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AntimonyЦTungsten Triple Bond A Stable Complex with a Terminal Antimony Ligand.

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Communications
Pnicogen Complexes
DOI: 10.1002/anie.200500781
Antimony–Tungsten Triple Bond: A Stable
Complex with a Terminal Antimony Ligand**
Gbor Balzs, Marek Sierka, and Manfred Scheer*
Dedicated to Professor Wolf-Walther du Mont
on the occasion of his 60th birthday
Complexes with transition-metal–element triple bonds of the
heavier main-group elements constitute an exciting area in
chemistry, since the investigation of the bonding situation as
well as the reactivity potential open up a significant area of
research. However, stability and reactivity are often opposing
tendencies; thus existing complexes are often kinetically
stabilized by bulky substituents to encumber the reactive
triple bond. Exciting examples for this particular development in the chemistry of Group 14 elements are the recently
synthesized complexes with a metal–lead triple bond.[1] Now,
this series in Group 14 chemistry is almost complete.[2] For
Group 15 elements however,[3] there still remains the challenge to synthesize stable complexes with terminal stibido as
well as bismutido ligands. Indications of existing complexes
with a terminal stibido ligand as intermediates were first
reported by Rheingold et al. They were able to generate
briefly existing complexes of the formulae [(OC)4MSb] (M =
Cr, Mo, W) and [(OC)3FeSb] in the gas phase under the
conditions of a Fourier transform cyclotron resonance spectrometer (FT-ICR).[4] The breakthrough for the synthesis of
stable triply bonded terminal ligands of heavier[5] Group 15
elements occurred almost 10 years ago in 1995 when we were
able to characterize spectroscopically the stable phosphido
complex [(tBuO)3WP!W(CO)5] (1) [6] which was structurally characterized in 1999.[7] The difficulties in isolation arise
from the high reactivity potential of this complex, since the
[*] Dr. G. Balzs, Prof. Dr. M. Scheer
Institut f%r Anorganische Chemie
Universit,t Regensburg
93040 Regensburg (Germany)
Fax: (+ 49) 941-943-4439
E-mail: mascheer@chemie.uni-regensburg.de
Dr. M. Sierka
Institut f%r Chemie
Humboldt-Universit,t zu Berlin
Unter den Linden 6, 10099 Berlin (Germany)
[**] This work was supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie. M. Sierka gratefully
acknowledges Prof. Joachim Sauer and the Humboldt-Universit,t
zu Berlin for providing computing facilities and Gregor Schnakenburg for helpful discussion. The recording of the Raman spectrum
of the title complex by Dr. G. StCßer (University of Karlsruhe) is
greatly appreciated.
Supporting information for this article is available on the WWW
under http://www.angewandte.org or from the author.
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2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2005, 44, 4920 –4924
Angewandte
Chemie
tBuO groups only protect the triple bond in the solid state,
whereas in solution the bond is still accessible.
Independently Cummins[8] and Schrock and co-workers[9]
chose the steric protection of the MP triple bond by bulky
substituents at the amido ligands, when they reported in 1995
the synthesis and the first structural characterization of
terminal phosphido complexes [(Ph’’RN)3MoP] (2; Ph’’ =
3,5-Me2C6H3 ; R = C(CD3)2CH3) and [(N3N)WP] (3; N3N =
tren = N(CH2CH2NSiMe3)3). Compound 3 was synthesized by
treating [(N3N)WCl] (5)[10] with two equivalents of LiP(H)Ph.
The use of Li[E(SiMe3)2] (E = P, As) in reaction with 5
enabled us, in addition to an alternative route to 3, the
synthesis of [(N3N)WAs] (4), the first terminal arsenido
complex,[11] which was independently obtained by Schrock
et al.[12] Our efforts to obtain the stibido complex
[(N3N)WSb] (6) in the same manner as the arsido and
phosphido complexes 4 and 3 failed, probably because of the
bulkiness of the [(Me3Si)2Sb] fragment which did not fit into
the cone formed by the three SiMe3 groups of the tren ligand.
