organic compounds
2-Isobutyl-2-phosphabicyclo[3.3.1]nonane 2-selenide
aSasol Technology Research & Development, 1 Klasie Havenga Road, Sasolburg 1947, South Africa, and bDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
*Correspondence e-mail: fanie.otto@sasol.com
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 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).
see: OttoExperimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2008); cell 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.
Supporting information
10.1107/S1600536809005492/hb2909sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809005492/hb2909Isup2.hkl
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).
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.
Data collection: APEX2 (Bruker, 2008); cell
SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004) 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 (Sheldrick, 2008).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 |
Bruker X8 APEXII 4K KappaCCD diffractometer | 3366 independent reflections |
Radiation source: fine-focus sealed tube | 1658 reflections with I > 2σ(I) |
Graphite monochromator | 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 |
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 |
C12H23PSe | V = 1355.6 (5) Å3 |
Mr = 277.23 | Z = 4 |
Monoclinic, P2/c | Mo Kα radiation |
a = 10.763 (2) Å | µ = 2.85 mm−1 |
b = 7.2540 (15) Å | T = 293 K |
c = 17.530 (4) Å | 0.14 × 0.12 × 0.08 mm |
β = 97.93 (3)° |
Bruker X8 APEXII 4K KappaCCD diffractometer | 3366 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | 1658 reflections with I > 2σ(I) |
Tmin = 0.691, Tmax = 0.804 | Rint = 0.062 |
9132 measured reflections |
R[F2 > 2σ(F2)] = 0.059 | 0 restraints |
wR(F2) = 0.181 | H-atom parameters constrained |
S = 1.02 | Δρmax = 0.58 e Å−3 |
3366 reflections | Δρmin = −0.58 e Å−3 |
129 parameters |
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. |
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* |
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) |
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) |
Experimental details
Crystal data | |
Chemical formula | C12H23PSe |
Mr | 277.23 |
Crystal system, space group | Monoclinic, P2/c |
Temperature (K) | 293 |
a, b, c (Å) | 10.763 (2), 7.2540 (15), 17.530 (4) |
β (°) | 97.93 (3) |
V (Å3) | 1355.6 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.85 |
Crystal size (mm) | 0.14 × 0.12 × 0.08 |
Data collection | |
Diffractometer | Bruker X8 APEXII 4K KappaCCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2008) |
Tmin, Tmax | 0.691, 0.804 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9132, 3366, 1658 |
Rint | 0.062 |
(sin θ/λ)max (Å−1) | 0.667 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.059, 0.181, 1.02 |
No. of reflections | 3366 |
No. of parameters | 129 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.58, −0.58 |
Computer programs: APEX2 (Bruker, 2008), SAINT-Plus (Bruker, 2004) and XPREP (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Berndt, 2001).
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 |
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). |
Acknowledgements
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.
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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.