Reactivity of chlorodimethylsilyl-η5-cyclopentadienyltrichlorotitanium with nitrogen based donors. X-ray molecular structure of [Ti{η5-C5H4SiMe2[η1-N(2,6-Me2C6H3<

Article abstract of DOI:10.1016/S0022-328X(98)00627-5

This paper reports the reactivity of [Ti(η⁵-C₅H₄SiMe₂Cl)Cl₃], 1 towards nitrogen based donor reagents. Complex 1 reacts with lithium benzamidinato Li[PhC(NSiMe₃)₂] to afford [Ti(

Full text of DOI:10.1016/S0022-328X(98)00627-5

Journal of Organometallic Chemistry 564 (1998) 93–100
Reactivity of chlorodimethylsilyl-p5-cyclopentadienyltrichlorotitanium
with nitrogen based donors. X-ray molecular structure of
[Ti{p5-C5H4SiMe2[p1-N(2,6-Me2C6H3)]}Cl2]
Rafael Go´mez, Pilar Go´mez-Sal 1, Avelino Mart´ın1, Aurora Nu´n˜ez, Pedro A. del Real,
Pascual Royo *
Departamento de Qu´ımica Inorga´nica, Uni6ersidad de Alcala´, Campus Uni6ersitario, 28871 Alcala´ de Henares, Spain
Received 10 February 1998; received in revised form 24 April 1998
Abstract
This paper reports the reactivity of [Ti(p5-C5H4SiMe2Cl)Cl3], 1 towards nitrogen based donor reagents. Complex 1 reacts with
lithium benzamidinato Li[PhC(NSiMe3)2] to afford [Ti(p5-C5H4SiMe2Cl){PhC(NSiMe3)2}Cl2] 2 and with lithium amide LiNMe2
to produce [Ti(p5-C5H4SiMe2NMe2)(NMe2)3] 3. The latter compound was converted into the dihalide derivatives [Ti(p5-
C5H4SiMe2NMe2)(NMe2)X2] [X=Cl (4) and Br (5)] by reaction with SiMe3X (X=Cl or Br, respectively). The constrained
geometry derivatives [Ti{p5-C5H4SiMe2(p1-NR)}Cl2] (R=C6H5 6, 2,6-Me2C6H3 7 and 2-Me-6-iPr-C6H3 8) have been synthesized
by treatment of 1 with the corresponding primary aryl amines H2NR. Complex 7 was readily converted into the dialkyl and
diamido compounds [Ti{p5-C5H4SiMe2[p1-N(C6H3Me2)]}X2] (X=Me (9), CH2Ph (10), CH2SiMe3 (11) or NMe2 (13)) by
metathesis using Grignard or organolithium reagents and into the monoalkyl derivative [Ti{p5-C5H4SiMe2[p1-
N(C6H3Me2)]}MeCl] (12) by reaction with AlMe3. The molecular structure of complex 7 [Ti{(p5-C5H4SiMe2[p1-N(2,6-
Me2C6H3)]}Cl2] was established by X-ray crystallography. © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Titanium; Amido-silylcyclopentadienyl; Amidotitanium; Alkyltitanium
In particular, the use of nitrogen based donors is
receiving considerable attention for both synthetic and
1. Introduction
catalytic purposes. In addition to the amido chemistry
The organometallic chemistry of Ti(IV) is dominated
[2], research effort has been devoted to the synthesis of
by complexes with ancillary cyclopentadienyl (Cp) lig-
pendant nitrogen functionalized Cp complexes and con-
ands [1]. More recently, there has been considerable
strained geometry derivatives of Group 4 metals [3,4].
interest in the use of alternative ligands either with or in
As part of our current research, we were interested in
place of the Cp moieties. Replacement of one of the Cp
the synthesis of 12- and 14-electron Cp Group 4 metal
rings in dicyclopentadienyl derivatives by a less electron
donating and less sterically demanding anionic ligand
complexes in order to compare their reactivity with the
analogous 16-electron dicyclopentadienyl derivatives.
of the same charge allows the investigation of its influ-
We herein report the synthesis and characterization of a
ence on the chemical reactivity and catalytic activity of
the metal center.
number of monocyclopentadienyl titanium complexes
with a second ancillary ligand in their coordination
environment in which the new ligand can be either
linked or unlinked to the Cp group. The starting mate-
* Corresponding author. Tel.: +34
8854683; e-mail: proyo@inorg.alcala.es
1 X-ray diffraction studies.
1 8854765; fax: +34 1
rial for our investigations was [Ti(p5-C5H4SiMe2Cl)Cl3],
1 [5] which has two reactive Ti–Cl and Si–Cl bonds.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00627-5

94
R. Go´mez et al. / Journal of Organometallic Chemistry 564 (1998) 93–100
1
2. Results and discussion
The H-NMR spectra of compounds 2–5 show the
expected AA%BB% spin system for the four ring protons.
The methyl resonances of the Ti-NMe2 group are
shifted down field in relation to the methyl signal due
to the silicon-bound amido group. In addition, the
chemical shift of the Si-NMe2 protons is slightly af-
fected by the metal substituents. The assignment of the
13C-NMR spectra for these compounds is also straight-
forward and consistent with the presence of three dif-
ferent types of ring carbon atoms. The ipso-carbon
atom signal, when observed, appears at lower field than
the other two resonances.
2.1. Synthesis and NMR characterization
The reaction of [Ti(p5-C5H4SiMe2Cl)Cl3] 1 with one
equivalent of lithium benzamidinato Li[PhC(NSiMe3)2]
in toluene afforded, after extraction into hot toluene,
the corresponding benzamidinato complex [Ti(p5-
C5H4SiMe2Cl){PhC(NSiMe3)2}Cl2] 2 as red crystals in
ca. 50% isolated yield. Complex 2 is scarcely soluble in
hexane and diethyl ether, soluble in hot toluene and
very soluble in THF and chlorinated solvents. Com-
pound 2 is moisture sensitive and decomposes slowly
both in solution and in the solid state with elimination
of SiMe3Cl to give unidentified products.
Reaction of complex 1 with four equivalents of
LiNMe2 in diethyl ether at room temperature (r.t.)
followed by extraction into hexane afforded the te-
traamido derivative [Ti(p5-C5H4SiMe2NMe2)(NMe2)3] 3
in high yield as a yellow oil. Using a reported method
[6,7], reaction of complex 3 with excess of SiMe3X
(X=Cl or Br) resulted in the replacement of only two
of the titanium-bonded amido groups by halogen giving
the dihalo derivatives Ti(p5-C5H4SiMe2NMe2)(NMe2)
X2] (X=Cl 4 or Br 5) in good yields with elimination
of two equivalents of volatile SiMe3(NMe2). Com-
pounds 3–5 are air- and moisture-sensitive but ther-
mally stable. Whilst the oily complex 3 is very soluble
in hexane or pentane, the reddish derivatives 4 and 5
are insoluble in hydrocarbon solvents but soluble in
toluene and more soluble in THF and chlorinated
solvents. Attempts to react compound 1 with one, two
or three equivalents of LiNMe2 led to mixtures of
complexes formed by unselective partial substitution of
Ti–Cl and Si–Cl bonds.
