[MoO(O2){B(C6F5)3}{ç2-PhN(O)C(O)Ph}2] 3. Yellow [Mo-
O(O2){η2-PhN(O)C(O)Ph}2] (0.568 g, 1 mmol) was suspended
in hexane (20 cm3) and a hexane solution (20 cm3) of B(C6F5)3
(512 mg, 1 mmol) added. There was an immediate change to
red-orange and the reaction stirred for 30 min. The pale yellow
filtrate was removed and the red-orange precipitate washed
with hexane (3 × 10 cm3) and then dried in vacuo.
Ϫ0.46 and 0.37 e ÅϪ3. Compound 4 was crystallised from tolu-
ene solution layered with pentane. One molecule of pentane is
incorporated in the unit cell with the central carbon atom,
C(101), lying on the centre of inversion such that one half of a
pentane molecule is in the asymmetric unit. Hydrogen atoms
were generated geometrically and allowed to ride on the corres-
ponding carbon atoms. For 4, 646 refined parameters and 4201
observations resulted in an observation/refined parameter ratio
of 6.50:1. Corrections for secondary extinction were applied
and refinement completed using a Chebyshev weighting
scheme11 with parameters 1.30, 0.078, 0.968. Refinement on
F converged at R = 0.0465, RЈ = 0.0455 and goodness of
fit = 1.1318. A final Fourier-difference synthesis showed min-
imum and maximum residual electron densities of Ϫ0.62
and 0.75 e ÅϪ3. All crystallographic calculations were carried
out using the CRYSTALS program package.12 Neutral atom
scattering factors were taken from ref. 13.
cis-[MoO{OB(C6F5)3}{ç2-PhN(O)C(O)Ph}2] 4. Off-white
[MoO2{η2-PhN(O)C(O)Ph}2] (0.552 g, 1 mmol) was suspended
in toluene (20 cm3) and a toluene solution (20 cm3) of B(C6F5)3
(512 mg, 1 mmol) added. There was an immediate change to
orange and after 1 h all the solid had dissolved. The solvent was
removed in vacuo and the residue washed with hexane. The resi-
due was extracted with toluene and the filtrate concentrated
and layered with pentane leading to the formation of orange
microcrystals. Yield: 0.87 g, 82%.
CCDC reference number 186/1105.
graphic files in .cif format.
Crystal structure determination of compounds 1 and 4
Crystals of compound 1 were grown from toluene solution at
253 K and of 4 from toluene layered with pentane at 298 K. In
each case a crystal from the mother-liquid was immersed in
highly viscous perfluoropolyether to exclude oxygen and pre-
vent solvent loss. It was mounted on a glass fibre and plunged
into a cold (150 K) nitrogen stream.
Acknowledgements
We thank the University of Oxford for a Violette and Samuel
Glasstone Fellowship (J. R. G.), the Deutsche Gemeinschaft
Forschung (M. M.), St. John’s College, Oxford (L. H. D.) and
the EPSRC for support of this work.
Crystal data. Compound 1, C26H20BF15MoN2O4ؒ0.5C7H8,
¯
M = 816.21 ϩ 46.04, triclinic, space group P1, a = 10.764(1),
References
b = 12.107(1), c = 12.563(1) Å, α = 86.673(2), β = 85.919(2),
γ = 86.480(2)Њ, V = 1627.6 Å3, Z = 2, Dc = 1.76 g cmϪ3, µ = 5.138
cmϪ1, colourless, crystal dimensions 0.23 × 0.31 × 0.18 mm.
Compound 4, C44H20BF15MoN2O6ؒ0.5C6H12, M = 1094.45,
1 For reviews concerning transition-metal catalysis of epoxidation
reactions see: J. E. Lyons, in Aspects of Homogeneous Catalysis, ed.
R. Ugo, Reidel, Dordrecht, Boston, 1977, vol. 3, ch. 1 and refs.
therein; R. A. Sheldon and J. K. Kochi, Metal Catalyzed Oxidations
of Organic Compounds, Academic Press, New York, 1981.
2 (a) S. Chan-Cheng, J. W. Reed and E. S. Gould, Inorg. Chem., 1973,
12, 337; (b) R. A. Sheldon, Recl. Trav. Chim. Pays-Bas, 1973, 92,
253, 367; (c) R. A. Sheldon and J. A. Van Doorn, J. Catal., 1973, 31,
427; (d) M. N. Sheng and J. G. Zajacek, Adv. Chem. Ser., 1968, 76,
418; (e) M. N. Sheng and J. G. Zajacek, J. Org. Chem., 1970, 35,
1839; ( f ) T. N. Baker, G. J. Mains, M. N. Sheng and J. G. Zajacek,
J. Org. Chem., 1973, 38, 1145; (g) G. R. Howe and R. R. Hiatt,
J. Org. Chem., 1971, 36, 2493; (h) J. Sobczak and J. Ziolkowski,
Inorg. Chim. Acta, 1976, 19, 15.
