Synthesis and some properties of 14 group element-containing alkylidene complexes of molybdenum and tungsten

Article abstract of DOI:10.1016/j.jorganchem.2005.07.035

Alkylidene complex of molybdenum Ph₃Si-CHMo(NAr)(OCMe ₂CF₃)₂ (1) (Ar=2,6-Pr2iC6H3) has been prepared by the reaction of Ph₃SiCHCH₂ with known alkylidene compounds Alkyl-CHMo(NAr)(OCMe₂CF₃)₂ (Alkyl = Bu^t, PhMe₂C). According to X-ray diffraction studies the geometry of the Mo atom in (1) can be described as a distorted tetrahedron. Reactions of heteroelement-containing imido alkyl compounds of molybdenum and tungsten (ArN)₂M(CH₂EMe₃)₂ (Ar=2,6-Pr2iC6H3; M = Mo. W; E = Si, Ge, Sn) with triflic acid were shown to yield a complex mixture of products among which carbene complexes have not been observed. The formation of carbene complexes of tungsten in low yields was observed by ¹H NMR spectroscopy in the reactions of (ArN) ₂W(CH₂EMe₃)₂ (E = Si, Ge, Sn) with hydrogen chloride in THF-d₈. Catalytic properties of heteroelement-containing alkylidene complexes of molybdenum R ₃E-CHMo(NAr)(OCMe₂CF₃)₂ (E = Si, Ge; R = Me, Ph) and also hydrocarbon analogs Alkyl-CHMo(NAr)(OCMe ₂CF₃)₂ (Alkyl = Bu^t, PhMe ₂C) in metathesis of 1-hexene were investigated. The catalytic activity of alkylidene complexes was shown to depend essentially on the nature of substituent bonded to carbene carbon atom.

Full text of DOI:10.1016/j.jorganchem.2005.07.035

Journal of Organometallic Chemistry 690 (2005) 5720–5727
www.elsevier.com/locate/jorganchem
Synthesis and some properties of 14 group element-containing
alkylidene complexes of molybdenum and tungsten
*
Leonid N. Bochkarev , Yulia E. Begantsova, Vladislav I. Shcherbakov,
Natalia E. Stolyarova, Irina K. Grigorieva, Irina P. Malysheva, Galina V. Basova,
Andrey L. Bochkarev, Yulia P. Barinova, Georgii K. Fukin, Evgenii V. Baranov,
Yurii A. Kurskii, Gleb A. Abakumov
G.A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, Russian Federation, Tropinina 49,
Nizhny Novgorod 603950, Russia
Received 30 May 2005; accepted 8 July 2005
Available online 30 August 2005
Abstract
i
2
Alkylidene complex of molybdenum Ph
tion of Ph SiCH@CH
3
Si–CH@Mo(NAr)(OCMe
2
CF
3
)
2
(1) ðAr ¼ 2; 6-Pr C
6
H
3
Þ has been prepared by the reac-
t
3
2
2 3 2 2
with known alkylidene compounds Alkyl-CH@Mo(NAr)(OCMe CF ) (Alkyl = Bu , PhMe C). According
to X-ray diffraction studies the geometry of the Mo atom in (1) can be described as a distorted tetrahedron. Reactions of heteroel-
i
2
ement-containing imido alkyl compounds of molybdenum and tungsten (ArN) M(CH EMe ) (Ar ¼ 2; 6-Pr C
6 3
H ; M = Mo. W;
2
2
3 2
E = Si, Ge, Sn) with triflic acid were shown to yield a complex mixture of products among which carbene complexes have not been
observed. The formation of carbene complexes of tungsten in low yields was observed by H NMR spectroscopy in the reactions of
1
(
ArN) W(CH EMe ) (E = Si, Ge, Sn) with hydrogen chloride in THF-d . Catalytic properties of heteroelement-containing alky-
2
2
3 2
8
lidene complexes of molybdenum R
Alkyl-CH@Mo(NAr)(OCMe CF
3
E–CH@Mo(NAr)(OCMe
(Alkyl = Bu , PhMe C) in metathesis of 1-hexene were investigated. The catalytic activity of
2
2
CF
3
)
2
(E = Si, Ge; R = Me, Ph) and also hydrocarbon analogs
t
2
3
)
2
alkylidene complexes was shown to depend essentially on the nature of substituent bonded to carbene carbon atom.
ꢀ
2005 Elsevier B.V. All rights reserved.
Keywords: Alkylidene complexes; Molybdenum; Tungsten; Silicon; Germanium; Tin; Synthesis; Structure elucidation; Olefin metathesis; Catalytic
activity
1
. Introduction
PhMe C). The reaction was originally developed by
2
Schrock and co-workers for preparation of trimethyl-
silyl-containing carbene compounds of molybdenum
and tungsten [2].
We have recently reported the synthesis of germa-
nium-containing alkylidene complexes of molybdenum
R Ge–CH@Mo(NAr)(OCMe CF ) (R = Me, Ph) [1]
prepared by the reaction of organogermanium vinyl
Herein we report the synthesis by the above method
of the triphenylsilyl-containing complex (1). The results
of attempted preparation of heteroelement-containing
carbene complexes of molybdenum and tungsten by
reactions of imido alkyl compounds (ArN) M(CH -
3
2
3 2
reagents R Ge–CH@CH with known alkylidene com-
3
2
t
pounds Alkyl-CH@Mo(NAr)(OCMe CF ) (Alkyl = Bu ,
2
3 2
2
2
*
EMe ) (M = Mo. W; E = Si, Ge, Sn) with triflic acid
3 2
and hydrogen chloride are reported and discussed as
well. Catalytic properties of a series of silicon- and
Corresponding author. Tel.: +7 8312 12 7010; fax: +7 8312 12
497.
