Title of Invention

HYDROCARBYL PHOSPHINIMINE/CYCLOPENTADIENYL COMPLEXES OF GROUP IV METALS AND PREPARATION THEREOF.

Abstract TITLE: HYDROCARBYL PHOSPHINIMINE/CYCLOPENTADIENYL COMPLEXES OF GROUP IV METALS AND PREPARATION THEREOF. An organometallic complex defined by the formula: FIGURE wherein M is group 4 metal in oxidation state 4; each Cp is selected from the group consisting of unsubstituted cyclopentadienyl, substituted cylcopentadienyl, unsubstituted indenyl, substituted indenyl, unsubstituted fluorenyl and substituted fluorenyl; each of R1,R2 and R3 is a hydrocarbyl group which is bonded to phosphorus by a carbon-phosphorus single bond; n is 2 or 3 and n+p=3; and when p=1, L is a monoanionic ligand, which is not -N=PR1R2R3; and where at least one of said Cp is either unsubstituted or substituted indenyl.
Full Text HYDROCARBYI. PHOSPHINIMINE/CYCLOPENTADIENYL COMPLEXES OF GROUP 4 AND THEIR USB IN OLEFIN
POLYMERIZATION
TECHNICAL FIELD
This invention relates to novel organometallic complexes.
Additionally, the complexes have been discovered to be surprisingly active
catalysts for the polymerization of olefins.
BACKGROUND ART
The polymerization of olefins using a catalyst having a
phosphinimine ligand and a cyclopentadienyl ligand is known and is
disclosed for example in copending and commonly assigned U.S. patent
application 08/959,589 (Stephan et al) (now U.S Patent 5,965,677).
These prior catalysts have an "activatable" ligand which is not a
cyclopentadienyl ligand. Exemplary activatable ligands include halides,
alkyls, amides and phosphides.
We have now surprisingly discovered and reproducibly synthesized
a group of novel organometallic complexes of group 4 metals having a
phosphinimine ligand and more than one cyclopentadienyl ligand. These
novel complexes form unique crystal structures which may be observed by
x-ray techniques.
The organometallic complexes of this invention might be regarded
as metallocenes because they contain two or more cyclopentadienyl
ligands. It is known that metallocenes of group 4 metals are active
catalysts for the polymerization of ethylene. However, we have
discovered that certain organometallic complexes of this invention are
substantially more active for ethylene polymerization than their simple
metallocene analogs.
DISCLOSURE OF INVENTION
In one embodiment, the invention provides an organometallic
complex defined by the formula:

