Synthesis and reactivity of new mixed dicyclopentadienyl Group 4 metal complexes with the doubly bridged bis(dimethylsilanediyl)-cyclopentadiene-(η5-cyclopentadienyl) ligand

Article abstract of DOI:10.1016/S0022-328X(99)00111-4

The monocyclopentadienyl titanium complex [Ti{(C₅H₄)(SiMe₂)₂(η ⁵-C₅H₃)} Cl₃] 3 and the dichloro mixed dicyclopentadienyl Group 4 metal complexes [M(η⁵-C₅R₅){(C₅H ₄)(SiMe₂)₂(η⁵-C ₅H₃)} Cl₂] (R=H; M=Ti 4, Zr 5, Hf 6; R=Me; M=Ti 7) containing the doubly bridged bis(dimethylsilanediyl)-cyclopentadiene-(η⁵-cyclopentadienyl) ligand were prepared in high yields by reaction of the monolithium salt Li[(C₅H₄)(SiMe₂)₂(C ₅H₃)] 2 with equimolar amounts of TiCl₄ or the monocyclopentadienyl complexes [Cp′MCl₃], respectively. Reactions of the chloro complexes with various alkylating agents afforded the chloroalkyl [M(η⁵-C₅H₅){(C₅H ₄)(SiMe₂)₂(η⁵-C ₅H₃)}ClR] (M=Ti; R=Me 8, Et 9; M=Zr, R=Me 10, Et 11, CH₂Ph 12; M=Hf, R=CH₂Ph 13) and dialkyl [M(η⁵-C₅R₅){(C₅H ₄)(SiMe₂)₂(η⁵-C ₅H₃)}Me₂] (M=Ti; R=H 14, Me 15; M=Zr; R=H 16, compounds. Formation of the heterodinuclear complex [Zr(η⁵-C₅H₅)Cl₂(η ⁵-C₅H₃)(SiMe₂) ₂(η⁵-C₅H₃)Ti(NMe ₂)₃] 17 with amine elimination was observed by ¹H-NMR spectroscopy when complex 5 was reacted with Ti(NMe₂)₄. The catalytic activity of compounds 3-5 for ethylene polymerization has been studied using MAO as cocatalyst.

Full text of DOI:10.1016/S0022-328X(99)00111-4

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 583 (1999) 86–93
Synthesis and reactivity of new mixed dicyclopentadienyl Group 4
metal complexes with the doubly bridged
bis(dimethylsilanediyl)-cyclopentadiene-(h5-cyclopentadienyl) ligandꢀ
Roberto Go´mez-Garc´ıa, Pascual Royo *
Departamento de Qu´ımica Inorga´nica, Uni6ersidad de Alcala´, Campus Uni6ersitario, E-28871 Alcala´ de Henares, Spain
Received 8 July 1998; received in revised form 7 October 1998
Abstract
The monocyclopentadienyl titanium complex [Ti{(C5H4)(SiMe2)2(h5-C5H3)} Cl3] 3 and the dichloro mixed dicyclopentadienyl
Group 4 metal complexes [M(h5-C5R5){(C5H4)(SiMe2)2(h5-C5H3)} Cl2] (R=H; M=Ti 4, Zr 5, Hf 6; R=Me; M=Ti 7)
containing the doubly bridged bis(dimethylsilanediyl)-cyclopentadiene-(h5-cyclopentadienyl) ligand were prepared in high yields
by reaction of the monolithium salt Li[(C5H4)(SiMe2)2(C5H3)] 2 with equimolar amounts of TiCl4 or the monocyclopentadienyl
complexes [Cp%MCl3], respectively. Reactions of the chloro complexes with various alkylating agents afforded the chloroalkyl
[M(h5-C5H5){(C5H4)(SiMe2)2(h5-C5H3)}ClR] (M=Ti; R=Me 8, Et 9; M=Zr, R=Me 10, Et 11, CH2Ph 12; M=Hf,
R=CH2Ph 13) and dialkyl [M(h5-C5R5){(C5H4)(SiMe2)2(h5-C5H3)}Me2] (M=Ti; R=H 14, Me 15; M=Zr; R=H 16,
compounds. Formation of the heterodinuclear complex [Zr(h5-C5H5)Cl2(h5-C5H3)(SiMe2)2(h5-C5H3)Ti(NMe2)3] 17 with amine
elimination was observed by 1H-NMR spectroscopy when complex 5 was reacted with Ti(NMe2)4. The catalytic activity of
compounds 3–5 for ethylene polymerization has been studied using MAO as cocatalyst. © 1999 Elsevier Science S.A. All rights
reserved.
Keywords: Titanium; Zirconium; Hafnium; Dicyclopentadienyl complexes; Polyethylene
1. Introduction
systems to bridge dinuclear metal compounds. We have
recently reported the use of the 1,1%-2,2%-(dimethylsi-
lanediyl)dicyclopentadienyl ligand to synthesize ansa-
dicyclopentadienyl and bridged homodinuclear mono-
and di-cyclopentadienyl complexes of the Group 4 and
6 metals [15–20]. This and related doubly silyl-bridged
ligands have also been used [14,21] to isolate mononu-
clear and dinuclear Group 4 metal compounds. The use
of this ligand to bridge two different metal atoms as
those recently reported [22] demands the earlier isola-
tion of monocyclopentadienyl-type compounds contain-
ing only one of the rings h5-coordinated to the metal.
This was the aim of the work presented here, which
includes the isolation and structural characterization of
complexes of the following types: [Ti{h5-C5H3-
(SiMe2)C5H4}Cl3],[M(h5-C5R5){h5-C5H3(SiMe2)C5H4}-
Cl2] (M=Ti, Zr, Hf; R=H; M=Ti; R=Me), [M(h5-
Cyclopentadienyl ligands constitute one of the vari-
ous bridging systems that can be used to obtain homo-
and hetero-dinuclear complexes. Many dinuclear com-
pounds containing bridging h5–h1 cyclopentadienyl
rings and h5–h5-fulvalene systems, resulting from ring
CꢀH activation in dicyclopentadienyl derivatives, have
been reported [1,11]. However di-h5–cyclopentadienyl
ligands singly bridged by various alkyl [2–5] and silyl
[6–14] groups are among the most frequently used
ꢀ Dedicated to Professor Alberto Ceccon on the occasion of his
65th birthday.
