2,3-Bis(bromo­meth­yl)-1,4-diphenyl­benzene

Jonathan B Briggs; Mikaël D Jazdzyk; Glen P Miller

doi:10.1107/S1600536809050764

. 2009 Dec 4;66(Pt 1):o12. doi: 10.1107/S1600536809050764

2,3-Bis(bromomethyl)-1,4-diphenylbenzene

Jonathan B Briggs ^a, Mikaël D Jazdzyk ^a, Glen P Miller ^a,^*

PMCID: PMC2980209 PMID: 21580009

Abstract

In the title compound, C₂₀H₁₆Br₂, the terminal phenyl groups are twisted away from the central ring by approximately 55 and −125° (average of four dihedral angles each), respectively. The crystal structure is stabilized by a combination of intermolecular and intramolecular interactions including intermolecular π–π stacking interactions [C atoms of closest contact = 3.423 (5) Å].

Related literature

For the synthesis of terphenyls, see: Ames (1958 ▶). For the synthesis and applications of the title compound, see: Bredow et al. (1970 ▶); Geng et al. (2002 ▶); Martin & Segura (1999 ▶). For related structures, see: Baudour et al. (1986 ▶); Baker et al. (1993 ▶).

Experimental

Crystal data

C₂₀H₁₆Br₂
M _r = 416.15
Monoclinic,
a = 8.8589 (10) Å
b = 11.5859 (13) Å
c = 16.655 (2) Å
β = 102.393 (4)°
V = 1669.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 4.85 mm⁻¹
T = 296 K
0.50 × 0.50 × 0.05 mm

Data collection

Bruker SMART X2S diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.195, T _max = 0.794
10674 measured reflections
2955 independent reflections
2395 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.031
wR(F ²) = 0.117
S = 0.90
2955 reflections
199 parameters
H-atom parameters constrained
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.84 e Å⁻³

Data collection: GIS (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809050764/fl2275sup1.cif

e-66-00o12-sup1.cif^{(18.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809050764/fl2275Isup2.hkl

e-66-00o12-Isup2.hkl^{(145.1KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯Br19	0.93	2.93	3.644 (4)	134
C20—H20A⋯Br19	0.97	2.80	3.563 (4)	136
C14—H14⋯Br20	0.93	2.96	3.704 (4)	139
C19—H19A⋯Br20	0.97	2.80	3.552 (4)	135
C19—H19B⋯Br20ⁱ	0.97	2.98	3.632 (4)	126

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the National Science Foundation for support of this work through the EPSCoR Research Infrastructure Improvement program (NSF 0432060) and the Center for High-rate Nanomanufacturing (NSF EEC-0425826).

supplementary crystallographic information

Comment

For a review on the synthesis of substituted terphenyls see Ames (1958). For the synthesis of the title compound, see Bredow et al. (1970). The title compound has been utilized as a reagent in the synthesis of spiro-configured terfluorenes (Geng et al., 2002) and is a potentially useful precursor to an o-quinodimethane derivative (Martin & Segura, 1999). For related crystal structures, see Baudour et al. (1986); Baker et al. (1993).

We define the three rings of the terphenyl moiety as α, β and γ (Figure 1). Thus, terminal ring α contains C7 – C12, central ring β contains C1 – C6, and terminal ring γ contains C13 – C18. The rotations of ring α and ring γ relative to central ring β are approximately 55 ° and -125 °, respectively.

The rotations of ring α and ring γ are influenced by nearly equivalent sets of intramolecular C–H···π and C–H···Br interactions (Tables 1–2) as illustrated in Figure 2. Each γ ring also engages in a stabilizing, intermolecular π–π stacking interaction (C14···C16, 3.423 (5) Å) with another γ ring, as illustrated in Figure 3. The spacing between π–π stacking γ rings is nearly identical to the 3.435 Å interlayer spacing in graphite suggesting a relatively strong π–π stacking interaction. Likewise, interacting pairs of γ rings lie in near perfect parallel orientations with respect to each other (Figure 3).

There are 3 intermolecular and 4 intramolecular interactions involving Br atoms (Table 2). The intermolecular interactions consist of one significant Br–C interaction (Br19···C6, 3.470 (3) Å), one significant Br–H interaction (Br20···H19B, 2.9788 (5) Å), and one relatively weak Br–Br interaction (Br19···Br20, 3.7743 (7) Å). With regards to intramolecular interactions involving bromine, each bromine atom (i.e., Br19 and Br20) interacts with one methylene hydrogen (Br19···H20A, 2.7993 (5) Å; Br20···H19A, 2.7965 (6) Å) and one aryl hydrogen (Br19···H12, 2.9348 (5) Å; Br20···H14, 2.9559 (6) Å). Both can be viewed as halogen variations of traditional H-bonding, the first set shorter and stronger presumably due to the greater acidity associated with a proton on a benzylic bromide as compared to an aryl proton. An MM2 calculated structure for the title compound (not parameterized for Br···H interactions) indicates much longer Br···H distances (Br19,20···H19A,20 A, 3.14 Å; Br19,20···H12,14 3.79 Å) suggesting that Br···H-bonding in the crystal is both real and stabilizing.

Several intermolecular C–H···π interactions are also observed in the crystal structure (Table 1) but all have H···π distances greater than 3 Å and appear to be relatively weak.

Experimental

The title compound was prepared via the published method (Bredow et al., 1970) as illustrated in Figure 4. ¹H NMR (400 MHz, CDCl₃) δ 4.72 (s, 4H), 7.27 (s, 2H), 7.40–7.54 (m, 10H); ¹³C NMR (100 MHz, CDCl₃) δ 29.2 (CH₂), 128.0 (CH), 128.6 (CH), 129.2 (CH), 131.0 (CH), 135.1 (C), 140.4 (C), 143.7 (C). An X-ray grade crystal was grown from slow evaporation of a saturated chloroform solution.