wherein M is a group 4 metal in oxidation state 4;
each Cp is selected from the group consisting of unsubstituted
cyclopentadienyl, substituted cyclopentadienyl, unsubstituted indenyl,
substituted indenyl, unsubstituted fluorenyl and substituted fluorenyl;
each of R1, R2 and R3 is a hydrocarbyl group which is bonded to
phosphorus by a carbon-phosphorus single bond;
n is 2 or 3 and n + p = 3; and
when p = 1, L is a monoanionic ligand.
Preferred metals are titanium, zirconium and hafnium, particularly
titanium.
As noted above, the novel complexes of this invention must contain
either 2 or 3 cyclopentadienyl ligands. As such, they may be regarded as
metallocenes. The term "cyclopentadienyl" ligand as used herein is meant
to convey its broad but conventional meaning and to be inclusive of both
substituted and unsubstituted cyclopentadienyl, indenyl and fluorenyl
ligands. Examples of suitable substituents include alkyl groups; halide
substituents (i.e. substituents which contain Br, Cl, I or F atoms) or
heteroatom substituents (i.e. substituents which contain N, S, O or P
atoms). For reasons of low cost and ease of organometallic synthesis, the
use of unsubstituted cyclopentadienyl and unsubstituted indenyl ligands is
preferred.
The hydrocarbyl groups are preferably alkyl group having from 1 to
10 carbon atoms. Tertiary butyl groups are particularly preferred. The
hydrocarbyl groups may also contain substituents, especially halide
substituents (i.e. containing Br, Cl, I or F atoms) or heteroatom
substituents (i.e. substituents which contain N. S, O or P atoms).
BRIEF DESCRIPTION OF DRAWINGS
The following abbreviations have been used in this specification:
Cp = cyclopentadienyl
t-Bu = tertiary butyl
Me = methyl
Figure 1: Oakridge Thermal Ellipsoid Plot ("ORTEP") drawings of
(lndenyl)Ti(NP-t-Bu3)Me2 (5), 30% thermal ellipsoids are shown. Hydrogen
atoms have been omitted for clarity. Ti-N 1.782(2) A; Ti-C(10) 2.123(3) A;
Ti-C(9) 2.133(3) A; P-N 1.585(2) A; N-Ti-C(10) 103.78(10) °; N-Ti-C(9)
101.83(9) °; C(10)-Ti-C(9) 99.50(13) °; P-N-Ti 178.38(11) °.
Figure 2: ORTEP drawings of (lndenyl)2Ti(NP-t-Bu3)CI (8), 30% thermal
ellipsoids are shown. Hydrogen atoms have been omitted for clarity. Ti-N
1.775(2) A; Ti-C(22) 2.229(3) A; Ti-CI 2.2947(10) A; P-N 1.609(3) A; N-Ti-
C(22) 99.17(12) °; N-Ti-CI 104.63(9) °; C(22)-Ti-CI 97.10(10)°; P-N-Ti
167.4(2)°.
Figure 3: ORTEP drawings of Cp(lndenyl)Ti(NP-t-Bu)CI (9), 30% thermal
ellipsoids are shown. Hydrogen atoms have been omitted for clarity. Ti-N
1.773(4) A; Ti-C(18) 2.198(5) A; Ti-CI(1) 2.299(2) A; P-N 1.604(4) A; (1)-
Ti-C(18) 98.9(2) °; N-Ti-CI(1) 103.03(14) °; C(18)-Ti-CI(1) 99.8(2) °; P-N-Ti
169.1(2)°.
Figure 4: ORTEP drawing of the two independent molecules (a) and (b)
of Cp3Ti(NP-t-Bu3) (10) in the asymmetric unit. 30% thermal ellipsoids are
shown. Hydrogen atoms have been omitted for clarity. Ti(1)-N(1)
1.844(2) A; Ti(1)-C(11) 2.378(2) A; Ti(2)-N(2) 1.850(2) A; Ti(2)-C(38)
2.355(2) A; P(1)-N(1) 1.590(2) A; P(2)-N(2) 1.590(2) A; N(1)-Ti(1)-C(11)
92.71(7)°; N(2)-Ti(2)-C(38) 92.79(7)°; P(1)-N(1)-Ti(1) 175.56(9)°; P(2)-
N(2)-Ti(2) 175.43(9)°.
Figure 5: ORTEP drawing of the two independent molecules (a) and (b)
of (lndenyl)3Ti(NP-t-Bu3) (11) in the asymmetric unit. 30% thermal
ellipsoids are shown. Hydrogen atoms have been omitted for clarity.
Ti(1)-N(1) 1.786(5) A; Ti(1)-C(22) 2.212(7) A; Ti(1)-C(31) 2.217(7) A; Ti(2)-
N(2) 1.774(5) A; Ti(2)-C(69) 2.205(7) A; Ti(2)-C(60) 2.221(8) A; P(1)-N(1)
1.613(5) A; P(2)-N(2) 1.627(5) A; N(1)-Ti(1)-C(22) 100.1(2)°; N(1)-Ti(1)-
C(31) 108.1(3) °; C(22)-Ti(1)-C(31) 98.0(3) °; N(2)-Ti(2)-C(69) 99.3(3) °;
N(2)-Ti(2)-C(60) 108.1(3)°; C(69)-Ti(2)-C(60) 98.2(3)°; P(1)-N(1)-Ti(1)
171.6(4) °; P(2)-N(2)-Ti(2) 175.2(4) °.
Figure 6: ORTEP drawing of the two independent molecules (a) and (b)
of Cp(lndenyO2Ti(NP-t-Bu3) (12) in the asymmetric unit. 30% thermal
ellipsoids are shown. Hydrogen atoms have been omitted for clarity.
Ti(1)-N(1) 1.77(2) A; Ti(1)-C(27) 2.26(2) A; Ti(1)-C(18) 2.27(2) A; Ti(2)-
N(2) 1.80(2) A; Ti(2)-C(62) 2.18(2) A; Ti(2)-C(53) 2.19(2) A; P(1)-N(1)
1.61(2) A; P(2)-N(2) 1.62(2) A; N(1)-Ti(1)-C(27) 100.9(7) °; N(1)-Ti(1)-
C(18) 108.3(8) °; C(27)-Ti(1)-C(18) 95.1(8) °; N(2)-Ti(2)-C(62) 100.4(8) °;
N(2)-Ti(2)-C(53) 107.8(9)°; C(62)-Ti(2)-C(53) 99.2(9)°; P(1)-N(1)-Ti(1)
174.5(11) °; P(2)-N(2)-Ti(2) 172.3(12) °.
BEST MODE FOR CARRYING OUT THE INVENTION
We have discovered a new series of group 4 metal complexes with
a phosphinimine ligand and two or more cyclopentadienyl ligands. These
compounds have been examined and characterized by various analytical
techniques including x-ray crystallography.
Synthetic routes to the species described herein are described in
detail in the Experimental section. We have previously described the
facile synthesis of CpTi(NP-t-Bu3)Cl2 1. In a similar manner, the reaction
of Me3SiNP-t-Bu3 2 and (lndenyl)TiCI3 3 affords the species
(lndenyl)Ti(NP-t-Bu3)CI2 4 in approximately 95% isolated yield. This
species is readily converted to (lndenyl)Ti(NP-t-Bu3)Me2 5 in 86% yield via
reaction with methyl Grignard. This light yellow crystalline product exhibits
methyl resonances in 1H NMR spectrum at 0.16 ppm. Compound 5 was
also characterized by x-ray crystallography (Figure 1). These data reveal
Ti-methyl carbon distances average 2.128(4) A with a C-Ti-C angle of
99.50(13) °. The phosphinimide ligand geometry is typical of that seen in
CpTi-phosphinimide complexes. The Ti-N and P-N distances in 5 are
1.782(2) A and 1.585(2) A respectively with a P-N-Ti angle approaching
linearity (178.38(11)°).
Reaction of 1 with one equivalent of the dimethyl ether complex of
sodium cyclopentadiene {"(dme)NaCp"] affords the dark red product
Cp2Ti(NP-t-Bu3)CI 7 in 93% isolated yield. The 1H NMR spectrum of 7
shows a single resonance at 6.21 ppm attributable to the cyclopentadienyl
protons. The spectral features are temperature invariant, thus inferring
that both cyclopentadienyl rings are bound to the metal in a n5 bonding
mode. In a similar synthetic procedure, reaction of 6 with Li(lndenyl)
yields the complex (lndenyl)2Ti(NP-t-Bu3)CI 8 in 86% isolated yield. The
1H NMR data infer the presence of both an ?5 and an ?1 bound indenyl
ligand as the overlapping resonances accounting for 14 protons give rise
to six signals. These NMR features of 8 are invariant with temperature
even on heating solutions of 8 to 80°C. Crystallographic study of 8 (Figure
2) confirmed the interpretation of the NMR data and the presence of ?5
and ?1 bound indenyl ligands. The Ti-N and Ti-CI distances in 8 are
1.775(2) A and 2.2947(10) A respectively. The TJ-C distance for the ?1-
indenyl ligand is 2.229(3) A. This distance is slightly longer than the cr-Ti-
C found in 5, consistent with the greater steric demands of the indenyl
ligands.
We have also discoveredjithat the mixed cyclopentadienyl-indenyl
species, Cp(lndenyl)Ti(NP-t-Bu3)CI 9 can also be prepared via two
alternative pathways. Either reaction of 4 with one equivalent of
(dme)NaCp or reaction of 1 with Li(lndenyl) afford dark red crystalline of 9.
Regardless of the synthetic route, 1H and 13C{1H} NMR data indicate that
the product 9 contains an ?5-cyclopentadienyl group and an V-indenyl