* Corresponding author. Tel.: +34-1-885-4765; fax: +34-1-885-
4683.
E-mail address: proyo@inorg.alcala.es (P. Royo)
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 9 9 ) 0 0 1 1 1 - 4

R. Go´mez-Garc´ıa, P. Royo / Journal of Organometallic Chemistry 583 (1999) 86–93
87
C5H5){h5-C5H3(SiMe2)C5H4}ClR] (M=Ti, Zr; R=
Me, Et, Bz) and [M(h5-C5R5){h5-C5H3(SiMe2)C5-
H4}Me2] (M=Ti, Zr; R=H, Me).
one singlet due to the unsubstituted cyclopentadienyl
ring protons or methyl groups is present in complexes
4–7.
2.2. Alkylation reactions
2. Results and discussion
Monoalkylated titanium and zirconium complexes
[M(h5-C5H5){(C5H4)(SiMe2)2(h5-C5H3)}ClR] (M=Ti;
R=Me 8, Et 9; M=Zr, R=Me 10, Et 11) were easily
isolated by stirring THF solutions of the dichloro com-
plexes 4 and 5 at room temperature with one equivalent
of MgClR (R=Me, Et). Formation of similar chloro-
methyl and chloro-ethyl compounds by alkylation of
complexes 6 and 7 could be detected by 1H-NMR
spectroscopy but the high solubility of the resulting
products prevented their purification and suitable char-
acterization in the solid state. The reaction of com-
plexes 5 and 6 with equimolar amounts or excess
Mg(CH2Ph)2 · 2THF afforded only the corresponding
chloro-benzyl compounds [M(h5-C5H5){(C5H4)(Si-
Me2)2(h5-C5H3)}Cl(CH2Ph)] (M=Zr 12, Hf 13),
whereas similar reactions of complexes 4 and 7 with
Mg(CH2Ph)2 · 2THF in various solvents, at various
temperatures and in different molar ratios, always led
to unidentified products.
Although further alkylation of the chloro-methyl
complexes took place using two equivalents of Mg-
ClMe, better yields of the dimethyl compounds [M(h5-
C5R5){(C5H4)(SiMe2)2(h5-C5H3)} Me2] (M=Ti; R=H
14, Me 15; M=Zr; R=H 16), resulted from direct
reactions of the dichloro-complexes with two equiva-
lents of LiMe in hexane. Reduction of the titanium
compound was not observed despite the greater reduc-
ing capacity of the alkylating agent. It is noteworthy
that titanium benzyl complexes could not be isolated
2.1. Chloro-complexes
The starting 4,4,8,8-tetramethyltetrahydro-4,8-disila-
s-indacene 1 was isolated using the alternative method
reported [14] to prepare various related silanes. As
shown in Scheme 1, reaction of the dilithium salt of the
mono-silyl-bridged dicyclopentadiene with SiCl2Me2
provided a more direct method to prepare 1 (as a
mixture of cis- and trans-isomers) in higher yield (54%)
than reported methods [23]. The monolithium salt
Li[(C5H4)(SiMe2)2(C5H3)] 2 was prepared by the re-
ported [23] deprotonation of 1 with one equivalent of
BuLi at room temperature using hexane instead of
THF as solvent.
Reaction of TiCl4 with a suspension of one equiva-
lent of the lithium salt 2 in refluxing toluene gave a
brown solid, which after purification, provided the
trichloro complex [Ti{(C5H4)(SiMe2)2(h5-C5H3)}Cl3] 3
as a brown yellowish solid in rather low yield (22%).
Similar yields were also obtained using various solvents
at different reaction temperatures. Following the
method reported [21] for related compounds, when
THF suspensions of the monolithium salt 2 were re-
acted with THF solutions of [Ti(h5-C5R5)Cl3] (R=H,
Me) and THF suspensions of [M(h5-C5H5)Cl3 · DME]
(M=Zr, Hf), the mixed dicyclopentadienyl complexes
[M(h5-C5R5){(C5H4)(SiMe2)2(h5-C5H3)}Cl2]
M=Ti 4, Zr 5, Hf 6; R=Me; M=Ti 7) were isolated
in high yields (Scheme 2).
(R=H;
and the reaction of complexes
5 and 6 with
All of these chloro complexes are air sensitive and
soluble in all of the usual organic solvents. They were
characterized by elemental analyses and 1H- and
13C-NMR spectroscopy. The lack of symmetry due to
the chiral sp3 carbon of the non-coordinated cyclopen-
tadiene ring makes all of the seven protons of both
rings non equivalent, appearing as seven multiplets in
the 1H spectrum whereas the 13C spectra show six
signals due to the Cb and Cg atoms, one signal dis-
placed to high field (l 55.8–56.4) for the sp3 carbon
and three lower intensity signals always displaced to
low field for the other three Ca atoms directly bonded
to silicon, although only two were observed for 5–7.
The four methyl groups bonded to silicon are also
non-equivalent although two signals are overlapped in
the titanium derivatives being observed as a unique
resonance, whereas four singlets, two of them with very
similar chemical shifts, are observed for the zirconium
and hafnium derivatives. The 13C spectra confirm the
presence of four signals for all compounds. In addition
Mg(CH2Ph)2 · 2THF always gave monoalkyl com-
plexes, even when a large excess of the alkylating agent
was used, probably due to the steric requirements of the
bulkier benzyl group. Complexes derived from further
Scheme 1.

R. Go´mez-Garc´ıa, P. Royo / Journal of Organometallic Chemistry 583 (1999) 86–93
88
Scheme 2.
intensity with some of the signals overlapped (see Sec-
tion 3). In fact, the non-equivalent methylenic protons
of the benzyl derivatives 12 and 13 appear as two
doublets (1JCꢀH=12 Hz) each containing the over-
lapped signals due to both diastereomers. A similar
observation was made for the characteristic methylene
multiplets of the ethyl derivatives 9 and 11 whose
methyl groups were also overlapped giving a signal
observed as a multiplet. The molar ratio of the
diastereomers for each chloro-alkyl complex, calculated
alkylation of 9 and 11 with MgClEt could not be
isolated because b-elimination of the resulting dialkyl
compounds takes place spontaneously even at low tem-
perature (−78°C) to give unidentified decomposition
products.
