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Acta Crystallographica Section E: Structure Reports Online logoLink to Acta Crystallographica Section E: Structure Reports Online
. 2009 Feb 21;65(Pt 3):o560–o561. doi: 10.1107/S1600536809005492

2-Isobutyl-2-phosphabicyclo­[3.3.1]nonane 2-selenide

Peter N Bungu a, Stefanus Otto a,b,*
PMCID: PMC2968513  PMID: 21582218

Abstract

The title compound, C12H23PSe, represents the first structure of a phosphine containing the bicyclic 2-phospha­bicyclo­[3.3.1]nonane (VCH) unit. It contains two chiral centres per mol­ecule which can be either R,R- or S,S and crystallizes as a centrosymmetric, racemic micture of the enanti­omers. The P—Se bond distance of 2.1360 (16) Å is typical for these compounds. The Tolman cone angle (2.28 Å from P) was calculated as 163°, and the effective cone angle (using the crystallographically determined P—Se bond distance) is 168°.

Related literature

For the synthesis of phosphine selenides, see: Otto et al. (2005 ▶). For the evaluation of ligand electronic properties, see: Allen & Taylor (1982 ▶); Bungu & Otto (2007b ▶); Muller et al. (2008 ▶); Otto & Roodt (2004 ▶); Roodt & Steyn (2000 ▶). For the application of bicyclic ligands in catalysis, see: Bungu & Otto (2007a ▶); Crause et al. (2003 ▶); Dwyer et al. (2004 ▶); Steynberg et al. (2003 ▶); Van Winkle et al. (1969 ▶). For information on cone angles, see: Tolman (1977 ▶); Otto (2001 ▶).graphic file with name e-65-0o560-scheme1.jpg

Experimental

Crystal data

  • C12H23PSe

  • M r = 277.23

  • Monoclinic, Inline graphic

  • a = 10.763 (2) Å

  • b = 7.2540 (15) Å

  • c = 17.530 (4) Å

  • β = 97.93 (3)°

  • V = 1355.6 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 2.85 mm−1

  • T = 293 K

  • 0.14 × 0.12 × 0.08 mm

Data collection

  • Bruker X8 APEXII 4K KappaCCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T min = 0.691, T max = 0.804

  • 9132 measured reflections

  • 3366 independent reflections

  • 1658 reflections with I > 2σ(I)

  • R int = 0.062

Refinement

  • R[F 2 > 2σ(F 2)] = 0.059

  • wR(F 2) = 0.181

  • S = 1.02

  • 3366 reflections

  • 129 parameters

  • H-atom parameters constrained

  • Δρmax = 0.58 e Å−3

  • Δρmin = −0.58 e Å−3

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus and XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Berndt, 2001 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809005492/hb2909sup1.cif

e-65-0o560-sup1.cif (17.8KB, cif)

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809005492/hb2909Isup2.hkl

e-65-0o560-Isup2.hkl (161.7KB, hkl)

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

Table 1. X-ray and spectroscopic data (Å, Hz) for selected phosphine selenides.

P Se—P 1JSe—P
PMe3i 2.111 (3) 684
PCy3ii 2.108 (1) 676
VCH-iBuiii 2.1360 (16) 672, 687
Phoban-Phiv 2.1090 (9) 689, 717
PPhCy2v 2.1260 (8) 701
P(o-Tol)3vi 2.116 (5) 708
PPh2Cyv 2.111 (2) 725
PPh3vii 2.106 (1) 733
P(NMe2)3viii 2.120 (1) 797
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Notes: (i) Cogne et al. (1980 ▶); (ii) Davies et al. (1991 ▶); (iii) this work; (iv) Bungu & Otto (2007b ▶); (v) Muller et al. (2008 ▶); (vi) Cameron & Dahlen (1975 ▶); (vii) Codding & Kerr (1979 ▶); (viii) Rømming & Songstad (1979 ▶).