Reactions of [Ti(p5-C5H4SiMe2Cl)Cl3] 1 with primary
aryl amines and their corresponding lithium salts have
been studied. Treatment of 1 with one equivalent of
NH2R (R=C6H5, 2,6-Me2C6H3 and 2-Me-6-iPr-C6H3)
in the presence of two equivalents of NEt3 gave the
corresponding constrained geometry derivatives [Ti{p5-
C5H4SiMe2(p1-NR)}Cl2], isolated as orange crystals
(R=C6H5 6 in ca. 30% yield) or as yellow crystals
(R=2,6-Me2C6H3 7 and 2-Me-6-iPr-C6H3 8 in 90 and
20% yield, respectively), after standard work-up. A
slightly better yield (41%) was obtained for compound
6 using the lithium amide Li(NHPh) in the presence of
one equivalent of NEt3. All attempts to prepare the
related 2,6-diiso-propylphenyl derivative failed under
these conditions. Complexes 6–8 are thermally stable in
C6D6 after 24 h at 120°C, but extremely oxygen and
moisture sensitive. It is worth noting that compound 6
is the most moisture sensitive; the steric hindrance
afforded by the bulkier 2,6-dimethylphenyl or 2-methyl-
6-iso-propylphenyl substituents probably impedes the
decomposition of 7 and 8. Compounds 6–8 were
scarcely soluble in hexane, soluble in toluene and very
soluble in THF and chlorinated solvents. The larger
branched aryl ligands give greater solubility than the
unsubstituted aryl ligand.
The NMR data and analytical composition of com-
plexes 2–5 (see Section 4) are consistent with the struc-
tures shown in Scheme 1.
The structures proposed for the new complexes 6–8
are shown in Scheme 2 and their spectroscopic and
analytical data are collected in Section 4.
1
The H-NMR spectra of complexes 6 and 7 show the
expected AA%BB% spin system for the C5H4 ring protons
and one singlet for the SiMe2 group. The presence of a
plane of symmetry is also consistent with the chemical
shifts observed for the freely rotating aryl amido sub-
stituents (C6H5 and 2,6-Me2C6H3). This behavior is
confirmed by their 13C-NMR spectra. However, the 1H-
and 13C-NMR spectra of complex 8 are indicative of
the asymmetric structure imposed by the two different
aryl substituents which make all the Cp proton and
1
carbon atoms chemically nonequivalent. The H-NMR
spectrum shows an ABCD coupling pattern for the ring
protons and five resonances for the corresponding car-
bon atoms are observed in the 13C-NMR spectrum. The
asymmetry is also observed in the presence of a set of
doublets (J2HH=6.6 Hz) due to the two different methyl
Scheme 1.

R. Go´mez et al. / Journal of Organometallic Chemistry 564 (1998) 93–100
95
carbon atoms are observed in their 13C-NMR spectra.
However, complex 12 shows an ABCD spin system in
1
the H-NMR spectrum and five carbon resonances in
the 13C-NMR spectrum. The asymmetry of this
molecule results in the presence of different signals
assigned to the methyl groups bound to the aryl frag-
ment and to the silicon atom. In complex 10, the
diastereotopic CH2 protons of the benzyl group appear
as two doublets at l=2.69 and 2.22, while in the
13C-NMR spectrum a triplet at l=86.2 with JCH
=
122.8 Hz is observed.
2.2. X-ray molecular structure of
[Ti{p5-C5H4SiMe2[p1-N(C6H3Me2)]}Cl2] (7)
Crystals of 7 suitable for X-ray diffraction were
obtained by slow cooling of its THF solution. The
molecular structure of 7 is shown in Fig. 1 and selected
bond lengths and angles are listed in Table 1.
Scheme 2.
groups for the iso-propyl fragment, along with the
presence of two resonances for the SiMe2 group. In
common with ansa-metallocene derivatives with bridg-
ing –SiMe2– groups [8] and other similar compounds
[9,10], the ring Cipso resonance for compounds 6–8
appears at higher field than those of the other carbon
atoms, consistent with the dimethylsilyldicyclopentadi-
enyl and amidosilylcyclopentadienyl ligands being in a
chelate coordination mode with the metal center.
Reactions of 7 with alkylating and amido reagents
have been studied. Treatment of [Ti{p5-C5H4SiMe2[p1-
N(C6H3Me2)]}Cl2] (7) with two equivalents of MgClMe
or one equivalent of Mg(CH2Ph)2 ·2THF gave the di-
alkyl complexes [Ti{p5-C5H4SiMe2[p1-N(C6H3Me2)]}
R2] (R=Me 9, CH2Ph 10) as yellow or red crystals,
respectively, in high yield. However, the addition of two
equivalents of LiCH2SiMe3 to 7 gave [Ti{p5-C5-
H4SiMe2[p1-N(C6H3Me2)]}(CH2SiMe3)2] 11 in low
yield, while the reaction with an excess of AlMe3 af-
forded the monoalkyl derivative [Ti{p5-C5H4SiMe2[p1-
N(C6H3Me2)]}MeCl] 12 as yellow crystals in 70% yield.
An analogous reaction of 7 with two equivalents of
LiNMe2 gave the diamido complex [Ti{p5-
C5H4SiMe2[p1-N(C6H3Me2)]}(NMe2)2] 13 as a brown
oil. All of these compounds are thermally stable but
extremely moisture sensitive. The thermal stability of
complex 9 with the bulkier 2,6-dimethylphenyl frag-
ment contrasts with the analogous complex [Ti{p5-
C5H4SiMe2[p1-N(CH2C6H5)]}Me2] which decomposes
in a few hours at r.t. [11]. The structures proposed for
the new complexes 9–13 are shown in Scheme 3 and
their spectroscopic and analytical data are collected in
Section 4.
