Chloro­bis­(naphthalen-1-yl)phosphane

Ana Foi; Sebastian A Suarez; Fabio Doctorovich

doi:10.1107/S1600536811033782

. 2011 Aug 31;67(Pt 9):o2524. doi: 10.1107/S1600536811033782

Chlorobis(naphthalen-1-yl)phosphane

Ana Foi ^a, Sebastian A Suarez ^a, Fabio Doctorovich ^a,^*

PMCID: PMC3200679 PMID: 22059061

Abstract

In the title compound, C₂₀H₁₄ClP, the dihedral angle between the naphthyl rings is 81.77 (6)°. The crystal packing suggests weak π–π stacking interactions between the naphthyl rings in adjacent units [minimum ring centroid separation 3.7625 (13) Å].

Related literature

For the structure of a similar compound, see: Schiemenz et al. (2003 ▶). For details of the synthetic procedures, see: Wesemann et al. (1992 ▶).

Experimental

Crystal data

C₂₀H₁₄ClP
M _r = 320.76
Monoclinic,
a = 12.4335 (6) Å
b = 10.4510 (4) Å
c = 11.9293 (7) Å
β = 93.180 (5)°
V = 1547.74 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.34 mm⁻¹
T = 298 K
0.30 × 0.20 × 0.10 mm

Data collection

Oxford Gemini E CCD diffractometer
8306 measured reflections
3531 independent reflections
1723 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.079
S = 0.78
3531 reflections
199 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS86 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811033782/zs2136sup1.cif

e-67-o2524-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811033782/zs2136Isup2.hkl

e-67-o2524-Isup2.hkl^{(169.7KB, hkl)}

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

Acknowledgments

The authors thank ANPCyT for grant No. PME-2006-01113 and R. Baggio for his helpful suggestions.

supplementary crystallographic information

Comment

The title compound, C₂₀H₁₄ClP, was obtained in the course of our continuing studies on the synthesis of phosphonium salts, with the aim of using them as building blocks in crystal engineering. In the structure (Fig. 1), the dihedral angle between the naphthyl rings is 81.77 (6)°, corresponding to torsion angles C1—P1—C11—C12 and C11—P1—C1—C2 of 100.58 (18)° and 2.03 (18)° respectively while an intramolecular C—H···Cl hydrogen-bonding interaction [C12—H12···Cl1, 3.128 (2) Å] stabilizes the conformation of one of the naphthyl rings [torsion angle Cl1—P1—C11—C12 = -1.68 (18)°]. Both of these naphthyl ring systems are essentially planar, with mean deviations from their least-square planes of 0.071 (2) Å for the C1–C10 system and 0.021 (2) Å for the C11–C20 system. The structural analysis of the title compound shows no significant bond differences compared to those found in similar structures, e.g. the P—Cl distance [2.0867 (8) Å cf. 2.10 (6) Å] and the P—C distances [P1—C1, 1.8294 (18) Å and P1–C11, 1.8309 (19) Å] comparing with 1.84 (3) Å.

A comparison with the previously reported structure of bis(8-diethylaminonaphth-1-yl)phosphine (Schiemenz et al., 2003) which shows no evidence of π–π stacking interactions, differs from that of the title compound which shows weak interactions between the naphthalene rings in adjacent molecules [minimum ring centroid separation, 3.7625 (13) Å]. It is likely that due to the presence of Cl instead of the group N(CH₃)₂ there is less steric repulsion between the substituents, which is evidenced by a smaller separation between the naphthyl moieties, allowing the π–π interactions between the aromatic rings to take place.

Experimental

The title compound was obtained as a by product in the synthesis of tris(1-naphthyl)phosphine (Wesemann et al., 1992). The synthesis was carried out in two steps. 7.27 mmol of 2-bromonaphthalene and 7.37 mmol of n-butyllithium were added to 20 ml of diethyl ether at -30°C, in order to obtain the naphthyllithium intermediate. 2.4 mmol of PCl₃ dissolved in 10 ml of diethyl ether were added to the reaction mixture and refluxed for 2 h. The by product chlorobis(1-naphthyl)phosphine was separated from the major product of the synthesis (tris(1-naphthyl)phosphine), after recrystallization of the reaction mixture from toluene.