Sterically less-demanding alkyl groups on the tris(amido)amine ligand such as isopropyl or neopentyl permitted the reaction of [(Me3Si)2E] (E = Sb, Bi) with 5 but did not
prevent further dimerization to form the heterocumulene
complexes [{N(CH2CH2NR)3W}2(m-Sb)] (R = iPr, Np).[13, 14]
Now we have finally succeeded in the synthesis and spectroscopic and structural characterization of the first isolable
stibido complex [(N3N)WSb] (6) which contains an antimony–tungsten triple bond.
For the synthesis of 6, (Me3Si)2CHSbH2 was lithiated at
60 8C with nBuLi in THF to generate Li[(Me3Si)2CHSb(H)]
as a reactive intermediate. The reaction of this solution with 5
leads to the formation of the stibido complex 6 [Eq. (1)].
Information).[16] The synthesis and spectroscopic data of 7
have been reported previously, as it is obtained in the reaction
of 5 with Li[CH2SiMe3].[17]
Complex 6 is a diamagnetic, air-sensitive, brown crystalline compound, which is readily soluble in hydrocarbons. In
the mass spectra the molecular ion peak was observed. The
relatively weak emission band at 240 cm1 in the Raman
spectra of 6 is in agreement with a tungsten–antimony triple
bond. In comparison the stretching frequencies for the lighter
WE homologues were found at 343 cm1 (E = As) and
516 cm1 (E = P).[18] The solution 1H- and 13C NMR spectra of
6 show the presence of a C3 symmetric ligand system. The C3
symmetry is also preserved in the solid state. Complex 6
crystallizes as brown cubes in the cubic space group Pa3̄.[16]
The main feature of the structure of 6 (Figure 1) is a
terminally coordinated antimony ligand. The observed WSb
distance in 6 of 2.5255(17) D is the shortest reported to date,
Figure 1. Crystal structure 6. Hydrogen atoms are omitted for clarity.
Selected bond lengths [G] and angles [8]: W1-Sb1 2.5255(17), W1-N1
1.994(8), W1-N2 2.330(12), Si1-N1 1.759(8); N1-W1-N1’ 115.93(15),
N1-W1-N2 78.2(2), N1-W1-Sb1 101.8(2), N2-W1-Sb1 180.0(4), Si1-N1W1 125.8(4), C1-N1-W1 118.1(6), C1-N1-Si1 115.8(6).
Owing to the instability of the lithiated stibane, it was
necessary to use an excess of RSbH2 and nBuLi to achieve
total consumption of 5. Thus, as side products the ethylidyne
complex [(N3N)WCCH3] and Sb73 were formed as a result
of the degradation of the tris(amido)amine ligand and the
stibane, respectively. Furthermore, depending on the solvents
used and the lithium base other side products could be
identified.[15]
Decrease of the steric bulkiness of the antimony reactant
was expected to increase the yield of 6. Therefore we treated
the comparatively slender [Me3SiCH2(H)Sb] moiety with 5
under the conditions described above. Against our expectations the alkylidyne complex [(N3N)WCSiMe3] (7) was
obtained in about 50 % yield. The low thermal stability of
Li[Me3SiCH2(H)Sb] gives rise to transmetalation reactions
with the formation of Li[Me3SiCH2], which reacts with 5 to
give 7. The characterization of 7 was achieved spectroscopically and by single-crystal X-ray diffraction (see Supporting
Angew. Chem. Int. Ed. 2005, 44, 4920 –4924
consistent with the representation as a triple bond, and is
comparable only with the WSb distances in the heterocumulene complexes [{N(CH2CH2NR)3W}2Sb] (2.5275(5) D
R = iPr;[13] 2.574(1) D R = CH2C(CH3)3[14]). Longer W–Sb
bonds were observed in the stibinidene complexes
[{(OC)5W}2SbCl(thf)] (2.662(1) and 2.670(2) D)[19] and
[{(OC)5W}2SbCH(SiMe3)2] (2.687(1) D).[20] The tungsten