fragment. This was also affirmed by the results of an x-ray
crystallographic study (Figure 3). While most of the metric parameters
within 9 are similar to those seen in 8, it is noteworthy that the lesser steric
congestion in 9 results in a shorter Ti-C bond of 2.198(5) A. The synthesis
of 9 from 1 involves a facile nucleophilic substitution. In contrast, the path
to 9 from 4 likely requires an interesting ?5-?1 -indenyl ring-slippage.
Complex 1 reacts with two equivalents of (dme)NaCp to give the
dark red crystalline product 10 formulated as Cp3Ti(NP-t-Bu3) in 89%
yield. 1H and 13C{1H} NMR spectra show single resonances at 6.03 and
114.57 ppm respectively attributable to the cyclopentadienyl ligands.
Cooling to —80°C reveals no change in these resonances suggesting a
rapid process of site exchange. It should be noted that the three
cyclopentadienyl ligands may be ?5 bonded although this proposition is
unlikely for both steric and electronic reasons. Moreover, an x-ray
crystallographic analysis of 10 (Figure 4) reveals that the molecule
contains two ?5- and one ?1-cyclopentadienyl groups in the solid state.
Whilst not wishing to be bound by theory, this geometry likely results in a
relatively electron rich metal center in 10 compared to 5, 8 and 9. The
significant lengthening of the Ti-N to 1.844(2) A and the Ti-C s-bonds to
2.366(4) A support this view.
The analogous species (lndenyl)3Ti(NP-t-Bu3) 11 is obtained from
the reaction of 4 with excess Li(lndenyl). This results in the dark red
crystalline product 11 in 95% yield. The 1H NMR data show four
resonances at 25°C, which sharpen on heating, again inferring an ?5-?1-
site exchange process. On cooling to —80°C eighteen resonances are
observed, inferring the presence of inequivalent ?5- and ?1-indenyl rings.
The precise assessment of the exchange barrier is a complicated issue as
the exchange process appears to involve three sites for each of seven
protons. Consequently, the coalescence of resonances can not be
unambiguously observed, although it appears that coalescence of the
resonances in the 1H NMR spectra of 11 occurs at approximately—25°C.
This infers an approximate barrier to ?5- and ?1-indenyl site exchange of
8-9 Kcal/mol.
An x-ray crystallographic study of 11 confirmed that this species in
the solid state contains a single ?5- and two V-indenyl ligands (Figure 5).
The Ti-Navg (1.780(6) A) in 11 are similar to those seen in 5, 8 and 9, while
the Ti-C are slightly longer (Ti-CaVg 2.215(7) A) although not as long as
those seen in the more electron rich species 10. Whilst not wishing to be
bound by theory, it is, presumably, the greater steric demands of the
indenyl ligands that preclude the binding of two of such ligands in rj5-
manner. However, it is not possible to exclude the possibility that the
phosphinimine ligand is in this compound a better 6-electron donor ligand
than indenyl.
The mixed cyclopentadienyl-indenyl species Cp(lndenyl)2Ti(NP-t-
Bu3) 12 is also accessible from the reaction of 1 and excess Li(lndenyl).
The 1H NMR data show four resonances inferring the presence of an ?5-
cyclopentadienyl and two ?1-indenyl ligands. This interpretation was
confirmed crystallographically (Figure 6). The metric parameters are
unexceptional as they mimic those observed for 5, 8, 9 and 11. In
contrast to 11, compound 12 appears to be a rigid molecule in which there
is no interchange of ?5-cyclopentadienyl and the two V-indenyl ligands.
Whilst not wishing to be bound by theory, it may be postulated that
steric crowding is a factor determining the binding modes of the
cyclopentadienyl and/or indenyl ligands in the series of compounds
described herein. The steric demands of the larger indenyl ligand and its
extended p-system likely facilitate ring slippage and thus favor V-binding.
While the geometries of the phosphinimide ligands are relatively constant,
with only minor changes in the P-N bond distance and Ti-N-P bond angle,
there is a clear effect of the electronic environment at the metal center on
the Ti-N bond distance. In the formally 18 electron species 10, the Ti-N
bond was observed to about 1.844(2) A. In contrast, in 5, 8, 9, 11 and 12
the electron count is formally 16 and the Ti-N is strengthened and
shortens to an observed length of about 1.77 A.
Group 4 metal complexes with only two cyclopentadienyl rings or
two indenyl rings classically have both rings T|5-bonded to the metal
center. We are not aware of any well characterized examples of such
species where the ring system is Tj1-bonded to the metal. The closest
exception to this observation is in the CP3MX and Cp4M complexes with
more than two cyclopentadienes. In these systems two of the
cyclopentadienes are ?5-bonded while the remaining cyclopentadienes are
V-bonded. These systems have been termed "whiz" compounds as the
sigma bound and p bound cyclopentadienes generally rapidly interchange.
The phosphinimine compounds described herein have at least two
cyclopentadienyl ligands which may be substituted cyclopentadienyl
ligands and a phosphinimine ligands. The compounds described are
unique in structure. The x-ray crystallographic data and NMR
spectroscopy data demonstrate that the cyclopentadienyl ligands or
indenyl ligands can be ? or ?5 bonded to the metal depending on the
number and type of cyclopentadienyl ligands or indenyl ligands present.
The NMR spectroscopy data also shows that, for some of the novel
compounds, ring whizzing can occur in solution. This ?1 - ?5 site
exchange can be slowed by lowering the temperature. Of course, the ?1
?5 site exchange is not observed when the complexes are frozen into
crystals for x-ray analysts.
PART A: EXPERIMENTAL
All preparations were done under an atmosphere of dry, O2-free N2
employing both Schlenk line techniques and an inert atmosphere glove
box. Solvents were purified employing a Grubb"s type column system. All
organic reagents were purified by conventional methods. 1H and 13C{1H}
NMR spectra were recorded on one of two spectrometers (Bruker Avance-
300 and 500 operating at 300 and 500 MHz, respectively). Trace amounts
of protonated solvents were used as references and chemical shifts are
reported relative to SiMe4. 31P NMR spectra were recorded on a Bruker
Avance-300 and are referenced to 85% H3PO4. The precursor complexes
CpTi(NP-t-Bu3)CI2 1, Me3SiNP-t-Bu3 2 and (lndenyl)TiCI3 3 were prepared
via conventional (previously reported) methods.
Synthesis of nndenvnTi(NP-t-Bu3)CI2 (4)
Compound 2 (0.250 g; 0.864 mmol) was added to a toluene
solution (50 mL) of 3 (0.230 g; 0.854 mmol). The solution was heated to
110°C for 12 hours. The volatile products were removed in vacuo to yield
a bright yellow solid. The solid was washed with hexane (3 x 25 mL),
filtered and dried under vacuum (0.365 g; 0.810 mmol; 95%). 1H NMR 5
7.80 (m, 2H, Indenyl), 7.19 (m, 2H, Indenyl), 6.85 (t. 1H, Indenyl). 6.60 (d,
2H, Indenyl), 1.15 (d, J3PH = 13.7 Hz; 27H; t-Bu). 13C{1H} NMR 8 129.07,
125.64, 125.29, 115.98, 105.21, 42.00 (d, J1pc = 44.5 Hz, PCMe3), 29.41.
31P{1H} NMR 8 46.12.
Synthesis of flndenvl)Ti(NP-t-Bu3)Me2 (5)
To a diethylether solution (25 mL) of complex 4 (0.250 g; 0.555
