Monocyclopentadienyl phenoxy-imine and phenoxy-amine complexes of titanium and zirconium and their application as catalysts for 1-alkene polymerisation

Article abstract of DOI:10.1016/S0022-328X(02)02106-X

Deprotonation of the phenol-imines 2-Bu^t-6- (RNCH)C₆H₃OH (R = 2,4,6-Me₃C₆H₂ (1a), C₆F₅ (1b), C₆H₁₁ (1c) and phenolamines leads to the bis(ligand)

Full text of DOI:10.1016/S0022-328X(02)02106-X

Journal of Organometallic Chemistry 665 (2003) 135ꢁ149
/
www.elsevier.com/locate/jorganchem
Monocyclopentadienyl phenoxy-imine and phenoxy-amine complexes
of titanium and zirconium and their application as catalysts for
1-alkene polymerisation
Robyn K.J. Bott, David L. Hughes, Mark Schormann, Manfred Bochmann *,
Simon J. Lancaster *
Wolfson Materials and Catalysis Centre, School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, UK
Received 9 September 2002; received in revised form 31 October 2002; accepted 31 October 2002
Abstract
Deprotonation of the phenol-imines 2-But-6-(RNCH)C6H3OH (Rꢀ
amines 2,4-But2-6-(R?NCH2)C6H2OH (R?ꢀ
C4H8 (1d), C5H10 (1e)) with n-BuLi gives the corresponding lithium phenoxides. The
reaction with MCl4 in THF solution leads to the bis(ligand) complexes {2-But-6-(RNCH)C6H3O}2MCl2 and {2,4-Bu2t -6-
(R?NCH2)C6H2O}2MCl2 (MꢀTi: 2a, 2d, 2e, Zr: 3a, 3d and 3e). The cyclopentadienyl phenoxy-imine and -amine complexes
Cp{2-But-6-(RNCH)C6H3O}MCl2 and Cp{2,4-Bu2t -6-(R?NCH2)C6H2O}MCl2 (Mꢀ
Ti: 4aꢁ4e, Zr: 5aꢁ5e) were prepared similarly
/2,4,6-Me3C6H2 (1a), C6F5 (1b), C6H11 (1c) and phenol-
/
/
/
/
/
through reaction with CpMCl3. The crystal and molecular structures of 2a, 3a, 4a and 4e have been determined. 2a and 3a are
isostructural and exhibit a distorted octahedral geometry. 4a has a distorted square-pyramidal structure whereas 4e is essentially
tetrahedral and the nitrogen does not coordinate. All new complexes are active for the polymerisation of ethene when activated with
methyaluminoxane. 4b, 5a, 5d and 5e are active for the copolymerisation of ethene and 1-hexene and the oligomerisation of 1-
hexene.
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Titanium; Zirconium; Alkene-polymerisation; Catalysis; Cyclopentadienyl; Phenoxy-imine
1. Introduction
monoanionic ligand. Amongst the first examples were
the cyclopentadienyl benzamidinate complexes (Plate 1,
Structure I) [3] [4]. More recently Sita has explored the
use of unsymmetrically substituted acetamidinate li-
gands derived from insertion of a carbodiimide into
Research into metallocene catalysts has resulted in a
good understanding of the mechanism of polymerisation
by soluble ZieglerꢁNatta catalysts. The minimum
/
the metal methyl bond of CpRMMe3 (Mꢀ
Ti, Zr) to
/
requirement for a catalyst precursor has been estab-
lished as an unreactive ancillary ligand system that
provides two-coordination sites which can be activated
to provide a metal alkyl cis to a vacant coordination site
for monomer binding [1]. The quest for alternatives to
the metallocene catalysts that can produce polymers
with novel properties has been one of the major goals of
transition metal coordination chemistry over the last
decade [2].
produce chiral metal complexes that are active for the
living stereoselective polymerisation of 1-alkenes (Struc-
ture II) [5ꢁ9].
/
An important example of cyclopentadienyl-free NÃ
/O
chelates are the bis(phenoxy-imine) complexes (Struc-
ture III), independently developed by Fujita and Coates
[10ꢁ18]. The activity of these catalysts is highly depen-
/
dent on the nature of the substituents in the ortho-
position on the phenoxy ring and on the imine nitrogen
A number of groups have explored the use of catalysts
with one cyclopentadienyl and a second, bidentate,
[11ꢁ18]. We expected that the combination of a
/
cyclopentadienyl and a phenoxy-imine or -amine ligand
with a Group 4 metal would lead to a novel series of
polymerisation catalysts [19,20]. More significantly,
* Corresponding authors
E-mail address: s.lancaster@uea.ac.uk (S.J. Lancaster).
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 2 1 0 6 - X

136
R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
Plate 1.
complexes of this type will by necessity be chiral-at-
metal and have potential for the stereoselective poly-
merisation of monomers such as 1-hexene. We reasoned
that the much larger bite angle of the phenoxy-imine or -
amine ligand might lead to a higher barrier to racemisa-
tion and hence greater configurational stability [21,22].
Here we report the synthesis and catalytic activity of a
number of novel titanium and zirconium complexes with
cyclopentadienyl, phenoxy-imine and closely related
phenoxy-amine ligands.
idine. The products were easily purified by crystal-
lisation from the reaction mixture.
The reaction of corresponding lithium imino-
(Scheme 2) and aminophenoxides (Scheme 3) with
MCl4(THF)2 in THF solution overnight produced the
bis(ligand) complexes 2a, 2d, 2e, (Mꢀ
/
Ti) 3a, 3d, and 3e
(MꢀZr) [23]. The metal complexes were separated from
/
the LiCl by-product by extraction with dichloro-
methane. Analytically pure samples were obtained by
layering concentrated dichloromethane solutions with
light petroleum and cooling. The titanium compounds
were obtained as dark red to brown and the zirconium
compounds as beige to orange crystalline solids or
powders in 40ꢁ60% yield. The essentially identical
/
2. Results and discussion
structures of complexes 2a and 3a have been confirmed
by X-ray crystallography.
Following a modified literature procedure the phenol-
Following a similar procedure to that employed for
the bis(ligand) complexes the monocyclopentadienyl
imines 1aꢁc are readily prepared through the reaction of
/
3-tert-butylsalicylaldehyde with 2,4,6-trimethylaniline,
pentafluoroaniline or cyclohexylamine, respectively
(Scheme 1) [12]. The phenol-amines 1d and 1e were
prepared in a very straightforward one-pot procedure by
reacting 2,4-di-tert-butylphenol, aqueous formaldehyde
and the cyclic secondary amines pyrrolidine and piper-
phenoxy-imine or phenoxy-amine complexes 4aꢁ
(MꢀTi) and 5aꢁe (MꢀZr) were prepared by reacting
the respective lithium phenoxides with one equivalent of
CpTiCl3 or CpZrCl3×DME (DMEꢀ1,2-dimethox-
yethane) respectively (Scheme 2 and Table 3). The
/
e
/
/
/
/
/
Scheme 1.

R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
137
Scheme 2.
compounds were obtained as red (titanium) or beige to
brown (zirconium) crystalline solids or powders in
variable yield.
substituents on the imine mesityl substituent and the
tert-butyl group on the phenoxide. Therefore, the
structure of complex 2a more closely resembles {2-
Integration of the 1H-NMR spectra of complexes 4aꢁ
/
But-6-(C6F5NCH)C6H3O}2TiCl2 (OÃ
ClÃTiÃClꢀ96.428) than the simple phenyl compound
{2-But-6-(C6H5NCH)C6H3O}2TiCl2
(OÃTiÃOꢀ
171.68, ClÃTiÃClꢀ103.18) [15], Table 5.
The zirconium analogue, 3a (Table 2), is isostructural
to 2a (Fig. 1) with similarly trans oxygen atoms (OÃZrÃ
Oꢀ157.80(5)8) and cis chloride atoms (ClÃZrÃClꢀ
90.63(2)8). The angles differ significantly from the less
bulky phenyl analogue (OÃZrÃOꢀ165.5(1)8, ClÃZrÃ
Clꢀ100.38(5)8) [12]. Again this is likely to be due to
/
TiÃ
/
Oꢀ163.618,
/
e and 5aꢁe confirms a 1:1 ratio of cyclopentadienyl to
/
/
/
/
phenoxy-imine or phenoxy-amine ligand [24]. 5a and 5b
retain one equivalent of THF even after extraction and
crystallisation from dichloromethane. The 1H-NMR
resonances for the THF on dissolving 5b in C6D6 are
observed at d 3.90 and 1.33 versus 3.56 and 1.41 for free
THF in C6D6. Addition of further THF to a solution of
5b gives only one set of THF resonances shifted towards
free THF, suggesting a rapid exchange of free and
coordinated THF on the NMR time scale. Assignment
of the geometry of complexes 5a and 5b will require a
structural determination.
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
significantly increased steric repulsion between the
ortho-substituents on the imine mesityl substituent and
the tert-butyl group on the phenoxide.
The crystal data for complexes 2a, 3a, 4a and 4e are
collected in Table 1. Selected bond lengths and angles
For the cyclopentadienyl phenoxy-imine titanium
dichloride 4a the asymmetric unit consists of two
virtually identical molecules (Fig. 2 and Table 3). In
each, the Ti atom is five-coordinate with the Cp ligand
in the apical site of a distorted square-pyramid. The
N,O-chelating ligand forms a plane which includes the
are given in Tables 2ꢁ
2a (Fig. 1) has a distorted octahedral coordination with
the same arrangement of trans oxygen atoms (OÃTiÃ
Oꢀ162.15(5)8) and cis chloride atoms (ClÃTiÃClꢀ
/4. The titanium atom in complex
/
/
/
/
/
/
90.24(2)8) as that previously observed for bis(phenoxy-
imine)titanium dichlorides [13,15,25]. The angles appear
to be governed by steric repulsion between the ortho-
phenoxide ring, the Ã
/
CÄ/N group and two of the atoms
of the tert-butyl group, C(61a/b) and C(64a/b); the other
two methyl groups are either side of the plane. The plane