The titanium atom is in a pseudo-tetrahedral envi-
ronment defined by one silylamido |-N coordinated Cp
ligand and two chloro ligands. The amido nitrogen is
planar (the sum of bond angles around N atom is 360°)
with sp2 hybridization. The Ti–N–C8 angle is 121.0
(2)°, which is smaller than that observed for the com-
plex [Ti{p5-C5H4SiMe2(p1-NtBu)}(NMe2)2] (128.1(4)°)
with a bulkier tBu group [6] and similar to that reported
for other related compounds such as [Ti{p5-
C5H4SiMe2[p1-N(CH2C6H3F2)]}Cl2] (119.7(1)°) [11] and
[Ti{p5-C5H4SiMe2(p1-NiPr)}Cl2] (117.4(1)°) [11]. The
˚
Ti–N distance (1.914(3) A) is consistent with a y-bond-
ing contribution from an interaction between the nitro-
The 1H-NMR spectra of complexes 9–11 and 13
show the expected AA%BB% spin system for the Cp ring
protons and three resonances for the corresponding
Scheme 3.

96
R. Go´mez et al. / Journal of Organometallic Chemistry 564 (1998) 93–100
that found in Cp–amido derivatives such as [Ti(p5-
C5R5){N(iPr)2}Cl2] (R=H 1.865(2), R=Me 1.865(5)
A) [12] and [Ti(p5-C5H5){N(SiMe3)2}Cl2] (R=H
˚
˚
1.879(2) A) [13] and chelating diamido complexes
such as
[Ti{[p1-N(2,6-iPr2C6H3)](CH2)3[p1-N(2,6-
Pr2C6H3)]}Cl2] (1.856(5) and 1.839(5) A) [14] or
i
˚
1
i
˚
[Ti{1,2-(p -NSi Pr3)2(C6H4)}Cl2] (1,878(4) A) [15].
An examination of the structural parameters associ-
ated with the Cp ring indicates a significant y-bond-
ing contribution from an p3-allyl-p2-olefin resonance
structure of the normal p5-coordination mode. The
˚
C3–C4 bond distance of 1.389(6) A is slightly shorter
than the remaining C–C bonds within the ring. Fur-
thermore, the Ti–C3 and Ti–C4 bond distances are
slightly longer than the rest. This contribution, proba-
bly determined by the dimethylsilyl bridge, has also
been observed in the ansa-metallocene derivative
[Ti{(C5H4)2SiMe2}X2] [8,16].
The Cp–Ti–N angle of 105.1° observed in 7 is
slightly smaller than that found in the analogous con-
strained geometry derivative Ti[C5H4SiMe2NtBu]Cl2
(107.0°) [6] and considerably smaller than in similar
unlinked Cp–amido complexes as in [Ti(C5H5)(NiPr)
Cl2] (116.2°) [12] or diamido complexes such as
[Ti{N(SiMe3)2}2(CH2Ph)2] (120.6°) [17]. In addition,
the replacement of the amido ligand with another Cp
ligand as in [Ti{(C5H4)2SiMe2}Cl2] produces a signifi-
cant increase in the corresponding Cp–M–Cp bond
angle to 128.7° [8]. However, the Cp–Ti–N angle in
7 is larger than the N–Ti–N angle observed in
bidentate diamide derivatives of the type [Ti{p1-
N(2,6-iPr2C6H3)}(CH2)3{p 1 -N(2,6-iPr2C6H3)}Cl2]
(99.2(2)°) [14] or [Ti{1,2-(p1-NSiiPr3)2(C6H4)}Cl2]
(92.6(2)°) [15], with six- and five-membered chelate
ring, respectively.
Fig.
1.
Molecular
structure
of
[Ti{p5-C5H4SiMe2[p1-
N(C6H3Me2)]}Cl2] (7).
gen py orbital with the appropriate vacant metal dy
orbital [2]. However, the magnitude of this interaction
is controlled both by the constrained geometry of the
molecule and by the electronic and steric properties of
the amido substituent, as observed in other complexes
of this type [Ti{p5-C5H4SiMe2(p1-NR)}Cl2] [6,11]. The
Ti–N bond distance found in compound 7 is longer
and therefore the y-bonding contribution smaller than
Table 1
3. Conclusions
˚
Selected bond lengths (A) and angles (°) for complex 7
[Ti(C5H4SiMe2Cl)Cl3] 1 is a very versatile starting
material for preparing new monocyclopentadienyl tita-
nium derivatives. In particular, reactions of 1 with
nitrogen based donor reagents gave amido–titanium
and –silicon compounds. New constrained geometry
amidosilylcyclopentadienyl derivatives containing aryl
groups bound to nitrogen have been synthesized by
reacting complex 1 with an appropriate primary aryl
amine in the presence of NEt3. [Ti{p5-C5H4SiMe2[p1-
N(C6H3Me2)]}Cl2] is readily converted into the dialkyl
and diamido complexes [Ti{p5-C5H4SiMe2[p1-N(C6H3
Me2)]}X2] (X=R or NMe2) and to the monoalkyl
derivative [Ti{p5-C5H4SiMe2[p1-N(C6H3Me2)]}MeCl]
by salt methatesis using Grignard, organolithium or
organoaluminium reagents.
˚
Bond length (A)
Ti(1)–N(1)
Ti(1)–Cl(2)
Ti(1)–C(5)
Ti(1)–C(4)
Si(1)–N(1)
N(1)–C(8)
C(1)–C(2)
C(3)–C(4)
Ti(1)–Cp(1)
1.914(3) Ti(1)–Cl(1)
2.273(1) Ti(1)–C(1)
2.325(4) Ti(1)–C(2)
2.374(4) Ti(1)–C(3)
1.755(3) Si(1)–C(1)
1.435(4) C(1)–C(5)
1.431(5) C(2)–C(3)
1.389(6) C(4)–C(5)
2.016
2.264(1)
2.320(4)
2.327(4)
2.386(4)
1.869(4)
1.419(5)
1.412(6)
1.410(6)
Bond angle (°)
N(1)–Ti(1)–Cl(1)
Cl(1)–Ti(1)–Cl(2) 101.1(1)
C(8)–N(1)–Si(1)
Si(1)–N(1)–Ti(1)
108.6(1)
N(1)–Ti(1)–Cl(2)
N(1)–Si(1)–C(1)
C(8)–N(1)–Ti(1)
Cp(1)–Ti(1)–Cl(1)
Cp(1)–Ti(1)–N(1)
108.5(1)
89.2(2)
121.0(2)
116.7
131.1(2)
108.0(1)
Cp(1)–Ti(1)–Cl(2) 116.6
105.1

R. Go´mez et al. / Journal of Organometallic Chemistry 564 (1998) 93–100
97
4. Experimental section
(t, 2H, C5H4), 6.12 (t, 2H, C5H4), 3.09 (s, 18H, 3
Ti–NMe2), 2.46 (s, 6H, Si–NMe2), 0.34 (s, 6H, SiMe2).