mmol) was added an excess of MeMgBr (0.42 mL; 3.0 M; 1.25 mmol) at
room temperature. The solution was stirred for 12 hours. The solvent
was removed in vacuo and the solid extracted with hexane (3 x 25 mL).
The volume of the solvent was reduced to 10 mL and the solution was left
to crystallize overnight. Light yellow crystalline 5 was isolated by filtration
and dried under vacuum (0.195 g; 0.476 mmol; 86%). 1H NMR 8 7.67 (m,
2H, Indenyl), 7.20 (m, 2H, Indenyl), 6.85 (d, 2H, Indenyl), 6.01 (t, 1H,
Indenyl), 1.20 (d, J3ph = 13.0 Hz, 27H, PtBua3), 0.16 (s, 6H, TiMe2). 13C{1H}
NMR 8 126.54, 125.02, 123.48, 112.71, 100.62, 42.86 (TiMe22), 41.30 (d,
J1pc = 46.1 Hz, PCMe3). 29.57. 31P{1H} NMR 8 31.93. This light yellow
crystalline product exhibits methyl resonances in 1H NMR spectrum at
0.16 ppm. Compound 5 was also characterized by x-ray crystallography
(Figure 1). These data reveal Ti-methyl carbon distances average
2.128(4) A with a C-Ti-C angle of 99.50(13) °. The phosphinimide ligand
geometry is similar to that seen in simple CpTi-phosphinimide complexes.
The Ti-N and P-N distances in 5 are 1.782(2) A and 1.585(2) A
respectively with a P-N-Ti angle approaching linearity (178.38(11)°).
Synthesis of (t-Bu2PN)TiCI3 (6)
To a solution of TiCU (0.327 g; 1.73 mmol) in xylenes (3.5 mL) was
added a solution of 2 (0.500 g; 1.73 mmol) in xylenes (3.5 mL). The
reaction was then heated to 135°C in an oil bath. After 17 hours the
solution was cooled and a filtration of the solution yielded (0.575 g; 1.55
mmol; 90%) of 6 as a yellow powder. 1H NMR 5 1.08 (d, J3 ph = 14.2 Hz;
27H; t-Bu).
Synthesis of Cp?Ti7NP-t-Bu3)Cl (7)
To a THF solution (10 mL) of complex 1 (0.250 g; 0.625 mmol) was
added one equivalent of NaCpDME (0.100 g; 0.625 mmol) at 20°C. The
yellow solution turned dark red within minutes. The solution was stirred for
12 hours and the solvent was removed under vacuum to yield a dark red
solid. The solid was extracted with hot benzene (3 x 25 mL). The volume
of the filtrate was reduced to 10 mL and the solution left to crystallize for
12 hours. Dark red crystalline 7 was isolated by filtration and dried under
vacuum (0.251 g; 0.584 mmol; 93%). 1H NMR 5 6.21 (s, 10H, Cp), 1.17
(d, J3ph = 13.1 Hz, 27H, PtBu3). 13C{1H} NMR 5 115.06, 41.80 (d, J1Pc =
45.9 Hz, PCMe3), 29.99. 31P{1H} NMR 8 39.45. The 1H NMR spectrum of
7 shows a single resonance at 6.21 ppm attributable to the
cyclopentadienyi protons. The spectral features are temperature invariant.
Whilst not wishing to be bound by theory, this suggests that both
cyclopentadienyi rings are bound to the metal in a ?5 bonding mode.
Synthesis of (Indenyl)2TUNP-t-Bu3)CI (8)
The synthesis of complex 8 is similar to that of 7. Complex 4
(0.300 g; 0.666 mmol) and Li(lndenyl) (0.081 g; 0.663 mmol) afford dark
red crystalline 8 (0.302 g; 0.570 mmol; 86%). Alternatively, complex 8 can
be synthesized from 6 and two equivalents of Li(lndenyl) 1H NMR 5 7.53
(m, 2H, Indenyl), 7.32 (m, 2H, Indenyl), 7.24 (m, 4H, Indenyl), 6.45 (broad
m, 2H, Indenyl), 6.45 (m, 2H, Indenyl), 6.14 (broad, 2H, Indenyl), 1.18 (d,
J3ph = 11.9 Hz, 27H, t-Bu). 13C{1H} NMR 8 124.68, 124.58, 123.53,
123.38, 115.55, 96.37, 41.50 (d, J1Pc = 44.1 Hz, PCMe3), 29.53. 31P{1H)
NMR 5 44.08. The 1H NMR data infer the presence of both an ?5 and an
tj1 bound indenyl ligand as the overlapping resonances accounting for 14
protons give rise to six signals. These NMR features of 8 are invariant
with temperature even on heating solutions of 8 to 80°C. Crystallographic
study of 8 (Figure 2) confirmed the interpretation of the NMR data and the
presence of -?5 and ?1 bound indenyl ligands. The Ti-N and Ti-CI
distances in 8 are 1.775(2) A and 2.2947(10) A respectively. The Ti-C
distance for the V-indenyl ligand is 2.229(3) A. This distance is slightly
longer than the s-Ti-C found in 5, consistent with the greater steric
demands of the indenyl ligands.
Synthesis of Cpnndenvl)Ti(NP-t-Bu3)CI (9)
The synthesis of complex 9 is similar to that of 7. Complex 4
(0.500 g; 1-11 mmol) and NaCpDME (0.160 g; 1.09 mmol) afford dark red
crystalline 9 (0.465 g; 0.973 mmol; 88%). Alternatively, complex 9 can be
synthesized from 1 and one equivalent of Li(lndenyl). 1H NMR 5 8.04 (d,
1H, Indenyl), 7.72 (d, 1H, Indenyl), 7.32 (m, 2H, Indenyl), 6.85 (m, 2H,
Indenyl), 6.24 (d, 1H Indenyl), 5.68 (s, 5H, Cp), 1.16 (d, J3PH = 13.4 Hz,
27H, P"Bua). 13C{1H} NMR 8 147.73, 142.44. 133.19, 124.65. 122.28,
122.13, 120.97, 115.35, 113.69. 93.77, 41.55 (d, J1PC = 44.1 Hz, PCMe3),
29.52. 31P{1H} NMR 5 44.44. Regardless of the synthetic route, 1H and
13C{1H} NMR data confirm that the product 9 contains an ?5-
cyclopentadienyl group and an V-indenyl fragment. This view was also
affirmed by the results of an x-ray crystallographic study (Figure 3). While
most of the metric parameters within 9 are similar to those seen in 8, it is
noteworthy that the lesser steric congestion in 8 results in a shorter Ti-C
bond of 2.198(5) A. The synthesis of 9 from 1 involves a facile
nucleophilic substitution. In contrast, the path to 8 from 4 requires an ?5-
?1-indenyl ring slippage.
Synthesis of Cp3Ti(NP-t-Bu3) (10)
The synthesis of complex 10 is similar to that of 7. Complex 1
(0.500 g; 1.25 mmol) and excess NaCp DME (0.401 g; 2.75 mmol) afford
dark red crystalline 10 (0.510 g; 1.11 mmol; 89%). 1H NMR 5 6.03 (s,
15H. Cp), 1.13 (d, J3pH = 13.1 Hz, 27H, P"Bu3). 13C{1H} NMR 5 114.57,
42.00 (d, J1pc = 46.6 Hz. PCMe3), 30.50. 31P{1H) NMR 5 37.48. 1H and
13C{1H} NMR spectra show single resonances at 6.03 and 114.57 ppm,
respectively, which are attributable to the cyclopentadienyl ligands.
Cooling to —80°C, reveals no change in these resonances, suggesting a
rapid process of site exchange. It should be noted that the presence of
three ?5-cyclopentadienyl ligands can not specifically be excluded
although this proposition is unlikely for both steric and electronic reasons.
An x-ray crystallographic analysis of 10 (Figure 4) reveals that the
molecule contains two ?5- and one V-cyclopentadienyl groups in the solid
state.
Synthesis of (Indenvl)3Ti(NP-t-Bu3) (11)
The synthesis of complex 11 is similar to that of 7. Complex 4
(0.500 g; 1.11 mmol) and excess Li(lndenyl) (0.300 g; 2.46 mmol) afford
dark red crystalline 11 (0.640 g; 1.05 mmol; 95%). Alternatively, complex
11 can be synthesized from 6 and three equivalents of Li(lndenyl). 1H
NMR 57.45 (broad m, 6H, Indenyl), 7.18 (m, 6H, Indenyl), 6.29 (t, 3H,
Indenyl), 5.53 (broad, 6H, Indenyl), 0.95 (d, J3™ = 13.5 Hz, 27H; PfBu3).
13C{1H} NMR 5 123.24, 41.35 (d, J1pc = 44.0 Hz, PCMe3), 15.53. 31P{1H}
NMR 5 44.08. The 1H NMR data show four resonances at 25°C, which
sharpen on heating, again inferring the type of ?5-?1-site exchange
process discussed above. On cooling to —80°C eighteen resonances are
observed, inferring the presence of inequivalent ?5- and ?1-indenyl rings.
The precise assessment of the exchange barrier is a complicated issue as
the exchange process appears to involve three sites for each of seven
protons. Consequently, the coalescence of resonances can not be
unambiguously observed, although it appears that coalescence of the
resonances in the 1H NMR spectra of 11 occurs at approximately —25°C.
