Bis(2,4-dimeth­oxy­phen­yl)(phen­yl)phosphine selenide

Alfred Muller

doi:10.1107/S1600536810049366

. 2010 Dec 11;67(Pt 1):o97. doi: 10.1107/S1600536810049366

Bis(2,4-dimethoxyphenyl)(phenyl)phosphine selenide

Alfred Muller ^a,^*

PMCID: PMC3050267 PMID: 21522806

Abstract

In the title molecule, C₂₂H₂₃O₄PSe, the P atom has a distorted tetrahedral environment formed by the selenide atom [P=Se = 2.1219 (5) Å] and three aryl rings. The orientations of the methoxy groups in the two 2,4-dimethoxyphenyl ligands are distinct, as seen from the torsion angles: C—C—O—C = 14.7 (3) and 175.97 (17)° in one ligand, and −9.1 (2) and 5.1 (3)° in the other. In the crystal, weak intermolecular C—H⋯Se interactions link the molecules into zigzag chains propagated in [010].

Related literature

For background to studies aimed at understanding the transition metal–phosphorus bond, see: Muller et al. (2006 ▶); Roodt et al. (2003 ▶) Tolman (1977 ▶). As part of this systematic investigation we are now also studying selenium-bonded phosphorus ligands, see: Muller et al. (2008 ▶). For the synthesis of ortho-substituted arylalkylphosphanes, see: Riihimäki et al. (2003 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

C₂₂H₂₃O₄PSe
M _r = 461.33
Monoclinic,
a = 9.3840 (13) Å
b = 13.3023 (14) Å
c = 16.667 (2) Å
β = 95.311 (4)°
V = 2071.6 (4) Å³
Z = 4
Mo Kα radiation
μ = 1.92 mm⁻¹
T = 150 K
0.34 × 0.28 × 0.06 mm

Data collection

Bruker X8 APEXII 4K Kappa CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.566, T _max = 0.891
24588 measured reflections
5151 independent reflections
4413 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.029
wR(F ²) = 0.078
S = 1.04
5151 reflections
257 parameters
H-atom parameters constrained
Δρ_max = 1.41 e Å⁻³
Δρ_min = −0.20 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/S1600536810049366/cv5007sup1.cif

e-67-00o97-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810049366/cv5007Isup2.hkl

e-67-00o97-Isup2.hkl^{(247.2KB, 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
C3—H3C⋯Seⁱ	0.98	2.94	3.8774 (19)	160

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

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

supplementary crystallographic information

Comment

There has been extensive development in understanding the transition metal phosphorous bond by various groups, including our own, with various techniques such as single-crystal X-ray crystallography, multi nuclear NMR and IR (Roodt et al., 2003). As part of this systematic investigation we are now also studying selenium bonded phosphorus ligands (see Muller et al., 2008) This way 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 angles variation from 156° to 167° was observed for the two phosphite ligands (Muller et al., 2006). The J(³¹P-⁷⁷Se) coupling can also be used as an additional probe to obtain more information regarding the nature of the phosphorous bond. Reported here is the first single-crystal structure of the compound PPh(2,4-OMe-C₆H₃)₂ to date (Cambridge Structural Database; Version 5.31, update of August; Allen, 2002).

Crystals of the title compound, (I), packs in the P2₁/c (Z=4) space group with the molecules lying on general positions. All geometrical features of the molecule (Allen, 2002) are as expected with the selenium atom and the three aryl groups adopting a distorted arrangement about phosphorous (see Fig. 1 and Table 1). The cone angle was found to be 176.9° when the Se—P distance is adjusted to 2.28 Å (the default value used in Tolman, 1977) Two different orientations for the methoxy moieties are noted and is probably due to some weak interactions (Table 1) forcing it into the conformations observed.

Experimental

PPh(2,4-OMe-C₆H₃)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-2,4-dimethoxybenzene followed by the addition of PPhCl₂ according to established methods (Riihimäki et al. 2003).

Eqimolar amounts of KSeCN and the PPh(2,4-OMe-C₆H₃)₂ compound (ca 0.04 mmol) were dissolved in the minimum amounts of methanol (10 – 20 ml). The KSeCN solution was added dropwise (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(2,4-OMe-C₆H₃)₂δ = -36.54 (s) For SePPh(2,4-OMe-C₆H₃)₂δ = 20.45 (t, ¹J_P—Se = 717.5 Hz)