(CDCl3): l 6.17 (m, 4H, C5H4), 3.03 (s, 18H, 3 Ti–
NMe2), 2.42 (s, 6H, Si–NMe2), 0.24 (s, 6H,
SiMe2).13C{1H}-NMR (CDCl3): l 117.9 (CH of C5H4),
112.5(CH of C5H4), 44.8 (Ti–NMe2), 38.3 (Si–NMe2),
−1.4 (SiMe2).
4.1. General considerations
All manipulations were performed under argon using
Schlenk and high-vacuum line techniques or a glovebox
model HE-63 or MBraun. Solvents were purified by
distillation under argon from an appropriate drying
agent (sodium for toluene, sodium–potassium alloy for
hexane and sodium–benzophenone for diethyl ether).
The lithium benzamidinate salt was prepared by a
known procedure [18] and LiNHPh was prepared in
hexane (in almost quantitative yield) as a solvent free
solid from NH2Ph and n-butyl-lithium (Aldrich, 1.6 M
in hexane). The following reagents LiNMe2, SiMe3Cl,
SiMe3Br, NEt3, MeMgCl, Mg(CH2Ph)2, LiCH2SiMe3,
AlMe3 and the primary amines H2NR (R=C6H5,
C6H3Me2, C6H3MeiPr) were purchased from Aldrich.
C, H and N microanalyses were performed on a Perkin-
Elmer 240B and/or Heraeus CHN-O-Rapid microana-
lyzer. NMR spectra, measured at 25°C, were recorded
on a Varian Unity 300 (1H-NMR at 300 MHz and
4.4. Synthesis of [Ti(p5-C5H4SiMe2NMe2)(NMe2)Cl2]
(4)
A sample of SiMe3Cl (0.4 ml, 3.1 mmol) was added
to a solution of 3 (0.20 g, 0.58 mmol) in THF at
−70°C. The mixture was warmed to r.t. and then
stirred for 2 h. Volatiles were removed in vacuo giving
4 as a red solid (0.14 g, 75% yield). Recrystallization
from toluene at −40°C afforded red microcrystals
suitable for analysis. Anal. Calc. for C12H22N2SiCl2Ti:
C: 40.01; H: 7.00; N: 8.48. Found: C: 40.14; H: 6.74; N:
1
8.51%. H-NMR (C6D6): l 6.49 (t, 2H, C5H4), 6.14 (t,
2H, C5H4), 3.25 (s, 6H, Ti–NMe2), 2.42 (s, 6H, Si–
NMe2), 0.47 (s, 6H, SiMe2). 13C{1H}-NMR (CDCl3): l
134.2 (Cipso of C5H4), 125.7 (CH of C5H4), 119.7 (CH of
C5H4), 52.6 (Ti–NMe2), 38.1 (Si–NMe2), −2.0
(SiMe2).
13C-NMR at 75 MHz) spectrometer. H and 13C chem-
ical shifts are reported in l units relative to TMS
standard.
1
4.2. Synthesis of
4.5. Synthesis of [Ti(p5-C5H4SiMe2NMe2)(NMe2)Br2]
(5)
[Ti(p5-C5H4SiMe2Cl){C(Ph)[N(SiMe3)]2}Cl2] (2)
A solution of Li{C(Ph)[N(SiMe3)]2} (0.87 g, 3.20
mmo1) in toluene (15 ml) was added to a solution of 1
(1.00 g, 3.20 mmol) in toluene (40 ml) at −30°C. The
reaction mixture was warmed to r.t. and stirred for 12
h. The solution was filtered and the volume of the
filtrate reduced to ca. 20 ml and cooled to −40°C to
give 2 as red–orange crystals (0.40 g, 50% yield). Anal.
Calc. for C20H33N2Si3Ti: C: 44.48; H: 6.15; N: 5.18.
In a similar way, SiMe3Br (0.4 ml, 3.0 mmol) was
added to a solution of 3 (0.20 g, 0.58 mmol) in THF at
−70°C. The mixture was warmed to r.t. and then
stirred for 2 h. The volatiles were removed in vacuo
giving 5 as a red dark solid (0.18 g, 76% yield). Recrys-
tallization from toluene at −40°C afforded red micro-
crystals suitable for analysis. Anal. Calc. for
C12H22N2SiBr2Ti: C: 31.53; H: 5.53; N: 6.68. Found: C:
1
1
Found: C: 44.94; H: 6.00; N: 5.84%. H-NMR (C6D6):
31.60; H: 5.30; N: 6.70%. H-NMR (C6D6): l 6.69 (t,
l 6.88 (m, 5H, C6H5), 6.84 (t, 2H, C5H4), 6.55 (t, 2H,
C5H4), 1.09 (s, 6H, SiMe2), −0.01 (s, 18H, SiMe3).
2H, C5H4), 6.04 (t, 2H, C5H4), 3.30 (s, 6H, Ti–NMe2),
2.43 (s, 6H, Si–NMe2), 0.50 (s, 6H, SiMe2). 13C{1H}-
NMR (CDCl3): l 135.1 (Cipso of C5H4), 125.7 (CH of
C5H4), 119.7 (CH of C5H4), 53.0 (Ti–NMe2), 38.2
(Si–NMe2), −1.6 (SiMe2).
13C{1H}-NMR (C6D6): l 173.5 (PhC
6
(NSiMe3)2), 136.5
(C6H5), 124.0, 125.9 (CH of C5
(NSiMe3).
6 H4R), 3.0 (SiMe2Cl), 2.5
4.3. Synthesis of [Ti(p5-C5H4SiMe2NMe2)(NMe2)3] (3)
4.6. Synthesis of [Ti{p5-C5H4SiMe2[p1-N(C6H5)]}Cl2]
(6)
A sample of LiNMe2 (0.34 g, 6.70 mmol) was added
to a diethyl ether solution (40 ml) of 1 (0.50 g, 1.60
mmol) at −78°C. After warming to r.t., the reaction
mixture was stirred for 12 h. The volatiles were re-
moved under reduced pressure and the residue was
extracted into hexane (40 ml). After filtration, solvent
was removed under vacuum to give 3 as an analytically
pure yellow–green oil (0.44 g, 80% yield). Anal. Calc.
for C15H34N4SiTi: C, 52.29; H, 10.19; N, 16.50. Found:
Samples of H2NPh (0.15 ml, 1.6 mmol) and NEt3
(0.44 ml, 3.2 mmol) were added to a cooled solution
(−60°C) of Ti(p5-C5H4SiMe2Cl)Cl3, 1 (0.50 g, 1.6
mmol) in toluene (50 ml). The reaction mixture was
slowly warmed to r.t. and stirred for 10 h, giving an
orange solution with a white residue. After filtration,
the solution was concentrated and cooled to −30°C to
give orange crystals. Concentration of the mother
liquor (10 ml) and subsequent cooling to −30°C gave
1
C: 52.01; H: 9.89; N: 16.17%. H-NMR (C6D6): l 6.20

98
R. Go´mez et al. / Journal of Organometallic Chemistry 564 (1998) 93–100
a second crop of product which was characterized as 6.