E-mail address: lnb@imoc.sinn.ru (L.N. Bochkarev).
7
0
022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.07.035

L.N. Bochkarev et al. / Journal of Organometallic Chemistry 690 (2005) 5720–5727
5721
1
3
germanium-containing carbene complexes of molybde-
(d, 256.6 ppm) – observed in C MNR spectrum of
product 1 are almost equal. Therefore, we can only
propose on the basis of signal intensities (typically a
syn isomer has a major signal [3]) that the resonances
num R E–CH@Mo(NAr)(OCMe CF ) (E = Si, Ge;
3
2
3 2
R = Me, Ph) and also hydrocarbon analogs Alkyl-
t
CH@Mo(NAr)(OCMe CF ) (Alkyl = Bu , PhMe C)
2
3 2
2
1
in metathesis of 1-hexene have been studied.
at 13.29 ppm and at 12.87 ppm are in the H NMR spec-
trum are related, respectively, to syn and anti rotamers
of the formed complex 1.
The molybdenum alkylidene complex 1 was isolated
as air-sensitive yellow-orange crystalline solid. It was
2
. Results and discussion
The reactions of Alkyl-CH@Mo(NAr)(OCMe CF )
1
13
characterized by elemental analysis, H NMR,
NMR spectroscopy. The structures of 1 known com-
pound Me Si–CH@Mo(NAr)(OCMe CF ) (4) were
C
2
3 2
t
(
Alkyl = Bu (2), PhMe C (3)) with Ph Si–CH@CH
2
3
2
were found to proceed much more slowly than the
3
2
3 2
determined by X-ray diffraction studies. According to
X-ray data the complexes 1 and 4 have a syn-conforma-
tion. The Mo and Si atoms have a typical tetrahedral
coordination environment (Figs. 1 and 2). The Mo(1)-
N(1)C(1) (in 1) and Mo(1)N(1)C(13) (in 4) angles in
diisopropylphenylimido ligands are equal to 174.8(2)ꢁ
and 168.3(1)ꢁ, respectively. It should be noted that the
coordinating environments of Mo and Si atoms in 1, 4
are a quite similar to coordinating environments of
Mo and Ge atoms in R Ge–CH@Mo(NAr)(OCMe -
analogous reactions with Me Si–CH@CH [2a] and
3
2
R Ge–CH@CH [1] and to complete in 2 months at
3
2
room temperature (Eq. (1)):
Alkyl-CH@MoðNArÞðOCMe
2
CF
3
Þ2 þ Ph
3
SiCH@CH
2
Benzene
!
1 þ Alkyl-CH@CH
2
t
Alkyl ¼ Bu ð2Þ; PhMe
2
Cð3Þ
ð1Þ
1
The course of the reactions was monitored by H
NMR. In contrast to previously studied similar reac-
tions of compounds 2 and 3 with organogermanium
vinyl reagents [1] the following interesting changes were
3
2
CF3)2 (R = Me, Ph) complexes [1]. The Mo(1)–N(1)
˚
distances are 1.725(2) and 1.722(2) A for 1 and 4, respec-
observed in the H region. Just after the mixing of the
reagents besides of the resonance at 11.61 ppm
tively. The geometries of the MoCSi fragments are
slightly different in 1 and 4. The main difference is
observed in the values of MoCSi angles. In more bulky
1, the Mo(1)C(21)Si(1) (144.8(2)ꢁ) angle is significantly
larger than the analogous value in 4 (138.5(1)ꢁ). The
a
(
JHC = 119.4 Hz) of the H of the starting compound
a
2
[2a] an additional signal at 11.16 (JHC = 137.0 Hz)
ppm was observed. The ratio of the signals was ꢀ6:1.
The following reaction led to the decreasing of the inten-
sities of the initial signals at 11.61 and at 11.16 ppm and
appearing the signals at 13.29 ppm and at 12.87 ppm
with ꢀ2:1 ratio of the forming complex 1. After the
completion of the reaction the signals at 11.61 and at
similar situation is observed in R Ge–CH@Mo(NAr)-
3
(OCMe CF ) (R = Me, Ph) complexes [1]. The Mo@
2
3 2
˚
C(SiR ) distances are close to each other (1.883(3) A
3
˚
in 1, 1.889(2) A in 4) and to the values of Mo@C(GeR )
3
˚
˚
distances (1.876(2) A for R = Ph and 1.889(2) A for
1
1.16 ppm were disappeared completely and the signals
R = Me [1]).
at 13.29 and at 12.87 ppm were increased and remained
with the ratio ꢀ2:1. The similar transformations were
observed in the reaction with 3 as a starting compound.
We propose that the minor signal at 11.16 ppm with the
lager JHC coupling constant (137.0 Hz) is related to anti
rotamer of the initial compound 2 and is unusually lo-
cated upfield from the major signal of the syn rotamer
(
11.61 ppm, JHC = 119.4 Hz [2a]). Syn–anti interconver-
sion of alkylidene complexes is well known [3] and the
lager JHC coupling constants (usually about 140 Hz)
for anti rotamers in comparison to syn rotamers (usually
about 125 Hz) is a characteristic feature for a wide
variety of molybdenum and tungsten alkylidene com-
pounds [3]. However, we have not yet a reasonable
explanation why just addition of silicon-containing vinyl
reagent in contrast to germanium-containing vinyl
reagents has led to syn–anti interconversion of the star-
ting compound 2. The JHC coupling constants for Ha
1
signals have not been observed in the H NMR spec-
trum of the product 1. The JCH coupling constants –
JCH = 112.4 Hz (d, 261.1 ppm) and JCH = 112.9 Hz
Fig. 1. Molecular structure of 1.