This infers an approximate barrier to ?5- and ?1- indenyl site exchange of
8-9 Kcal/mol. An x-ray crystallographic study of 11 confirmed that this
species in the solid state contains a single ?5- and two V-indenyl ligands.
The average Ti-N (1.780(6) A) in 11 are similar to those seen in 5, 8 and
9, while the average Ti-C are slightly longer (Ti-CaVg 2.215(7) A) although
not as long as those seen in 10. Whilst not wishing to be bound by theory,
space roups in each case. The data sets were collected (4.5° it is presumably the greater steric demands of the indenyl ligands that
preclude the binding of two of such ligands in ?5-manner.
Synthesis of Cpgndenvl)2Ti(NP-t-Bu3) (121
Complex 1 (0.500 g, 1.25 mmol) and Li(lndenyl) (0.366 g, 3.00
mmol) were combined as solids and toluene (25 mL) was added. The
reaction was allowed to stir for 72 hours and then was filtered and
concentrated in vacuo. Heptane was then added slowly and the product
crystallized as a dark red solid (0.407 g; 0.728 mmol; 58%). 1H NMR 5
7.78 (m, 4H; Indenyl), 7.22 (m, 4H; Indenyl), 6.67 (m, 2H; Indenyl), 6.24
(m, 4H; Indenyl), 5.53 (s, 5H; Cp), 0.92 (d, J3ph =13.3 Hz; 27H; P"Bu3).
The 1H NMR data show four resonances inferring the presence of an ?s-
cyclopentadienyt and two v1-indenyl ligands. This interpretation was
confirmed crystallographically for the solid state. The metric parameters
are unexceptional as they mimic those observed for 5, 8, 9 and 11. In
contrast to 11, compound 12 appears to be a rigid molecule in which there
is no interchange of ?5-cyclopentadienyl and the two ?1-indenyl ligands.
X-Rav Data Collection and Reduction
X-ray quality crystals of 5, 8-12 were obtained directly from the
preparation as described above. The crystals were manipulated and •
mounted in capillaries in a glove box, thus maintaining a dry, O2-free
environment for each crystal. Diffraction experiments were performed on
a diffractometer (Siemens SMART System CCD) collecting a hemisphere
of data in 1329 frames with 10 second exposure times. Crystal data are
summarized in Table 1. The observed extinctions were consistent with the
space groups in each case. The data sets were collected (4.5° 50.0°). A measure of decay was obtained by re-collecting the first 50
frames of each data set. The intensities of reflections within these frames
showed essentially no statistically significant change over the duration of
the data collections. The data were processed using a conventional data
processing package in particular, using software known as SAINT and
XPREP. An empirical absorption correction based on redundant data was
applied to each data set. Additional solution and refinement was
performed using conventional techniques (i.e. TEXSAN software solution
package operating on a mainframe computer ("SGI Challenge"
computers) with remote X-terminals or a personal computer employing X-
emulation). The reflections with Fo2>3sFo2 were used in the refinements.
Structure Solution and Refinement
Non-hydrogen atomic scattering factors were taken from the
literature tabulations. The heavy atom positions were determined using
direct methods (with software known as SHELX-TL). The remaining non-
hydrogen atoms were located from successive difference Fourier map
calculations. The refinements were carried out by using full-matrix least
squares techniques on F, minimizing the function ?(IFol-IFcl)2 where the
weight ? is defined as 4F02/2s(F02) and F o and Fc are the observed and
calculated structure factor amplitudes. In the final cycles of each
refinement, all non-hydrogen atoms were assigned anisotropic
temperature factors. Carbon bound hydrogen atom positions were
calculated and allowed to ride on the carbon to which they are bonded
assuming a C-H bond length of 0.95 A. Hydrogen atom temperature
factors were fixed at 1.10 times the isotropic temperature factor of the
carbon atom to which they are bonded. The hydrogen atom contributions
were calculated, but not refined. The locations of the largest peaks in the
final difference Fourier map calculation as well as the magnitude of the
residual electron densities in each case were of no chemical significance.
X-ray crystallography data which further characterize the above
described complexes are provided in the accompanying tables.
PART B: GAS PHASE POLYMERIZATION
Catalyst Preparation and Polymerization Testing Using a Semi-Batch,
Gas Phase Reactor
Standard Schlenk and drybox techniques were used in the
preparation of supported catalyst systems using the organometallic
complexes from Part A. Solvents were purchased as anhydrous materials
and further treated to remove oxygen and polar impurities by contact with
a combination of activated alumina, molecular sieves and copper oxide on
silica/alumina. Where appropriate, elemental compositions of the
supported catalysts were measured by Neutron Activation analysis and a
reported accuracy of + 1% (weight basis).
The supported catalysts were prepared by initially supporting a
commercially available MAO on a silica support (12 weight % aluminum,
based on the weight of the silica support), followed by deposition of the
organometallic complex. The aiming point for the Al/Ti mole ratio was
120/1.
All the polymerization experiments described below were
conducted using a semi-batch, gas phase polymerization reactor of total
internal volume of 2.2 L. Reaction gas mixtures (ethylene/butene
mixtures) were measured to the reactor on a continuous basis using a
calibrated thermal mass flow meter, following passage through purification
media as described above. Reaction pressure was set at 200°C. A pre-
determined mass of the catalyst sample (Table B1) was added to the
reactor under the flow of the inlet gas with no pre-contact of the catalyst
with any reagent, such as a catalyst activator. The catalyst was activated
in-situ (in the polymerization reactor) at the reaction temperature in the
presence of the monomers, using a metal alkyl complex which has been
previously added to the reactor to remove adventitious impurities. Purified
and rigorously anhydrous sodium chloride (160 g) was used as a catalyst
dispersing agent.
The internal reactor temperature was set at 90°C and monitored by
a thermocouple in the polymerization medium and controlled to +/- 1.0°C.
The duration of the polymerization experiment was one hour. Following
the completion of the polymerization experiment, the polymer was
separated from the sodium chloride and the yield determined.
Table B1 illustrates data concerning the Al/transition metal ratios of
the supported catalyst and polymer yield. Table B2 provides data which
describe polymer properties.
Experiments 1 -3 are inventive. Experiment 4, using titanocene
dichloride (Cp2TiCla) is comparative. Titanocene dichloride is substantially
less active than the inventive complexes. This is an unusual and
surprising result. Whilst not wishing to be bound by theory, the
experimental results suggests that the MAO (which is a Lewis acid) does
not preferentially/completely abstract the phosphinimide ligand of the
inventive complexes. Instead, the results strongly suggest that the MAO
preferentially abstracts a Cp-type ligand from the inventive complexes.