Acknowledgments

Financial support from Sasol Technology Research & Development and the University of the Free State is gratefully acknowledged. Part of this material is based on support by the South African National Research Foundation (NRF) under Grant Number (GUN 2053397). Any opinion, finding and conclusions or recommendations in this material are those of the authors and do not reflect the views of the NRF.

supplementary crystallographic information

Comment

It is well established that the steric and electronic properties of phosphine ligands have a major influence on the chemistry of its metal species. Sevaral methods are used to quantify the electronic characteristics of phosphines, including NMR measurements of first order Pt—P, Rh—P, Se—P and P—BH3 coupling constants (Allen & Taylor, 1982 and Roodt & Steyn, 2000) and measuring of CO stretching frequencies in complexes such as [Ni(L)(CO)3] (Tolman, 1977) or trans-[RhCl(CO)(L)2] (Otto & Roodt, 2004).

Phosphine ligands containing bicyclic substituents have been shown to add significant benefits to the catalytic performance of several homogeneously catalysed systems (Bungu & Otto, 2007a). The best known example is the 9-phosphabicyclo[3.3.1]nonane and 9-phosphabicyclo[4.2.1]nonane mixture of isomers (Phoban family of ligands) patented by Shell (Van Winkle et al., 1969) for modified cobalt hydroformylation. Sasol has reported on the use of bicyclic phosphines derived from (R)-(+)-Limonene (Lim family) (Crause et al., 2003, Dwyer et al., 2004) and vinylcyclohexene (VCH family) (Steynberg et al., 2003) for similar applications.

After a convenient synthetic protocol for phosphine selenides were developed (Otto et al., 2005) we extensively used the Se—P coupling constants for the quantification of electronic properties of phosphine ligands (Bungu & Otto, 2007b). Smaller values for the coupling constants correspond with ligands of higher basicity (more electron donating). We now report the synthesis and crystallographic characterization of the title compound, (I), 2-isobutyl-2-phosphabicyclo[3.3.1]nonane 2-selenide (VCH-iBu) which represents the first crystal structure of a VCH family member.

Compound (I) crystallizes in the monoclinic space group P2/c and consists of the VCH backbone, the iso-butyl side chain and the selenium atom coordinated to phosphorus in a tetrahedral fashion. The compound contains two chiral centres on the VCH backbone (C13 and C15) which can be R,R- or S,S (as in the arbitrarily chosen asymmetric molecule; Fig. 1) and it crystallizes as a racemic mixture on account of the centrosymmetric space group. The P atom could also be considered as chiral based on the four different substituents. All bond distances and angles are within normal ranges. Even though larger Se—P coupling constants are indicative of more effective s-orbital overlap no clear trends are evident in the Se—P bond distances.

The packing in the unit cell is governed by van der Waals forces alone since no pertinent intramolecular interactions were evident. The Tolman- (2.28 Å from P) and effective cone angles (using the crystallographically determined Se—P bond distance) were calculated (Otto, 2001) resulting in values of 163 and 168° respectively.

Experimental

2-Isobutyl-2-phosphabicyclo[3.3.1]nonane was generously supplied by Cytec; it exists as two stereo isomers in close to equal quantities. 31P (CDCl3): -36.23 and -35.22 p.p.m..

The title compound was prepared according to the procedure described previously (Bungu & Otto, 2007b), colourless blocks of (I) were obtained by evaporation of a dichloromethane solution. 31P (CDCl3): 29.72 p.p.m. (1JSe—P = 684 Hz) and 29.88 p.p.m. (1JSe—P = 670 Hz).

Refinement

The H atoms were placed in geometrically idealized positions (CH = 0.98, CH2 = 0.97 and CH3 = 0.96 Å) and constrained to ride on their parent atoms with Uiso(H) = 1.2Ueq(C) for CH and CH2 and Uiso(H) = 1.5Ueq(C) for CH3.

Figures

Fig. 1.

Fig. 1.

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Molecular diagram of (I) showing 30% displacement ellipsoids.