(0.16 g, 30% yield). Anal. Calc. for C13H15NCl2SiTi: C:
46.47; H: 4.56; N: 4.12. Found: C: 47.01; H: 4.55; N:
C5H4), 6.15 (m, 1H, C5H4), 2.84 (hp, 1H, C6H3MeiPr),
2.04 (s, 3H, C6H3MeiPr), 1.52 (d, 3H, C6H3MeiPr), 1.03
(d, 3H, C6H3MeiPr), 0.20 (s, 3H, SiMe2), 0.05 (s, 3H,
1
4.21%. H-NMR (C6D6): l 7.27 (d, 2Hortho, Ph), 7.15 (t,
SiMe2). (CDCl3): l 7.16–7.06 (m, 3H, C6H6 3
MeiPr),
2Hmeta, Ph), 6.83 (t, 1Hpara, Ph), 6.53 (t, 2H, C5H4), 6.15
(t, 2H, C5H4), 0.15 (s, 6H, SiMe2). (CDCl3): l 7.34 (d,
2Hortho, Ph), 7.12 (t, 2Hmeta, Ph), 7.05 (t, 1Hpara, Ph),
7.14 (t, 2H, C5H4), 6.68 (t, 2H, C5H4), 0.66 (s, 6H,
SiMe2). 13C{1H}-NMR (CDCl3): l 152.3 (Cipso of
C6H5), 129.1 (Cortho of C6H5), 126.6 (Cmeta of C6H5),
125.0 (Cpara of C6H5), 125.5 (CH of C5H4), 118.9 (CH
of C5H4), 111.3 (Cipso of C5H4), −2.4 (SiMe2).
Following the same procedure described above using
Ti(p5-C5H4SiMe2Cl)Cl3, 1 (0.5 g, 1.6 mmol), LiNHPh
(0.15 ml, 1.6 mmol) and NEt3 (0.22 ml, 1.6 mmol), 6
was obtained in higher yield (0.22 g, 41% yield).
7.22–7.16 (m, 2H, C5H4), 6.77 (m, 2H, C5H4), 2.66 (hp,
1H, C6H3MeiPr), 2.00 (s, 3H, C6H3MeiPr), 1.29 (d, 3H,
J
HH=6.6 Hz, C6H3MeiPr), 1.01 (d, 3H, JHH=6.6 Hz,
C6H3MeiPr), 0.62 (s, 3H, SiMe2), 0.58 (s, 3H, SiMe2).
13C{1H}-NMR (CDCl3): l 141.5 (Cipso of C6H3MeiPr),
129.1, 128.6, 126,5, 126,4 (rest of C6
H3MeiPr), 126.1
6
6
(CH of C5H4), 126.0 (CH of C5H4), 125.3 (CH of
C5H4), 124.8 (CH of C5H4), 112.0 (Cipso of C5H4), 27.9,
26.5, 23.9 (C6H3MeiPr), 20.7 (C6H3MeiPr), −0.7
(SiMe2), −0.9 (SiMe2).
4.9. Synthesis of
[Ti{p5-C5H4SiMe2[p1-N(2,6-Me2C6H3)]}Me2] (9)
4.7. Synthesis of
[Ti{p5-C5H4SiMe2[p1-N(2,6-Me2C6H3)]}Cl2] (7)
A 2 M solution of MeMgCl (5.75 ml, 11.5 mmol) was
added to a solution of [Ti{p5-C5H4SiMe2[p1-N(2,6-
Me2C6H3)]}Cl2] (7) (2.0 g, 5.5 mmol) in diethylether
(100 ml) and the reaction mixture was stirred at r.t. for
12 h in the glovebox. After the solvent was completely
removed under vacuum, the green solid was extracted
into hexane (100 ml) and the solution filtered. The
solution was concentrated and cooled to −40°C to
give yellow green crystals of 9 (1.21 g, 69%). Anal.
Calc. for. C17H25NSiTi: C: 63.97; H: 7.83; N: 4.38.
Some H2N(C6H3Me2) (0.20 ml, 1.6 mmol) and NEt3
(0.44 ml, 3.2 mmol) were added to a cooled solution
(−60°C) of Ti(p5-C5H4SiMe2Cl)Cl3, 1 (0.5 g, 1.6
mmol) in 50 ml of toluene. The reaction mixture was
slowly warmed to r.t. and stirred for 10 h, giving an
orange solution with a white residue. After filtration,
the solution was concentrated and cooled to −30°C to
give yellow crystals of 7. (0.52 g, 90% yield). Anal.
Calc. for C15H19NCl2SiTi: C: 50.23; H: 5.56; N: 3.91.
1
Found: C: 63.78; H: 7.92; N: 4.34%. H-NMR (C6D6):
1
Found: C: 50.01; H: 5.36; N: 3.88%. H-NMR (C6D6):
l 7.18 (d, 2Hmeta, C6H6 3Me2), 7.00 (t, 1Hpara, C6H6 3Me2),
l 7.01 (d, 2Hmeta, C6H3
6.58 (t, 2H, C5H4), 6.15 (t, 2H, C5H4), 2.07 (s, 6H,
6
Me2), 6.92 (t, 1Hpara, C6H3
6
Me2),
6.71 (t, 2H, C5H4), 5.95 (t, 2H, C5H4), 2.08 (s, 6H,
C6H3Me2), 0.65 (s, 6H, Ti–Me), 0.11 (s, 6H, SiMe2).
C6H3Me2), 0.06 (s, 6H, SiMe2). (CDCl3): l 7.08–6.96
1H-NMR (CDCl3): l 7.16–6.95 (m, 3H, C6H3
6 Me2),
(m, 3H, C6H3
6
Me2), 7.17 (t, 2H, C5H4), 6.73 (t, 2H,
7.16 (t, 2H, C5H4), 6.36 (t, 2H, C5H4), 2.07 (s, 6H,
C6H3Me2), 0.48 (s, 6H, Ti–Me), 0.36 (s, 6H, SiMe2).
C5H4), 2.00 (s, 6H, C6H3Me2), 0.56 (s, 6H, SiMe2).