5722
L.N. Bochkarev et al. / Journal of Organometallic Chemistry 690 (2005) 5720–5727
E(1)
E(2)
Fig. 3. Molecular structure of 5 (E = Si) and 6 (E = Ge). (The carbon
atoms at C(7), C(10) and C(19), C(22) are omited for clarity.)
Fig. 2. Molecular structure of 4.
Although the reactions of alkylidene compounds 2
Complexes (ArN)(ArNH)Mo(CH SiMe ) (OTf) (5),
2
3 2
and 3 with organosilicon or organogermanium vinyl re-
agents allowed to obtain heteroelement-containing car-
bene complexes of molybdenum, this method seemed
to us somewhat inconvenient due to the multistep syn-
thesis of the starting materials. Therefore, we attempted
the synthesis of heteroelement-containing carbene com-
plexes of molybdenum and tungsten by the reactions of
(ArN)(ArNH)Mo(CH GeMe ) (OTf)(6),(ArN)(ArNH)-
2 3 2
W(CH GeMe ) (OTf) (7) were isolated in 60–80% yields
2
3 2
as air-sensitive orange (Mo) or pale green (W) crystal-
line solids. They were identified by elemental analysis,
1
13
29
H, C, Si NMR spectroscopy. According to X-ray
analysis the Mo atoms in compounds 5 and 6 have a
distorted trigonal-bipiramidal coordination with CH2-
silicon-, germanium- and tin-containing imido alkyl
EMe , ArNH ligands in the equatorial plane, whereas
ArN and OTf groups are apical positioned (Fig. 3).
3
i
compounds (ArN) M(CH EMe ) (Ar ¼ 2; 6-Pr C
6
H
3
;
2
2
3 2
2
M = Mo. W; E = Si, Ge, Sn) [4,5] with triflic acid and
hydrogen chloride. This method was successfully used
for preparation of hydrocarbon imido alkylidene com-
The Mo(1)–N(1) distances and Mo(1)N(1)C(1), Mo(1)
N(2)C(13) angles are close to each other (1.925(5) A˚
and 138.2(4)ꢁ, 174.8(4)ꢁ in 5; 1.917(2) A˚ and 136.3(1)ꢁ,
pounds of the type Alkyl-CH@M(NAr)(OTf) (DME)
175.6(2)ꢁ in 6) except for the bond lengths Mo(1)–N(2)
2
t
(
M = Mo, W; Alkyl = Bu , PhMe C) [2b,6].
which are distinctly different (1.716(4) A˚ in 5 and
2
The reactions of (ArN) M(CH EMe ) (M = Mo. W;
1.748(1) A˚ in 6). The Mo(1)–O(Tf) distances are also dif-
ferent (2.214(4) A˚ in 5 and 2.243(1) A˚ in 6) in contrast to
2
2
3 2
E = Si, Ge, Sn) with 3 equiv. of triflic acid in DME at
50 ꢁC followed with slow warming to room tempera-
ture led to the formation of amido imido compounds
ArN)(ArNH)M(CH EMe ) (OTf) (20–30%), anilinium
ꢁ
the equal bond lengths Mo–O(CMe CF ) in 1, 4
2
3
(1.901(1)–1.906(1) A˚ ). The Mo(1)–C(EMe ) distances
3
(
in 5, 6 vary in the narrow range of 2.091(5)–2.104(2)
A˚ . The MoCE bond angles (115.9(1)–126.8(3)ꢁ) are
2
3 2
salt (15–20%), Me E (15–20%) and some unidentified
4
3
products. Carbene complexes have not been observed
in the reaction mixtures. Amido imido compounds are
obviously the products of the first stage of the reactions.
To confirm this we showed that the reactions of imido al-
kyl compounds with 1 equiv. of triflic acid yielded the
amido imido compounds as the major products (Eq. (2)):
somewhat bigger than the typical values for sp carbon
atoms.
Similar chloro-containing amido imido complexes of
tungsten (ArN)(ArNH)W(CH EMe ) (Cl) (E = Si (8),
2
3 2
Ge (9)) were isolated in 30–35% yields in the reactions
of (ArN) W(CH EMe ) (E = Si, Ge) with 1 equiv. of
2
2
3 2
hydrogen chloride in THF (Eq. (3)):
ðArNÞ MðCH
2
EMe
3
Þ2 þ HOTf
EMe
2
DME
THF
!
ðArNÞðArNHÞMðCH
2
3
Þ2ðOTfÞ
ðArNÞ WðCH EMe Þ þ HCl
!
8ð9Þ E ¼ Si; Ge
2
2
3
2
ꢁ30 to 20 ꢂ
ꢂ
ꢁ
50
C
C
M ¼ Mo; W; E ¼ Si; Ge
ð2Þ
ð3Þ

L.N. Bochkarev et al. / Journal of Organometallic Chemistry 690 (2005) 5720–5727
5723
Table 1
Kinetic data for the metathesis of 1-hexene using molybdenum
a
catalysts
4
ꢁ1 ꢁ1
s )
Catalyst
Temp (ꢁC)
Conversion (%)
10 k (L mol
E(2)
2
3
4
22
22
20
26
26
40.55
30.17
13.98
19.01
7.63
4.77
3.22
1.14
1.73
0.35
1
1
0
1
a
E(1)
[
1-hexene]/[catalyst] = 300; neat 1-hexene; time of the reaction – 3
min.
