2,3,6,7-Tetra­kis(bromo­meth­yl)naphthalene

Skibiński, M.; Azov, V.A.; Jones, P.G.

doi:10.1107/S1600536810024311

organic compounds

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ISSN: 2056-9890

Volume 66| Part 7| July 2010| Pages o1846-o1847

doi:10.1107/S1600536810024311

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2,3,6,7-Tetrakis(bromomethyl)naphthalene

Maciej Skibiński,^a Vladimir A. Azov ^a and Peter G. Jones ^b ^*

^aDepartment of Chemistry, University of Bremen, Leobener Strasse NW 2C, 28359 Bremen, Germany, and ^bInstitute of Inorganic and Analytical Chemistry, Technical University of Braunschweig, Postfach 3329, 38023 Braunschweig, Germany
^*Correspondence e-mail: p.jones@tu-bs.de

(Received 3 June 2010; accepted 22 June 2010; online 26 June 2010)

The title compound, C₁₄H₁₂Br₄, crystallizes with imposed inversion symmetry. In the crystal, the molecules pack in layers parallel to (10 $[\overline{1}]$ ). The layers involve two Br⋯Br and one H⋯Br contact. Between the layers, one contact each of types Br⋯Br, H⋯Br and Br⋯π is observed.

Related literature

For the use of 2,3,6,7-tetrakis(bromomethyl)naphthalene in the preparation of cyclophanes, see: Otsubo et al. (1983 , 1989 ); Yano et al. (1999 ); Skibiński et al. (2009 ). For its applications in the synthesis of hydrogen-bonded molecular capsules, see: Valdes et al. (1995 ); Rivera et al. (2001 ). For reviews on halogen–halogen contacts and `weak' hydrogen bonding, see: Desiraju & Steiner (1999 ); Metrangolo & Resnati (2001 ); Metrangolo et al. (2008 ); Rissanen (2008 ). For the X-ray structures of the full series of ten isomeric bis(bromomethyl)naphthalenes, see: Jones & Kuś (2010 ). For the X-ray structures of two isomeric tetrakis(bromomethyl)benzene derivatives, see: Jones & Kuś (2007 ).

Experimental

Crystal data

C₁₄H₁₂Br₄
M_r = 499.88
Triclinic, $[P \overline 1]$
a = 6.6144 (2) Å
b = 7.1770 (2) Å
c = 8.7761 (3) Å
α = 84.744 (3)°
β = 78.251 (3)°
γ = 64.555 (3)°
V = 368.32 (2) Å³
Z = 1
Mo Kα radiation
μ = 10.91 mm⁻¹
T = 100 K
0.20 × 0.06 × 0.04 mm

Data collection

Oxford Diffraction Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ) T_min = 0.356, T_max = 1.000
17701 measured reflections
2122 independent reflections
1716 reflections with I > 2σ(I)
R_int = 0.031

Refinement

R[F² > 2σ(F²)] = 0.016
wR(F²) = 0.034
S = 0.92
2122 reflections
82 parameters
H-atom parameters constrained
Δρ_max = 0.50 e Å⁻³
Δρ_min = −0.49 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6A⋯Br2ⁱ	0.99	2.96	3.7967 (17)	143
C6—H6A⋯Br2ⁱⁱ	0.99	2.98	3.7359 (16)	134
C5—H5⋯Br1ⁱⁱⁱ	0.95	3.11	3.9399 (16)	147
Symmetry codes: (i) x, y-1, z; (ii) -x, -y+1, -z+1; (iii) -x+1, -y+1, -z.

Table 2
Bromine–bromine and related contacts and angles (Å, °)

Cg is the centroid of the C1–C5,C1(−x, 1 − y, −z) ring.

System C—Br⋯Br—C or C—Br⋯Cg	Br⋯Br or Br⋯Cg	C—Br⋯Br (or C—Br⋯Cg), Br⋯Br—C	Operator
C6—Br1⋯Br2—C7	3.8972 (3)	76.45 (5), 134.79 (5)	1-x, 1-y, 1-z
C7—Br2⋯Br2—C7	3.8873 (4)	134.93 (5) × 2	-x, 2-y, 1-z
C7—Br2⋯Br2—C7	3.8913 (4)	76.72 (5) × 2	1-x, 1-y, 1-z
C6—Br1⋯Cg	3.89	158	1+x, -1+y, z

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1994 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810024311/fk2020sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810024311/fk2020Isup2.hkl

checkCIF report

Comment top

The title compound is a symmetric rigid molecule with four bromomethyl groups. The bromine atoms can be easily substituted by other nucleophiles, which offers the opportunity of employing the compound as a building block for construction of various functional architectures. The title compound was prepared to serve as a spacer between two tetrathiafulvalene (TTF) groups in TTF-containing molecular tweezers (Skibiński et al., 2009). It was first employed as an intermediate in the preparation of triple-layered [2.2]naphthalenophane (Otsubo et al., 1983), and several other triple-layered cyclophanes (Otsubo et al., 1983; Yano et al., 1999). It was also used as an intermediate in the synthesis of H-bonded molecular capsules (Valdes et al., 1995; Rivera et al., 2001).