13C{1H}-NMR (CDCl3): l 147.1 (Cipso of C6
129.8 (Cortho of C6H3Me2), 128.8 (Cmeta of C6
126.0 (Cpara of C6
6
H3Me2),
H3Me2),
13C-NMR (CDCl3): l 148.1 (Cipso of C6
6
H3Me2), 131.2
6
6
(Cortho of C6
(Cpara,of C6 6H3Me2), 122.5 (CH of C5H4), 119.6 (CH of
6 H3Me2), 128.4 (Cmeta of C6 6H3Me2), 123.2
6
H3Me2), 126.3 (CH of C5H4), 125.3
(CH of C5H4), 112.3 (Cipso of C5H4), 19.7 (C6H3Me2),
C5H4), 104.2 (Cipso of C5H4), 56.5 (Ti–Me), 19.3
−0.7 (SiMe2).
(C6H3Me2), −0.2 (SiMe2).
4.8. Synthesis of
4.10. Synthesis of
[Ti{p5-C5H4SiMe2[p1-N(2-Me-6-iPr-C6H3)]}Cl2] (8)
[Ti{p5-C5H4SiMe2[p1-N(2,6-Me2C6H3)]}(CH2Ph)2] (10)
A mixture of Ti(p5-C5H4SiMe2Cl)Cl3 1 (0.5 g, 1.6
mmol), H2N(C6H3MeiPr) (0.25 ml, 1.6 mmol) and NEt3
(0.44 ml, 3.2 mmol) in hexane (50 ml) were allowed to
stir at r.t. for 15 h and the color of the solution
gradually changed to red brown. The solution was
filtered off and the residue was extracted into diethyl
ether (2×25 ml). After filtration, the solution was
cooled to −30°C affording 8 as yellow crystals (0.12 g,
19% yield). Anal. Calc. for C17H23NCl2SiTi: C: 51.69;
H: 6.00; N: 3.28. Found: C: 52.39; H: 5.86; N: 3.56%.
A solution of Mg(CH2Ph)2. 2THF (0.97 g, 2.77
mmol) in diethyl ether (15 ml) was added to another
solution of 7 (1.0 g, 2.77 mmol) in diethylether (50 ml)
and the reaction mixture was stirred at r.t. for 12 h in
the glovebox. After the solvent was completely removed
under vacuum, the red solid was extracted into hexane
(100 ml) and the solution filtered. The solution was
concentrated and cooled to −40°C to give complex 10
(0.85 g, 65%) as red crystals. Anal. Calc. for
C29H33NSiTi: C: 73.90; H: 7.00; N: 2.97. Found: C:
1
1H-NMR (C6D6): l 7.15–6.84 (m, 3H, C6H3
6
MeiPr),
74.35; H: 7.10; N: 3.02%. H-NMR (C6D6): l 7.17 (d,
2Hmeta, C6H6 3Me2, JHH=7.9 Hz), 7.09 (t, 4Hmeta,
6.59 (m, 1H, C5H4), 6.54 (m, 1H, C5H4), 6.21 (m, 1H,

R. Go´mez et al. / Journal of Organometallic Chemistry 564 (1998) 93–100
99
CH2C6H5
HH=7.9 Hz), 6.86 (t, 4Hpara, CH2C6H5
6.67 (d, 4Hortho, CH2C6H5, JHH=7.3 Hz), 6.35 (t, 2H,
C5H4, JHH=2.4 Hz), 5.96 (t, 2H, C5H4, JHH=2.4 Hz),
2.73 (d, 2H, CH2Ph, JHH=9.7 Hz), 2.24 (d, 2H, CH2Ph,
HH=9.7 Hz), 2.14 (s, 6H, C6H3Me2), 0.11 (s, 6H, SiMe2).
1H-NMR (CDCl3): l 7.20 (d, 2Hmeta, C6H3
Me2), 7.12 (t,
4Hmeta, CH2C6H5), 7.03 (t, 1Hpara, C6H3Me2), 6.87 (t,
4Hpara, CH2C6H5), 6.68 (d, 4Hortho, CH2C6H5
C5H4), 6.18 (t, 2H, C5H4), 2.69 (d, 2H, CH2
6H, C6H3Me2), 2.22 (d, 2H, CH2
13C{1H}-NMR (CDCl3): l 149.4 (Cipso of CH2C6
148.9 (Cipso of C6H3Me2), 130.7 (Cortho of C6H3Me2), 128.8
(Cmeta of C6H3Me2), 128.2 (Cortho of CH2C6
(Cmeta of CH2C6H5), 125.05 (Cpara of CH2C6
(CH of C5H4), 123.7 (Cpara of C6
C5H4), 106.9 (Cipso of C5H4), 86.2 (JCH=122.8 Hz,
H2Ph), 20.0 (C6H3Me2), −0.2 (SiMe2).
6
, JHH=6.1 Hz), 7.02 (t, 1Hpara, C6H3
6
Me2,
yellow crystals. Anal. Calc. for. C16H22ClNSiTi: C: 56.55;
H: 6.52; N: 4.12. Found: C: 56.36; H: 6.51; N: 4.11%.
J
6
, JHH=7.3 Hz),
6
1H-NMR (C6D6): l 7.09 (d, 2Hmeta, C6H3
6
Me2), 6.97 (t,
6 Me2), 6.63 (t, 1H, C5H4), 6.45 (t, 1H, C5H4),
1Hpara, C6H3
6
6
6.02 (t, 2H, C5H4), 2.19 (s, 3H, C6H3Me2), 1.96 (s, 3H,
C6H3Me2), 1.01 (s, 3H, Ti–Me), 0.07 (s, 3H, SiMe2), 0.06
(s, 3H, SiMe2). 1H-NMR (CDCl3): l 7.28 (s, 1H, C5H4),
J
6
6
6
7.07(m, 2Hmeta, C6H6 3Me2), 6.94(t, 1Hpara, C6H6 3Me2), 6.86
6
6
), 6.43 (t, 2H,
Ph), 2.24 (s,
(s, 1H, C5H4), 6.56 (s, 1H, C5H4), 6.45 (s, 1H, C5H4). 2.06
(s, 3H, C6H3Me2), 1.99 (s, 3H, C6H3Me2), 0.93 (s, 3H,
Ti–Me), 0.44 (s, 3H, SiMe2), 0.41 (s, 3H, SiMe2).
6
6
Ph), 0.40 (s, 6H, SiMe2).
H5),
6
13C-NMR (CDCl3): l 147.7 (Cipso of C6
6
H3Me2), 130.6
6
6
(Cortho of C6
(Cmeta of C6H3Me2), 128.5 (Cmeta of C6
of C5H4), 124.0 (CH of C5H4), 122.4 (Cpara of C6
6 H3Me2), 130.4 (Cortho of C6 6H3Me2), 128.8
6
6
H5), 125.3
H5), 123.9
6
6
H3Me2), 124.4 (CH
H3Me2),
6
6
6
6
H3Me2), 122.0 (CH of
122.0 (CH of C5H4), 120.7 (CH of C5H4), 108.15 (Cipso
ofC5H4), 62.0(Ti–Me), 20.1(C6H3Me2), 18.9(C6H3Me2),
−0.2 (SiMe2), −0.8 (SiMe2).