atom has a distorted trigonal bipyramidal coordination
geometry with three N atoms in equatorial and one N and a
Sb atom in axial positions. The NeqW distance of 1.994(8) D
is comparable with the corresponding distances in
[(N3N)WCl] (5) (1.985(11) D),[10] [(N3N)WP] (3)
(1.975(6) D)[9] and [(N3N)WAs] (4) (1.989(4) D).[11] The
NaxW distance (2.330(12) D) is longer than in 5 (2.182(6) D)
but similar to those in 3 (2.343(4) D) and 4 (2.336(6) D). The
Neq-W-Neq (115.9(2)8) and Neq-W-Nax (78.2(2)8) angles compare well with the equivalent angles in 5 and 3 (115.8(11),
78.1(2)8, and 115.69(8), 77.9(1)8, respectively). Along the
series 3, 4, and 6 a very slight shortening of the Nax–W distance
is observed, reflecting the increase of the electropositive
2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Table 2: Results of the bonding analyses for compounds 3, 4, 6, and 8.[a]
character of the terminal Group 15
ligand. None other structural
Compound Partial
NBO
WBI De
parameters of the tren ligands is
charge
occ
% W W hyb (% s)[b] % E E hyb (% s)[b]
significantly influenced by the
3
nature of the terminal ligand. As
W: 0.84
s: 1.917 42.2
sd1.30 (43.5)
57.8 sp3.30 (23.2)
2.38 481.9
the size of the ligand E increases
P: 0.03 p: 1.652 46.9
d
53.1 p
going from As to Sb, the cone
p: 1.664 47.3
d
52.7 p
4
formed from the three SiMe3
57.2 sp3.96 (20.1)
2.35 429.0
W: 0.81
s: 1.913 42.8
sd1.24 (44.6)
groups is widened. This effect can
As: 0.01
p: 1.636 47.3
d
52.7 p
be observed in the W-Neq-Si angles
p: 1.636 48.2
d
51.8 p
(125.0(2) for 4 and 125.8(4)8 for 6).
6
The wider angle for 3 (125.5(4)8) in
W: 0.73
s: 1.890 45.8
sd1.10 (47.6)
54.2 sp4.75 (17.4)
2.28 333.4
comparison to 4 can be explained
Sb: 0.11
p: 1.591 47.3
d
52.7 p
p: 1.643 49.4
d
50.6 p
by the shorter WP bond.
8
Density functional theory
W: 0.71
s: 1.887 46.0
sd1.09 (47.8)
54.0 sp6.06 (14.2)
2.27 293.3
(DFT) calculations of complexes
Bi: 0.15
p: 1.664 51.4
d
48.6 p
3, 4, 6, and a hypothetical complex
p: 1.555 47.2
d
52.8 p
[(N3N)WBi] (8) were performed
[a] NBO partial charges, NBO occupancies (occ), bond polarizations in % W and % E (3: E = P, 4: E = As,
to compare the [(N3N)WE] (E =
6: E = Sb, 8: E = Bi), orbital hybridizations (hyb), Wiberg bond indices (WBI), and bond dissociation
P, As, Sb, Bi) triple bonds of the
energies (De, kJ mol1). [b] Contribution of the s orbital [%].
Group 15 elements (Table 1 and
Table 2). The calculated structural
parameters of 3, 4, and 6 (Table 1) are similar to other
The W atom in the WE s bond is approximately sd hybrireported values[11, 21] and in a reasonable agreement with
dized, with a slight increase of s character for heavier
pnicogen atoms. This situation is in disagreement with earlier
experimental data, except for the WN2 distance. The
published results using the PESHO
method,[11] which indicate a largely d charTable 1: Comparison of selected experimental and calculated structural parameters [G,8] of complexes 3,
acter of the tungsten contribution. The
4, 6, and 8.
hybridization of the pnicogen atom in
W–E[a]
W–N
W–N2
E-W-N1[a]
N1-W-N1
N1-W-N2
WE s bond has a significant p character
[9]
which increases from P to Bi and the two
3 exp
2.162(4)
1.975(6)
2.34(1)
101.9(2)
115.8(11)
78.1(2)
p components are composed mainly of d
3 calcd
2.185
2.017
2.504
103.6
114.7
76.5
and p orbitals of the tungsten and pnicogen
4 exp[11]
2.2903(11)
1.989(4)
2.336(6)
102.15(11)
115.69(8)
77.85(11)
4 calcd
2.294
2.017
2.499
103.6
114.7
76.4
atoms, respectively.