3 (a) K. Wieghardt, W. Holzbach, J. Weiss, B. Nuber and B. Prikner,
Angew. Chem., Int. Ed. Engl., 1979, 18, 548; (b) P. Jaitner, W. Huber,
A. Gieren and H. Betz, Z. Anorg. Allg. Chem., 1986, 538, 53;
(c) K. Wieghardt, W. Holzbach, E. Hofer and J. Weiss, Inorg. Chem.,
1981, 20, 343; (d) C. Redshaw, G. Wilkinson, B. Hussain-Bates
and M. B. Hursthouse, J. Chem. Soc., Dalton Trans., 1992, 555;
(e) K. Wieghardt, E. Hofer, W. Holzbach, B. Nuber and J. Weiss,
Inorg. Chem., 1980, 19, 2927.
¯
triclinic, space group P1, a = 10.2840(8), b = 12.4090(8), c =
18.598(2) Å, α = 102.500(5), β = 98.190(4), γ = 106.397(4)Њ, V =
2169.74 Å3, Z = 2, Dc = 1.68 g cmϪ3, µ = 4.14 cmϪ1, yellow
block, crystal dimensions 0.25 × 0.25 × 0.10 mm.
Data collection and processing. The data for compounds 1
and 4 were collected at 150 and 100 K respectively on an Enraf-
Nonius DIP2000 image plate diffractometer with graphite-
monochromated Mo-Kα radiation (λ = 0.71069 Å). For
compound 1 19362 reflections were measured (1 < θ < 26Њ,
Ϫ13 р h р 13, Ϫ15 р k р 15, Ϫ15 р l р 15). 6304 Unique
reflections were obtained giving 5950 reflections with I > 3σ(I).
For compound 4 4580 reflections were measured (2 < θ < 25Њ,
0 р h р 12, Ϫ13 р k р 13, Ϫ21 р l р 20). 4580 Unique reflec-
tions were obtained giving 4201 reflections with I > 3σ(I). The
images were processed with the DENZO and SCALEPACK
programs.10 Corrections for Lorentz-polarisation effects were
performed but not for absorption.
4 L. Saussine, H. Mimoun, A. Mitschler and J. Fisher, New J. Chem.,
1980, 4, 235.
5 J. Fischer, J. Kress, J. A. Osborn, L. Ricard and M. Wesolek,
Polyhedron, 1987, 6, 1839; J. Kress, M. Wesolek, J.-P. Le Ny and J. A.
Osborn, J. Chem. Soc., Chem. Commun., 1982, 514.
Structure solution and refinement. The crystal structures were
solved by direct methods and refined by the full-matrix least-
squares method. Compound 1 crystallised with toluene in a
1:0.5 ratio. The toluene molecules are disordered at the crystal-
lographic inversion centre with a translation of about 1.4 Å
along their molecular twofold axis. All non-hydrogen atoms of
1 were refined with anisotropic displacement parameters. All
hydrogen atoms of the molybdenum compound could be
located in Fourier-difference maps and were refined isotropic-
ally. The hydrogen atoms of the disordered toluene were added
geometrically and included in the final refinement with fixed
positional and thermal parameters. For compound 1, 548
refined parameters and 5960 observations resulted in an
observation/refined parameter ratio of 10.9:1. Corrections for
secondary extinction were applied and refinement completed
using a Chebyshev weighting scheme11 with parameters 1.67,
0.875, 1.28. Refinement on F converged at R = 0.025, RЈ = 0.031
and goodness of fit = 1.07. A final Fourier-difference synthesis
showed minimum and maximum residual electron densities of
6 J. R. Galsworthy, M. L. H. Green, M. Müller and K. Prout, J. Chem.
Soc., Dalton Trans., 1997, 1308; J. R. Galsworthy, J. C. Green, M. L.
H. Green and M. Müller, J. Chem. Soc., Dalton Trans., 1998, 15.
7 H. Tomioka, K. Takai, K. Oshima and H. Nozaki, Tetrahedron
Lett., 1980, 21, 4843.
8 W. R. Thiel, Chem. Ber., 1996, 129, 575.
9 A. N. Chernega, A. J. Graham, M. L. H. Green, J. Haggitt, J. Lloyd,
C. P. Mehnert, N, Metzler and J. Souter, J. Chem. Soc., Dalton
Trans., 1997, 2293.
10 D. Gewirth, The HKL Manual, written with the co-operation of the
program authors, Z. Otwinowski and W. Minor, Yale University,
1995.
11 E. Prince, Mathematical Techniques in Crystallography and Material
Sciences, Springer, New York, 1982.
12 D. J. Watkin, C. K. Prout, J. R. Carruthers and P. W. Betteridge,
CRYSTALS, Issue 10, Chemical Crystallography Laboratory,
University of Oxford, 1996.
13 International Tables for Crystallography, Kluwer, Dordrecht, 1992,
vol. C.
Paper 8/03126F
3194
J. Chem. Soc., Dalton Trans., 1998, 3191–3194