Crystal data

C12H23PSe F(000) = 576
Mr = 277.23 Dx = 1.358 Mg m−3
Monoclinic, P2/c Mo Kα radiation, λ = 0.71073 Å
a = 10.763 (2) Å Cell parameters from 1002 reflections
b = 7.2540 (15) Å θ = 2.8–25.7°
c = 17.530 (4) Å µ = 2.85 mm−1
β = 97.93 (3)° T = 293 K
V = 1355.6 (5) Å3 Block, colourless
Z = 4 0.14 × 0.12 × 0.08 mm
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Data collection

Bruker X8 APEXII 4K KappaCCD diffractometer 3366 independent reflections
Radiation source: fine-focus sealed tube 1658 reflections with I > 2σ(I)
graphite Rint = 0.062
Detector resolution: 512 pixels mm-1 θmax = 28.3°, θmin = 1.9°
φ and ω scans h = −11→14
Absorption correction: multi-scan (SADABS; Bruker, 2008) k = −8→9
Tmin = 0.691, Tmax = 0.804 l = −23→23
9132 measured reflections
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Refinement

Refinement on F2 Primary atom site location: structure-invariant direct methods
Least-squares matrix: full Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.059 Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.181 H-atom parameters constrained
S = 1.02 w = 1/[σ2(Fo2) + (0.0816P)2 + 0.9034P] where P = (Fo2 + 2Fc2)/3
3366 reflections (Δ/σ)max < 0.001
129 parameters Δρmax = 0.58 e Å−3
0 restraints Δρmin = −0.58 e Å−3
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Special details

Experimental. The intensity data were collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 40 s/frame with a frame width of 0.3°; a total of 1315 frames were collected.The crystals were of poor quality and were, as a precautionary measure, covered with Canada balsam. Consequently some intensity in the reflextions were sacrificed and the completeness is somewhat low at high angles.
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.
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Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

x y z Uiso*/Ueq
P 0.21847 (13) −0.0934 (2) −0.03355 (8) 0.0418 (4)
Se 0.23308 (6) 0.16679 (9) 0.02405 (4) 0.0633 (3)
C11 0.1179 (6) −0.0851 (9) −0.1269 (3) 0.0588 (16)
H11A 0.0957 −0.2100 −0.1433 0.071*
H11B 0.0410 −0.0206 −0.1207 0.071*
C12 0.1797 (6) 0.0105 (11) −0.1899 (4) 0.0712 (19)
H12A 0.1870 0.1411 −0.1780 0.085*
H12B 0.1251 −0.0022 −0.2384 0.085*
