Bis(2-meth­oxy­phen­yl)(phen­yl)phosphine selenide

Alfred Muller

doi:10.1107/S1600536810051317

. 2010 Dec 11;67(Pt 1):o89. doi: 10.1107/S1600536810051317

Bis(2-methoxyphenyl)(phenyl)phosphine selenide

Alfred Muller ^a,^*

PMCID: PMC3050330 PMID: 21522797

Abstract

The title compound, C₂₀H₁₉O₂PSe or SePPh(2-OMe-C₆H₃)₂, crystallizes with two distinct orientations for the methoxy groups. The Se=P bond is 2.1170 (7) Å and the cone angle is 176.0°. Intramolecular C—H⋯Se interactions occur. In the crystal, molecules are linked by intermolecular C—H⋯Se interactions.

Related literature

For bond-length data, see: Allen et al. (2002 ▶). For our study of phosphorus ligands, see: Muller et al. (2006 ▶, 2008 ▶). For the cone angle, see: Tolman (1977 ▶). For the synthesis of ortho-substituted arylalkylphosphanes, see: Riihimäki et al. (2003 ▶).

Experimental

Crystal data

C₂₀H₁₉O₂PSe
M _r = 401.28
Monoclinic,
a = 8.9552 (4) Å
b = 13.2737 (6) Å
c = 15.9593 (6) Å
β = 104.885 (1)°
V = 1833.40 (14) Å³
Z = 4
Mo Kα radiation
μ = 2.14 mm⁻¹
T = 100 K
0.1 × 0.07 × 0.06 mm

Data collection

Bruker X8 APEXII 4K Kappa CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.814, T _max = 0.882
37384 measured reflections
5078 independent reflections
3483 reflections with I > 2σ(I)
R _int = 0.068

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.096
S = 1.05
5078 reflections
219 parameters
H-atom parameters constrained
Δρ_max = 0.66 e Å⁻³
Δρ_min = −0.56 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus and XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810051317/kp2295sup1.cif

e-67-00o89-sup1.cif^{(20KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810051317/kp2295Isup2.hkl

e-67-00o89-Isup2.hkl^{(243.7KB, 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
C13—H13⋯Se1ⁱ	0.95	2.9	3.775 (3)	154
C15—H15⋯Se1ⁱⁱ	0.95	2.96	3.740 (3)	140
C16—H16⋯Se1	0.95	2.75	3.333 (3)	120
C32—H32⋯Se1	0.95	2.97	3.462 (3)	114

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The University of the Free State (Professor A. Roodt) is thanked for the use of its diffractometer.

supplementary crystallographic information

Comment

The evaluation of the electronic parameter of tertiary phosphines is a study that spans over several decades, and even today attracts attention due to its importance. As part of a systematic investigation we are studying selenium bonded phosphorus ligands (see Muller et al. 2008) to give insight on the nature of these ligands. There is no steric crowding effect, albeit crystal packing effects, as normally found in transition metal complexes with bulky ligands, e.g. in trans-[Rh(CO)Cl{P(OC₆H₅)₃}₂] cone angle variations from 156° to 167° was observed for the two phosphite ligands (Muller, et al. 2006). Using the geometries obtained from the selenium bonded phosphorus ligands and the ³¹P NMR J(³¹P-⁷⁷Se) couplings, it would be possible to obtain more information regarding the nature of the phosphorous substituted ligands.

Geometrical parameters of the molecule are as expected (Allen, 2002). Selenium atom and the three aryl groups adopt a distorted tetrahedral arrangement about phosphorous (Fig. 1). The cone angle of 176.0 ° can be calculated for the Se—P distance adjusted to 2.28 Å (the default value from Tolman, 1977). The cone value observed in the title compound is close to the value 178 (7) ° calculated from data of 5 metal bonded phosphines extracted from Cambridge Structural Database (Version 5.31, update of August; Allen, 2002).

Two different orientations for the methoxy moieties might be explained by some weak interactions (Table 2) forcing them into the conformations observed.

Experimental

PPh(2-OMe-C₆H₄)₂ were prepared either by direct ortho metallation of anisole with BuLi followed the addition of the appropriate chlorophosphine or by metal/halogen exchange between BuLi and 1-bromo-2-methoxybenzene followed by the addition of PPhCl₂ according to established methods (Riihimäki et al. 2003).

Eqimolar amounts of KSeCN and the PPh(2-OMe-C₆H₄)₂ compound (ca. 0.04 mmol) were dissolved in the minimum amounts of methanol (10 – 20 mL). The KSeCN solution was added drop wise (5 min.) to the phosphine solution with stirring at room temperature. The final solution was left to evaporate slowly until dry to give crystals suitable for a single crystal X-ray study.

Analytical data: ³¹P {H} NMR (CDCl₃, 121.42 MHz): For PPh(2-OMe-C₆H₄)₂δ = -26.41 (s) For SePPh(2-OMe-C₆H₄)₂δ = 28.42 (t, ¹J_P-Se = 717.5 Hz)