All of the chloro-alkyl and dialkyl complexes 8–16
are air and moisture sensitive but can be stored without
decomposition under an inert atmosphere at room tem-
perature. Thermal decomposition of complexes 9 and
11 was observed at 40°C in THF with elimination of
ethane to give the corresponding dichloro complexes
and other unidentified products, whereas no decompo-
sition was observed at 70–80°C in non-polar solvents.
All of the dialkyl compounds were characterized by
elemental analyses and NMR spectroscopy. The
1H- and 13C-NMR spectra for the dimethyl complexes
14–16 are similar to those described above for the
dichloro complexes, with all signals slightly displaced to
higher field, and show additional signals due to the
metal-bonded diastereotopic methyl groups.
1
from the signals of the SiMe2 bridges in the H-NMR
spectra, were 1:2 for the chloro-methyl and chloro-ethyl
compounds and 1:6 for the chloro-benzyl compounds
[see detailed assignments to major (M) and minor (m)
components in Section 3].
Table 1
Catalytic polymerization of ethylenea
Catalyst
[Catalyst] T (h) a (105 g l mol−1 h−1 atm−1
/[MAO]
)
In contrast, the chloro-alkyl complexes have two
chiral centres, the sp3 carbon of the non-coordinated
cyclopentadiene ring and the metal, providing a mix-
ture of two diastereomeric components in different
molar ratios. Each diastereomer shows the same
1H- and 13C-NMR spectrum as those described above
leading, therefore, to two sets of signals of different
ZrCp2Cl2 1/1000
1/2000
0.5
1.0
1.0
1.0
1.0
1.0
7.32
4.41
0.09
1.41
0.73
0.02
4
1/1000
1/2000
1/2000
1/2000
5
6
a [Catalyst]=4.4×10−6 mol l−1; T=21°C.

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R. Go´mez-Garc´ıa, P. Royo / Journal of Organometallic Chemistry 583 (1999) 86–93
3. Experimental
The behaviour, observed for reactions with alkylat-
ing agents, demonstrates that selective alkylation of
the MꢀCl bonds instead of deprotonation of the un-
coordinated ring occurred, favoured by the formation
of LiCl. Consequently, deprotonation of the acidic
Csp3 bonded hydrogen (observed between l 4.82 and
3.1. General methods
All reactions were carried out in dried Schlenk tubes
under argon and the manipulations were carried out
using cannulas through Subaseals. Solvents were dried
and distilled under argon; THF from sodium benzophe-
none ketyl; hexane from sodium and potassium amal-
gam; toluene from sodium; dichloromethane from
P2O5. Unless otherwise stated, reagents were obtained
from commercial sources and used as received.
Ti(NMe2)4 was synthesized according to the reported
method [24].The 1H- and 13C-NMR spectra were
recorded at 299.95 and 75.43 MHz, respectively, on a
Varian Unity 300 spectrometer; chemical shifts, in ppm,
are positive down field relative to external SiMe4, and
coupling constants are in Hz. C, H analyses were
performed with a Perkin–Elmer 240-B instrument.
1
5.08 in the H-NMR spectrum of all the chloro com-
plexes) of the non-coordinated cyclopentadiene ring
by basic alkylating agents, does not occur in these
dichloro compounds. All attempts made to deproto-
nate this ring in dialkyl derivatives only led to
unidentified products, thus preventing use of the un-
coordinated ring to obtain heterodinuclear com-
pounds. However, effective deprotonation was
observed when the reaction of complex
5 with
Ti(NMe2)4 was monitored by 1H-NMR in a sealed
tube. This reaction, which has been successfully used
[24–27] for related ansa-metallocene complexes, gave
the titanium–zirconium complex [Zr(h5-C5H5)Cl2(h5-
C5H3)(SiMe2)2(h5-C5H3)Ti(NMe2)3] 17, with two h5-
coordinated cyclopentadienyl rings, as the unique
reaction product and is consistent with the observed
1H-NMR spectrum. This dinuclear TiꢀZr complex has
Cs symmetry and the expected two singlets due to the
bridging methyl–silicon groups and two doublets and
two triplets due to the AA%B spin system of the two
non-equivalent cyclopentadienyl rings were observed.
In addition, the spectrum shows two singlets that can
be easily assigned to the unsubstituted cyclopentadi-
enyl ring and the nitrogen-bonded methyl groups. So-
lutions of complex 17 in polar and non-polar solvents
decomposed rapidly at room temperature to give a
mixture of unidentified products and for this reason
when this reaction was carried out at a preparative
level it was not possible to isolate the desired hetero-
dinuclear compound.
3.2. Synthesis of [(C5H4)2(SiMe2)2] 1
Me2SiCl2 (32.14 ml; 0.26 mol) was added to a cooled
(0°C) solution of CpNa (87.90 g; 0.53 mol) in pentane
(400 ml). The mixture was warmed to room tempera-
ture and stirred overnight. The solution was filtered and
the solvent was removed in vacuo to obtain the mono-
bridged cyclopentadienyl compound [(C5H5)2(SiMe2)]
as a pale yellow liquid (43 ml; 84%).
BuLi (277 ml; 0.44 mol) was added to a cooled (0°C)
solution of [(C5H5)2(SiMe2)] (43 ml; 0.22 mol). The
mixture was warmed to room temperature and stirred
for 20 h. A solution of Me2SiCl2 (26.7 ml; 0.22 mol) in
THF (40 ml) was added dropwise to the resulting
suspension cooled to 0°C. The mixture was warmed to
room temperature and stirred overnight. The solvent
was removed in vacuo and the residue was extracted
into hexane (400 ml). Compound 1 was then obtained
by crystallization as pale yellow crystals (35 g; 54% with
respect to starting CpNa).
2.3. Catalytic polymerization of ethylene
The catalytic activity of the dichloro titanium, zir-
conium and hafnium complexes for the polymeriza-
tion of ethylene was studied using MAO as
cocatalyst. When ethylene was bubbled through stir-
ring toluene solutions containing the mixed dicy-
clopentadienyl complexes 4–6 and excess MAO under
rigorously anhydrous and anaerobic conditions, solid
polyethylene precipitated. The activity was determined
by quenching the reaction after a measured time in-
terval and weighing the dried polymer (Table 1). All
three compounds show rather low activities, that of
the zirconium derivative being about eight times
higher than that of the titanium complex and 30
times higher than that of the hafnium derivative. The
characteristics of the resulting polymers were not
studied further.