6 exp
2.5255(17)
1.994(8)
2.330(12)
101.8(2)
115.93(15)
78.2(2)
Further support for the WE triple6 calcd
2.514
2.015
2.516
104.1
114.3
75.9
bond character arise form the inspection of
8 calcd
2.590
2.016
2.507
103.9
114.4
76.1
calculated molecular orbitals. The orbital
[a] 3: E = P, 4: E = As, 6: E = Sb, 8: E = Bi.
picture of the WE is very similar for all
investigated Group 15 elements and shows
one s and two degenerate p components.
Figure 2 shows an example of the WSb bond orbitals of 6.
experimental values are 0.16–0.19 D shorter which may be
The calculated NBO partial charges indicate that the tungsten
due to solid-state effects.[21] As expected, the calculated WE
atom carries significant positive charge while the pnicogen
bond lengths increase from E = P to E = Bi. This trend has
atoms are almost neutral or slightly positive charged (Sb, Bi).
also been found in similar metal–pnicogen complexes with
This result supports a strong covalent character of the
alkoxy ligands.[22] The calculated WE harmonic stretching
tungsten–pnicogen triple bond. The calculated bond-dissocifrequencies of 515 cm1 (E = P) and 342 cm1 (E = As) are in
ation energies decrease monotonically from P to Bi confirmexcellent agreement with observed data.[18] For E = Sb the
ing that the heavier pnicogen atoms have significantly weaker
calculated value of 264 cm1 is slightly overestimated with
WE bonds. Finally, the calculated [(N3N)WE] complexes
respect to the experiment, probably due to the neglect of
anharmonicity and approximate treatment of relativistic
effects. Additionally, the WSb stretching mode shows a
strong coupling to other framework modes.
Analysis of the bonding situation using the natural bond
orbital (NBO)[23] scheme and Wiberg bond indices (WBI)[24]
strongly support the presence of WE triple bond in all
calculated complexes (Table 2). Similar to other terminal
pnicogen ligands in alkoxy substituted tungsten–pnicogen
complexes[22] the s and p components of the triple bonds
Figure 2. Kohn–Sham orbitals of the s component (left) and two
obtained by the NBO analysis show only weak polarization.
p components (middle and right) of the WSb triple bond.
4922
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2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2005, 44, 4920 –4924
Angewandte
Chemie
show orbital and partial-charge patterns similar to those
calculated for [(MeO)3WE] by Pandey and Frenking,[22]
except for less positively charged tungsten atoms.
The results have shown the tris(amido)amine ligand
complex of tungsten to be an excellent system for stabilization
of terminal pnicogenido ligand complexes containing a WE
triple bond. Now that the synthesis of the first stable terminal
stibido ligand complex has been realized the path has been
cleared for reactivity studies and the synthesis of the unknown
bismutido complex.
[3]
[4]
[5]
Experimental Section
All manipulations were performed under an atmosphere of dry
nitrogen using a glovebox and Schlenk techniques. Solvents were
purified and degassed by standard procedures.
6: nBuLi in hexane (1.59 mL, 2.55 mmol, 1.6 m) was added to a
stirred solution of (Me3Si)2CHSbH2 (720 mg 2.55 mmol) in THF
(5 mL), at 60 8C. The solution became dark red and gas evolution
was observed. The reaction mixture was allowed to warm slowly to
room temperature and a solution of [N(CH2CH2NSiMe3)3WCl]
(369 mg, 0.64 mmol) in toluene (12 mL) was added. The mixture
was stirred for 20 h at 80 8C. All volatiles were removed in vacuum
and the remaining black product was extracted with pentane (70 mL).