138
R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ149
/
Scheme 3.
˚
˚
of the mesityl group is rotated almost perpendicular to
the phenoxide ring, with angles between their normals of
76.18(14) and 76.05(13)8 in the two molecules. The Cp
TiÃ
/
Cpꢀ
/
2.022(4) A (4e: TiÃ
/
Cpꢀ
/
2.020 A) and ClÃ
/
TiÃ
/
Clꢀ
/
998 (4e: ClÃ
/
TiÃClꢀ101.26(3)8) [28].
/
/
ring is almost parallel with the phenoxide ring in each
˚
Cp distance at 2.053 A is typical for
2.1. Bonding of the phenoxy-amine ligands
molecule. The TiÃ
/
Ti(IV) Cp complexes [26]. In contrast to zirconium there
are relatively few crystallographically characterised ex-
amples of Cp(L)TiX2, where L is a monoanionic
bidentate ligand. Two benzamidinate complexes
(C5Me5){(Me3Si)NC(4-C6H4OMe)N(SiMe3)}TiF2 [27]
and Cp{CPh(NSiMe3)2}TiMe2 [26] have been described.
The crystallographic observation that the phenoxy-
amine ligand in titanium complex 4e binds only in
monodentate fashion poses the question whether the
pyrrolidine and piperidine groups are bound to the
metal in any of the complexes prepared. Unfortunately
4e is the only example with these ligands to give X-ray
quality crystals. It would have been particularly helpful
to characterise structurally a zirconium complex where
the greater size of the central metal favours higher
coordination numbers.
Circumstantial evidence for the bidentate coordina-
tion of the phenoxy-amine ligand in 5d and 5e comes
from a comparison with complex 5b. As discussed
above, 5b not only features a bidentate phenoxy-imine
ligand but also a THF molecule bound to a sixth-
coordination site. Unlike 5b, 5d and 5e do not retain a
THF molecule, suggesting steric saturation resulting
from bidentate coordination of the bulky phenoxy-
amine ligands.
In the latter complex the small MeÃ
(84.41(7)8) was ascribed to the considerable steric bulk
of the benzamidinate ligand. In 4a the ClÃTiÃCl angles
/
TiÃ
/
Me angle
/
/
of 87.00(4) and 87.07(4)8 indicate slightly less steric
congestion in the plane of the four basal ligands.
The most striking structural feature of complex 4e
(Fig. 3 and Table 4) is the pseudo tetrahedral geometry
about the metal atom; the phenoxy-amine ligand is
˚
Oꢀ1.7932(11) A) but the
bound via the oxygen (TiÃ
/
/
amine function is not coordinated (Ti(1)Ã
/
N(1)ꢀ4.062
/
˚
A). 4e therefore, closely resembles the structure of other
cyclopentadienyl phenoxide complexes with bulky
ortho-substituents rather than the five-coordinate phen-
oxy-imine complex 4a. For example Cp(2-Ph-4,6-
But2C6H2O)TiCl2 has a TiÃ
Many of the metal complexes 2dꢁ
/
5d 2e, 3e and 5e
exhibit complex 1H signals for the diastereotopic
˚
O distance of 1.785(2) A,
/

R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
139
Table 1
Crystallographic data for 2a, 3a, 4a and 4e
Parameters
2a
3a
4a
4e
Empirical formula
Formula weight
Crystal system
C40H48Cl2N2O2Ti
707.6
C40H48Cl2N2O2Zr
750.9
C25H29Cl2NOTi, CH2Cl2
563.2
Monoclinic
C25H37Cl2NOTi
486.3
Monoclinic
P21/c
Monoclinic
P21/c
Monoclinic
P21/c
Space group
Unit cell dimensions
Aa (equivalent to no. 9)
˚
a (A)
13.134(3)
16.878(3)
17.003(3)
103.52(3)
3664.7(13)
4
13.208(3)
17.102(3)
17.023(3)
103.22(3)
3743.3(13)
4
15.734(1)
14.903(2)
23.180(2)
90.65(1)
5435.0(9)
8
6.5860(13)
20.344(4)
19.520(4)
96.95(3)
2596.2(9)
4
˚
b (A)
˚
c (A)
b (8)
Volume (A )
3
˚
Z
Dcalc (mg mꢂ3
Absorption coefficient (mmꢂ1
F(000)
)
1.283
0.416
1496
1.332
0.472
1568
1.377
0.728
2336
1.244
0.551
1032
)
Crystal size (mm)
0.4ꢃ
25.4
15Bh B
20Bk B
20Bl B20
12 471
6706 (Rint
/
0.3ꢃ
/
0.3
0.5ꢃ
2.0ꢁ25.4
15Bh B
20Bk B
20Bl B20
12 463
6525 (Rint
/
0.2ꢃ
/
0.2
0.55ꢃ
2.1ꢁ25.3
18Bh B
17Bk B
27Bl B27
32 924
9480 (Rint
/
0.25ꢃ
/
0.15
0.5ꢃ
2.3ꢁ25.4
7Bh B
24Bk B
23Bl B23
8973
4680 (Rint
/
0.3ꢃ
/
0.2
u Range for data collection (8) 1.7ꢁ
Range of indices
/
/
/
/
ꢂ
/
/
/
15,
ꢂ
/
/
/
15,
ꢂ
/
/
/18,
ꢂ
/
/
/7,
ꢂ
/
/
/
20,
ꢂ
/
/
/
20,
ꢂ
/
/
/
17,
ꢂ
/
/
/
24,
ꢂ/
/
/
ꢂ/
/
/
ꢂ/
/
/
ꢂ/
/
/
Reflections collected
Independent reflections
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices
ꢀ
/
0.023)
ꢀ
/
0.031)
ꢀ/0.028)
ꢀ0.020)
/
6706/0/430
1.092
6525/0/430
1.064
9480/2/628
1.026
4680/0/271
1.081
R1ꢀ
/
0.031, wR2ꢀ
/
0.089 R1ꢀ
/
0.027, wR2ꢀ
/
0.073 R1ꢀ/0.045, wR2ꢀ
/
0.120
0.124
R1ꢀ/0.032, wR2ꢀ
/
0.088
0.090
[I ꢀ2s(I)]
/
R indices (all data)
Largest difference peak
R1ꢀ
/
0.037, wR2ꢀ
/
0.092 R1ꢀ
/
0.031, wR2ꢀ
/
0.075 R1ꢀ/0.051, wR2ꢀ
/
R1ꢀ/0.039, wR2ꢀ
/
0.23 and ꢂ
/
0.39
0.36 and ꢂ
/
0.52
0.45 and ꢂ
/
0.76
0.23 and ꢂ
/
0.34
ꢂ3
˚
and hole (e A
)
methylene groups in the heterocyclic ring adjacent to
nitrogen at room temperature. Only one signal is
observed for both of the free ligands and monodentate
4e.
tions are included for comparison (runs 29ꢁ
merisations with the bis(phenoxy-amine) complexes of
both titanium and zirconium (runs 1ꢁ3, 5 and 6) yielded
only traces of polymer. The new mesityl substituted
phenoxy-imine complexes also polymerised poorly, the
zirconium complex 3a giving low molecular weight
polymer with a productivity of 17 kg molꢂ1 hꢂ1
barꢂ1 (run 4).
The results for the new cyclopentadienyl phenoxy-
imine and -amine complexes 4 and 5 were significantly
better than those for the bis(ligand) complexes 2 and 3.
For titanium and zirconium the cyclopentadienyl phen-
oxy-imine complexes show remarkably similar produc-
/
32). Poly-
/
The chemical shift difference, Dd, for the methylene
group ArÃ
/
CH2N in the free ligand 1e and complex 4e,
in which we know the nitrogen is not coordinated, is
only ꢂ0.04 ppm, whereas Dd for 1e and 5e is 0.56 ppm.
/
1
(For Hd ArCH2N of complexes 1ꢁ
/
5d and 1ꢁ5e see
/
Table 5.) An indication that the nitrogen atom is
coordinated to the metal centre in complexes 2e, 3e
come from even larger values for Dd of 1.06 and 0.86
ppm, respectively.
The pyrrolidine derived metal complexes 2dꢁ5d also
/
tivities (runs 7ꢁ
/
14 and 17ꢁ23) with the complexes
/
exhibit significant differences in the chemical shifts of
the methylene groups adjacent to nitrogen compared
bearing cyclohexyl and pentafluorophenyl imine sub-
stituents, giving broadly similar results and approxi-
mately ten times the productivity of the mesityl
compounds.
In contrast, there is a significant difference between
the cyclopentadienyl phenoxy-amine titanium and zir-
conium catalysts. Whereas for zirconium the amine
with the free ligand. Here the value of Dd (dfree lig.
dcomplex) for the methylene groups in the heterocyclic
ring is greater than for ArÃCH2N.
ꢂ
/
/
2.2. Polymerisation studies
complexes exhibit very similar productivities (runs 24ꢁ
/
28) to the cyclohexyl and pentafluorophenyl imine
catalysts at ca. 200 kg molꢂ1 hꢂ1 barꢂ1, the titanium
catalysts are almost two orders of magnitude less
productive (runs 15 and 16).
The ethene polymerisation productivity was deter-
mined for the new metal complexes when activated with
MAO (Table 6). The results for CpTiCl3, CpZrCl3×
/
DME, Cp2ZrCl2 and Cp2TiCl2 under identical condi-