The molecule of the title compound is shown in Fig. 1. It displays crystallographic inversion symmetry (operator #1 - x, 1 - y, 1 - z); for this reason, the crystallographic numbering does not correspond to the IUPAC numbering scheme. Bond lengths and angles may be considered normal; the bromine atoms are directed to opposite sides of the ring system, with C(2)—C(3)—C(6)—Br(1) 92.22 (16), C(3)—C(4)—C(7)—Br2 - 79.86 (17)°, which leads to a +/-/-/+ pattern of Br atoms about the ring plane for the IUPAC-numbered C2,3,6,7; this contrasts with the -/-/+/+ pattern in 1,2,4,5-tetrakis(bromomethyl)benzene (Jones & Kuś, 2007), which is also inversion-symmetric.

Details of the packing interactions are given in the Tables. The molecules pack in layers parallel to (101). Within the layers, the contacts Br1···Br2, the longer Br2···Br2 and the shorter H6A···Br2 are observed. These combine to form columns of interactions parallel to the b axis; chains of molecules parallel to [101] (horizontal in Fig. 2) are also formed. The contacts Br2···Br2 (the shorter), H6A···Br2 (the longer) and Br1···Cg (Cg = centre of gravity of the ring C1–5 and C1#1) link the layers (Fig. 3). H5···Br1 3.11 Å between the layers is a borderline interaction. The Br···Cg interaction could alternatively be interpreted as Br···C5, which at 3.450 (2) Å is by far the shortest of the six Br···C contacts; it is often unclear which is the better interpretation in such systems (Jones & Kuś, 2010). Despite the presence of the naphthalene ring systems, there are no significant Cg···Cg interactions. The shortest H···Cg contact is H7A···Cg (1 - x,1 - y,-z) 3.10 Å between layers, but this is both long and has a narrow angle (124°). We can conclude that the crystal packing of the title compound is dominated by the contacts involving bromomethylene groups.

Related literature top

For the use of 2,3,6,7-tetrakis(bromomethyl)naphthalene in the preparation of cyclophanes, see: Otsubo et al. (1983, 1989); Yano et al. (1999); Skibiński et al. (2009). For its applications in the synthesis of hydrogen-bonded molecular capsules, see: Valdes et al. (1995); Rivera et al. (2001). For reviews on halogen–halogen contacts and `weak' hydrogen bonding, see: Desiraju & Steiner (1999); Metrangolo & Resnati (2001); Metrangolo et al. (2008); Rissanen (2008). For the X-ray structures of the full series of ten isomeric bis(bromomethyl)naphthalenes, see: Jones & Kuś (2010). For the X-ray structures of two isomeric tetrakis(bromomethyl)benzene derivatives, see: Jones & Kuś (2007).

Experimental top

The title compound was prepared as described by Rivera et al. (2001) by treatment of a solution of 2,3-bis[{[(1,1-dimethylethyl)dimethylsilyl]oxy}methyl]- 6,7-bis[(phenylmethoxy)methyl]-naphthalene in chloroform with gaseous HBr. The compound was obtained as a colourless microcrystalline solid. Yield: 87%. Crystals suitable for X-ray diffraction were grown by slow evaporation of a solution in EtOH/hexane/CH₂Cl₂. M.p. (decomp.) 230–231° C (lit. 230° C). ¹H NMR (CDCl₃): δ = 7.83 (s, 4H), 4.84 (s, 8H) p.p.m..

The title compound is poorly soluble (< 1 g/L) in most organic solvents at room temperature, but is much more soluble in aromatic solvents, such as toluene or chlorobenzene, upon reflux.

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. Structure of the title compound in the crystal. Ellipsoids represent 50% probability levels. Only the asymmetric unit is numbered.
	Fig. 2. Molecular packing of the title compound as a layer parallel to (101). Br···Br and H···Br contacts are shown as thick dashed bonds.
	Fig. 3. Linking between the layers of the title compound. Br···Br and H···Br contacts are shown as thick dashed bonds. One representative Br···Cg contact is shown as a thin dashed bond (top left).