The lithium salt Li[(C5H4)(SiMe2)2(C5H3)] 2 was pre-
pared in hexane by the reported method [23].
3.3. Synthesis of [Ti{(C5H4)(SiMe2)2(p5-C5H3)}Cl3] 3
A solution of TiCl4 (0.61 ml; 5.59 mmol) in toluene
(30 ml) was added at room temperature to a suspension
of the lithium salt 2 (1.40 g; 5.59 mmol) in toluene (30
ml). The reaction mixture was refluxed for 5 h and then
the solvent was removed in vacuo to give a brown solid.
Complex 3 was extracted into hexane (5×20 ml) and
the solution was cooled at −35°C overnight to isolate
complex 3 as a brown yellowish solid (0.5 g, 22%).
Anal. Calc. for C14H19Cl3Si2Ti: C, 42.28; H, 4.82.
Found: C, 42.29; H, 5.03. 1H-NMR (CDCl3, 300 MHz):
d −0.59 (s, 3H, SiMe2 bridges); 0.45 (s, 3H, SiMe2

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R. Go´mez-Garc´ıa, P. Royo / Journal of Organometallic Chemistry 583 (1999) 86–93
bridges); 0.47 (s, 3H, SiMe2 bridges); 0.64 (s, 3H, SiMe2
bridges); 4.66 (s, 1H, H allylic-C5H4); 6.84 (m, 1H,
C5H4–C5H3); 6.93 (m, 1H, C5H4–C5H3); 7.06 (m, 2H,
C5H4–C5H3); 7.30 (m, 1H, C5H4–C5H3); 7.59 (m, 1H,
−5.2, −1.0, −0.6, 1.5 (SiMe2 bridges); 55.8 (Csp3-
C5H4); 114.2, 115.6, 129.5, 132.0, 139.4, 140.6 (Cb, Cg
to the SiMe2 bridges); 137.2, 142.1 (Ca to the SiMe2
bridges).
1
C5H4–C5H3). H-NMR (C6D6, 300 MHz): l −0.72 (s,
3H, SiMe2 bridges); 0.17 (s, 3H, SiMe2 bridges); 0.43 (s,
3H, SiMe2 bridges); 0.46 (s, 3H, SiMe2 bridges); 4.71 (s,
1H, H allylic-C5H4); 6.22 (m, 1H, C5H4–C5H3); 6.62
(m, 1H, C5H4–C5H3); 6.70 (m, 2H, C5H4–C5H3); 6.89
(m, 1H, C5H4–C5H3); 6.95 (m, 1H, C5H4–C5H3).
13C{1H}-NMR (C6D6, 75 MHz): l −6.3, −1.8, −1.6,
1.4 (SiMe2 bridges); 54.7 (Csp3-C5H4); 130.8, 131.0,
132.6, 133.1, 139.0, 142.1 (Cb, Cg to the SiMe2 bridges);
132.4, 133.0, 140.1 (Ca to the SiMe2 bridges).
3.4.3. Complex 6
Anal. Calc. for C19H24Si2HfCl2: C, 40.90, H, 4.34.
Found: C, 40.73, H, 4.17. H-NMR (C6D6, 300 MHz):
1
l −0.57 (s, 3H, SiMe2 bridges); 0.34 (s, 3H, SiMe2
bridges); 0.54 (s, 3H, SiMe2 bridges); 0.56 (s, 3H, SiMe2
bridges); 5.00 (s, 1H, H allylic-C5H4); 5.56 (m, 1H,
C5H4–C5H3); 5.89 (s, 5H, C5H5); 6.30 (m, 1H, C5H4–
C5H3); 6.42 (m, 1H, C5H4–C5H3); 6.81 (m, 1H, C5H4–
C5H3); 6.85 (m, 1H, C5H4–C5H3); 7.01 (m, 1H,
C5H4–C5H3). 13C{1H}-NMR (C6D6, 75 MHz): l −5.1,
−1.0, −0.5, 1.5 (SiMe2 bridges); 55.8 (Csp3-C5H4);
114.5 (C5H5); 112.5, 128.3, 132.0, 139.4, 140.7 (Cb, Cg
to the SiMe2 bridges); 135.6, 142.0 (Ca to the SiMe2
bridges).
3.4. Synthesis of [M(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}Cl2] (M=Ti 4, Zr 5, Hf 6) and [Ti(p5-
C5-Me5){(C5H4)(SiMe2)2(p5-C5H3)}Cl2] 7
The same procedure was used to prepare these com-
pounds. A suspension of the lithium salt 2 (2.95 g; 11.7
mmol) in THF (40 ml) was added dropwise to a cooled
(−78°C) solution of CpTiCl3 or CpMCl3 · DME
(M=Zr, Hf) (11.7 mmol) in THF (60 ml). The reaction
mixture was warmed to room temperature and stirred
overnight. After removing the solvent, the residue was
extracted into CH2Cl2 (3×30 ml). The solvent was
removed in vacuo and the solid was washed with
pentane (30 ml) to give red 4 (3.8 g; 77.5%), pale yellow
5 (3.3 g; 75%), pale yellow 6 (2.5 g; 75%) and dark red
7 (2.3 g; 76%).
3.4.4. Complex 7
Anal. Calc. for C24H34Si2TiCl2: C, 57.94; H, 6.89.
Found: C, 57.18; H, 6.62. 1H-NMR (CDCl3, 300 MHz):
l −0.73 (s, 3H, SiMe2 bridges); 0.36 (s, 6H, SiMe2
bridges); 0.45 (s, 3H, SiMe2 bridges); 2.04 (s, 15H,
C5Me5); 4.83 (s, 1H, H allylic-C5H4); 6.08 (m,1H,
C5H3–C5H4); 6.43 (m, 1H, C5H4–C5H3); 6.67 (m, 1H,
C5H4–C5H3); 6.75 (m, 1H, C5H4–C5H3); 6.87 (m, 1H,
C5H4–C5H3); 6.92 (m, 1H, C5H4–C5H3). 13C{1H}-
NMR (C6D6, 75 MHz): l −5.2, −0.7, −0.3, 2.2
(SiMe2 bridges); 13.5 (C5Me5); 56.4 (Csp3-C5H4); 117.6,
128.2, 132.1, 132.8, 139.5 (Cb, Cg to the SiMe2 bridges);
140.1, 143.0 (Ca to the SiMe2 bridges).