140
R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ149
/
Table 2
Table 3
Selected bond lengths (A) and bond angles (8) for 4a
˚
˚
Selected bond lengths (A) and bond angles (8) for 2a and 3a
Complex 2a
Complex 3a
Molecule a
Molecule b
Bond lengths
Bond lengths
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
C(11)Ã
N(1)ÃC(12)
C(31)ÃN(2)
N(2)ÃC(32)
/
O(1)
O(2)
Cl(1)
Cl(2)
N(1)
N(2)
1.8506(12) Zr(1)Ã
1.8432(12) Zr(1)Ã
/
O(1)
O(2)
Cl(1)
Cl(2)
N(1)
N(2)
1.9805(13)
1.9763(12)
2.4299(7)
2.4308(6)
2.4344(14)
2.401(2)
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
Ti(1a)Ã
C(12a)Ã
N(2a)ÃC(21a)
/
O(1a)
1.875(3)
2.268(4)
2.381(4)
2.388(5)
2.378(4)
2.374(4)
2.378(4)
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
/
O(1b)
1.873(2)
2.262(3)
2.384(4)
2.370(4)
2.372(4)
2.386(4)
2.387(4)
2.3677(11)
2.3388(10)
2.055
/
/
/N(2a)
/N(2b)
/
2.3001(6)
2.3084(6)
Zr(1)Ã
/
/
C(31a)
C(32a)
C(33a)
C(34a)
C(35a)
Cl(4a)
Cl(5a)
C(3xa)
/
C(31b)
C(32b)
C(33b)
C(34b)
C(35b)
Cl(4b)
Cl(5b)
C(3xb)
/
Zr(1)Ã
/
/
/
/
2.3112(13) Zr(1)Ã
2.2866(14) Zr(1)Ã
/
/
/
/
/
/
/
/N(1)
1.303(2)
1.468(2)
1.301(2)
1.464(2)
C(11)Ã
N(1)ÃC(12)
C(31)ÃN(2)
N(2)ÃC(32)
/N(1)
1.308(2)
1.467(2)
/
/
/
/
/
2.3596(12) Ti(2b)Ã
2.3354(10) Ti(2b)Ã
2.053
1.305(5)
1.483(5)
/
/
/
1.306(2)
1.460(2)
/
/
/
/
/
Ti(2b)Ã
C(12b)Ã
N(2b)ÃC(21b)
/
/N(2a)
/N(2b)
1.286(4)
1.479(4)
Bond angles
O(2)ÃTi(1)Ã
O(2)ÃTi(1)Ã
O(1)ÃTi(1)Ã
O(2)ÃTi(1)Ã
O(1)ÃTi(1)Ã
N(2)ÃTi(1)Ã
O(2)ÃTi(1)Ã
O(1)ÃTi(1)Ã
N(2)ÃTi(1)Ã
Cl(1)ÃTi(1)Ã
O(2)ÃTi(1)Ã
O(1)ÃTi(1)Ã
N(2)ÃTi(1)Ã
Cl(1)ÃTi(1)Ã
Cl(2)ÃTi(1)Ã
C(1)ÃO(1)Ã
C(21)ÃO(2)Ã
/
/
/
/
O(1)
N(2)
N(2)
Cl(1)
Cl(1)
162.15(5)
81.13(5)
88.28(5)
97.66(4)
95.83(4)
85.76(3)
96.26(4)
95.31(4)
174.88(3)
90.24(2)
86.46(5)
80.95(5)
98.69(5)
174.38(4)
85.50(4)
O(2)Ã
O(2)Ã
O(1)Ã
O(2)Ã
O(1)Ã
N(2)Ã
O(2)Ã
O(1)Ã
N(2)Ã
Cl(1)Ã
O(2)ÃZr(1)Ã
O(1)ÃZr(1)Ã
N(2)ÃZr(1)Ã
Cl(1)ÃZr(1)Ã
Cl(2)ÃZr(1)Ã
O(1)Ã
145.20(10) C(21)ÃO(2)Ã
/
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
Zr(1)Ã
/
O(1)
N(2)
N(2)
Cl(1)
Cl(1)
157.80(5)
77.14(5)
90.32(5)
101.32(4)
95.81(4)
85.62(3)
95.99(4)
97.84(4)
171.34(3)
90.63(2)
86.83(5)
76.69(5)
97.83(5)
171.70(4)
86.94(4)
147.31(11)
146.46(11)
/
/
/
/
Bond angles
O(1a)ÃTi(1a)Ã
O(1a)ÃTi(1a)Ã
O(1a)ÃTi(1a)Ã
N(2a)ÃTi(1a)Ã
N(2a)ÃTi(1a)Ã
Cl(5a)ÃTi(1a)Ã
O(1a)ÃTi(1a)ÃC(3xa) 112.30
N(2a)ÃTi(1a)ÃC(3xa) 107.94
Cl(4a)ÃTi(1a)Ã
C(3xa)
/
/
/
/
/
/
N(2a)
78.78(11) O(1b)Ã
/
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
Ti(2b)Ã
Cl(4a) 87.00(4) Cl(5b)ÃTi(2b)Ã
O(1b)ÃTi(2b)ÃC(3xb) 112.10
N(2b)ÃTi(2b)ÃC(3xb) 109.55
Cl(4b)ÃTi(2b)Ã
C(3xb)
/
N(2b)
78.41(10)
/
/
/
/
/
/Cl(4a)
85.49(9) O(1b)Ã
/
/
Cl(4b)
85.14(8)
/
/
/
/
/
/
Cl(5a) 135.82(8) O(1b)Ã
Cl(4a) 143.08(9) N(2b)Ã
Cl(5a)
81.69(8) N(2b)Ã
/
/
Cl(5b) 137.86(8)
Cl(4b) 141.73(8)
/
/
Cl(1)
Cl(2)
Cl(2)
/
/
Cl(1)
Cl(2)
Cl(2)
/
/
/
/
/
/
/
/
/
/
/
/
Cl(5b)
82.65(7)
/
/
/
/
/
/
/
/
Cl(4b) 87.07(4)
/
/
Cl(2)
/
/
Cl(2)
Cl(2)
/
/
/
/
/
/
Cl(2)
/
/
/
/
/
/
/
/N(1)
/
/N(1)
/
/
108.91
111.33
/
/
108.63
109.64
/
/N(1)
/
/N(1)
/
/
N(1)
/
/
N(1)
Cl(5a)Ã
/
Ti(1a)Ã
/
Cl(5b)Ã
/
Ti(2b)Ã
/
/
/
N(1)
N(1)
/
/N(1)
C(3xa)
C(3xb)
/
/
/
/N(1)
C(1a)Ã
/
O(1a)Ã
/
Ti(1a) 136.5(2)
C(1b)Ã
/
O(1b)ÃTi(2b) 137.6(2)
/
/
/
Ti(1)
144.54(10) C(1)Ã
/
/
Zr(1)
Zr(1)
C(3xa) and C(3xb) are the centroids of the Cp rings in the two
molecules.
/
/Ti(1)
/
/
As was the case with bis(phenoxy-imine) complexes
the highest molecular weights were obtained with
titanium and a pentafluorophenyl imine-substituent,
i.e. complex 4b. While many of these catalysts produce
polymer samples with high Mw values, the GPC traces
were abnormally complex with clearly bimodal and in
some cases tetramodal distributions (for example see
Fig. 4), consequently sensible values for Mn and the
polydispersity could not be determined. These multi-
modal GPC traces are consistent with multiple cataly-
tically active species possibly as a result of ligand
dissociation and redistribution reactions under poly-
merisation conditions.
Table 4
˚
Selected bond lengths (A) and bond angles (8) for 4e
Bond lengths
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
Ti(1)Ã
/
O(1)
1.7932(11)
2.2761(6)
2.333(2)
2.357(2)
2.020
/
Cl(1)
C(25)
C(21)
C(2x)
Cl(2)
C(23)
C(22)
C(24)
/
/
/
/
2.2688(7)
2.334(2)
2.365(2)
2.311(2)
/
/
/
Bond angles
O(1)ÃTi(1)Ã
Cl(2)ÃTi(1)Ã
Cl(1)ÃTi(1)Ã
C(2x)Ã
O(1)ÃTi(1)Ã
C(1)ÃO(1)ÃTi(1)
Cl(2)ÃTi(1)ÃC(2x)
/
/
Cl(2)
103.69(4)
101.26(3)
114.1
/
/
Cl(1)
A number of closely related complexes, in particular
asymmetric acetamidinate complexes and the zirconium
aminoalkyl bis(phenolate) catalysts prepared by Kol et
al. [29,30] are active for the stereoregular and living
polymerisation of 1-hexene. We wished to explore
whether our chiral cyclopentadienyl phenoxy-imine
and phenoxy-amine complexes could also promote
stereoregular polymerisation. Activating the zirconium
complexes with MAO produces 1-hexene oligomers with
modest productivity (Table 7). Analysis by mass spec-
/
/
C(2x)
/
Ti(1)Ã
/O(1)
118.4
/
/Cl(1)
104.50(4)
163.74(10)
113.0
/
/
/
/
C(2x) is the centroid of the Cp ring.
of the alternative activator system Al(i-Bu)3ꢁ
[CPh3][B(C6F5)4] and carrying out the polymerisations
in neat 1-hexene gave similar values for molecular
weight and catalyst productivity.
/
1
trometry and H-NMR of the end groups indicates an
average of four to six hexene units per oligomer. The use

R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
141
Fig. 1. Molecular structure and crystallographic numbering scheme
for 2a. 3a is isostructural and numbered identically. Full thermal
ellipsoids at 50% probability. Hydrogen atoms are omitted for clarity.
Fig. 3. Molecular structure and crystallographic numbering scheme
for 4e. Full thermal ellipsoids at 50% probability. All hydrogen atoms
have been omitted.
Table 5
1H d ArCH2N
Nomura’s cyclopentadienyl phenoxide titanium cata-
lysts [31].
Complex
d (ppm)
1d
2d
3d
4d
5d
1e
2e
3e
4e
5e
3.77
4.0
4.2
2.3. Conclusion
4.08
3.8, 4.0
3.64
4.7
A series of novel cyclopentadienyl phenoxy-imine and
phenoxy-amine complexes of titanium and zirconium
have been prepared and representative examples crystal-
lographically characterised. For all but one example the
ligands appear to be bound to the metal centre in a
bidentate fashion. When activated with MAO all com-
plexes are active for the polymerisation of ethene, but
give multimodal molecular weight distributions consis-
tent with multiple active sites. The most active systems
were demonstrated to be effective for the copolymerisa-
tion of 1-hexene and ethene. In the absence of ethene,
1-hexene is oligomerised.
4.5
3.60
4.20
The most effective ethene homopolymerisation cata-
lysts were employed in preliminary etheneꢁ1-hexene
copolymerisation experiments (Table 8). 1-Hexene in-
corporation levels at 1ꢁ2% were significantly lower than
the less bulky cyclopentadienyl phenoxy-imine titanium
complexes studied by Qian [20] and much lower than
/
/
Fig. 2. One of the two virtually identical molecules in crystals of complex 4a. Carbon atoms C(n) are shown with labels ‘n’. Thermal ellipsoids of 50%
probability are shown. Hydrogen atoms have been omitted for clarity.