C6
4.11. Synthesis of
4.13. Synthesis of
[Ti{p5-C5H4SiMe2[p1-N(2,6-Me2C6H3)]}(CH2SiMe3)2]
(11)
[Ti{p5-C5H4SiMe2[p1-N(2,6-Me2C6H3)]}(NMe2)2] (13)
A solution of LiNMe2 (0.15 g, 2.8 mmol) in diethylether
(20 ml) was added to a solution of 7 (0.5 g, 1.4 mmol)
indiethylether(40ml)andthereactionmixturewasstirred
at r.t. for 12 h in the glovebox. After the solvent was
completely removed under vacuum, the compound was
extracted with hexane (50 ml) and the solution filtered.
The solvent was removed under vacuum to give complex
13 (0.35g, 66%) as black, viscous oil. Anal. Calc. for.
C19H31N3SiTi: C: 60.46; H: 8.28; N: 11.13. Found: C:
60.10; H: 7.99; N: 10.89%. 1H-NMR (C6D6): l 7.10–6.80
A solution of LiCH2SiMe3 (0.27 g, 2.94 mmol) in
diethylether (15 ml) was added to a solution of 7 (0.5 g,
1.4 mmol) in diethylether (40 ml) and the reaction was
stirred at r.t. for 12 h in the glovebox. After the solvent
was completely removed under vacuum, the product was
extracted with hexane (50 ml) and the solution filtered.
The solution was concentrated and cooled to −40°C to
afford the complex 11 (0.35 g, 59%) as dark green solid.
Anal. Calc. for. C23H41NSi3Ti: C: 59.61; H: 8.85; N: 3.02.
1
Found: C: 59.02; H: 8.48; N: 2.78%. H-NMR (C6D6):
(m, 3H, C6H6 3Me2), 6.26 (t, 2H, C5H4, JHH=2.2 Hz), 6.20
l 7.12–6.9 (m, 3H, C6H3
(t, 2H, C5H4), 2.13 (s, 6H, C6H3Me2), 1.58 (d, 2H,
CH2SiMe3, JHH=10.6 Hz), 0.87 (d, 2H, CH2SiMe3,
HH=10.6 Hz), 0.17 (s, 6H, SiMe2), 0.04 (s, 18H,
CH2SiMe3). 1H-NMR (CDCl3): l 7.1–6.9 (m, 3H,
C6H3Me2), 7.09 (t, 2H, C5H4), 6.42 (t, 2H, C5H4), 2.09
(s,6H,C6H3Me2),1.48(d,2H,CH2SiMe3,JHH=10.2Hz),
0.75 (d, 2H, CH2SiMe3, JHH=10.2 Hz), 0.32 (s, 6H,
SiMe2), −0.06 (s, 18H, CH2SiMe3). 13C-NMR (CDCl3):
l 150.3 (Cipso of C6H3Me2), 130.7 (Cortho of C6H3Me2),
128.6 (Cmeta of C6H3Me2), 123.0 (Cpara of C6H3Me2), 121.9
(CH of C5H4), 117.7 (CH of C5H4), 105.4 (Cipso of C5H4),
81.4(CH2SiMe3), 19.9(C6H3Me2), 2.4 (CH2SiMe3), −0.1
6 Me2), 6.96 (t, 2H, C5H4), 6.27
(t, 2H, C5H4, JHH=2.2 Hz), 2.80 (s, 12H, NMe2), 2.12
(s, 6H, C6H3Me2), 0.35 (s, 6H, SiMe2). 1H-NMR (CDCl3):
6
6
l 7.10–6.78 (m, 3H, C6H6 3Me2), 6.63 (t, 2H, C5H4), 6.43
J
(t, 2H, C5H4), 3.01 (s, 12H, NMe2), 2.12 (s, 6H, C6H3Me2),
0.47 (s, 6H, SiMe2). 13C-NMR (CDCl3): l 150.1 (Cipso of
6
C6
6
H3Me2), 132.3 (Cortho of C6
6 H3Me2), 127.3 (Cmeta of
6
C6
6H3Me2), 120.8 (Cpara of C6
6
H3Me2), 119.1 (CH of C5H4),
6
117.5 (CH of C5H4), 109.9 (Cipso of C5H4), 47.9 (Ti–
NMe2), 19.4 (C6H3Me2), 0.8 (SiMe2).
6
6
6
6
4.14. X-ray structure determination of 7
6
(SiMe2).
A yellow crystal of compound 7 crystallized from THF
was mounted in a glass capillary in a random orientation
on an Enraf-Nonius Cad4 four-circle automatic diffrac-
tometerwithgraphite-monochromatedMo–Kh radiation
4.12. Synthesis of
[Ti{p5-C5H4SiMe2[p1-N(2,6-Me2C6H3)]}MeCl] (12)
˚
(u=0.7073 A). Crystallographic and experimental details
A 2 M solution of AlMe3 in toluene (1 ml, 2 mmol.)
was added to a solution of 7 (0.5 g, 1.4 mmol) in 40 ml
of toluene at r.t. and the mixture stirred for 12 h. The
yellow solution was then filtered, concentrated and cooled
overnight to −40°C to give complex 12 (0.30 g, 62%) as
of 7 are summarized in Table 2. Data were collected at
r.t. IntensitieswerecorrectedforLorentzandpolarization
effects in the usual manner. No absorption or extinction
corrections were made. Intensity measurements were
performed by ꢀ−2q scans in the range 4B2qB50°.

100
R. Go´mez et al. / Journal of Organometallic Chemistry 564 (1998) 93–100
Table 2
Acknowledgements
Crystal data and structure refinement for complex 7
We are grateful to the DGICYT (Project PB-92-
0178-C) and University of Alcala´ for financial support
of this research.
Empirical formula
Formula weight
Temperature (K)
C15H19Cl2NSiTi
360.20
293(2)
˚
Wavelength (A)
0.71073
Crystal system
Space group
Monoclinic
P21/c
13.185(6)
7.566(2)
17.233(8)
˚
a (A)
References
˚
b (A)
˚
c (A)
[1] M. Bochmann, in: E.W. Abel, F.G.A. Stone, G. Wilkinson (Eds.),
Comprehensive Organometallic Chemistry II, vol. 4, Elsevier, New
York, 1995, pp. 273–431.
i (°)
96.39(2)
1708(1)
4
1.400
0.873
744
0.35×0.32×0.28
2.00–25.00
0BhB15, 0BkB8,
−20BlB20
3122
2984 (Rint=0.0305)
2063
C-scan
3
˚
Volume (A )
Z
[2] M.F. Lappert, P.P. Power, A.R. Sanger, R.C. Srivastava, Metal
and Metalloid Amides, Ellis Horwood, Chichester, 1980.