Fig. 4. Molecular structure of 8 (E = Si) and 9 (E = Ge).
Complexes 8 and 9 are unstable in air pale green crys-
Fig. 5. Second-order kinetic plot for the metathesis of 1-hexene with
talline solids. They were characterized by elemental
ꢁ1
1
13
10 (d) and 11 (h) as catalysts; [1-hexene]
0
= 7.99 mol L
Cat] = 0.027 mol L at 26 ꢁC. Kinetic plots for other catalysts 2, 3
and 4 have a similar second-order character.
,
analysis, H, C NMR spectroscopy and X-ray diffrac-
tion studies.
ꢁ1
[
According to X-ray analysis the W atoms in com-
pounds 8 and 9 have a distorted trigonal-bipiramidal
coordination. As in 4 and 5, the equatorial positions oc-
cupy CH EMe , ArNH ligands. The chlorine atom and
(
ꢀ3–5%), Me ECl (ꢀ80%), ArNH (ꢀ80%), carbene
3
2
2
3
complexes (ꢀ3–5%) of the proposed composition
amido substituent are located in the apical sites (Fig. 4).
The W(1)–N(1,2) distances and the values of angles
[
(ArN)W(@CH–EMe )(Cl) ], and some other products
3
2
with W–CH fragments. The resonance signal of H
3
a
˚
around N(1), N(2) atoms are 1.924(2), 1.755(2) A and
atom in the fragment W@CH-SiMe3 was found at
1.82 ppm, in the fragment W@CH–GeMe – at 11.81
˚
1
1
36.6(1)ꢁ, 176.6(1)ꢁ for 8 and 1.933(2), 1.745(2) A and
35.0(1)ꢁ, 176.7(1)ꢁ for 9. It should be noted that the
1
3
ppm and in the fragment W@CH–SnMe – at 12.15
ppm downfield from TMS.
Catalytic properties of 14 group element-containing
carbene complexes of molybdenum in olefin metathesis
reactions have been explored using neat 1-hexene as a
testing substrate (Eq. (4)):
3
geometrical parameters of imido and amido fragments
in 8 and 9 are close to the appropriate parameters in
Mo-complexes 5 and 6. The W(1)–Cl(1) distances in 8
˚
and 9 (2.4920(5) and 2.4942(6) A correspondingly) are
significantly longer than the respective distances in
t
Ph E–CH@WCl (OBu )
2
(E = Si, Ge) (2.373(1)–
3
2
2
˚
Cat
.385(1) A [7]). The bond lengths W(1)–C(25, 29) and
2
CH
2
@CH–C
4
H
9
!C
4
H
9
–CH@CH–C
4
H
9
þCH
2
@CH
ð4Þ
The compounds R Ge–CH@Mo(NAr)(OCMe CF )
2
the values of W(1)C(25, 26)E(1, 2) angles in 8
˚
˚
(
(
2.104(2), 2.112(2) A; 118.85(9)ꢁ, 125.4(1)ꢁ) and in 9
2.111(2), 2.093(2) A; 116.2(1)ꢁ, 122.9(1)ꢁ) are close to
3
2
3 2
those in 5 and 6. The distances E(1)–C(25) and E(2)–
(R = Me (10), Ph (11)), and 4 were found to reveal high
catalytic activity in metathesis of 1-hexene, comparable
with catalytic activity of known, one of the most active
catalysts 2 and 3 (Table 1, Fig. 5). Comparison of the
rate constants presented in Table 1 allows to conclude
that germanium- and silicon-containing complexes 10,
11,4 are 2–14 times less active catalysts than hydrocar-
bon analogs 2 and 3. The activities of silicon-containing
complex 4 and germanium-containing analog 10 do not
differ significantly. The activity of the compounds 10,
11, 4 depends on the nature of radicals bonded to E
˚
C(29) are 1.889(2), 1.887(2) A for 8 and 1.973(2),
.976(2) A for 9. The difference between E–C distances
˚
1
is close to the difference between covalent radii of Si
and Ge atoms.
The reactions of tungsten imido alkyl compounds
(
ArN) W(CH EMe ) (E = Si, Ge, Sn) with 3 equiv. of
2 2 3 2
1
hydrogen chloride in THF-d according to H NMR
8
spectroscopy data completed at room temperature
within 10–30 min and yielded (ArN)(ArNH)W(CH2-
EMe ) (Cl) (ꢀ3–5%), [ArNH ][Cl] (ꢀ3–5%), Me E
3
2
3
4

5724
L.N. Bochkarev et al. / Journal of Organometallic Chemistry 690 (2005) 5720–5727
element. Complexes with Me radicals (10, 4) are more
active catalysts than complex with Ph radicals (11). It
is interesting to note that a similar feature was observed
for the hydrocarbon analogs 2 and 3. Complex with
Mo@CH–C(CH ) fragment (2) appeared to be some-
3.2. Preparation of Ph Si–CH@Mo(NAr)(OCMe -
3
2
CF ) (1)
3
2
A solution of Ph SiCH@CH (0.135 g, 0.48 mmol) in
3
2
2 mL of benzene was added to a solution of 2 (0.28 g,
0.48 mmol) in 3 mL of benzene. The reaction mixture
was kept at room temperature for 2 months. Evapora-
tion of the solvent and volatiles in vacuo and crystalliza-
tion of the solid residue from pentane (2 mL) afforded
0.17 g (45%) of 1 as yellow-orange crystals. Anal. Calc.