142
R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
Table 6
Selected ethene polymerisation data
a
b
c
Run
Catalyst
Co-catalyst (mmol)
Temperature (8C)
Yield (g)
Productivity (g molꢂ1 hꢂ1 barꢂ1
)
Mw
1
2a
2d
2e
3a
3d
3e
4000
4000
4000
4000
4000
4000
8000
4000
4000
20000
4000
4000
4000
4000
8000
8000
4000
20000
4000
20000
20000
4000
20000
4000
4000
4000
4000
20000
4000
4000
4000
20000
25
25
25
25
25
25
25
0
trace
trace
2
3
trace
0.087
trace
4
1.7ꢃ
/
104
5740
5
6
trace
7
4a (40 mmol)
4b
0.129
0.7257
0.446
0.4914
0.1535
0.731
0.800
0.527
0.068
0.020
0.099
0.4246
0.368
0.6878
0.9831
0.575
0.5479
0.1891
0.794
0.9159
0.084
1.0603
0.063
0.027
0.42
1.3ꢃ
1.4ꢃ
8.9ꢃ
9.8ꢃ
3.1ꢃ
1.5ꢃ
1.6ꢃ
1.1ꢃ
6.8ꢃ
2.0ꢃ
1.6ꢃ
8.5ꢃ
7.4ꢃ
1.4ꢃ
2.0ꢃ
1.1ꢃ
1.1ꢃ
3.8ꢃ
1.6ꢃ
1.8ꢃ
1.7ꢃ
2.1ꢃ
1.3ꢃ
5.5ꢃ
2.1ꢃ
2.4ꢃ
/
104
105
104
104
104
105
105
105
103
103
104
104
104
105
105
105
105
104
105
105
104
105
104
103
106
106
328 000
486 000
576 000
8
/
9
4b
4b
25
25
60
0
/
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
/
4b
4c
/
627 000
587 000
/
4c
4c
25
60
25
25
25
0
/
/
162 000
343 000
497 000
308 000
142 000
513 000
4d (40 mmol)
4e (40 mmol)
5a
/
/
/
5b
/
5b
5b
25
25
60
25
25
0
/
/
5b
/
137 000
5c
/
5c
/
5d
5d
/
302 000
89 600
39 200
173 000
25
60
25
25
25
25
25
25
/
5d
/
5e
/
5e
/
CpTiCl3
/
CpZrCl3×
Cp2TiCl2
/
DME
d
/
/
d
Cp2ZrCl2
0.484
/
a
b
c
The polymerisations were performed in 50 ml toluene over 15 min at 1 bar ethene pressure.
The catalyst loading was 20 mmol unless specified.
The co-catalyst was MAO unless otherwise stated.
d
Polymerisations were conducted for 3 min.
Fig. 4. Molecular weight distribution (Run 27, Table 6).

R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
143
Table 7
1-Hexene hompolymerisations
a
b
c
Run
Catalyst
Co-catalyst (mmol)
Temperature (8C)
Yield (g)
Conversion (%)
Productivity (g molꢂ1 hꢂ1 barꢂ1
)
33
34
35
36
37
4b
5a
5b
5d
5e
4000
4000
4000
4000
4000
25
25
25
25
25
0.95
2.02
1.05
1.53
1.45
28
60
31
45
43
2.6ꢃ
5.6ꢃ
2.9ꢃ
4.3ꢃ
4.0ꢃ
/
103
103
103
103
103
/
/
/
/
a
b
c
All polymerisations were carried out in 5 ml hexene and 3.7 ml toluene over 18 h.
The catalyst loading was 20 mmol.
The co-catalyst was MAO.
3. Experimental
CpZrCl3×
/
DME [33] and CpTiCl3 [34] were prepared
according to the literature procedures.
3.1. General
3.2. Ligand synthesis
Syntheses were performed under nitrogen using
standard Schlenk techniques. Solvents were distilled
over sodiumꢁ
dium (toluene), sodiumꢁ
leum, b.p. 40ꢁ60 8C), or CaH2 (dichloromethane).
NMR solvents (CDCl3, C6D6) were dried over activated
/
benzophenone (diethyl ether, THF), so-
3.2.1. 2-tert-Butyl-6-[(2,4,6-trimethylphenylimino)-
methyl]-phenol (1a)
/potassium alloy (light petro-
/
To a stirred solution of 2,4,6-trimethylaniline (21.2 g,
119 mmol) and 3-tert-butylsalicylaldehyde (16.0 g, 119
mmol) in toluene (350 ml), p-toluenesulfonic acid
monohydrate (2.26 g, 11.86 mmol) was added. The
solution was refluxed for 15 h and allowed to cool to
room temperature (r.t.) before removing the volatiles
under vacuum. The resulting dark yellow oil was
extracted with light petroleum, and filtered to remove
p-toluenesulfonic acid. The product was purified by
˚
4 A molecular sieves and degassed by several freezeꢁ
/
thaw cycles. NMR spectra were recorded using a Bruker
DPX300 spectrometer. Chemical shifts are reported in
ppm and referenced to residual solvent resonances (1H,
13C), 19F is relative to CFCl3. Nitrogen, argon and
ethene (BOC, 99.5%) were purified by passing through
columns of supported P2O5 with moisture indicator, and
˚
activated 4 A molecular sieves. GPC analyses were
column chromatography (eluent 30:1 light petroleumꢁ
/
performed at UEA on a Polymer Labs PL-GPC-220 or
by RAPRA Technology Ltd. Elemental analyses were
performed by the School of Chemical Sciences Micro-
analysis Service. Mass spectrometry was provided by the
EPSRC National Mass Spectrometry Service Centre,
Swansea.
Hexene, pyrrolidine, 2-t-butyl phenol, paraformalde-
hyde and pentafluoroaniline (Aldrich), piperidine and
cyclohexylamine (Lancaster), formaldehyde and 2,4,6-
trimethylaniline (Acros Organics) were obtained from
commercial sources and used as supplied. 3-tert-Butyl
salicylaldehyde [12], 2-tert-butyl-6-[(pentafluoropheny-
diethylether) to afford 2-tert-butyl-6-[(2,4,6-trimethyl-
phenylimino)-methyl]-phenol as a bright yellow oil,
which crystallised from light petroleum at 5 8C as
bright, lemon-yellow crystals (14.1 g, 47.6 mmol, 40%).
1H-NMR (300 MHz, 300 K, CDCl3): d 8.32 (s, 1H,
CH Ä
1H, Jꢀ
Jꢀ7.7 Hz, Ar), 2.30 (s, 3H, CH3), 2.19 (s, 6H, CH3),
1.48 (s, 9H, But). 13C-NMR (75.5 MHz, 300 K, CDCl3):
d 167.3 (C ÃO), 160.6 (C ÄN), 145.7 (Ar), 137.7 (Ar),
/
N), 7.40 (dd, 1H, Jꢀ/7.8, 1.5 Hz, Ar), 7.18 (dd,
/7.6, 1.6 Hz, Ar), 6.92 (s, 2H, Ar), 6.88 (t, 1H,
/
/
/
134.3 (Ar), 130.4 (Ar), 130.2 (Ar), 129.0 (Ar), 128.3 (Ar),
118.6 (Ar), 118.0 (Ar), 34.9 (CMe3), 29.3 (C(CH3)3),
20.8 (p-CH3), 18.5 (o-CH3). Anal. Found: C, 81.47; H,
limino)-methyl]-phenol
[15],
ZrCl4(THF)2
[32],
Table 8
Etheneꢁ1-hexene copolymerisations
/
a
b,c
Run
Catalyst
Temperature (8C)
Yield (g)
Productivity (g molꢂ1 hꢂ1 barꢂ1
)
Hexene incorporation (%)
Mw
38
39
40
41
4b
5a
5d
5e
25
25
25
25
0.0348
0.0900
0.7180
0.1686
1.4ꢃ
3.6ꢃ
2.9ꢃ
6.7ꢃ
/
104
104
105
104
2.1
1.9
2.1
1.3
1 190 000
250 000
31 800
/
/
/
171 000
a
b
c
All polymerisations were conducted in 20 ml toluene over 15 min.
The catalyst loading was 20 mmol.
The co-catalyst was 4000 mmol MAO.