C13 0.3099 (7) −0.0640 (12) −0.1997 (4) 0.078 (2)
H13 0.3411 0.0092 −0.2401 0.094*
C14 0.3999 (6) −0.0340 (10) −0.1255 (4) 0.0699 (19)
H14A 0.3940 0.0930 −0.1090 0.084*
H14B 0.4852 −0.0554 −0.1353 0.084*
C15 0.3697 (5) −0.1675 (8) −0.0582 (4) 0.0528 (15)
H15 0.4336 −0.1494 −0.0133 0.063*
C16 0.3785 (6) −0.3676 (8) −0.0870 (4) 0.0610 (17)
H16A 0.4652 −0.3938 −0.0924 0.073*
H16B 0.3544 −0.4505 −0.0481 0.073*
C17 0.2984 (7) −0.4081 (11) −0.1622 (4) 0.082 (2)
H17A 0.2112 −0.4131 −0.1538 0.099*
H17B 0.3208 −0.5285 −0.1802 0.099*
C18 0.3119 (8) −0.2667 (14) −0.2240 (5) 0.091 (2)
H18A 0.2446 −0.2859 −0.2661 0.110*
H18B 0.3903 −0.2900 −0.2438 0.110*
C21 0.1449 (5) −0.2707 (7) 0.0190 (3) 0.0452 (13)
H21A 0.0547 −0.2558 0.0076 0.054*
H21B 0.1655 −0.3899 −0.0010 0.054*
C22 0.1795 (5) −0.2755 (8) 0.1068 (3) 0.0490 (14)
H22 0.1706 −0.1505 0.1266 0.059*
C23 0.0893 (6) −0.4026 (10) 0.1427 (4) 0.0680 (18)
H23A 0.0046 −0.3618 0.1277 0.102*
H23B 0.1087 −0.3991 0.1978 0.102*
H23C 0.0981 −0.5265 0.1250 0.102*
C24 0.3154 (6) −0.3372 (10) 0.1303 (4) 0.0708 (19)
H24A 0.3258 −0.4603 0.1121 0.106*
H24B 0.3350 −0.3345 0.1854 0.106*
H24C 0.3707 −0.2554 0.1080 0.106*
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Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23
P 0.0394 (8) 0.0373 (7) 0.0482 (8) −0.0002 (6) 0.0044 (6) −0.0054 (6)
Se 0.0709 (5) 0.0383 (4) 0.0804 (5) −0.0015 (3) 0.0100 (3) −0.0152 (3)
C11 0.056 (4) 0.061 (4) 0.057 (4) 0.000 (3) 0.002 (3) 0.007 (3)
C12 0.062 (4) 0.085 (5) 0.063 (4) −0.003 (4) −0.001 (3) 0.022 (4)
C13 0.067 (5) 0.105 (7) 0.060 (4) −0.018 (4) 0.001 (3) 0.017 (4)
C14 0.062 (4) 0.074 (5) 0.077 (5) −0.013 (3) 0.020 (4) −0.006 (4)
C15 0.039 (3) 0.054 (4) 0.065 (4) −0.005 (3) 0.006 (3) −0.014 (3)
C16 0.055 (4) 0.047 (4) 0.083 (5) 0.008 (3) 0.018 (3) −0.010 (3)
C17 0.091 (6) 0.080 (5) 0.078 (5) −0.010 (4) 0.019 (4) −0.032 (4)
C18 0.093 (6) 0.108 (7) 0.075 (5) −0.014 (5) 0.020 (4) −0.018 (5)
C21 0.047 (3) 0.036 (3) 0.052 (3) 0.001 (2) 0.008 (3) −0.003 (2)
C22 0.056 (4) 0.042 (3) 0.049 (3) 0.000 (3) 0.009 (3) −0.004 (3)
C23 0.073 (5) 0.063 (4) 0.073 (4) −0.001 (4) 0.027 (4) 0.010 (3)
C24 0.068 (4) 0.078 (5) 0.062 (4) −0.008 (4) −0.009 (3) 0.013 (4)
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Geometric parameters (Å, °)

