(1R,2R,5R,6S,9R,10S,13S,14S,18R)-1,6,7,8,9,14,15,16,17,17,18-Undeca­chloro­penta­cyclo­[12.2.1.16,9.02,13.05,10]octa­deca-7,15-diene

Nicole Riddell; Robert McCrindle; Gilles Arsenault; Alan J Lough

doi:10.1107/S160053680801622X

. 2008 Jun 13;64(Pt 7):o1250. doi: 10.1107/S160053680801622X

(1R,2R,5R,6S,9R,10S,13S,14S,18R)-1,6,7,8,9,14,15,16,17,17,18-Undecachloropentacyclo[12.2.1.1^6,9.0^2,13.0^5,10]octadeca-7,15-diene

Nicole Riddell ^a, Robert McCrindle ^b, Gilles Arsenault ^a, Alan J Lough ^c,^*

PMCID: PMC2961815 PMID: 21202884

Abstract

The title compound, C₁₈H₁₃Cl₁₁, is an undecachlorinated commercial flame retardant. The asymmetric unit contains two independent half-molecules. The complete molecules are generated by crystallographic inversion symmetry, causing the terminal H atoms and one of the Cl atoms to be disordered equally over two sites in each molecule. The central eight-membered rings are in chair-type conformations. In the crystal structure, there is a single weak intermolecular C—H⋯Cl hydrogen bond.

Related literature

For related literature, see: Riddell et al. (2008 ▶).

Experimental

Crystal data

C₁₈H₁₃Cl₁₁
M _r = 619.23
Monoclinic,
a = 13.3129 (5) Å
b = 12.1263 (6) Å
c = 14.7229 (7) Å
β = 99.505 (3)°
V = 2344.18 (18) Å³
Z = 4
Mo Kα radiation
μ = 1.31 mm⁻¹
T = 150 (1) K
0.26 × 0.20 × 0.15 mm

Data collection

Bruker–Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1995 ▶) T _min = 0.715, T _max = 0.825
15654 measured reflections
5338 independent reflections
3481 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.118
S = 1.05
5338 reflections
272 parameters
H-atom parameters constrained
Δρ_max = 0.53 e Å⁻³
Δρ_min = −0.68 e Å⁻³

Data collection: COLLECT (Nonius, 2002 ▶); cell refinement: DENZO–SMN (Otwinowski & Minor, 1997 ▶); data reduction: DENZO–SMN; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXTL (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680801622X/pk2101sup1.cif

e-64-o1250-sup1.cif^{(19.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680801622X/pk2101Isup2.hkl

e-64-o1250-Isup2.hkl^{(261.4KB, 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
C1B—H1B⋯Cl4Aⁱ	1.00	2.70	3.656 (4)	160

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors acknowledge NSERC Canada and the University of Toronto for funding.

supplementary crystallographic information

Comment

For background information and related references see the previous paper (Riddell et al., 2008). Dechlorane Plus (DP) is a commercial chlorinated flame retardant used in styrenic plastics (http://www.inchem.org/documents/ehc/ehc/ehc192.htm) to protect human life and property against fires. We have synthesized the dechlorinated compound (1R,2R,5R,6S,9R,10S,13S,14S,18R)-1,6,7,8,9,14,15,16,17,17,18- undecachloropentacyclo[12.2.1.1^6,9.0^2,13.0^5,10]-octadeca-7,15-diene. GC/MS and ¹H NMR spectroscopy have confirmed the basic structure of as having the DP-like structure with only 11 chlorine atoms. An NOE NMR experiment also strongly indicated that the proton on the bridging carbon atom was facing towards the cyclooctadiene ring since a positive through space interaction was observed. However, an X-ray structure determination was required to positively confirm the stereochemistry.

The asymmetric unit contains two independent half molecules. The symmetry complete molecules are generated by crystallographic inversion symmetry, causing atoms Cl6A and Cl6B, as well as the H atoms bonded to C9A and C9B to be disordered over two sites with equal occupancies. In both independent molecules the geometric parameters are the same within experimental error. The asymmetric unit is shown in Fig. 2. In the crystal structure there is a single weak intermolecular C—H···Cl interaction (Table 1).

Experimental

The synthesis of the title compound was carried out at Wellington Laboratories using proprietary methods. The compound was isolated and purified using chromatographic techniques. For single-crystal x-ray crystallography, colourless crystals were grown from a solution in toluene.