144
R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ149
/
8.53; N, 4.61. Calc. for C20H25NO: C, 81.31; H, 8.53; N,
4.74%.
methanol to afford the desired product as colourless
1
crystals (21.0 g, 69 mmol, 69%). H-NMR (300 MHz,
300 K, CDCl3): d 11 (br, 1H, OH), 7.21 (d, 1H, Jꢀ
/2.4
3.2.2. 2-tert-Butyl-6-[(cyclohexylimino)-methyl]phenol
(1c)
To a stirred mixture of 3-tert-butylsalicylaldehyde
Hz, Ar), 6.82 (d, 1H, Jꢀ2.4 Hz, Ar), 3.64 (s, 2H,
/
CH2N), 2.6 (br, 4H, piperidinyl CH2N), 1.63 (br, 4H,
piperidinyl CH2), 1.50 (br, 2H, piperidinyl CH2), 1.45 (s,
9H, But), 1.31 (s, 9H, But). 13C-NMR (75.5 MHz, 300
˚
(9.74 g, 55 mmol) and molecular sieves 4 A (4 g) in
ethanol (50 ml), a solution of cyclohexylamine (6.00 g,
61 mmol) in ethanol (20 ml) was added dropwise at r.t.
The mixture was stirred for 18 h, filtered and the
molecular sieves washed with ethyl acetate (20 ml).
The volatiles were removed under vacuum and the
K, CDCl3): d 154.4 (C Ã
/
O), 140.1 (Ar), 135.2 (Ar), 123.3
(Ar), 121.0 (Ar), 62.9 (CH2N), 53.7 (piperidinyl CH2N),
34.8 (C(CH3)3), 34.1 (CMe3), 31.7 (C(CH3)3), 29.6
(C(CH3)3), 25.8 (piperidinyl CH2), 24.1 (piperidinyl
CH2). Anal. Found: C, 79.17; H, 10.97; N, 4.40. Calc.
for C20H33NO: C, 79.15; H, 10.96; N, 4.62%. MS: 303
[Mꢄ], 260, 219, 83, 57.
product recrystallised from light petroleum at ꢂ
/
20 8C
as a yellow solid (4.0 g, 14 mmol, 25%). H-NMR (300
MHz, 298 K, C6D6): d 8.37 (s, 1H, CH ÄN), 7.31 (d, 1H,
Jꢀ6.5, ArÃH), 7.10 (d, 1H, Jꢀ6.5, Ar), 6.80 (t, 1H,
Jꢀ6.5, Ar), 3.2 (br, 1H, cyclohexyl CH), 1.84 (m, 4H,
cyclohexyl CH2), 1.7ꢁ1.2 (br, 6H, cyclohexyl CH2), 1.45
(s, 9H, But). 13C-NMR (75.5 MHz, 298 K, C6D6): d
162.9 (CHÄN), 160.7 (C ÃO), 137.3 (Ar), 129.4 (Ar),
1
/
/
/
/
3.3. Complex syntheses
/
/
3.3.1. {2-But-6-(2,4,6-Me3C6H2NCH)C6H3O}2TiCl2
(2a)
The lithium salt Li1a was prepared by the dropwise
addition of n-BuLi (3.3 ml, 1.6 M in hexanes) to a
stirred solution of 1a (1.48 g, 5 mmol) in dry THF (50
/
/
129.0 (Ar), 118.9 (Ar), 117.5 (Ar), 67.6 (cyclohexyl CH),
34.8 (cyclohexyl CH2), 34.4 (cyclohexyl CH2). 29.3
(CMe3), 25.6 (C(CH3)3), 24.5 (cyclohexyl CH2). Anal.
Found: C, 78.58; H, 9.69; N, 5.12. Calc. for C19H25NO:
C, 78.72; H, 9.71; N, 5.40%. MS: 259.3 [Mꢄ], 244.3,
216.2, 162.2, 134.1, 83.2, 55.3, 41.3.
ml) at ꢂ
solution was stirred for a further 30 min before warming
to r.t. for 1 h. The Li1a solution was cooled to ꢂ78 8C
and TiCl4 (0.47 g, 2.5 mmol) was added. The reaction
was maintained at ꢂ78 8C for 1 h before warming
/
78 8C. To ensure complete deprotonation the
/
/
3.2.3. 2,4-di-tert-Butyl-6-pyrrolidin-1-ylmethyl-phenol
(1d) [35,36]
slowly to r.t. and stirring overnight. The volatiles were
then removed under vacuum and the resulting foam
extracted with CH2Cl2 (20 ml). The solution was
concentrated, layered with light petroleum and cooled
to 5 8C, affording dark red, cubic crystals (0.55 g, 1.15
To a stirred solution of 2,4-di-tert-butylphenol (20.3
g, 0.1 mol) and 37% aq. formaldehyde (8.1 g, 0.1 mol) in
methanol (250 ml), pyrrolidine (7.2 g, 0.1 mol) was
added. The solution was then refluxed for 15 h in air and
allowed to cool to r.t. The product crystallised on
cooling and was separated by filtration and washing
with cold methanol, affording large white crystals (27.5
g, 95 mmol, 95%). 1H-NMR (300 MHz, 300 K, CDCl3):
1
mmol, 46%). H-NMR (300 MHz, 300 K, CDCl3): d
8.18 (s, 2H, CH Ä
/
N), 7.53 (dd, 2H, Jꢀ
/
7.7, 1.6 Hz, Ar),
7.22 (dd, 2H, Jꢀ
/
7.7, 1.6 Hz, Ar), 6.98 (t, 2H, Jꢀ
/7.7
Hz, Ar), 6.86 (s, 4H, Ar), 2.37 (s, 6H, Me), 2.26 (s, 6H,
Me), 1.87 (s, 6H, Me), 1.17 (s, 18H, But). 13C-NMR
d 7.18 (d, 1H, Jꢀ
/
2.4 Hz, Ar), 6.81 (d, 1H, Jꢀ
/
2.3 Hz,
(75.5 MHz, 300 K, CDCl3), 171.6 (CHÄ
/
N), 162.9 (C Ã
/
Ar), 3.77 (s, 2H, CH2Ã
/
N), 2.60 (m, 4H, pyrrolidinyl H),
1.81 (m, 4H, pyrrolidinyl H), 1.40 (s, 9H, But), 1.26 (s,
9H, But). 13C-NMR (75.5 MHz, 300 K, CDCl3): d 154.4
O), 149.5 (Ar), 138.7 (Ar), 136.0 (Ar), 134.2 (Ar), 132.8
(Ar), 132.4 (Ar), 125.0 (Ar), 121.3 (Ar), 34.9 (CMe3),
29.3 (C(CH3)3), 20.4 (CH3), 19.7 (CH3), 19.5 (CH3).
Anal. Found: C, 67.08; H, 6.91; N, 3.79; Cl, 11.28. Calc.
for C40H48N2O2Cl2Ti: C, 67.89; H, 6.84; N, 3.96; Cl,
10.02%.
(C Ã/O), 140.1 (Ar), 135.2 (Ar), 122.6 (Ar), 122.6 (Ar),
121.8 (Ar), 59.6 (CH2N), 53.3 (pyrrolidinyl CH2N), 34.8
(CMe3), 34.1 (CMe3), 31.7 (C(CH3)3), 29.6 (C(CH3)3),
23.7 (pyrrolidinyl CH2). Anal. Found: C, 79.08; H,
10.91; N, 4.72. Calc. for C19H31NO: C, 78.83; H, 10.79;
N, 4.83%. MS: 289 [Mꢄ], 274, 203, 70, 57.
3.3.2. {2,4-But2-6-(C4H8NCH2)C6H2O}2TiCl2 (2d)
The lithium salt Li1d was prepared from 1d (1.45 g, 5
mmol) and n-BuLi (3.3 ml, 1.6 M) in a similar procedure
to that employed for Li1a. Li1d was treated with TiCl4
(0.47 g, 2.5 mmol) following the procedure used for 2a.
The solvents were removed under vacuum and the
product extracted with CH2Cl2 (20 ml). The solution
was concentrated, layered with light petroleum and
cooled overnight to 5 8C, giving small brown crystals
3.2.4. 2,4-di-tert-Butyl-6-piperidin-1-ylmethyl-phenol
(1e)
Following a similar procedure to the preparation of
1d, a mixture of 2,4-di-tert-butylphenol (20.3 g, 0.1
mol), formaldehyde (8.1 g, 0.1 mol, 37% aq.), piperidine
(8.5 g, 0.1 mol) and methanol (175 ml) was refluxed for
15 h in air before allowing to cool to r.t. The crystals
formed on cooling were filtered and washed with cold
1
(1.02 g, 1.5 mmol, 59%). H-NMR (300 MHz, 300 K,
CDCl3): d 7.28 (s, 2H, Ar), 6.99 (s, 2H, Ar), 4.0 (br, 4H,