P—C15 1.822 (6) C16—H16A 0.9700
P—C21 1.825 (6) C16—H16B 0.9700
P—C11 1.835 (6) C17—C18 1.514 (12)
P—Se 2.1360 (16) C17—H17A 0.9700
C11—C12 1.531 (9) C17—H17B 0.9700
C11—H11A 0.9700 C18—H18A 0.9700
C11—H11B 0.9700 C18—H18B 0.9700
C12—C13 1.534 (10) C21—C22 1.533 (8)
C12—H12A 0.9700 C21—H21A 0.9700
C12—H12B 0.9700 C21—H21B 0.9700
C13—C14 1.527 (9) C22—C24 1.530 (9)
C13—C18 1.532 (12) C22—C23 1.536 (8)
C13—H13 0.9800 C22—H22 0.9800
C14—C15 1.594 (9) C23—H23A 0.9600
C14—H14A 0.9700 C23—H23B 0.9600
C14—H14B 0.9700 C23—H23C 0.9600
C15—C16 1.544 (8) C24—H24A 0.9600
C15—H15 0.9800 C24—H24B 0.9600
C16—C17 1.501 (9) C24—H24C 0.9600
C15—P—C21 112.0 (3) C17—C16—H16B 108.6
C15—P—C11 103.6 (3) C15—C16—H16B 108.6
C21—P—C11 103.3 (3) H16A—C16—H16B 107.6
C15—P—Se 111.27 (19) C16—C17—C18 113.3 (6)
C21—P—Se 113.12 (19) C16—C17—H17A 108.9
C11—P—Se 112.9 (2) C18—C17—H17A 108.9
C12—C11—P 113.3 (4) C16—C17—H17B 108.9
C12—C11—H11A 108.9 C18—C17—H17B 108.9
P—C11—H11A 108.9 H17A—C17—H17B 107.7
C12—C11—H11B 108.9 C17—C18—C13 116.4 (6)
P—C11—H11B 108.9 C17—C18—H18A 108.2
H11A—C11—H11B 107.7 C13—C18—H18A 108.2
C11—C12—C13 114.6 (6) C17—C18—H18B 108.2
C11—C12—H12A 108.6 C13—C18—H18B 108.2
C13—C12—H12A 108.6 H18A—C18—H18B 107.3
C11—C12—H12B 108.6 C22—C21—P 117.4 (4)
C13—C12—H12B 108.6 C22—C21—H21A 107.9
H12A—C12—H12B 107.6 P—C21—H21A 107.9
C14—C13—C18 110.0 (7) C22—C21—H21B 107.9
C14—C13—C12 109.6 (6) P—C21—H21B 107.9
C18—C13—C12 114.7 (6) H21A—C21—H21B 107.2
C14—C13—H13 107.4 C24—C22—C21 111.5 (5)
C18—C13—H13 107.4 C24—C22—C23 110.5 (5)
C12—C13—H13 107.4 C21—C22—C23 110.1 (5)
C13—C14—C15 112.0 (5) C24—C22—H22 108.2
C13—C14—H14A 109.2 C21—C22—H22 108.2
C15—C14—H14A 109.2 C23—C22—H22 108.2
C13—C14—H14B 109.2 C22—C23—H23A 109.5
C15—C14—H14B 109.2 C22—C23—H23B 109.5
H14A—C14—H14B 107.9 H23A—C23—H23B 109.5
C16—C15—C14 107.5 (5) C22—C23—H23C 109.5
C16—C15—P 116.8 (4) H23A—C23—H23C 109.5
C14—C15—P 106.0 (4) H23B—C23—H23C 109.5
C16—C15—H15 108.7 C22—C24—H24A 109.5
C14—C15—H15 108.7 C22—C24—H24B 109.5
P—C15—H15 108.7 H24A—C24—H24B 109.5
C17—C16—C15 114.7 (6) C22—C24—H24C 109.5
C17—C16—H16A 108.6 H24A—C24—H24C 109.5
C15—C16—H16A 108.6 H24B—C24—H24C 109.5
C15—P—C11—C12 −45.9 (6) C11—P—C15—C14 50.9 (4)
C21—P—C11—C12 −162.9 (5) Se—P—C15—C14 −70.7 (4)
Se—P—C11—C12 74.6 (5) C14—C15—C16—C17 −54.2 (7)
P—C11—C12—C13 52.2 (8) P—C15—C16—C17 64.7 (7)
C11—C12—C13—C14 −62.0 (8) C15—C16—C17—C18 48.6 (9)
C11—C12—C13—C18 62.3 (8) C16—C17—C18—C13 −45.1 (10)
C18—C13—C14—C15 −55.5 (8) C14—C13—C18—C17 48.8 (9)
C12—C13—C14—C15 71.5 (8) C12—C13—C18—C17 −75.3 (8)
C13—C14—C15—C16 58.2 (7) C15—P—C21—C22 87.0 (5)
C13—C14—C15—P −67.5 (6) C11—P—C21—C22 −162.1 (4)
C21—P—C15—C16 41.8 (6) Se—P—C21—C22 −39.8 (5)
C11—P—C15—C16 −68.9 (5) P—C21—C22—C24 −69.3 (6)
Se—P—C15—C16 169.6 (4) P—C21—C22—C23 167.7 (4)
C21—P—C15—C14 161.6 (4)
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Table 1 X-ray and spectroscopic data (Å, Hz) for selected phosphine selenides.

P Se—P 1JSe—P
PMe3i 2.111 (3) 684
PCy3ii 2.108 (1) 676
VCH-iBuiii 2.1360 (16) 672,687
Phoban-Phiv 2.1090 (9) 689,717
PPhCy2v 2.1260 (8) 701
P(o-Tol)3vi 2.116 (5) 708
PPh2Cyv 2.111 (2) 725
PPh3vii 2.106 (1) 733
P(NMe2)3viii 2.120 (1) 797
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Notes: (i) Cogne et al. (1980); (ii) Davies et al. (1991); (iii) this work; (iv) Bungu & Otto (2007b); (v) Muller et al. (2008); (vi) Cameron & Dahlen (1975); (vii) Codding & Kerr (1979); (viii) Rømming & Songstad (1979).

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB2909).

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809005492/hb2909sup1.cif

e-65-0o560-sup1.cif (17.8KB, cif)

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809005492/hb2909Isup2.hkl

e-65-0o560-Isup2.hkl (161.7KB, hkl)

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

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography

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