3.4.1. Complex 4
Anal. Calc. for C19H24Si2TiCl2: C, 53.4; H, 5.66.
Found: C, 52.93; H, 5.73. 1H-NMR (CDCl3, 300 MHz):
l −0.69 (s, 3H, SiMe2 bridges); 0.38 (s, 6H, SiMe2
bridges); 0.53 (s, 3H, SiMe2 bridges); 4.82 (s, 1H, H
allylic-C5H4); 6.54 (s, 5H, C5H5); 6.34 (m, 1H, C5H4–
C5H3); 6.77 (m, 1H, C5H4–C5H3); 6.91 (m, 1H, C5H4–
C5H3); 6.97 (m, 1H, C5H4–C5H3); 7.00 (m, 1H,
C5H4–C5H3); 7.12 (m, 1H, C5H4–C5H3). 13C{1H}-
NMR (CDCl3, 75 MHz): l −5.3, −1.0, −0.7, 1.5
(SiMe2 bridges); 56.2 (Csp3-C5H4); 119.9 (C5H5); 115.1,
131.7, 132.0, 132.7, 139.8, 140.7 (Cb, Cg to the SiMe2
bridges); 140.5, 141.7, 144.7 (Ca to the SiMe2 bridges).
3.5. Synthesis of [Ti(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}ClMe] 8
A 3 M THF solution of MgClMe (0.74 ml; 2.22
mmol) was added at low temperature (−78°C) to a
solution of 4 in THF (30 ml). The solution was warmed
to room temperature and stirred for 2 h. The solvent
was removed in vacuo and the residue was extracted
into pentane (3×15 ml). After removing the solvent in
vacuo, complex 8 was isolated as a red solid (0.87 g,
96%). Anal. Calc. for C20H27Si2TiCl: C, 59.03; H, 6.69.
1
Found: C, 59.63; H, 7.03. H-NMR (C6D6, 300 MHz):
3.4.2. Complex 5
Anal. Calc. for C19H24Si2ZrCl2: C, 48.48; H, 5.14.
Found: C, 48.44; H, 5.04. H-NMR (C6D6, 300 MHz):
l −0.57 (s, 3H, SiMe2 bridges); 0.33 (s, 3H, SiMe2
bridges); 0.55 (s, 3H, SiMe2 bridges); 0.56 (s, 3H, SiMe2
bridges); 5.08 (m, 1H, H allylic-C5H4); 5.63 (m, 1H,
C5H4–C5H3); 5.97 (s, 5H, C5H5); 6.37 (m, 1H, C5H3–
C5H4); 6.49 (m, 1H, C5H4–C5H3); 6.81 (m, 1H, C5H4–
C5H3); 6.86 (m, 1H, C5H4–C5H3); 7.01 (m, 1H,
C5H4–C5H3). 13C{1H}-NMR (Tol-d8, 75 MHz): l
l −0.41, 0.10, 039, 0.76, 0.89 (M, s, 3H, SiMe2 bridges
and TiꢀMe); −0.47, 0.11, 0.51, 0.76, 0.89 (m, s, 3H,
SiMe2 bridges and TiꢀMe); 4.81 (M, m, 1H, H allylic-
C5H2); 4.93 (m, m, 1H, H allylic-C5H4); 4.97 (m, m, 1H,
C5H4–C5H3); 5.18 (m, m, 1H, C5H4–C5H3); 5.21 (M,
m, 1H, C5H4–C5H3); 5.38 (M, m, 1H, C5H4–C5H3);
5.81 (m+M, s, 10H, C5H5); 6.85, 6.92, 6.96, 7.00, 7.09
(m+M, m, 8H, C5H4–C5H3). 13C{1H}-NMR (C6D6,
75 MHz): l −4.9, −1.2, −1.0, 1.7 (M, SiMe2
bridges); −5.5, −0.8, 0.1, 1.0 (m, SiMe2 bridges); 48.9
1

R. Go´mez-Garc´ıa, P. Royo / Journal of Organometallic Chemistry 583 (1999) 86–93
91
(M, TiꢀMe); 49.2 (m, TiꢀMe); 56.3 (m+M, Csp3-
C5H4); 116.2 (M, C5H5); 115.8 (m, C5H5); 114.5, 115.5,
119.2, 131.8, 134.0, 138.9 (M, Cb, Cg to the SiMe2
bridges); 114.9, 117.5, 119.8, 132.0, 134.3, 138.9 (m, Cb,
Cg to the SiMe2 bridges); 138.6, 141.9, 142.4 (M, Ca to
the SiMe2 bridges); not observed (m, Ca to the SiMe2
bridges).
m, 1H, C5H4–C5H3); 5.23 (m, m, 1H, C5H4–C5H3);
5.47 (m, m, 1H, C5H4–C5H3); 5.66 (M, m, 1H, C5H4–
C5H3); 5.81 (m+M, m, 10H, C5H5); 6.82, 6.88, 7.04
(m+M, m, 8H, C5H4–C5H3). 13C{1H}-NMR (C6D6,
75 MHz): l −4.9, −1.1, −0.2, 1.4 (M, SiMe2
bridges); 31.8 (M, ZrꢀMe); 55.8 (M, Csp3-C5H4); 110.7
(M, C5H5); 113.7, 119.2, 121.6, 132.2, 138.9, 140.8 (M,
Cb, Cg to the SiMe2 bridges); 139.9, 140.5, 142.6 (M, Ca
to the SiMe2 bridges).
3.6. Synthesis of [Ti(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}ClEt] 9
3.8. Synthesis of [Zr(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}ClEt] 11
A 2 M ethyl ether solution of MgClEt (0.53 ml; 1.07
mmol) was added to a cooled solution of complex 4
(0.4 g, 1.07 mmol) in THF (30 ml). The mixture was
warmed to 0°C and stirred for 2 h. Then the solvent
was removed in vacuo and the residue was extracted
into hexane (3×15 ml). The solvent was removed in
vacuo to give 9 as a brown reddish solid (0.35 g, 77%).