R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
145
CH2N), 3.2 (br, 8H, pyrrolidinyl CH2), 1.95 (br, 8H,
pyrrolidinyl CH2), 1.40 (s, 18H, But), 1.31 (s, 18H, But).
3.3.5. {2,4-But2-6-(C4H8NCH2)C6H2O}2ZrCl2 (3d)
The reaction between Li1d (5 mmol) and ZrCl4×
/
13C-NMR (75.5 MHz, 300 K, CDCl3): d 160.4 (C Ã
/
O),
143.7 (Ar), 134.1 (Ar), 126.5 (Ar), 124.6 (Ar), 124.0 (Ar),
N), 53.4 (pyrrolidinyl CH2N), 34.9 (CMe3),
(THF)2 (0.94 g, 2.5 mmol) was performed following a
similar procedure to that for 2a. The product was
extracted with CH2Cl2. The solution was concentrated,
layered with light petroleum and cooled to 5 8C, yielding
60.8 (CH2Ã
/
34.4 (CMe3), 31.5 (C(CH3)3), 30.6 (C(CH3)3), 21.9
(pyrrolidinyl CH2). Anal. Found: C, 60.79; H, 8.18; N,
1
small, colourless crystals (1.05 g, 1.3 mmol, 52%). H-
3.51; Cl, 16.80. Calc. for C38H60N2O2Cl2Ti×
/CH2Cl2: C,
NMR (300 MHz, 300 K, CDCl3): d 7.30 (d, 2H, Jꢀ
/
2.4
60.01; H, 8.01; N, 3.59; Cl, 18.17%.
Hz, Ar), 6.94 (d, 2H, Jꢀ2.4 Hz, Ar), 4.2 (br, 4H,
/
CH2N), 3.7 (br, 4H, pyrrolidinyl CH2N), 3.2 (br, 4H,
pyrrolidinyl CH2N), 2.1 (br, 8H, pyrrolidinyl CH2), 1.45
(s, 18H, But), 1.29 (s, 18H, But). 13C-NMR (75.5 MHz,
3.3.3. {2,4-But2-6-(C5H10NCH2)C6H2O}2TiCl2 (2e)
The lithium salt Li1e was prepared from 1e (1.52 g, 5
mmol) and n-BuLi (3.3 ml, 1.6 M) in a similar procedure
to that employed for Li1a. Li1e was treated with TiCl4
(0.47 g, 2.5 mmol) following the procedure used for 2a.
Removal of the volatiles under vacuum gave a brown
foam which was extracted with CH2Cl2 (20 ml). The
solution was concentrated, layered with light petroleum
and cooled overnight to 5 8C, yielding small brown
300 K, CDCl3): d 156.2 (CÃ
/
O), 142.0 (Ar), 135.6 (Ar),
124.8 (Ar), 124.6 (Ar), 124.3 (Ar), 60.0 (CH2N), 53.4
(pyrrolidinyl CH2N), 34.8 (CMe3), 34.2 (CMe3), 31.6
(C(CH3)3), 30.4 (C(CH3)3), 22.4 (pyrrolidinyl CH2).
Anal. Found: C, 56.72; H, 7.55; N, 3.14; Cl, 15.14. Calc.
for C38H60N2O2Cl2Zr×
/1/2CH2Cl2: C, 56.64; H, 7.47; N,
3.43; Cl, 17.37%.
3.3.6. {2,4-But2-6-(C5H10NCH2)C6H2O}2ZrCl2 (3e)
1
crystals (0.95 g, 1.3 mmol, 52%). H-NMR (300 MHz,
The reaction between Li1e (5 mmol) and ZrCl4×
(THF)2 (0.94 g, 2.5 mmol) was performed following a
similar procedure to that for 2a. The product was
extracted with CH2Cl2. The solution was concentrated,
layered with light petroleum and cooled to 5 8C
precipitating a beige solid (1.66 g, 2.1 mmol, 82%).
/
300 K, CDCl3): d 7.28 (d, 2H, Jꢀ
2H, Jꢀ2.1 Hz, Ar), 4.7 (br, 4H, CH2Ã
piperidinyl CH2ÃN), 3.4 (br, 4H, piperidinyl CH2N), 1.8
/2.1 Hz, Ar), 7.14 (d,
/
/
N), 4.4 (br, 4H,
/
(br, 8H, piperidinyl CH2), 1.4 (br, 4H, piperidinyl CH2),
1.42 (s, 18H, But), 1.32 (s, 18H, But). 13C-NMR (75.5
MHz, 300 K, CDCl3): d 143.9 (Ar), 134.3 (Ar), 125.0
(Ar), 123.8 (Ar), 54.5 (CH2N), 41.3 (piperidinyl CH2N),
34.8 (CMe3), 34.4 (CMe3), 31.7 (C(CH3)3), 30.6
(C(CH3)3), 23.2 (piperidinyl CH2), 20.4 (piperidinyl
CH2). Anal. Found: C, 67.23; H, 9.35; N, 3.54; Cl,
9.14. Calc. for C40H64N2O2Cl2Ti: C, 66.38; H, 8.91; N,
3.87; Cl, 9.80%.
1H-NMR (300 MHz, 300 K, CDCl3): d 7.29 (d, 2H, Jꢀ
2.2 Hz, Ar), 7.08 (d, 2H, Jꢀ2.2 Hz, Ar), 4.5 (br, 4H,
/
/
CH2N), 3.8 (br, 4H, piperidinyl CH2N), 3.2 (br, 4H,
piperidinyl CH2N), 1.8 (br, 8H, piperidinyl CH2), 1.5
(br, 4H, piperidinyl CH2), 1.42 (s, 18H, But), 1.31 (s,
18H, But). 13C-NMR (75.5 MHz, 300 K, CDCl3) d
156.5 (Ar), 142.1 (Ar), 135.5 (Ar), 125.2 (Ar), 124.4 (Ar),
123.2 (Ar), 53.5 (CH2Ã
31.6 (C(CH3)3), 30.2 (C(CH3)3), 23.0 (piperidinyl
CH2N), 19.1 (piperidinyl×CH2), 18.9 (piperidinyl×
CH2). Anal. Found: C, 59.56; H, 7.83; N, 3.20; Cl,
13.70. Calc. for C40H64N2O2Cl2Zr×LiCl: C, 59.35; H,
7.97; N, 3.46; Cl, 13.14%.
/
N), 34.7 (CMe3), 34.2 (CMe3),
3.3.4. {2-But-6-(2,4,6-Me3C6H2NCH)C6H3O}2ZrCl2
/
/
(3a)
The reaction between Li1a (5 mmol) and ZrCl4×
/
/
(THF)2 (0.94 g, 2.5 mmol) was performed following a
similar procedure to that for the titanium analogue 2a.
The solvents were taken off and the product extracted
with CH2Cl2. The solution was concentrated and
layered with light petroleum. Pale yellow, needle-like
crystals (suitable for X-ray diffraction) grew overnight
3.3.7. Cp{2-But-6-(2,4,6-Me3C6H2NCH)C6H3O}TiCl2
(4a)
The lithium salt of 1a was prepared by the dropwise
addition of n-BuLi (3.3 ml, 1.6 M in hexanes) to a
stirred solution of 1a (1.48 g, 5 mmol) in dry THF (50
1
at r.t. (0.56 g, 0.75 mmol, 30%). H-NMR (300 MHz,
300 K, CDCl3): d 8.32 (s, 2H, CH Ä
Jꢀ7.7, 1.6 Hz, Ar), 7.23 (dd, 2H, Jꢀ
6.95 (t, 2H, Jꢀ7.7 Hz, Ar), 6.89 (s, 2H, Ar), 2.33 (s,
12H, o-CH3), 1.80 (s, 6H, p-CH3), 1.22 (s, 18H, But).
13C-NMR (75.5 MHz, 300 K, CDCl3): d 173.9 (CHÄ
N), 160.5 (Ar), 148.0 (Ar), 138.6 (Ar), 135.8 (Ar), 134.4
(Ar), 133.8 (Ar), 130.3 (Ar), 129.0 (Ar), 123.5 (Ar), 123.2
(Ar) 34.9 (CMe3), 29.6 (C(CH3)3), 19.9 (o-CH3), 19.2
(p-CH3). Anal. Found: C, 63.88; H, 6.46; N, 3.59. Calc.
for C40H48N2O2Cl2Zr: C, 63.98; H, 6.44; N, 3.73%.
/
N), 7.54 (dd, 2H,
ml) at ꢂ78 8C. To ensure complete deprotonation, the
solution was stirred for a further 30 min before warming
to r.t. and stirring for a further 1 h. The solution of Li1a
/
/
/7.7, 1.6 Hz, Ar),
/
was cooled to ꢂ78 8C and CpTiCl3 (1.09 g, 5 mmol)
/
/
added. The reaction temperature was maintained for 1 h
before warming to r.t. and stirring overnight. The
volatiles were removed under reduced pressure and the
resulting foam extracted with CH2Cl2. The solution was
concentrated, layered with light petroleum and cooled to
5 8C, giving dark red needle-like crystals (fragments of