for C H F SiMoNO : C, 58.71; H, 5.70. Found: C,
3
3
what more active than complex with Mo@CH–
C(CH ) Ph fragment (3). Unfortunately, we could not
3
2
find in the literature an exact comparable data on activ-
ities of compounds 2 and 3 in metathesis of terminal ole-
fins. According [8] when a neopentylidene molybdenum
t
complex Bu -CH@Mo(NR)(ORÕ) (R = 2,6-Me C H ;
2
6
3
39 45
6
2
0
1
R = CMe(CF ) ) and a similar neophylidine complex
58.62; H, 5.64%. H NMR (200 MHz, C D ) d 13.29
6 6
3
2
PhMe C–CH@Mo(NR)(ORÕ) were used as catalysts
for metathesis of 1-hexene (in methyl cyclohexane as a
and 12.87 (s, 1H, MoCHSiPh ), 7.74–6.86 (m, 18H,
2
3
3
Harom), 3.56 (sept, 2H, CHMe , J = 6.8), 1.35 and
2
HH
solvent) a conversion rate was the same.
1.23 (s, 6H each, OCMe CF ), 1.06 (d, 12H, CHMe ).
C NMR (50 MHz, C D ) d 261.1 (J = 112.4 Hz)
6 6 CH
2
3
2
1
3
The rate of olefin metathesis reactions is well known
to depend on many factors. The main are the compo-
sition and structure of the catalyst, reaction conditions,
the nature of the substrate. We found that the rate
constants of 1-hexene metathesis were correlated with
the steric crowding of the used heteroelement-contain-
ing catalysts 4, 10, 11. The sum of ligands solid angles
and 256.6 (JCH = 112.9 Hz) (MoCHSiPh ), 154.0,
3
145.7, 136.3, 135.7, 129.8, 128.3 (Carom), 127.0 (q,
1
JCF = 285.6, OCMe CF ), 122.8 (Carom), 79.7 (q,
2
3
2
JCF = 28.8, OCMe CF ), 24.9 (CHMe ), 24.6 and
2
3
2
24.5 (CHMe ), 23.7 (OCMe CF ). The reaction of
2
2
3
Ph SiCH@CH with 3 was carried out in a similar
3
2
(
Q, sterad) around Mo atom was selected as a charac-
way. The yield of 1 was 55%.
teristic of molecular structure [9]. The Q-value indicates
the degree of saturation of the coordination sphere
around Mo atom and therefore can serve as a param-
eter characterizing the steric crowding of molybdenum
alkylidene complexes. It should be noted that the Q
values for 4, 10 and 11 were calculated from own X-
ray data. Unfortunately, the X-ray data for the com-
plexes 2 and 3 are absent. The Q values for 10, 4
and 11 are equal 11.39, 11.42 and 11.73 sterad, respec-
tively (full coordination sphere is 4p sterad). The in-
3.3. Preparation of (ArN)(ArNH)Mo(CH SiMe ) -
2
3 2
(OTf) (5)
To a dark red solution of (ArN) Mo(CH SiMe )
3 2
2
2
(0.58 g, 0.93 mmol) in 15 ml of DME at ꢁ50 ꢁC 0.14
g (0.93 mmol) of HOTf was added. The reaction mixture
was stirred and allowed to warm slowly to room temper-
ature. The solution became bright orange-red. The sol-
vent was removed in vacuo. The solid residue was
recrystallized from minimal amount of ether to afford
orange crystals of 5 0.6 g (83.3%). Anal. Calc. for
C H F MoN O SSi : C, 51.36; H, 7.39. Found: C,
crease of
Q values for heteroelement-containing
catalysts in the row 10 < 4 < 11 is in accordance with
the decrease of the rates of metathesis of 1-hexene
using these catalysts in the same order.
3
3
57
3
2
3
2
1
51.40; H, 7.44%. H NMR (200 MHz, C D ) d 9.39 (s,
6
6
1
H, NH), 7.10–6.70 (m, 6H, H (3,4)), 3.66 (d, 2H,
2
MoHCHSiMe , J = 9.0), 3.63 (sept, 2H, CHMe2),
3
HH
3
. Experimental
3.52 (sept, 2H, CHMe ), 2.35 (d, 2H, MoHCHSiMe ,
2 3
2
3
JHH = 9.0), 1.00 (d, 24H, CHMe , J = 6.8), 0.24
2
HH
1
3
3
.1. General
(s, 18H, SiMe3). C NMR (50 MHz, C D ) d 150.81,
6 6
1
49.06, 142.87, 131.19, 127.29, 124.18, 123.95 (Carom.);
All manipulations were carried out in evacuated
75.42 (CH SiMe ); 28.73, 28,33 (CHMe ); 24.68,
2
3
22
2
9
sealed ampoules using standard Schlenk techniques.
The solvents were thoroughly dried and degassed.
Compounds 2 and 3 [2a] and Ph SiCH@CH [10] were
23.57 (CHMe ); 1.38 (CH SiMe ). Si NMR (39.7
2
2
3
MHz, C D ) d ꢁ21.50.
6
6
3
2
1
13
prepared according to a literature procedure. H, C,
3.4. Preparation of (ArN)(ArNH)Mo(CH GeMe ) -
2 3 2
2
9
Si NMR spectra were recorded on a Bruker DPX-
00 NMR spectrometer. NMR data are listed in parts
(OTf) (6)
2
per million downfield from TMS. GLC analysis of
methatesis products were performed on ‘‘Tsvet-800’’
gas chromatograph with a 0.3 · 300 cm stainless-steel
column filled with SE-30 (5%) on Inerton AW (with
katharometer as a detector and helium as the carrier
gas).