Anal. Calc. for C21H29Si2TiCl: C, 59.92, H, 6.94,
A 2 M ethyl ether solution of MgClEt (0.44 ml; 0.89
mmol) was added to a cooled solution of complex 5
(0.42 g; 0.89 mmol) in THF (30 ml). The procedure
described for 9 was used to isolate complex 11 as a pale
yellow solid (0.32 g, 78%). Anal. Calc. for
C21H29Si2ZrCl: C, 54.32; H, 6.30. Found: C, 53.80; H,
1
1
Found: C, 59.81, H, 7.10. H-NMR (C6D6, 300 MHz):
6.26. H-NMR (C6D6, 300 MHz): l −0.49 (m, s, 3H,
l −0.47 (m, s, 3H, SiMe2 bridges), 0.07 (m, s, 3H,
SiMe2 bridges), 0.53 (m, s, 3H, SiMe2 bridges), 0.77 (m,
s, 3H, SiMe2 bridges); −0.39 (M, s, 3H, SiMe2
bridges), 0.04 (M, s, 3H, SiMe2 bridges), 0.38 (M, s,
3H, SiMe2 bridges), 0.77 (M, s, 3H, SiMe2 bridges);
SiMe2 bridges); 0.26 (m, s, 3H, SiMe2 bridges); 0.42 (m,
s, 3H, SiMe2 bridges); 0.70 (m, s, 3H, SiMe2 bridges);
−0.49 (M, s, 3H, SiMe2 bridges); 0.24 (M, s, 3H,
SiMe2 bridges); 0.39 (M, s, 3H, SiMe2 bridges); 0.70
(M, s, 3H, SiMe2 bridges); 1.00 (m+M, m, 2H,
ꢀCH2CH3); 1.40 (m+M, m, 6H, ꢀCH2CH3); 1.49 (m+
M, m, 2H, ꢀCH2CH3); 4.95 (m, m, 1H, H allylic-C5H4);
5.10 (M, m, 1H, H allylic-C5H4); 5.25 (M, m, 1H,
C5H4–C5H3); 5.29 (m, m, 1H, C5H4–C5H3); 5.42 (m, m,
1H, C5H4–C5H3); 5.62 (M, m, 1H, C5H4–C5H3); 5.84
(m+M, s, 10H, C5H5); 6.83, 6.88, 7.04 (m+M, m, 8H,
C5H4–C5H3). 13C{1H}-NMR (C6D6, 75 MHz): l −4.9,
−1.2, 0.2, 1.1 (M, SiMe2 bridges); 20.2 (M, ꢀCH2CH3);
47.2 (M, ꢀCH2CH3); 55.7 (M, Csp3-C5H4); 110.5 (M,
C5H5); 113.6, 121.9, 132.0, 134.9, 140.9, 141.8 (M, Cb,
Cg to the SiMe2 bridges); 135.7, 138.9, 142.0 (Ca to the
SiMe2 bridges).
1
1.16 (M, t, JCꢀH=7.3 Hz, 3H, ꢀCH2CH3); 1.23 (m, t,
1JCꢀH=7.3 Hz, 3H, ꢀCH2ꢀCH3); 1.51 (m+M, m, 2H,
ꢀCH2CH3); 2.26 (m+M, m, 2H, ꢀCH2CH3); 4.89 (M,
m, 1H, H allylic-C5H4); 4.92 (m, m, 1H, H allylic-
C5H4); 5.02 (m, m, 1H, C5H4–C5H3); 5.12 (m, m, 1H,
C5H4–C5H3); 5.18 (M, m, 1H, C5H4–C5H3); 5.32 (M,
m, 1H, C5H4–C5H3); 5.86 (m+M, s, 10H, C5H5); 6.84,
6.93, 7.05, 7.19 (m+M, m, 8H, C5H4–C5H3). 13C{1H}-
NMR (C6D6, 50 MHz): l −4.9, −1.3, −1.2, 1.4 (M,
SiMe2 bridges); 21.7 (M, ꢀCH2CH3); 56.2 (M, Csp3-
C5H4); 63.9 (M, ꢀCH2CH3); 114.4, 119.5, 131.8, 133.9,
139.8, 140.1 (M, Cb, Cg to the SiMe2 bridges); 115.9
(M, C5H5); 134.9, 139.8, 141.9 (Ca to the SiMe2
bridges).
3.9. Synthesis of [Zr(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}Cl(CH2Ph)] 12
3.7. Synthesis of [Zr(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}ClMe] 10
Cooled (−30°C) THF (30 ml) was added to a mix-
ture of 5 (0.5 g; 1.06 mmol) and Mg(CH2Ph)2 · 2THF
(0.37 g; 1.06 mmol). The mixture was warmed to room
temperature and stirred for 3 h. The solvent was re-
moved in vacuo and the residue was extracted into
pentane (3×15 ml). The solution was concentrated by
evaporation of the solvent to half volume and kept at
−35°C overnight to give complex 12 as an orange solid
(0.42 g, 75%). Anal. Calc. for C26H31Si2ZrCl: C, 59.33;
H, 5.94. Found: C, 58.70; H, 6.26. 1H-NMR (C6D6, 300
MHz): d −0.50 (M, s, 3H, SiMe2 bridges); 0.21 (M, s,
3H, SiMe2 bridges); 0.37 (M, s, 3H, SiMe2 bridges);
0.73 (M, s, 3H, SiMe2 bridges); −0.50 (m, s, 3H, SiMe2
bridges); 0.22 (m, s, 3H, SiMe2 bridges); 0.42 (m, s, 3H,
SiMe2 bridges); 0.79 (m, s, 3H, SiMe2 bridges); 2.01
A 3 M THF solution of MgClMe (0.31 ml, 0.93
mmol) was added to a cooled (−78°C) solution of 5
(0.43 ml, 0.93 mmol) in THF (30 ml). The mixture was
warmed to room temperature and stirred for 4 h. After
removing the solvent in vacuo the residue was extracted
into hexane (3×30 ml). The solvent was removed in
vacuo to give complex 10 as a pale yellow solid (0.33 g;
78%). Anal. Calc. for C20H27Si2ZrCl: C, 53.35; H, 6.04.