146
R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ149
/
which were suitable for X-ray diffraction) (1.84 g, 3.9
1
mmol, 77%). H-NMR (300 MHz, 300 K, CDCl3): d
Found: C, 53.01; H, 6.45; N, 2.39; Cl, 15.96. Calc. for
C22H29NOCl2Ti: C, 54.41; H, 6.02; N, 2.88; Cl, 14.60%.
8.42 (s, 1 H, CH Ä
/
N), 7.72 (dd, 1H, Jꢀ
/
7.7, 1.6 Hz, Ar),
7.7
7.42 (dd, 1H, Jꢀ
/
7.7, 1.6 Hz, Ar), 7.12 (t, 1H, Jꢀ
/
3.3.10. Cp{2,4-But2-6-(C4H8NCH2)C6H2O}TiCl2 (4d)
The lithium salt Li1d was prepared from 1d (1.45 g, 5
mmol) and n-BuLi (3.3 ml, 1.6 M) in a similar procedure
to that employed for Li1a. Li1d was treated with
CpTiCl3 (1.09 g, 5 mmol) following the procedure
used for 4a. The solvents were removed under vacuum
and the product extracted with CH2Cl2 (20 ml). The
resulting solution was concentrated, layered with light
Hz, Ar), 6.92 (s, 2H, Ar), 6.58 (s, 5H, Cp), 2.30 (s, 3H,
Me), 2.20 (s, 6H, Me), 1.56 (s, 9H, But). 13C-NMR (75.5
MHz, 300 K, CDCl3): 168.9 (CHÄ
(Ar), 138.3 (Ar), 135.8 (Ar), 133.7 (Ar), 131.3 (Ar), 129.2
(Ar), 122.2 (Cp), 121.8 (Ar), 121.6 (Ar), 35.2 (CMe3),
29.4 (C(CH3)3), 20.8 (p-CH3), 19.2 (o-CH3). Anal.
Found: C, 59.35; H, 6.07; N, 2.61. Calc. for
/
N), 165.6 (Ar), 154.6
C25H29NOCl2Ti×
/
(CH2Cl2)0.5: C, 58.81; H, 5.81; N,
petroleum and cooled to ꢂ
product as a brownꢁorange powder (1.30 g, 2.8 mmol,
55%). H-NMR (300 MHz, 300 K, CDCl3): d 7.26 (d,
1H, Jꢀ2.0 Hz, Ar), 6.89 (d, 1H, Jꢀ2.0 Hz, Ar), 6.72 (s,
5H, Cp), 4.08 (s, 2H, CH2N), 3.32 (m, 4H, pyrrolidinyl
CH2), 1.92 (m, 4H, pyrrolidinyl CH2), 1.42 (s, 9H, But),
1.31 (s, 9H, But). 13C-NMR (75.5 MHz, 300 K, CDCl3):
/
20 8C to afford the desired
2.69%.
/
1
3.3.8. Cp{2-But-6-(C6F5NCH)C6H3O}TiCl2 (4b)
The lithium salt Li1b was prepared from 1b (1.26 g,
3.67 mmol) and n-BuLi (2.4 ml, 1.6 M) in a similar
procedure to that employed for Li1a. Li1b was treated
with CpTiCl3 (0.80 g, 3.67 mmol) following the proce-
dure used for 4a. The product was extracted with
CH2Cl2 (20 ml). The resulting solution was concen-
trated, layered with light petroleum and cooled to
/
/
d 144.7 (ArÃ
/
O), 135.7 (Ar), 123.2 (Ar), 122.4 (Ar), 121.8
N), 57.0 (pyrrolidinyl
(Cp), 118.2 (Ar), 61.7 (CH2Ã
/
CH2N), 35.0 (CMe3), 34.5 (CMe3), 31.5 (C(CH3)3),
29.6 (C(CH3)3), 23.5 (pyrrolidinyl CH2). Anal. Found:
C, 60.05; H, 7.62; N, 2.56; Cl, 15.50. Calc. for
C24H35NOCl2Ti: C, 61.03; H, 7.47; N, 2.97; Cl, 15.01%.
ꢂ20 8C, precipitating 4b as dark red oil. The oil was
/
dried under vacuum and the resulting foam broken up
1
to give an orange powder (1.64 g, 3.1 mmol, 61%). H-
NMR (300 MHz, 300 K, CDCl3): d 7.83 (s, 1H, CH Ä
N), 7.41 (dd, 1H, Jꢀ7.6, 1.5 Hz, Ar), 7.02 (dd, 1H, Jꢀ
7.6, 1.5, Ar), 6.74 (t, 1H, Jꢀ7.6, Ar), 6.16 (s, 5H, Cp),
1.44 (s, 9H, But). 13C-NMR (75.5 MHz, 300 K, CDCl3):
N), 166.7 (Ar), 139.4 (Ar), 135.2 (Ar), 132.4
/
3.3.11. Cp{2,4-But2-6-(C5H10NCH2)C6H2O}TiCl2 (4e)
The lithium salt Li1e was prepared from 1e (1.52 g, 5
mmol) and n-BuLi (3.3 ml, 1.6 M) in a similar procedure
to that employed for Li1a. Li1e was treated with
CpTiCl3 (1.09 g, 5 mmol) following the procedure
used for 4a. The solvents were removed under vacuum
and the product extracted with CH2Cl2 (20 ml). The
solution was concentrated, layered with light petroleum
and cooled to 5 8C, affording the product as large, dark
orange, cubic crystals (1.48 g, 3.1 mmol, 61%). 1H-NMR
/
/
/
173.0 (CHÄ
/
(Ar), 122.4 (Cp), 121.8 (Ar), 121.4 (Ar), 35.2 (CMe3),
29.6 (C(CH3)3). 19F-NMR (282.4 MHz, 300 K, C6D6): d
ꢂ
/
148.2 (br, 2F, o-F), ꢂ
/
157.8 (br, 1F, p-F), ꢂ162.7 (br,
/
2F, m-F). Anal. Found: C, 50.68; H, 3.92; N, 2.33; Cl,
14.21. Calc. for C22H18NOCl2F5Ti: C, 50.22; H, 3.45; N,
2.66; Cl, 13.48%.
(300 MHz, 300 K, CDCl3): d 7.24 (tr, 2H, Jꢀ
/
2.5 Hz,
Ar), 6.85 (s, 5H, Cp), 3.60 (s, 2H, CH2ÃN), 2.51 (m, 4H,
/
3.3.9. Cp{2-But-6-(C6H11NCH)C6H3O}TiCl2 (4c)
The lithium salt Li1c, was prepared from 1c (1.30 g, 5
mmol) and n-BuLi (3.3 ml, 1.6 M) in a similar procedure
to that employed for Li1a. Li1c was treated with
CpTiCl3 (1.09 g, 5 mmol) following the procedure
used for 4a. The solvents were removed under vacuum
and the product extracted with CH2Cl2 (40 ml). The
solution was concentrated, layered with light petroleum
and cooled to 5 8C to afford the product as an orange
solid (1.32 g, 3.0 mmol, 60%). 1H-NMR (300 MHz, 298
piperidinyl CH2N), 1.61 (m, 4H, piperidinyl CH2), 1.47
(m, 2H, piperidinyl CH2), 1.41 (s, 9H, But), 1.31 (s, 9H,
But). 13C-NMR (75.5 MHz, 300 K, CDCl3): d 165.5
(ArÃ
/
O), 145.8 (Ar), 137.7 (Ar), 129.1 (Ar), 126.6 (Ar),
122.4 (Ar), 121.6 (Cp), 58.0 (CH2N), 54.3 (piperidinyl
CH2N), 35.4 (CMe3), 34.6 (CMe3), 31.4 (C(CH3)3), 30.6
(C(CH3)3), 25.8 (piperidinyl×/CH2), 24.4 (piperidinyl
CH2). Anal. Found: C, 62.25; H, 7.75; N, 2.63; Cl,
14.44. Calc. for C25H37NOCl2Ti: C, 61.74; H, 7.67; N,
2.88; Cl, 14.58%.
K, CDCl3): d 8.56 (s, 1H, CH Ä
7.7, 1.6 Hz, Ar), 7.37 (dd, 1H, Jꢀ
(t, 1H, Jꢀ7.7 Hz, Ar), 6.43 (s, 5H, Cp), 4.41 (m, 1H,
cyclohexyl CH), 2.5ꢁ1.1 (br, 10H, cyclohexyl CH2), 1.47
(s, 9H, But). 13C-NMR (75.5 MHz, 298 K, CDCl3): d
164.9 (CHÄN), 163.7 (Ar ÃO), 138.3 (Ar), 132.9 (Ar),
131.8 (Ar), 121.8 (Cp), 68.8 (cyclohexyl CH), 35.0
(CMe3), 29.7 (C(CH3)3), 29.3 (cyclohexyl CH2), 25.7
(cyclohexyl CH2), other resonances obscured. Anal.
/
N), 7.59 (dd, 1H, Jꢀ
/
/
7.7, 1.6 Hz, Ar), 7.05
3.3.12. Cp{2-But-6-(2,4,6-
/
Me3C6H2NCH)C6H3O}2ZrCl2 (5a)
The reaction between Li1a (5 mmol) and CpZrCl3×
(DME) (1.76 g, 5 mmol) was performed following a
similar procedure to that for the titanium analogue 4a.
The solvents were removed under vacuum and the
product extracted with CH2Cl2 (20 ml). The solution
was concentrated, layered with light petroleum and
/
/
/
/