[3] (a) P. Jutzi, J. Organomet. Chem. 500 (1995) 175. (b) J. Okuda,
Comments Inorg. Chem. 16 (1994) 185. (c) J. Arnold, C.G.
Hoffman,D.Y.Dawson,F.J.Hollander,Organometallics12(1993)
3645. (d) S. Trofimenko, Chem. Rev. 93 (1993) 943. (e) C.J.
Schaverien, Organometallics 13 (1994) 69. (f) A.K. Saxena, N.S.
Hosmane, Chem. Rev. 93 (1993) 1081. (g) M.D. Fryzuk, T.S.
Haddad, S.J. Rettig, Organometallics 11 (1992) 2967. (h) F. Guerin,
D.H. McConville, J.J. Vittal, Organometallics 16 (1997) 1491. (i)
F.T. Edelmann, Coord. Chem. Rev. 137 (1994) 403.
[4] (a) J.C. Stevens, F.J. Timmers, D.R. Wilson, et al., Eur. Pat. Appl.
EP 416,815 (Dow), 1991 (Chem. Abstr. 115 (1991) 93163). (b) J.M.
Canich, Eur. Pat. Appl. EP-420-436-A1, 1991. (c) J.M. Canich,
G.G. Hlatky, H.W. Turner, US Pat. Appl. 542-236, 1990. (d) D.D.
Devore, F.J. Timmers, D.L. Hasha, R.K. Rosen, T.J. Marks, P.A.
Deck, C.L. Stern, Organometallics 14 (1995) 3132. (c) K.E. du
Ploon, U. Moll, S. Wocadlo, W. Massa, J. Okuda, Organometallics
14 (1995) 3129. (d) F. Amor, J. Okuda, J. Organomet. Chem. 520
(1996) 245. (e) J. Okuda, Chem. Ber. 123 (1990) 1649.
[5] S. Ciruelos, T. Cuenca, P. Go´mez-Sal, A. Manzanero, P. Royo,
Organometallics 14 (1995) 177.
Dcalc. (g cm−3
)
Absorption coefficient (mm−1
F(000)
)
Crystal size (mm)
q range for data collection (°)
Index ranges
Reflections collected
Independent reflections
Observed reflections [I\2|(I)]
Absorption correction
Max. and min. transmission
Goodness-of-fit on F2
Final R indices [I\2|(I)]
R indices (all data)
0.301 and 0.265
0.951
R1=0.042, wR2=0.113
R1=0.077, wR2=0.121
Calc.
Weighting scheme
w=1/[|2(F2o)+(0.081P)2]a
Largest difference peak and hole (e 0.432 and −0.325
−3
˚
A
)
a P=(F2o+2F2c)/3.
[6] D.W. Carpenetti, L. Kloppenburg, J.T. Kupec, J.L. Petersen,
Organometallics 15 (1996) 1572.
[7] G.M. Diamond, S. Rodewald, R.F. Jordan, Organometallics 14
(1995) 5.
[8] C.S.Bajgur,W.R.Tikkannen,J.L.Petersen,Inorg.Chem.24(1985)
2539.
[9] N. Winkhofer, H.W. Roesky, M Noltemeyer, W.T. Robinson,
Angew. Chem. Int. Ed. Engl. 31 (5) (1992) 599.
[10] (a) M.D. Curtis, J.J. D’Errico, D.N. Duffy, P.S. Epstein, L.G. Bell,
Organometallics 2 (1983) 1808. (b) Y. Wang, X, Zhon, H. Wang,
X. Yas, Huaxue Xuebao, 49(11) (1991) 129129s.
[11] J. Okuda, T. Eberle, T.P. Spaniol, Chem Ber. 130 (1997) 209 and
references therein.
[12] R.M. Pupi, J.N. Coalter, J.L. Petersen, J. Organomet. Chem. 497
(1995) 17.
[13] Y. Bai, H.W. Roesky, M. Noltemeyer, N. Anorg. Allg. Chem. 595
(1991) 21.
The structure was solved by direct methods
(SHELXS-90) [19] and refined by least-squares against
F2 (SHELXL-93) [20]. Of the 3122 measured reflec-
tions, 2984 were independent; R1=0.042 and wR2=
0.113 [for 2063 reflections with F\4|(F)]. The values
of R1 and wR2 are defined as R1=SꢀFoꢁ−ꢁFcꢀ/[SꢁFoꢁ]
and wR2={[Sw(F2o−Fc2)2]/[Sw(F2o)2]}1/2, where w=1/
[|2(F2o)+(0.081P)2], P=(Fo2 +2F2c)/3 and | was ob-
tained from counting statistics. All non-hydrogen
atoms were refined anisotropically, and the hydrogen
atoms were introduced in the last cycle of refinement
from geometrical calculations and refined using a rid-
ing model with thermal parameters fixed at U=0.08
2
˚
A .
[14] J.D. Scollard, D.H. McConville, N.C. Payne, J.J. Vittal, Macro-
molecules 29 (1996) 5241.
[15] K. Aoyagi, O.K. Gantzel, K. Kalay, T.D. Tilley, Organometallics
15 (1996) 923.
5. Supplementary material available
[16] (a) R. Go´mez, T. Cuenca, P. Royo, E. Hovestreydt, Organometal-
lics 10 (1991) 2516. (b) R. Go´mez, T. Cuenca, P. Royo, W.A.
Herrmann, E. Herdtweck, J. Organomet. Chem. 382 (1990) 103.
[17] R.K. Minhas, L. Scoles, S. Wong, S. Gambarotta, Organometallics
15 (1996) 1113.
[18] M. Wedler, F. Knosel, F.T. Edelmann, U. Behrens, Chem. Ber.
125 (1992) 1313 and references therein.
[19] G.M. Sheldrick, Acta Crystallogr. Sect. A 46 (1990) 467.
[20] G.M. Sheldrick, SHELXL 93, University of Go¨ttingen, Go¨ttingen,
Germany, 1993.
The supplementary material includes a list of the
positional parameters and their standard deviations, a
complete list of bond lengths and angles, anisotropic
displacement parameters, the calculated fractional co-
ordinates of the hydrogen atoms and a list of ob-
served and calculated structure factors. This is
available on request from the authors.