Compound 6 was isolated from the orange-brown solution as brown
cubes by fractionated crystallization at 5 8C. Yield: 37 mg (9 %).
1
H NMR (250 MHz, C6D6, 25 8C, TMS): d = 0.847 (s, 2J(Si,H) =
5.85 Hz, 27 H; CH3), 1.40 (t, 3J (H,H) = 5.6 Hz, 6 H; CH2), 3.58 ppm
(t, 3J(H,H) = 5.6 Hz, 6 H; CH2); 13C NMR (62.89 MHz, C6D6, 25 8C,
TMS): d = 7.70 (s, CH3), 51.66 (s, CH2), 54.36 ppm (s, CH2); EI-MS
(70 eV): m/z (%): 666 (40) [M+], 651 (100) [MCH3]+, 636 (2)
[M2 CH3]+, 621 (4) [M3 CH3]+, 593 (5) [M(CH3)3Si]+, 73 (95)
[(CH3)3Si]+. Raman (solid): ñ = 240 cm1 (WSb). Elemental analysis
(%)calcd for C15H39N4Sb1Si3W1 (665.35): C 27.08, H 5.91, N 8.42;
found: C 27.39, H 6.19, N 8.37.
The synthesis and X-ray structure of 7 is given in the Supporting
Information
Structure optimizations and vibrational analyses at the DFT level
were performed using the TURBOMOLE program package.[25] The
BP86[26] exchange-correlation functional was used along with the
triple zeta plus polarization (TZVP) basis set on all atoms.[27] To speed
up calculations the Coulomb part was evaluated using the MARI-J
method.[28] Quasi-relativistic pseudopotentials were used for the
elements W, Sb, and Bi.[29] The NBO analysis was performed using the
Gaussian03 program.[30] Calculations for 3, 4, 6, and 8 were performed
assuming C3 symmetry and the nature of the stationary points was
confirmed by vibrational analysis (no imaginary frequencies).
Received: March 3, 2005
Published online: July 6, 2005
.
Keywords: antimony · bond analysis · density functional
calculations · pnicogen ligands · tungsten
[1] a) A. C. Filippou, N. Weidemann, G. Schnakenburg, H. Rohde,
A. I. Philippopoulos, Angew. Chem. 2004, 116, 6674 – 6678;
Angew. Chem. Int. Ed. 2004, 43, 6512 – 6516; b) A. C. Filippou,
H. Rohde, G. Schnakenburg, Angew. Chem. 2004, 116, 2293 –
2297; Angew. Chem. Int. Ed. 2004, 43, 2243 – 2247; c) For a recent
review in this field see: M. Weidenbruch, Angew. Chem. 2003,
115, 2322 – 2324; Angew. Chem. Int. Ed. 2003, 42, 2222 – 2224.
[2] For a discussion of the possible existence of the to date missing
complex with a metal–silicon triple bond see: B. V. Mork, D. T.
Angew. Chem. Int. Ed. 2005, 44, 4920 –4924
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
Tilley, Angew. Chem. 2003, 115, 371 – 374; Angew. Chem. Int. Ed.
2003, 42, 357 – 360.
For a recent review in this field see: B. P. Johnson, G. BalMzs, M.
Scheer, Top. Curr. Chem. 2004, 232, 1 – 23, which continues the
review: M. Scheer, Coord. Chem. Rev. 1997, 163, 271 – 286.
F. P. Arnold, D. P. Ridge, A. L. Rheingold, J. Am. Chem. Soc.
1995, 117, 4427 – 4428.
For reviews concerning the long-existing nitride complexes see:
a) K. Dehnicke, J. StrOhle, Angew. Chem. 1981, 93, 451 – 464;
Angew. Chem. Int. Ed. Engl. 1981, 20, 413 – 426; b) W. A.
