trans-(Ethene-1,2-di­yl)bis­(diphenyl­phosphine selenide)

Zanele Phasha; Sizwe Makhoba; Alfred Muller

doi:10.1107/S160053681105183X

. 2011 Dec 7;68(Pt 1):o44. doi: 10.1107/S160053681105183X

trans-(Ethene-1,2-diyl)bis(diphenylphosphine selenide)

Zanele Phasha ^a,^*, Sizwe Makhoba ^a, Alfred Muller ^a,^*

PMCID: PMC3254404 PMID: 22259547

Abstract

In the title molecule, C₂₆H₂₂P₂Se₂, both P atoms have distorted tetrahedral environments, resulting in effective cone angles of 177 and 174°. Inversion twinning was detected and refined to a ratio of 0.35:0.65. Weak intermolecular C—H⋯Se interactions are observed.

Related literature

For background to the steric and electronic effects of group 15 ligands, see: Roodt et al. (2003 ▶); Muller et al. (2008 ▶). For information on cone angles, see: Tolman (1977 ▶); Otto (2001 ▶).

Experimental

Crystal data

C₂₆H₂₂P₂Se₂
M _r = 554.3
Orthorhombic,
a = 9.0604 (9) Å
b = 14.3239 (14) Å
c = 17.9617 (18) Å
V = 2331.1 (4) Å³
Z = 4
Mo Kα radiation
μ = 3.32 mm⁻¹
T = 100 K
0.26 × 0.21 × 0.04 mm

Data collection

Bruker APEX DUO 4K CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.479, T _max = 0.879
14567 measured reflections
5814 independent reflections
5356 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.053
S = 1.01
5814 reflections
272 parameters
H-atom parameters constrained
Δρ_max = 0.51 e Å⁻³
Δρ_min = −0.48 e Å⁻³
Absolute structure: Flack (1983 ▶), 2517 Friedel pairs
Flack parameter: 0.354 (6)

Data collection: APEX2 (Bruker, 2011 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT and XPREP (Bruker, 2008 ▶); 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 datablock(s) global, I. DOI: 10.1107/S160053681105183X/fj2485sup1.cif

e-68-00o44-sup1.cif^{(30.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681105183X/fj2485Isup2.hkl

e-68-00o44-Isup2.hkl^{(278.9KB, 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—H3⋯Se2ⁱ	0.95	3.02	3.953 (2)	168
C21—H21⋯Se1ⁱⁱ	0.95	3.06	3.812 (2)	138
C17—H17⋯Se2ⁱⁱⁱ	0.95	3.01	3.885 (3)	155

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

Acknowledgments

Research funds of the University of Johannesburg are gratefully acknowledged.

supplementary crystallographic information

Comment

The study of the transition metal phosphorous bond spans over several decades using various techniques such as crystallography, multi nuclear NMR and IR (Roodt et al., 2003). As part of this systematic investigation we have extended this study to selenium derivatives of the phosphorus ligands (see Muller et al., 2008). Reported as part of the above continuing study, the single-crystal structure of the bis-phosphorus containing compound, (SePPh₂)₂C₂H₂ where Ph = C₆H₅, is reported here.

The structure of the title compound (see Figure 1, Table 1) shows distorted tetrahedral environments for both the phosphorus centers. The P═Se bond distances (2.1026 (6), 2.1054 (6) Å for Se1 and Se2 respectively) are marginally statistically different, possibly due to the weak C—H···Se intermolecular hydrogen bonding observed (see Figure 2, Table 2; comparison based on 1% normal distribution coefficient).

The phosphorus ligand bulkiness was evaluated by using an adaptation of the well known Tolman cone angle model (Tolman, 1977). Instead of using a CPK model, the actual geometry from the crystal structure was taken to determine an 'effective cone angle' (Otto et al. 2001). The Se═P distances were also adjusted to 2.28 Å (the default value used by Tolman) to remove the effect of bond distance variation. Two different cone angles of 177° and 174° were obtained for P₁and P₂ respectively. The difference in cone angles may also be attributed to the weak interactions mentioned previously.

Experimental

Trans-1,2-bis(diphenylphosphino)ethylene and KSeCN were purchased from Sigma-Aldrich and used without purification. Eqimolar amounts of KSeCN and the trans-1,2-bis(diphenylphosphino)ethylene 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.