The procedure was essentially the same as described
above. From 1.0 g (1.41 mmol) of complex (ArN)2-
Mo(CH GeMe ) and 0.22 g (1.41 mmol) of HOTf com-
2
3 2
pound 6 was obtained as orange crystals (0.73 g, 60.0%).
Anal. Calc. for C H F MoN O SGe : C, 46.04; H,
3
3
57
3
2
3
2
1
6.63. Found: C, 46.07; H, 6.63%. H NMR (200 MHz,

Table 2
The details of crystallographic, collection and refinement data for 1, 4, 5, 6, 8 and 9
1
4
5
6
8
9
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
C
797.79
100(2)
Monoclinic
P2(1)/n
11.0593(5)
19.3476(9)
18.1742(8)
39
H
45
F
6
MoNO
2
Si
C
611.59
100(2)
Monoclinic
P2(1)/c
10.2681(6)
30.548(2
24
H
39
F
6
MoNO
2
Si
C
770.99
293(2)
33
H
57
F
3
MoN O
2 3
SSi
2
C
859.99
100(2) K
Triclinic
33
H
57
F
3
Ge
2
MoN
2
3
O S
C
745.28
100(2)
32
H
57ClN
2
Si
2
W
C
834.28
100(2)
32 2 2
H57ClGe N W
Triclinic
Triclinic
Triclinic
ꢀ
ꢀ
ꢀ
ꢀ
P1
P1
P1
P1
˚
a (A)
10.644(4)
10.694(4)
18.510(6)
83.96(3)
79.07(3)
73.06(3)
1976(1)
2
10.468(4)
10.733(4)
18.897(6)
83.40(3)
78.51(3)
71.82(3)
1974(1)
2
10.5125(5)
11.9802(6)
14.6522(7)
88.6150(1)
84.499(1)
73.871(1)
1764.5(2)
2
10.5342(5)
12.0078(6)
14.7439(7)
88.696(1)
84.507(1)
73.760(1)
1782.3(2)
2
˚
b (A)
˚
c (A)
10.5567(6)
a (ꢁ)
b (ꢁ)
c (ꢁ)
96.523(1)
117.710(1)
˚
3
Volume (A )
3863.6(3)
4
1.372
0.433
1648
2931.6(3)
4
1.386
0.546
1264
Z
3
D
calc (g/cm )
1.296
0.492
812
1.445
1.923
884
1.403
3.439
764
1.555
4.991
836
ꢁ1
Absorption coefficient (mm
F(000)
)
Crystal size (mm)
0.27 · 0.19 · 0.15
24.25
0.12 · 0.10 · 0.08
25.00
ꢁ12 6 h 6 12,
ꢁ36 6 k 6 24,
ꢁ11 6 l 6 12
0.4 · 0.3 · 0.2
25.05
ꢁ12 6 h 6 12,
ꢁ12 6 k 6 12,
ꢁ22 6 l 6 21
0.96 · 0.64 · 0.16
28.00
ꢁ14 6 h 6 13,
ꢁ13 6 k 6 14,
ꢁ13 6 l 6 24
0.21 · 0.16 · 0.08
24.50
ꢁ12 6 h 6 12,
ꢁ13 6 k 6 13,
ꢁ17 6 l 6 17
0.20 · 0.12 · 0.04
25.00
ꢁ8 6 h 6 12,
ꢁ12 6 k 6 14,
ꢁ17 6 l 6 17
hmax range for data collection (ꢁ)
Index ranges
ꢁ12 6 h 6 12,
ꢁ
17 6 k 6 22,
20 6 l 6 16
ꢁ
Reflections collected
19892
16044
7406
13529
13383
9771
Independent reflections (Rint
)
6247 (0.0326)
5161 (0.0356)
6993 (0.0619)
9374 (0.0272)
5838 (0.0165)
6244 (0.0148)
Absorption correction
Max/min transmission
SADABS
0.9379/0.8921
0.9576 / 0.9373
0.8956/0.7534
0.7484/0.2597
0.7705/0.5320
0.8253/0.4351
2
Refinement method
Full-matrix least-squares on F
Data/restraints/parameters
6247/12/619
1.038
5161/0/472
1.003
6993/0/410
1.018
9374/0/634
5838/0/571
1.038
6244/4/571
1.038
2
Goodness-of-fit on F
1.006
Final R indices [I > 2r(I)]
R
1
= 0.0359,
R
1
= 0.0304,
R
1
= 0.0643, wR
2
2
= 0.1167
= 0.1339
R
R
1
= 0.0400, wR
2
2
= 0.1070
= 0.1102
R
1
= 0.0159,
R
1
= 0.0234,
wR = 0.0907
2
wR = 0.0650
2
wR = 0.0386
2
wR = 0.0565
2
R indices (all data)
R
1
= 0.0465,
R
1
= 0.0439,
R
1
= 0.1410, wR
1
= 0.0458, wR
R
1
= 0.0173,
R
1
= 0.0270,
wR = 0.0948
2
wR = 0.0684
2
wR = 0.0391
2
wR = 0.0577
2
Largest difference peak
1.007/ꢁ0.499
0.534/ꢁ0.226
0.637/ꢁ0.463
1.308/ꢁ1.260
0.670/ꢁ0.472
1.788/ꢁ1.072
˚
ꢁ3
and hole (e A
)

5726
L.N. Bochkarev et al. / Journal of Organometallic Chemistry 690 (2005) 5720–5727
2
Table 3
MoHCHSiMe , JHH = 8.0), 0.99 (d, 24H, CHMe ,
3
2
˚
3
13
Selected distances (A) and angles (ꢁ) for 1 and 4
JHH = 6.8), 0.40 (s, 18H, GeMe3). C NMR (50
MHz, C D ) d 150.75, 150.58, 148.95, 141.78, 131.05,
˚
Distance (A)
Angle (ꢁ)
6
6
1
127.04, 124.08, 123.86 (Carom.); 76.94 (CH GeMe );
2 3
Mo(1)–N(1)
Mo(1)–O(1)
Mo(1)–O(2)
Mo(1)–C(21)
Si(1)–C(21)
1.725(2)
1.910(2)
1.904(2)
1.883(3)
1.857(3)
Si(1)–C(21)–Mo(1)
C(1)–N(1)–Mo(1)
144.8(2)
174.83(19)
28.72, 28,30 (CHMe ); 24.64, 23.52 (CHMe ); 1.85
22 2
(
CH GeMe ).
