 1/[σ2(Fo2) + (0.0321P)2 + 2.5078P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max < 0.001
662 reflections	Δρmax = 0.42 e Å−3
54 parameters	Δρmin = −0.38 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0097 (9)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	0.19165 (3)	0.13056 (5)	0.2500	0.0696 (4)
C1	0.3008 (3)	0.0990 (4)	0.2500	0.0416 (11)
C2	0.3248 (3)	−0.0185 (4)	0.2500	0.0407 (12)
H2	0.2883	−0.0804	0.2500	0.049*
C3	0.4037 (3)	−0.0430 (4)	0.2500	0.0373 (11)
H3	0.4210	−0.1220	0.2500	0.045*
C4	0.4574 (3)	0.0500 (3)	0.2500	0.0318 (10)
C5	0.4314 (3)	0.1684 (4)	0.2500	0.0332 (10)
C6	0.3527 (3)	0.1946 (4)	0.2500	0.0392 (11)
H6	0.3350	0.2734	0.2500	0.047*
C7	0.5000	0.2560 (5)	0.2500	0.0373 (15)
C8	0.5000	0.3344 (4)	0.0682 (8)	0.0533 (14)
H8A	0.5000	0.2845	−0.0442	0.080*
H8B	0.5481	0.3785	0.0613	0.080*	0.50
H8C	0.4569	0.3894	0.0736	0.080*	0.50

	U11	U22	U33	U12	U13	U23
Br1	0.0319 (4)	0.0648 (5)	0.1121 (6)	0.0034 (3)	0.000	0.000
C1	0.026 (2)	0.048 (3)	0.051 (3)	0.001 (2)	0.000	0.000
C2	0.038 (3)	0.039 (3)	0.046 (3)	−0.006 (2)	0.000	0.000
C3	0.043 (3)	0.026 (2)	0.043 (3)	−0.0029 (19)	0.000	0.000
C4	0.034 (2)	0.029 (2)	0.033 (2)	0.0008 (18)	0.000	0.000
C5	0.036 (3)	0.028 (2)	0.036 (2)	−0.0029 (19)	0.000	0.000
C6	0.036 (3)	0.031 (2)	0.050 (3)	0.006 (2)	0.000	0.000
C7	0.032 (3)	0.027 (3)	0.053 (4)	0.000	0.000	0.000
C8	0.047 (3)	0.042 (2)	0.071 (4)	0.000	0.000	0.017 (3)

Br1—C1	1.899 (4)	C5—C6	1.377 (6)
C1—C2	1.374 (7)	C5—C7	1.528 (6)
C1—C6	1.388 (7)	C6—H6	0.9300
C2—C3	1.377 (6)	C7—C5i	1.528 (6)
C2—H2	0.9300	C7—C8ii	1.531 (6)
C3—C4	1.386 (6)	C7—C8	1.531 (6)
C3—H3	0.9300	C8—H8A	0.9561
C4—C5	1.394 (6)	C8—H8B	0.9600
C4—C4i	1.457 (9)	C8—H8C	0.9600
C2—C1—C6	122.9 (4)	C5—C6—C1	117.5 (4)
C2—C1—Br1	118.1 (4)	C5—C6—H6	121.2
C6—C1—Br1	119.1 (4)	C1—C6—H6	121.2
C1—C2—C3	118.8 (4)	C5—C7—C5i	100.3 (5)
C1—C2—H2	120.6	C5—C7—C8ii	111.47 (14)
C3—C2—H2	120.6	C5i—C7—C8ii	111.47 (14)
C2—C3—C4	120.0 (4)	C5—C7—C8	111.47 (14)
C2—C3—H3	120.0	C5i—C7—C8	111.47 (14)
C4—C3—H3	120.0	C8ii—C7—C8	110.3 (5)
C3—C4—C5	119.9 (4)	C7—C8—H8A	109.5
C3—C4—C4i	131.5 (2)	C7—C8—H8B	109.5
C5—C4—C4i	108.6 (3)	H8A—C8—H8B	104.9
C6—C5—C4	120.9 (4)	C7—C8—H8C	109.5
C6—C5—C7	127.9 (4)	H8A—C8—H8C	113.8
C4—C5—C7	111.2 (4)	H8B—C8—H8C	109.5
C6—C1—C2—C3	0.0	C7—C5—C6—C1	180.0
Br1—C1—C2—C3	180.0	C2—C1—C6—C5	0.0
C1—C2—C3—C4	0.0	Br1—C1—C6—C5	180.0
C2—C3—C4—C5	0.0	C6—C5—C7—C5i	180.0
C2—C3—C4—C4i	180.0	C4—C5—C7—C5i	0.0
C3—C4—C5—C6	0.0	C6—C5—C7—C8ii	61.9 (3)
C4i—C4—C5—C6	180.0	C4—C5—C7—C8ii	−118.1 (3)
C3—C4—C5—C7	180.0	C6—C5—C7—C8	−61.9 (3)
C4i—C4—C5—C7	0.0	C4—C5—C7—C8	118.1 (3)
C4—C5—C6—C1	0.0