The resulting catalysts according to this invention are substantially more
active than the comparative titanocene as shown in Table B1.
PART C: THE CONTINUOUS SOLUTION POLYMERIZATION
All the polymerization experiments described below were
conducted on a continuous solution polymerization reactor. The process
is continuous in all feed streams (solvent, monomers and catalyst) and in
the removal of product. All feed streams were purified prior to the reactor
by contact with various absorption media to remove catalyst killing
impurities such as water, oxygen and polar materials as is known to those
skilled in the art. All components were stored and manipulated under an
atmosphere of purified nitrogen.
All the examples below were conducted in a reactor of 71.5 cc
internal volume. In each experiment the volumetric feed to the reactor
was kept constant and as a consequence so was the reactor residence
time.
The catalyst solutions were pumped to the reactor independently
and in some cases were mixed before entering the polymerization reactor
(as indicated in the examples). Because of the low solubility of the
catalysts, activators and MAO in cyclohexane, solutions were prepared in
purified xylene. The catalyst was activated in-situ (in the polymerization
reactor) at the reaction temperature in the presence of the monomers.
The polymerizations were carried out in cyclohexane at a pressure of 1500
psi. Ethylene was supplied to the reactor by a calibrated thermal mass
flow meter and was dissolved in the reaction solvent prior to the
polymerization reactor. If comonomer (for example 1 -octene) was used it
was also premixed with the ethylene before entering the polymerization
reactor. Under these conditions the ethylene conversion is a dependent
variable controlled by the catalyst concentration, reaction temperature and
catalyst activity, etc.
The internal reactor temperature is monitored by a thermocouple in
the polymerization medium and can be controlled at the required set point
to +/- 0.5°C. Down stream of the reactor the pressure was reduced from
the reaction pressure (1500 psi) to atmospheric. The solid polymer was
then recovered as a slurry in the condensed solvent and was dried by
evaporation before analysis.
The ethylene conversion was determined by a dedicated on line
gas chromatograph by reference to propane which was used as an
internal standard. The average polymerization rate constant was
calculated based on the reactor hold-up time, the catalyst concentration in
the reactor and the ethylene conversion and is expressed in l/(mmol*min).
Average polymerization rate (kp) = (Q/(100-Q)) x (1/[TM]) x (1/HUT)
where: Q is the percent ethylene conversion;
[TM] is the catalyst concentration in the reactor expressed in
mM; and
HUT is the reactor hold-up time in minutes.
Polymer Analysis
Melt index (Ml) measurements were conducted according to ASTM
method D-1238-82.
Polymer densities were measured on pressed plaques (ASTM D-
1928-90) with a densitometer.
Polymerization and polymer data for the following examples are
shown in Table C1.
Example 1
CpTiNP(lBu)3lnd2 was added to the reactor at 2.3 x 10"6 mol/l along
with Ph3C B(C6F5)4 (Asahi Glass) at B/Ti = 1.00 (mol/mol). The two
components were mixed in the polymerization reactor. The reaction
temperature was 160°C and 2.1 gram/min of ethyfene was continuously
added to the reactor. An ethylene conversion of 98.7% was observed.
Example 2
CpTiNP("Bu)3lnd2 was added to the reactor at 9.3 x 10"6 mol/l along
with B(C6F5)3 (Boulder Scientific) at B/Ti = 2.00 (mol/mol). The two
components were mixed before the polymerization reactor. The reaction
temperature was 160°C and 2.1 gram/min of ethylene was continuously
added to the reactor. An ethylene conversion of 43.0% was observed.
Example 3
CpTiNP(tBu)3lnd2 was added to the reactor at 9.3 x 10-6 mol/l along
with B(C6F5)3 (Boulder Scientific) at B/Ti = 1.00 (mol/moi). The two
components were mixed before the polymerization reactor. The reaction
temperature was 160°C and 2.1 gram/min of ethylene was continuously
added to the reactor. An ethylene conversion of 45.6% was observed.
Example 4
CpTiNP(tBu)3lnd2 was added to the reactor at 2.3 x 10-6 mol/l along
with Ph3C B(C6F5)4 (Asahi Glass) at B/Ti = 1.00 (mol/mo!) and MMAO-7
(Akzo-Nobel) Al/Ti = 100. The three components were mixed in the
polymerization reactor. The reaction temperature was 160°C and 2.1
gram/min of ethylene was continuously added to the reactor. An ethylene
conversion of 89.4% was observed.
Example 5
CpTiNP(tBu)3lnd2 was added to the reactor at 9.3 x 10-6 mol/l along
with B(C6F5)3 (Boulder Scientific) at B/Tl = 2.00 (mol/mol). The two
components were mixed in the polymerization reactor. The reaction
temperature was 160°C and 2.1 gram/min of ethylene was continuously
added to the reactor. An ethylene conversion of 83.3% was observed.
Example 6
CpTiNP(tBu)3lnd2 was added to the reactor at 2.3 x 10"6 mol/l along
with MMAO-7 (Akzo-Nobel) at Al/Ti = 80.0 (mol/mol). The two
components were mixed in the polymerization reactor. The reaction
temperature was 160°C and 2.1 gram/min of ethylene was continuously
added to the reactor. An ethylene conversion of 87.1% was observed.
Example 7
CpTiNP(lBu)3lndCI was added to the reactor at 2.3 x 10-6 mol/l
along with MMAO-7 (Akzo-Nobel) at Al/Ti = 80.0 (mol/mol). The two
components were mixed in the polymerization reactor. The reaction
temperature was 160°C and 2.1 gram/min of ethylene was continuously
added to the reactor. An ethylene conversion of 85.7% was observed.
Example 8
CpTiNP(tBu)3lndCI was added to the reactor at 2.3 x 10-6 mol/l
along with B(C6F5)3 (Boulder Scientific) at B/Ti = 2.00 (mol/mol). The two
components were mixed in the polymerization reactor. The reaction
temperature was 160°C and 2.1 gram/min of ethylene was continuously
added to the reactor. No ethylene conversion was observed.
Example 9
CpTiNP(tBu)3lndCI was added to the reactor at 2.3 x 10-6 mol/l
along with B(C6Fs)3 (Boulder Scientific) at B/Ti = 2.00 (mol/mol) and
MMAO-7 (Akzo-Nobel) at Al/Ti = 20.0 mol/mol. The three components
were mixed in the polymerization reactor. The reaction temperature was
160°C and 2.1 gram/min of ethylene was continuously added to the
reactor. An ethylene conversion of 85.2% was observed.
Comparative Example 10C
(CsMe5)2ZrCl2 (Strem) was added to the reactor at 37 x 10-6 mol/l
along with MMAO-3 (Akzo-Nobel, Al/Ti = 400 motfmol). The reaction
temperature was 140°C and 1.0 gram/min of ethylene was continuously
added to the reactor. An ethylene conversion of 55.5% was observed.
Comparative Example 11C
Cp2TiCI2 was used with MAO activator. This titanocene dichloride
is not very active under solution polymerization conditions similar to those
described in the inventive examples, although a small amount of low
molecular weight polymer was recovered.
INDUSTRIAL APPLICABILITY
The inventive complexes are well suited for use as a component in
a cataiyst system for the polymerization of olefins, especially ethyiene.
Polyethylene produced with the inventive complexes is useful, for
example, in the production of film, extruded parts and profiles and molded
plastic goods.
We Claim:
1. An organometallic complex defined by the formula:

wherein M is a group 4 metal in oxidation state 4;
each Cp is selected from the group consisting of unsubstituted
cyclopentadienyl, substituted cyclopentadienyl, unsubstituted
indenyl, substituted indenyl, unsubstituted fluorenyl and
substituted fluorenyl;
each of R1, R2 and R3 is a hydrocarbyl group which is bonded to
phosphorus by a carbon-phosphorus single bond;
n is 2 or 3 and n + p = 3; and
when p = 1, L is a monoanionic ligand, which is not —N=PR1R2R3;
and where at least one of said Cp is either unsubstituted or
substituted indenyl.
2. The organometallic complex as claimed in claim 1 wherein M is
Ti.
3. The organometallic complex as claimed in claim 1 wherein n is 3
and each Cp is selected from unsubstituted cyclopentadienyl and
unsubstituted indenyl.
4. The organometallic complex as claimed in claim 1 wherein each R
is an alkyl group.
5. The organometallic complex as claimed in claim 4 wherein each R
is tertiary butyl.
6. An olefin polymerization process wherein at least one alpha olefin
having from 2 to 10 carbon atoms is polymerized in the presence
of a catalyst system comprising:
a) an organometallic complex as defined in claim 1; and
b) an activator.
7. The process as claimed in claim 6 wherein:
(i) said organometallic complex and said activator are
supported or a particular support; and
(ii) said polymerization process is a gas phase
copolymerization of ethylene and at least one alpha
olefin selected from butene, pentene and hexane,
wherein said gas phase copolymerization is undertaken at a
pressure of from 1 to 20 atmosphere and a temperature of from
60 to 130°C.
8. The process as claimed in claim 6 wherein said olefin
polymerization is conducted in the presence of a hydrocarbon
diluent or hydrocarbon solvent.
An organometallic complex defined by the formula:
wherein M is a group 4 metal in oxidation state 4;
each Cp is selected from the group consisting of unsubstituted
cyclopentadienyl, substituted cyclopentadienyl, unsubstituted indenyl,
substituted indenyl, unsubstituted fluorenyl and substituted fluorenyl;
each of R1, R2 and R3 is a hydrocarbyl group which is bonded to phosphorus
by a carbon-phosphorus single bond;
n is 2 or 3 and n + p = 3; and
when p = 1, L is a monoanionic ligand, which is not —N=PR1R2R3; and
where at least one of said Cp is either unsybstituted or substituted indenyl.