R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ
/
149
147
cooled to ꢂ
orange powder (0.97 g, 1.7 mmol, 33%). 1H-NMR
(300.13 MHz, 300 K, CDCl3): d 8.38 (s, 1H, CH ÄN),
7.71 (dd, 1H, Jꢀ7.7, 1.6 Hz, Ar), 7.35 (dd, 1H, Jꢀ7.7,
1.6, Ar), 7.05 (t, 1H, Jꢀ7.7 Hz, Ar), 6.95 (s, 2H, Ar),
/
20 8C, precipitating the product as an
(Cp), 68.6 (cyclohexyl CH), 34.9 (CMe3), 34.1 (cyclo-
hexyl CH2), 29.6 (C(CH3)3), 25.6 (cyclohexyl CH2), 22.3
(cyclohexyl CH2). Anal. Found: C, 58.43; H, 6.65; N,
2.93; Cl, 17.53. Calc. for C22H29NOCl2Zr: C, 59.75; H,
6.61; N, 3.17; Cl, 16.03%.
/
/
/
/
6.51 (s, 5H, Cp), 3.79 (m, 4H, THF), 2.32 (s, 3H, p-Me),
2.25 (s, 6H, o-Me), 1.86 (m, 4H, THF), 1.55 (s, 9 H,
But). 13C-NMR (75.5 MHz, 300 K, CDCl3): d 172.8
3.3.15. Cp{2,4-But2-6-(C4H8NCH2)C6H2O}ZrCl2 (5d)
The reaction between Li1d (5 mmol) and CpZrCl3×
/
(CHÄ
/
N), 162.1 (ArÃ/O), 151.7 (Ar), 139.5 (Ar), 135.9
(DME) (1.76 g, 5 mmol) was performed following a
similar procedure to that for 4a. The solvents were
removed under vacuum and the product extracted with
CH2Cl2 (20 ml). The solution was concentrated, layered
with light petroleum and cooled to 5 8C, precipitating 5d
(Ar), 134.5 (Ar), 132.7 (Ar), 129.4 (Ar), 128.9 (Ar), 122.3
(Ar), 120.3 (Ar), 116.8 (Cp), 68.0 (THF), 35.1 (CMe3),
29.3 (C(CH3)3), 25.6 (THF), 20.8 (CH3), 19.2 (CH3).
Anal. Found: C, 58.55; H, 6.75; N, 2.03; Cl, 10.85. Calc.
1
for C25H29NOCl2Zr×
/
C4H8O: C, 58.66; H, 6.28; N, 2.36;
as a pale brown powder (1.16 g, 2.3 mmol, 45%). H-
Cl, 11.94%.
NMR (300 MHz, 300 K, CDCl3): d 7.28 (d, 1H, Jꢀ
/2.4
Hz, Ar), 6.84 (d, 1H, Jꢀ2.2 Hz, Ar), 6.66 (s, 5H, Cp),
/
3.3.13. Cp{2-But-6-(C6F5NCH)C6H3O}ZrCl2 (5b)
4.0 (br, 1H, CH2N), 3.8 (br, 1H, CH2N), 3.5 (br, 2H,
pyrrolidinyl CH2N), 2.9 (br, 2H, pyrrolidinyl CH2N),
2.0 (br, 4H, pyrrolidinyl CH2), 1.41 (s, 9H, But), 1.30 (s,
9H, But). 13C-NMR (75.5 MHz, 300 K, CDCl3): d 156.4
(Ar), 142.7 (Ar), 137.4 (Ar), 124.1 (Ar), 123.7 (Ar), 121.4
(Ar), 116.8 (Cp), 61.1 (CH2N), 41.3 (pyrrolidinyl
CH2N), 34.8 (CMe3), 34.3 (CMe3), 31.6 (C(CH3)3),
29.4 (C(CH3)3), 22.9 (pyrrolidinyl CH2). Anal. Found:
56.05; H, 7.13; N, 2.60; Cl, 12.58. Calc. for
C24H35NOCl2Zr: C, 55.90; H, 6.84; N, 2.72; Cl, 13.75%.
The reaction between Li1b (4 mmol) and CpZrCl3×
(DME) (1.42 g, 4 mmol) was performed following a
similar procedure to that for 4a. The solvents were
removed under vacuum and the product extracted with
CH2Cl2 (20 ml). The solution was concentrated, layered
/
with light petroleum and cooled to ꢂ
the product 5b as yellowꢁgreen crystals (1.56 g, 2.3
mmol, 57%). 1H-NMR (300 MHz, 300 K, C6D6): d 7.60
(s, 1H, CH ÄN), 7.43 (dd, 1H, Jꢀ7.6, 1.7 Hz, Ar), 6.85
(dd, 1H, Jꢀ7.6, 1.7 Hz, Ar), 6.64 (t, 1H, Jꢀ7.6 Hz,
/
20 8C, affording
/
/
/
/
/
Ar), 6.34 (s, 5H, Cp), 4.25 (s, 1H, CH2Cl2), 3.90 (m, 4H,
THF), 1.45 (s, 9H, But), 1.33 (m, 4 H, THF). 13C-NMR
3.3.16. Cp{2,4-But2-6-(C5H10NCH2)C6H2O}ZrCl2 (5e)
The reaction between Li1e (5 mmol) and CpZrCl3×
/
(75.5 MHz, 300 K, C6D6): d 175.8 (CHÄ/N), 164.0 (Ar),
(DME) (1.76 g, 5 mmol) was performed following a
similar procedure to that for 4a. The solvents were
removed under vacuum and the product extracted with
CH2Cl2 (20 ml). The solution was concentrated, layered
with light petroleum and cooled overnight to 5 8C,
precipitating the product as a beige powder (0.85 g, 1.6
140.6 (Ar), 136.4 (Ar), 134.8 (Ar), 121.3 (Ar), 119.9 (Ar),
119.2 (Ar), 118.8 (Ar), 117.4 (Cp), 71.1 (THF), 35.1
(CMe3), 30.0 (C(CH3)3), 25.3 (THF). 19F-NMR (282
MHz, 300 K, C6D6): d ꢂ
1F, p-F), ꢂ162.9 (m, 2F, m-F). Anal. Found: C, 46.54;
H, 4.09; N, 1.73; Cl, 15.07. Calc. for C22H18NOF5Cl2Zr×
/
150 (br, 2F, o-F), ꢂ157.7 (m,
/
/
1
/
mmol, 32%). H-NMR (300 MHz, 300 K, CDCl3): d
(THF)(CH2Cl2)0.5: C, 46.53; H, 3.98; N, 2.05; Cl,
15.55%.
7.30 (d, 1H, Jꢀ
6.64 (s, 5H, Cp), 4.20 (s, 2H, CH2N), 3.0ꢁ
/
2.3Hz, Ar), 6.98 (d, 1H, Jꢀ
2.7 (br, 4H,
1.7 (br, 4H, piperidinyl CH2),
/
2.2 Hz, Ar),
/
piperidinyl CH2N), 2.0ꢁ
/
3.3.14. Cp{2-But-6-(C6H11NCH)C6H3O}ZrCl2 (5c)
The lithium salt, Li1c, was prepared from 1c (1.30 g, 5
mmol) and n-BuLi (3.3 ml, 1.6 M) in a similar procedure
to that employed for Li1a. Li1c was treated with
1.50 (m, 2H, piperidinyl CH2), 1.41 (s, 9H, But), 1.32 (s,
9H, But). 13C-NMR (75.5 MHz, 300 K, CDCl3): d 156.8
(ArÃ
/
O), 142.9 (Ar), 137.2 (Ar), 124.2 (Ar), 120.8 (Ar),
118.2 (Ar), 117.1 (Cp), 54.1 (CH2N), 41.3 (piperidinyl
CH2N), 34.8 (CMe3), 34.4 (CMe3), 31.6 (C(CH3)3),
29.5 (C(CH3)3), 22.6 (piperidinyl CH2), 20.4 (piperidinyl
CH2). Anal. Found: C, 55.94; H, 7.54; N, 2.26; Cl,
13.65. Calc. for C25H37NOCl2Zr: C, 56.69; H, 7.04; N,
2.64; Cl, 13.39.
CpZrCl3×/DME (1.76 g, 5 mmol) following the proce-
dure used for 4a. The solvents were removed under
vacuum and the product extracted with CH2Cl2 (40 ml).
The solution was concentrated, layered with light
petroleum and cooled to 5 8C, to afford the product as
1
yellow crystals (0.60 g, 1.2 mmol, 25%). H-NMR (300
MHz, 298 K, CDCl3): d 8.47 (s, 1H, CH Ä
1H, Jꢀ7.7, 1.6 Hz, Ar), 7.28 (dd, 1H, Jꢀ
Ar), 6.96 (t, 1H, Jꢀ7.7 Hz, Ar), 6.53 (s, 5H, Cp), 3.78
(m, 1H, cyclohexyl CH), 2.3ꢁ1.0 (br, 10H, cyclohexyl
CH2), 1.45 (s, 9H, But). 13C-NMR (75.5 MHz, 298 K,
CDCl3): d 167.9 (CHÄN), 160.4 (ArÃC ÃO), 139.6 (Ar),
133.4 (Ar), 132.8 (Ar), 121.9 (Ar), 119.9 (Ar), 116.6
/
N), 7.55 (dd,
3.4. X-ray crystallography
/
/7.7, 1.6 Hz,
/
Crystal data for 2a, 3a, 4a and 4e are collected in
Table 1. Crystals were selected from samples under
perfluoropolyether oil, mounted on glass fibres and
fixed in the cold nitrogen stream. They were mounted on
/
/
/
/
a
Rigaku R-Axis IIc image plate diffractometer

148
R.K.J. Bott et al. / Journal of Organometallic Chemistry 665 (2003) 135ꢁ149
/
equipped with a rotating anode X-ray source (Moꢁ
/
Ka
4. Supplimentary material
radiation) and graphite monochromator. Using 48
oscillations, 48 exposures of 30 min each (40 min for
3a) were made. Data were processed using the DENZO/
SCALEPACK programs [37].
The structures of all the complexes were determined
by the direct methods routines in the XS program and
refined by full-matrix least-squares methods, on F2’s, in
XL [38] or SHELXL [39]. The non-hydrogen atoms were
refined with anisotropic thermal parameters. Hydrogen
atoms were included in idealised positions and their Uiso
values were set to ride on the Ueq values of the parent
carbon atoms. Scattering factors for neutral atoms were
taken from the literature [40].
Full tables of bond lengths and angles, tables of non-
hydrogen and hydrogen atomic coordinates and aniso-
tropic thermal parameters for non-hydrogen atoms are
available upon quoting the CCDC deposition numbers
192841ꢁ192844 for 2a, 3a, 4a and 4e, respectively.
/
Copies of the information may be obtained free of
charge from The Director, CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (Fax: ꢄ44-1223-336033;
/
e-mail: deposit@ccdc.cam.ac.uk or http://www.ccdc.
cam.ac.uk).
In 4a, there are two, virtually identical Ti-complex
molecules in the asymmetric unit, in quite different
orientations; these were well-resolved and refined with
anisotropic thermal parameters. There are also (prob-
ably) two CH2Cl2 solvent molecules in the asymmetric
unit; these were not satisfactorily resolved and were
disordered over several orientations. There was a
persistent difference peak between the two principal
solvent regions; this, we suspect, was occupied as the
methylene carbon atom (spanning chlorine atoms in the
two regions) when there was only one solvent molecule
in the asymmetric unit.
Acknowledgements
The support of the Engineering and Physical Sciences
Research Council and the University of East Anglia are
gratefully acknowledged. We thank Dr. Shaun Garratt
for assistance with GPC measurements.
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/
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/
polymer was collected by filtration, washed with metha-
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before drying overnight at 80 8C.

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