2 3
3
(
.5. Preparation of (ArN)(ArNH)W(CH GeMe ) -
2 3 2
OTf) (7)
4
Mo(1)–N(1)
Mo(1)–O(1)
Mo(1)–O(2)
Mo(1)–C(1)
Si(1)–C(1)
1.722(2)
1.906(1)
1.902(1)
1.889(2)
1.862(2)
Si(1)–C(1)–Mo(1)
138.5(1)
To an orange solution of (ArN) W(CH GeMe ) (1.5
2
2
3 2
g, 1.90 mmol) in 15 ml of DME at ꢁ50 ꢁC 0.30 g (2.00
mmol) of HOTf was added. The reaction mixture was
stirred and allowed to warm slowly to room tempera-
ture. The solution became pale yellow-green. The
solvent was removed in vacuo. The solid residue was
recrystallized from of pentane to afford pale green crys-
tals of 7 1.13 g (65.0%). Anal. Calc. for C H F -
Table 4
˚
Selected distances (A) and angles (ꢁ) for 5 and 6
3
3
57 3
˚
Distance (A)
Angle (ꢁ)
WN O SGe : C, 41.83; H, 6.06. Found: C, 41.56; H,
2
3
1
2
5
5
.95%. H NMR (200 MHz, toluene-d ) d 8.22 (s, 1H,
8
Mo(1)–N(1)
Mo(1)–N(2)
Mo(1)–O(1)
Mo(1)–C(25)
Mo(1)–C(29)
Si(1)–C(25)
Si(2)–C(29)
1.925(5)
1.716(4)
2.214(4)
2.091(5)
2.098(5)
1.883(5)
1.880(5)
C(1)–N(1)–Mo(1)
C(13)–N(2)–Mo(1)
Si(1)–C(25)–Mo(1)
Si(2)–C(29)–Mo(1)
138.2(4)
174.8(4)
126.8(3)
120.9(3)
NH), 6.90–6.70 (m, 6H, H (3,4)), 3.52 (sept, 2H,
2
CHMe ), 3.39 (d, 2H, WHCHGeMe , JHH = 9.0),
2
3
2
2.06 (d, 2H, WHCHGeMe , J = 9.0), 0.99 (d, 24H,
CHMe , J = 6.8), 0.37 (s, 18H, GeMe3). C NMR
3
HH
3
13
2
HH
(
1
(
(
50 MHz, toluene-d ) d 149.04, 148.93, 147,09, 142.21,
8
37.45, 129.74, 127.12, 123.77 (Carom), 79.45
CH GeMe ,
J
C
–183W ¼ 92.8 Hz), 28.45, 28.26
6
2
3
Mo(1)–N(1)
Mo(1)–N(2)
Mo(1)–O(1)
Mo(1)–C(25)
Mo(1)–C(29)
Ge(1)–C(25)
Ge(2)–C(29)
1.917(2)
1.748(2)
2.243(2)
2.104(2)
2.091(2)
1.954(2)
1.953(2)
C(1)–N(1)–Mo(1)
C(13)–N(2)–Mo(1)
Ge(1)–C(25)–Mo(1)
Ge(2)–C(29)–Mo(1)
136.3(1)
175.6(1)
124.3(1)
115.9(1)
CHMe ), 24.82 (CHMe ),2.14 (CH GeMe ).
2
2
2
3
3.6. Preparation of (ArN)(ArNH)W(CH SiMe ) (Cl)
2 3 2
(8)
Gaseous HCl (15.8 mL, 0.71 mmol) was condensed
into an orange solution of (ArN) W(CH SiMe ) (0.5
2
2
3 2
g, 0.71 mmol) in 5 ml of THF at ꢁ50 ꢁC. The reaction
mixture was stirred and allowed to warm during 1 h to
room temperature. The solution became pale yellow-
green. The solvent was removed in vacuo. The solid res-
idue was recrystallized from of pentane to afford pale
green crystals of 8 0.16 g (30.0%). Anal. Calc. for
Table 5
˚
Selected distances (A) and angles (ꢁ) for 8 and 9
˚
Distance (A)
Angle (ꢁ)
8
W(1)–N(1)
W(1)–N(2)
W(1)–Cl(1)
W(1)–C(25)
W(1)–C(29)
Si(1)–C(25)
Si(2)–C(29)
1.924(2)
1.755(2)
2.4920(5)
2.104(2)
2.112(2)
1.889(2)
1.887(2)
C(1)–N(1)–W(1)
C(13)–N(2)–W(1)
Si(1)–C(25)–W(1)
Si(2)–C(29)–W(1)
136.6(1)
176.6(1)
118.85(9)
125.4(1)
C H ClN Si W: C, 51.57; H, 7.71. Found: C, 51.48;
32 57
2
2
1
H, 7.76%. H NMR (200 MHz, C D ) d 8.69 (s, 1H,
6
6
NH), 7.12–6.76 (m, 6H, H (3,4)), 3.50 (sept, 2H,
2
CHMe ), 3.20 (d, 2H, WHCHSiMe , J = 9.0), 1.75
2
3
HH
2
(
d, 2H, WHCHSiMe , JHH = 9.0), 1.03 (d, 24H,
CHMe , J = 6.8), 0.33 (s, 18H, SiMe3).