Documents:

in-pct-2002-348-kol-granted-abstract.pdf

in-pct-2002-348-kol-granted-claims.pdf

in-pct-2002-348-kol-granted-correspondence.pdf

in-pct-2002-348-kol-granted-description (complete).pdf

in-pct-2002-348-kol-granted-drawings.pdf

in-pct-2002-348-kol-granted-examination report.pdf

in-pct-2002-348-kol-granted-form 1.pdf

in-pct-2002-348-kol-granted-form 18.pdf

in-pct-2002-348-kol-granted-form 2.pdf

in-pct-2002-348-kol-granted-form 26.pdf

in-pct-2002-348-kol-granted-form 3.pdf

in-pct-2002-348-kol-granted-form 5.pdf

in-pct-2002-348-kol-granted-letter patent.pdf

in-pct-2002-348-kol-granted-specification.pdf

in-pct-2002-348-kol-granted-translated copy of priority document.pdf


Patent Number 214284
Indian Patent Application Number IN/PCT/2002/348/KOL
PG Journal Number 06/2008
Publication Date 08-Feb-2008
Grant Date 07-Feb-2008
Date of Filing 13-Mar-2002
Name of Patentee NOVA CHEMICALS (INTERNATIONAL) S.A.
Applicant Address SWITZERLAND, CHEMINSADES MAZOTS 2, CH-1700 FRIBOURG, SWISS COMPANY.
Inventors:
# Inventor's Name Inventor's Address
1 WURZ RYAN PAUL CANADA, NO.2306-15 MCKINNON ROAD, N.E., CALGARY, ALBERT T2E 7V3, CANADA.
2 JEREMIC DUSAN CANADA 240 SADDATONE DRIVE N.W., CALGARY, ALBERT T3K 3S6, CANADA.
3 STEPHEN DOUGLAS W CANADA 1635 ARGUE STREET, LASALLE, ONTARIOAN 9J 3G5, CANADA.
4 SPENCE, RUPERT, EDWARD VON HAKEN 401-11 STREET, N.W.CALGRRY, ALBERT, T2N 1X5.
5 BROWN STEPHEN JOHN CANADA,157 MOUNT SPPPRROW HAWK PLACE S.E., CALGARY, ALBERT T2Z 2G7.
PCT International Classification Number B01J31/22,C07H7/00,
PCT International Application Number PCT/CA00/00978
PCT International Filing date 2000-08-24
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2,282,070 1999-09-10 Canada