Herrmann, Angew. Chem. 1986, 98, 57 – 77; Angew. Chem. Int.
Ed. Engl. 1986, 25, 56 – 76; c) K. Dehnicke, J. StrOhle, Angew.
Chem. 1992, 104, 978 – 1000; Angew. Chem. Int. Ed. Engl. 1992,
31, 955 – 978; d) K. Dehnicke, F. Weller, J. StrOhle, Chem. Soc.
Rev. 2001, 30, 125 – 135.
M. Scheer, K. Schuster T. A. Budzichowski, M. H. Chisholm,
W. E. Streib, J. Chem. Soc. Chem. Commun. 1995, 1671 – 1672.
a) P. Kramkowski, G. Baum, U. Radius, M. Kaupp, M. Scheer,
Chem. Eur. J. 1999, 5, 2890 – 2898; b) M. Scheer, P. Kramkowski,
K. Schuster, Organometallics 1999, 18, 2874 – 2883.
C. E. Laplaza, W. M. Davis, C. C. Cummins, Angew. Chem. 1995,
107, 2181 – 2183; Angew. Chem. Int. Ed. Engl. 1995, 34, 2042 –
2043.
R. R. Schrock, N. C. Zanetti, W. N. Davis, Angew. Chem. 1995,
107, 2184 – 2186; Angew. Chem. Int. Ed. Engl. 1995, 34, 2044 –
2046.
K.-Y. Shih, K. Totland, S. W. Seidel, R. R. Schrock, J. Am. Chem.
Soc. 1994, 116, 12 103 – 12 104.
M. Scheer, J. MPller, M. HOser, Angew. Chem. 1996, 108, 2637 –
2641; Angew. Chem. Int. Ed. Engl. 1996, 35, 2492 – 2494.
N. C. MQsch-Zanetti, R. R. Schrock, W. M. Davis, K. Wanninger,
S. W. Seidel, M. B. ORDonoghue, J. Am. Chem. Soc. 1997, 119,
11 037 – 11 048.
M. Scheer, J. MPller, M. Schiffer, G. Baum, R. Winter, Chem.
Eur. J. 2000, 6, 1252 – 1257.
M. Scheer, J. MPller, G. Baum, M. HOser, Chem. Commun. 1998,
2505 – 2506.
A large number of reactions according to Eq. (1) were carried
out to clarify the formation of the additional side-products
(besides [(N3N)WCCH3] and Sb73): for example, the reaction
in toluene with nBuLi as metalation reagent leads to [N3NW
CC3H7] as a result of the reaction of 5 with nBuLi, whereas with
tBuLi in toluene, [N3NWCC6H5] was observed, formed as a
result of the metalation of toluene and subsequent reaction with
5. In contrast the use of THF or toluene as solvent with KH as
metalation reagent as well as the reaction in benzene at 5 8C with
nBuLi leads only to the “usual” side-products [(N3N)WCCH3]
and Sb73.
Crystal-structure analyses of 6 and 7 were performed on a STOE
IPDS diffractometer with AgKa radiation (l = 0.56087 D). The
structures were solved by direct methods with the program
SHELXS-97,[31a] and full-matrix least-squares refinement on F2
in SHELXL-97[31b] was performed with anisotropic displacements for non-Hydrogen atoms. Hydrogen atoms were located
in idealized positions and refined isotropically according to the
riding model 6: C15H39N4SbSi3W, Mr = 665.37, Crystal size 0.20 U
0.15 U 0.04 mm3, cubic space group Pa3̄ (no. 205); a =
17.297(2) D, T = 203(2) K, Z = 8, V = 5174.8(10) D3, 1calcd =
1.708 Mg m3, m(AgKa) = 3.022 mm1, 1640 unique reflections
(2qmax = 408), 79 parameters, R1 = 0.0527, wR2 = 0.1565. 7:
C19H48N4SbSi4W, Mr = 628.82, crystal size 0.50 U 0.40 U
0.20 mm3, monoclinic space group P21 (no. 4); a = 10.266(2),
b = 11.711(2), c = 12.290(3) D, b = 91.628, T = 203(2) K, Z = 2,
V = 1477.0(5) D3, 1calcd = 1.414 Mg m3, m(AgKa) = 2.199 mm1,
6620 unique reflections (2qmax = 458), 267 parameters, R1 =
0.0217, wR2 = 0.0554, flack parameter 0.019(9). CCDC263922 (6) and CCDC-263921 (7) contain the supplementary
2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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4923
Communications
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
4924
crystallographic data for this paper. These data can be obtained
free of charge from the Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
R. R. Schrock, S. W. Seidel, N. C. MQsch-Zanetti, D. A. Dobbs,
K.-Y. Shih, W. M. Davis, Organometallics 1997, 16, 5195 – 5208.