1
Found: C, 53.36; H, 6.49. H-NMR (C6D6, 300 MHz):
l −0.49, 0.28, 0.39, 0.51, 0.69 (M, s, 3H, SiMe2
bridges and ZrꢀMe); −0.52, 0.30, 0.42, 0.51, 0.69 (m, s,
3H, SiMe2 bridges and ZrꢀMe); 4.94 (m, m, 1H, H
allylic-C5H4); 5.12 (M, m, 1H, H allylic-C5H4); 5.20 (M,

92
R. Go´mez-Garc´ıa, P. Royo / Journal of Organometallic Chemistry 583 (1999) 86–93
1
(m+M, d, JCꢀH=12 Hz, 2H, ꢀCH2Ph); 2.74 (m+M,
d, 1JCꢀH=12 Hz, 2H, ꢀCH2Ph); 4.91 (m, m, 1H, H
allylic-C5H4); 5.14 (M, m, 1H, H allylic-C5H4); 5.27 (M,
m, 1H, C5H4–C5H3); 5.31 (m, m, 1H, C5H4–C5H3);
5.48 (m, m, 1H, C5H4–C5H3); 5.65 (m, s, 5H, C5H5);
5.66 (M, s, 5H, C5H5); 5.72 (M, m, 1H, C5H4–C5H3);
6.63, 6.68, 6.84, 6.93, 7.04, 7.10, 7.27 (m+M, 18H,
C5H4–C5H3, ꢀCH2Ph). 13C{1H}-NMR (C6D6, 75
MHz): −5.1, −1.1, −0.8, 2.2 (M, SiMe2 bridges);
55.9 (M, Csp3-C5H4); 59.9 (M, ꢀCH2Ph); 113.8 (M,
C5H5); 113–152 (M+m, ten signals C5H4–C5H3,
ꢀCH2Ph).
3.11.1. Complex 14
Anal. Calc. for C21H30Si2Ti: C, 65.26, H, 7.82.
Found: C, 64.97, H, 7.53. H-NMR (C6D6, 300 MHz):
1
l −0.38 (s, 3H, SiMe2 bridges), 0.22 (s,br, 6H, TiMe2),
0.25 (s, 3H, SiMe2 bridges), 0.32 (s, 3H, SiMe2 bridges),
0.47 (s, 3H, SiMe2 bridges); 4.29 (s, 1H, H allylic-
C5H4); 5.77 (s, 5H, C5H5); 5.08 (m, 1H, C5H4–C5H3);
5.92 (m, 1H, C5H4–C5H3); 6.00 (m, 1H, C5H4–C5H3);
6.85 (m, 2H, C5H4–C5H3); 7.09 (m, 1H, C5H4–C5H3).
13C{1H}-NMR (C6D6, 75 MHz): l −4.9, −1.4, 0.3,
1.0 (SiMe2 bridges); 47.0, 47.1 (TiꢀMe); 56.0 (Csp3-
C5H4); 113.9 (C5H5); 114.2, 123.0, 124.5, 132.2, 139.1,
140.8 (Cb, Cg to the SiMe2 bridges); 137.2, 140.3, 142.7
(Ca to the SiMe2 bridges).
3.10. Synthesis of [Hf(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}Cl(CH2Ph)] 13
3.11.2. Complex 15
Cooled (−30°C) THF (30 ml) was added to a mix-
ture of 6 (0.3 g; 0.53 mmol) and Mg(CH2Ph)2 · 2THF
(0.18 g; 0.53 mmol). The mixture was warmed to room
temperature and stirred for 5 h. The procedure de-
scribed for 12 was used to obtain complex 13 as a pale
yellow solid (0.22 g; 69%). Anal. Calc. for
C26H31Si2HfCl: C, 50.89; H, 5.09. Found: C, 51.23; H,
Anal. Calc. for C21H40Si2Ti: C, 68.39; H, 8.83.
Found: C, 68.01; H, 8.41. H-NMR (C6D6, 300 MHz):
1
l −0.33 (s, 3H, SiMe2 bridges), −0.08 (s, 3H, TiMe2),
−0.06 (s, 3H, TiMe2), 0.36 (s, 3H, SiMe2 bridges), 0.40
(s, 3H, SiMe2 bridges), 0.58 (s, 3H, SiMe2 bridges); 1.66
(s, 15H, C5Me5); 4.46 (s, 1H, H allylic-C5H4); 5.08 (m,
1H, C5H4–C5H3); 5.84 (m, 1H, C5H4–C5H3); 6.09 (m,
1H, C5H4–C5H3); 6.89 (m, 3H, C5H4–C5H3). 13C{1H}-
NMR (C6D6, 75 MHz): l −4.7, −0.5, 0.4, 1.7 (SiMe2
bridges); 12.4 (C5Me5); 47.2 (TiꢀMe); 56.4 (Csp3-C5H4);
116.0, 120.5, 121.4, 125.4, 132.2, 139.8 (Cb, Cg to the
SiMe2 bridges); 132.4, 134.1, 143.3 (Ca to the SiMe2
bridges).
1
5.38. H-NMR (C6D6, 300 MHz): l −0.52 (M, s, 3H,
SiMe2 bridges); 0.24 (M, s, 3H, SiMe2 bridges); 0.38
(M, s, 3H, SiMe2 bridges); 0.72 (M, s, 3H, SiMe2
bridges); −0.52 (m, s, 3H, SiMe2 bridges); 0.24 (m, s,
3H, SiMe2 bridges); 0.40 (m, s, 3H, SiMe2 bridges); 0.79
1
(m, s, 3H, SiMe2 bridges); 1.60 (m+M, d, JCꢀH=12
1
Hz, 2H, ꢀCH2Ph); 2.58 (m+M, d, JCꢀH=12 Hz, 2H,
ꢀCH2Ph); 4.84 (m, m, 1H, H allylic-C5H4); 5.06 (M, m,
1H, H allylic-C5H4); 5.17 (M, m, 1H, C5H4–C5H3); 5.22
(m, m, 1H, C5H4–C5H3); 5.54 (m, m, 1H, C5H4–C5H3);
5.61 (m+M, s, 10H, C5H5); 5.77 (M, m, 1H, C5H4–
C5H3); 6.55 (M, m, 1H, C5H4–C5H3); 6.61 (m, m, 1H,
C5H4–C5H3), 6.84, 6.94, 7.04, 7.09, 7.12, 7.30, 7.32
(m+M, 16H, C5H4–C5H3, ꢀCH2Ph). 13C{1H}-NMR
(C6D6, 75 MHz): −4.9, −1.2, −0.8, 2.2 (M, SiMe2
bridges); 55.9 (M, Csp3-C5H4); 60.8 (M, ꢀCH2Ph);
112.8 (M, C5H5); 114.5–151.9 (M+m, ten signals
C5H4–C5H3, ꢀCH2Ph).