2,3,6,7-Tetrakis(bromomethyl)naphthalene top

Crystal data top

C₁₄H₁₂Br₄	Z = 1
M_r = 499.88	F(000) = 236
Triclinic, P1	D_x = 2.254 Mg m⁻³
Hall symbol: -P 1	Melting point: 503 K
a = 6.6144 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.1770 (2) Å	Cell parameters from 9533 reflections
c = 8.7761 (3) Å	θ = 2.4–30.7°
α = 84.744 (3)°	µ = 10.91 mm⁻¹
β = 78.251 (3)°	T = 100 K
γ = 64.555 (3)°	Prism, colourless
V = 368.32 (2) Å³	0.20 × 0.06 × 0.04 mm

Data collection top

Oxford Diffraction Xcalibur Eos diffractometer	2122 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1716 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
Detector resolution: 16.1419 pixels mm^-1	θ_max = 30.0°, θ_min = 2.4°
ω–scan	h = −9→9
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −10→10
T_min = 0.356, T_max = 1.000	l = −11→12
17701 measured reflections

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) = 0.034	H-atom parameters constrained
S = 0.92	w = 1/[σ²(F_o²) + (0.0181P)²] where P = (F_o² + 2F_c²)/3
2122 reflections	(Δ/σ)_max = 0.001
82 parameters	Δρ_max = 0.50 e Å⁻³
0 restraints	Δρ_min = −0.49 e Å⁻³

Crystal data top

C₁₄H₁₂Br₄	γ = 64.555 (3)°
M_r = 499.88	V = 368.32 (2) Å³
Triclinic, P1	Z = 1
a = 6.6144 (2) Å	Mo Kα radiation
b = 7.1770 (2) Å	µ = 10.91 mm⁻¹
c = 8.7761 (3) Å	T = 100 K
α = 84.744 (3)°	0.20 × 0.06 × 0.04 mm
β = 78.251 (3)°

Data collection top

Oxford Diffraction Xcalibur Eos diffractometer	2122 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	1716 reflections with I > 2σ(I)
T_min = 0.356, T_max = 1.000	R_int = 0.031
17701 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.016	0 restraints
wR(F²) = 0.034	H-atom parameters constrained
S = 0.92	Δρ_max = 0.50 e Å⁻³
2122 reflections	Δρ_min = −0.49 e Å⁻³
82 parameters

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	U_iso*/U_eq
Br1	0.64988 (3)	−0.00387 (3)	0.24985 (2)	0.01628 (5)
Br2	0.23208 (3)	0.72525 (3)	0.44061 (2)	0.01672 (5)
C1	−0.0170 (3)	0.4100 (3)	0.02483 (19)	0.0108 (3)
C2	0.0922 (3)	0.2877 (3)	0.14549 (19)	0.0122 (3)
H2	0.0699	0.1672	0.1791	0.015*
C3	0.2297 (3)	0.3393 (3)	0.21518 (19)	0.0111 (3)
C4	0.2621 (3)	0.5223 (3)	0.16547 (19)	0.0110 (3)
C5	0.1575 (3)	0.6419 (3)	0.04994 (19)	0.0112 (3)
H5	0.1791	0.7633	0.0185	0.013*
C6	0.3431 (3)	0.2029 (3)	0.34014 (19)	0.0136 (3)
H6A	0.2495	0.1316	0.3945	0.016*
H6B	0.3563	0.2876	0.4173	0.016*
C7	0.4062 (3)	0.5854 (3)	0.24055 (18)	0.0135 (3)
H7A	0.4559	0.6799	0.1704	0.016*
H7B	0.5437	0.4620	0.2592	0.016*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.01360 (10)	0.01494 (10)	0.01724 (10)	−0.00349 (8)	−0.00312 (7)	0.00232 (7)
Br2	0.01615 (10)	0.01865 (11)	0.01468 (9)	−0.00544 (8)	−0.00321 (7)	−0.00581 (7)
C1	0.0099 (8)	0.0112 (9)	0.0093 (8)	−0.0031 (7)	0.0001 (6)	−0.0012 (6)
C2	0.0130 (8)	0.0120 (9)	0.0105 (8)	−0.0053 (7)	0.0000 (7)	−0.0003 (6)
C3	0.0085 (8)	0.0127 (9)	0.0087 (8)	−0.0016 (7)	−0.0006 (6)	−0.0008 (6)
C4	0.0092 (8)	0.0139 (9)	0.0097 (8)	−0.0050 (7)	0.0011 (6)	−0.0040 (6)
C5	0.0111 (8)	0.0104 (8)	0.0120 (8)	−0.0055 (7)	0.0012 (6)	−0.0020 (6)
C6	0.0111 (8)	0.0156 (9)	0.0115 (8)	−0.0033 (7)	−0.0017 (7)	0.0003 (7)
C7	0.0128 (8)	0.0177 (9)	0.0101 (8)	−0.0064 (7)	−0.0017 (7)	−0.0023 (7)