J. A. Johnson-Carr, N. C. Zanetti, R. R. Schrock, M. D. Hopkins,
J. Am. Chem. Soc. 1996, 118, 11 305 – 11 306.
M. Schiffer, diplom thesis, Karlsruhe, 1997.
A. M. Arif, A. H. Cowley, N. C. Norman, M. Pakulski, Inorg.
Chem. 1986, 25, 4836 – 4840.
T. Wagener, G. Frenking, Inorg. Chem. 1998, 37, 1805 – 1811.
K. K. Pandey, G. Frenking, Eur. J. Inorg. Chem. 2004, 4388 –
4395.
a) J. P. Foster, F. Weinhold, J. Am. Chem. Soc. 1980, 102, 7211 –
7218; b) A. E. Reed, L. A. Curtiss, F. Weinhold, Chem. Rev.
1988, 88, 899 – 926.
K. A. Wiberg, Tetrahedron 1968, 24, 1083 – 1096.
a) R. Ahlrichs, M. BOr, M. HOser, H. Horn, C. KQlmel, Chem.
Phys. Lett. 1989, 162, 165 – 169; b) O. Treutler, R. Ahlrichs, J.
Chem. Phys. 1995, 102, 346 – 354.
www.angewandte.org
[26] a) A. D. Becke, Phys. Rev. A 1988, 38, 3098 – 3100; b) S. H.
Vosko, L. Wilk, M. Nusair, Can. J. Phys. 1980, 58, 1200 – 1211;
c) J. P. Perdew, Phys. Rev. B 1986, 33, 8822 – 8824; erratum: J. P.
Perdew, Phys. Rev. B 1986, 34, 7406.
[27] a) A. SchOfer, H. Horn, R. Ahlrichs, J. Chem. Phys. 1992, 97,
2571 – 2577; b) A. SchOfer, C. Huber, R. Ahlrich, J. Chem. Phys.
1994, 100, 5829 – 5835; c) K. Eichkorn, F. Weigend, O. Treutler,
R. Ahlrichs, Theor. Chem. Acc. 1997, 97, 119 – 124.
[28] a) K. Eichkorn, O. Treutler, H. Whm, M. HOser, R. Ahlrichs,
Chem. Phys. Lett. 1995, 242, 652 – 660; b) M. Sierka, A.
Hogekamp, R. Ahlrichs, J. Chem. Phys. 2003, 118, 9136 – 9148.
[29] a) D. Andrae, U. HOußermann, M. Dolg, H. Stoll, H. Preuss,
Theor. Chim. Acta 1990, 77, 123 – 141; b) W. KPchle, M. Dolg, H.
Stoll, H. Preuss, Mol. Phys. 1991, 74, 1245 – 1263; c) A. Bergner,
M. Dolg, W. KPchle, H. Stoll, H. Preuss, Mol. Phys. 1993, 80,
1431 – 1441.
[30] Gaussian 03 (Revision B.04): M. J. Frisch, et al., see Supporting
Information.
[31] a) G. M. Sheldrick, SHELXS-97, UniversitOt GQttingen, 1996;
b) G. M. Sheldrick, SHELXL-97, UniversitOt GQttingen, 1997.
2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2005, 44, 4920 –4924
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