3.11.3. Complex 16
Anal. Calc. for C21H30Si2Zr: C, 58.68; H, 7.03.
1
Found: C, 59.01; H, 6.87. H-NMR (C6D6, 300 MHz):
l −0.47 (s, 3H, SiMe2 bridges), 0.00 (s, br, 6H,
ZrMe2), 0.31 (s, 3H, SiMe2 bridges), 0.34 (s, 3H, SiMe2
bridges), 0.41 (s, 3H, SiMe2 bridges); 4.31 (s, 1H, H
allylic-C5H4); 5.51 (m, 1H, C5H4–C5H3); 5.78 (s, 5H,
C5H5); 5.93 (m, 1H, C5H4–C5H3); 6.12 (m, 1H, C5H4–
C5H3); 6.83 (m, 2H, C5H4–C5H3); 7.04 (m, 1H, C5H4–
C5H3). 13C{1H}-NMR (C6D6): l −4.9, −1.1, 0.2, 1.4
(SiMe2 bridges); 31.8, 32.3 (ZrꢀMe); 55.8 (Csp3-C5H4);
110.7 (C5H5); 113.7, 119.2, 121.6, 132.2, 138.9, 140.8
(Cb, Cg to the SiMe2 bridges); 139.9, 140.4, 142.6 (Ca to
the SiMe2 bridges).
3.11. Synthesis of [M(p5-C5H5){(C5H4)(SiMe2)2(p5-
C5H3)}Me2] (M=Ti 14, Zr 16) and [Ti(p5-C5Me5)-
{(C5H4)(SiMe2)2(p5-C5H3)}Me2] 15
3.12. Reaction of complex 5 with Ti(NMe2)4
The same procedure was used to prepare these com-
pounds. A 1.6 M ethyl ether solution of LiMe (1.65 ml;
2.8 mmol) was added to a cooled solution (−78°C) of
complexes 4, 5 or 6 (1.4 mmol) in hexane (30 ml). The
mixture was warmed to room temperature and stirred
for 2 h (14, 15) or 4 h (16). The solvent was removed in
vacuo and the residue was extracted into hexane (3×20
ml). After removing the solvent in vacuo, orange oily
solid 14 (0.38 g, 71%), pale yellow solid 5 (0.46 g; 77%)
and yellow oily solid 16 (0.26 g; 70%) were isolated.
Ti(NMe2)4 (0.023 g; 0.109 mmol) was added at room
temperature to a C6D6 solution of complex 5 (0.048 g;
0.109 mmol) in a valved NMR tube. After 2 h, the
1
reaction was complete as observed from the H-NMR
spectrum, which showed the signals expected for com-
plex 17. 1H-NMR (C6D6, 300 MHz): l 0.45 (s, 6H,
SiMe2 bridges); 0.71 (s, 6H, SiMe2 bridges); 2.93 (s,
1
18H, TiꢀNMe2); 5.84 (t, JCꢀH=3Hz, 1H, C5H3); 5.99
1
(s, 5H, C5H5); 6.33 (t, JCꢀH=3Hz, 1H, C5H3); 6.39 (d,

R. Go´mez-Garc´ıa, P. Royo / Journal of Organometallic Chemistry 583 (1999) 86–93
93
1JCꢀH=3Hz, 2H, C5H3); 6.74 (d, 1JCꢀH=3Hz, 2H,
C5H3). 13C{1H}-NMR (C6D6, 75 MHz): l 2.0, 4.0
(SiMe2 bridges); 50.3 (TiꢀNMe2); 113.8 (Cg to the
SiMe2 bridges); 115.7 (C5H5); 116.4 (Cg to the SiMe2
bridges); 120.6 (Cb to the SiMe2 bridges); 125.0 (Ca to
the SiMe2 bridges); 130.2 (Cb to the SiMe2 bridges);
134.5 (Ca to the SiMe2 bridges).
[10] G.Ciruelo, T. Cuenca, P. Go´mez-Sal, A. Mart´ın, P. Royo, J.
Chem. Soc. Dalton Trans. (1995) 231.
[11] T. Cuenca, A. Padilla, P. Royo, M. Parra-Hake, M.A.
Pellinghelli, A. Tiripicchio, Organometallics 14 (1995) 848.
[12] F. Amor, P. Go´mez-Sal, E. de Jesu´s, A. Mart´ın, A.I. Pe´rez, P.
Royo, A. Va´zquez de Miguel, Organometallics 15 (1996) 2103.
[13] I. Mieling, Ph.D. Dissertation, University Bielefeld, 1993.
[14] J.L. Huhmann, J.Y. Corey, N.P. Rath, Organometallics 15
(1996) 4063.
[15] A. Cano, T. Cuenca, P. Go´mez-Sal, P. Royo, Organometallics
13 (1994) 1688.
[16] A. Cano, T. Cuenca, P. Go´mez-Sal, A. Manzanero, P. Royo, J.
Organomet. Chem. 526 (1996) 227.
Acknowledgements
[17] F.J. Ferna´ndez, P. Go´mez-Sal, A. Manzanero, P. Royo, H.
Jacobsen, H. Berke, Organometallics 16 (1997) 1553.
[18] A.M Barriola, A.M. Cano, T. Cuenca, F.J. Ferna´ndez, P.
Go´mez-Sal, A. Manzanero, P. Royo, J. Organomet. Chem. 542
(1997) 247.
The authors acknowledge DGICYT (PB97-0776) and
CAM (I+D0033/94) for financial support. R.G-G ac-
knowledges CAM for a fellowship.
[19] M. Calvo, M.V. Galakhov, R. Go´mez-Garc´ıa, P. Go´mez-Sal, A.
Mart´ın, P. Royo, A. Va´zquez de Miguel, J. Organomet. Chem.
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