Geometric parameters (Å, º) top

Br1—C6	1.9801 (16)	C4—C7	1.493 (2)
Br2—C7	1.9806 (16)	C5—C1ⁱ	1.422 (2)
C1—C2	1.418 (2)	C2—H2	0.9500
C1—C1ⁱ	1.420 (3)	C5—H5	0.9500
C1—C5ⁱ	1.422 (2)	C6—H6A	0.9900
C2—C3	1.377 (2)	C6—H6B	0.9900
C3—C4	1.436 (2)	C7—H7A	0.9900
C3—C6	1.494 (2)	C7—H7B	0.9900
C4—C5	1.363 (2)

C2—C1—C1ⁱ	118.85 (18)	C1—C2—H2	119.2
C2—C1—C5ⁱ	122.57 (15)	C4—C5—H5	119.0
C1ⁱ—C1—C5ⁱ	118.58 (19)	C1ⁱ—C5—H5	119.0
C3—C2—C1	121.68 (15)	C3—C6—H6A	109.6
C2—C3—C4	119.29 (15)	Br1—C6—H6A	109.6
C2—C3—C6	119.30 (15)	C3—C6—H6B	109.6
C4—C3—C6	121.41 (15)	Br1—C6—H6B	109.6
C5—C4—C3	119.70 (15)	H6A—C6—H6B	108.1
C5—C4—C7	119.52 (15)	C4—C7—H7A	109.6
C3—C4—C7	120.77 (15)	Br2—C7—H7A	109.6
C4—C5—C1ⁱ	121.90 (15)	C4—C7—H7B	109.6
C3—C6—Br1	110.35 (11)	Br2—C7—H7B	109.6
C4—C7—Br2	110.18 (11)	H7A—C7—H7B	108.1
C3—C2—H2	119.2

C1ⁱ—C1—C2—C3	0.0 (3)	C6—C3—C4—C7	−1.7 (2)
C5ⁱ—C1—C2—C3	179.24 (16)	C3—C4—C5—C1ⁱ	−0.5 (2)
C1—C2—C3—C4	0.5 (2)	C7—C4—C5—C1ⁱ	−179.53 (15)
C1—C2—C3—C6	−179.09 (15)	C2—C3—C6—Br1	92.22 (16)
C2—C3—C4—C5	−0.2 (2)	C4—C3—C6—Br1	−87.36 (16)
C6—C3—C4—C5	179.34 (15)	C5—C4—C7—Br2	99.15 (16)
C2—C3—C4—C7	178.76 (15)	C3—C4—C7—Br2	−79.86 (17)

Symmetry code: (i) −x, −y+1, −z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6A···Br2ⁱⁱ	0.99	2.96	3.7967 (17)	143
C6—H6A···Br2ⁱⁱⁱ	0.99	2.98	3.7359 (16)	134
C5—H5···Br1^iv	0.95	3.11	3.9399 (16)	147

Symmetry codes: (ii) x, y−1, z; (iii) −x, −y+1, −z+1; (iv) −x+1, −y+1, −z.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₂Br₄
M_r	499.88
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	6.6144 (2), 7.1770 (2), 8.7761 (3)
α, β, γ (°)	84.744 (3), 78.251 (3), 64.555 (3)
V (Å³)	368.32 (2)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	10.91
Crystal size (mm)	0.20 × 0.06 × 0.04

Data collection
Diffractometer	Oxford Diffraction Xcalibur Eos diffractometer
Absorption correction	Multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)
T_min, T_max	0.356, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	17701, 2122, 1716
R_int	0.031
(sin θ/λ)_max (Å⁻¹)	0.704

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.016, 0.034, 0.92
No. of reflections	2122
No. of parameters	82
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.50, −0.49

Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Siemens, 1994).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6A···Br2ⁱ	0.99	2.96	3.7967 (17)	143.4
C6—H6A···Br2ⁱⁱ	0.99	2.98	3.7359 (16)	134.0
C5—H5···Br1ⁱⁱⁱ	0.95	3.11	3.9399 (16)	147.2

Symmetry codes: (i) x, y−1, z; (ii) −x, −y+1, −z+1; (iii) −x+1, −y+1, −z.

Bromine–bromine and related contacts and angles (Å, °) top

Cg is the centroid of the C1–C5,C1(-x, 1-y, -z) ring.

System C—Br···Br—C or C—Br···Cg	Br···Br or Br···Cg	C—Br···Br (or C—Br···Cg), Br···Br—C	Operator
C6—Br1···Br2—C7	3.8972 (3)	76.45 (5), 134.79 (5)	1-x, 1-y, 1-z
C7—Br2···Br2—C7	3.8873 (4)	134.93 (5) × 2	-x, 2-y, 1-z
C7—Br2···Br2—C7	3.8913 (4)	76.72 (5) × 2	1-x, 1-y, 1-z
C6—Br1···Cg	3.89	158	1+x, -1+y, z

Acknowledgements

We are grateful to Dr P. Kuś, Silesian University, Katowice, Poland, for crystallizing the title compound.

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