3
3
9
2
HH
W(1)–N(1)
W(1)–N(2)
W(1)–Cl(1)
W(1)–C(25)
W(1)–C(29)
Ge(1)–C(25)
Ge(2)–C(29)
1.933(2)
1.745(2)
2.4942(6)
2.111(2)
2.093(2)
1.973(2)
1.976(2)
C(1)–N(1)–W(1)
C(13)–N(2)–W(1)
Ge(1)–C(25)–W(1)
Ge(2)–C(29)–W(1)
135.0(1)
176.7(1)
122.9(1)
116.2(1)
3
(
.7. Preparation of (ArN)(ArNH)W(CH GeMe ) (Cl)
2 3 2
9)
The procedure was essentially the same as described
above. From 0.4 g (0.63 mmol) of complex (ArN) W-
2
(
CH GeMe ) and 14.0 ml (0.63 mmol) of HCl gas com-
2 3 2
C D ) d 9.12 (s, 1H, NH), 7.10–6.70 (m, 6H, H (3,4)),
pound 9 was obtained as pale green crystals (0.18 g,
6
6
2
3
.93 (d, 2H, MoHCHGeMe , J = 8.0), 3.64 (sept,
35.0%). Anal. Calc. for C H ClGe N W: C, 46.08;
3
HH
32 57
2
2
1
2
H, CHMe ), 3.53 (sept, 2H, CHMe ), 2.68 (d, 2H,
H, 6.89. Found: C, 45.94; H, 6.92%. H NMR (200
2
2

L.N. Bochkarev et al. / Journal of Organometallic Chemistry 690 (2005) 5720–5727
5727
MHz, THF-d ) d 8.25 (s, 1H, NH), 7.40–6.60 (m, 6H, H
be obtained free of charge at www.ccdc.cam.ac.uk/
const/retrieving.html [or from the Cambridge Crystallo-
graphic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK; fax: (internat.) +44 1223 336 033; e-mail:
deposit@ccdc.cam.ac.uk].
8
(
3,4)), 3.66 (sept, 2H, CHMe2), 3.13 (d, 2H,
2
WHCHGeMe , JHH = 8.3), 1.80 (d, 2H, WHCH-
GeMe3, JHH = 8.3), 1.01 (d, 24H, CHMe2, JHH
3
2
3
=
6
.8), 0.32 (s, 18H, GeMe3).
3
.8. Metathesis of 1-hexene
Acknowledgments
The kinetic experiments and determinations of rate
constants were performed as described in the literature
11,12]. In a typical experiment to an ampule containing
.4 mg of catalyst and connected with gas burette 0.60 g
0.85 mL) of neat 1-hexene was added in argon atmo-
This work was supported by the Grant of President
RF (Projects No. 58.2003.3 and No. 1652.2003.3) and
the Russian Foundation for Basic Research (Project
No. 02-03-32694). The authors thank Dr. T.I. Kulikova
for GLC analysis of metathesis products.
[
1
(
sphere. The mixture was stirred magnetically. Amount
of ethylene was determined volumetrically. At appropri-
ate time the reaction was quenched by adding of Al O
2
3
to the reaction mixture and volatiles were removed in
vacuo and analyzed by GLC. The amounts of formed
ethylene (determined volumetrically) and 5-decene
References
[
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(
determined by GLC) and the rested 1-hexene (deter-
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(
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chromated, Mo Ka-radiation, u-x-scan technique,
[
2003) 4592.
[
˚
k = 0.71073 A). The intensity data were integrated in
(
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6] R.R. Schrock, R.T. DePue, J. Feldman, K.B. Yap, D.C. Yang,
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(
1990) 2262.
[
15]. All non-hydrogen atoms were refined anisotropi-
[7] A.V. Safronova, L.N. Bochkarev, N.E. Stolyarova, I.K. Grigor-
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cally. The hydrogen atoms in 1, 4, 6, 8 and 9 were found
from Fourier synthesis and refined isotropically and the
H atoms in 5 (except for H(1) which was found from
Fourier synthesis) were placed in calculated positions
and refined in the ‘‘riding-model’’. The details of crystal-
lographic, collection and refinement data are shown in
Table 2. The selected bond lengths and angles are listed
in Tables 3–5.
(
2004) 1127.
[
[
8] E. Thorn-Csanyi, J.U. Zilles, J. Mol. Catal. A 190 (2002) 85.
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[
[
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6
35.
[
[
[
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6
.02a, Bruker AXS, Madison, WI, USA, 2000.
4
. Supplementary data
14] G.M. Sheldrick, SADABS v.2.01, Bruker/Siemens Area Detector
Absorption Correction Program, Bruker AXS, Madison, WI,
USA, 1998.
CCDC-273135 (1), -273136 (4), -273137 (5), -273138
(
6), -273139 (8) and -273140 (9) contain the supplemen-
[15] G.M. Sheldrick, SHELXTL v. 6.12, Structure Determination Soft-
tary crystallographic data for this paper. These data can
ware Suite, Bruker AXS, Madison, WI, USA, 2000.