An approach to catalyst design: Cyclopentadienyl-titanium phosphinimide complexes in ethylene polymerization

Article abstract of DOI:10.1021/om020954t

A strategy for polymerization catalyst design has been developed based on the steric and electronic analogy of bulky phosphinimides to cyclopentadienyl ligands. To this end, the family of complexes of the form (Cp^?)TiCl₂(NPR₃) has been prepared and characterized. Alkyl and aryl derivatives of these species have also been synthesized, and a number have been evaluated for use as catalyst precursors in olefin polymerization. The polymerization of ethylene has been examined employing several types of cocatalyst activators. Trends and patterns in the structure-activity relationship are discussed, and the implications for catalyst design are evaluated.

Full text of DOI:10.1021/om020954t

Organometallics 2003, 22, 1937-1947
1937
An Ap p r oa ch to Ca ta lyst Design :
Cyclop en ta d ien yl-Tita n iu m P h osp h in im id e Com p lexes in
Eth ylen e P olym er iza tion
Douglas W. Stephan,*,† J effrey C. Stewart,† Fre´de´ric Gue´rin,† Silke Courtenay,†
J ames Kickham,† Emily Hollink,† Chad Beddie,† Aaron Hoskin,† Todd Graham,†
Pingrong Wei,† Rupert E. v. H. Spence,‡ Wei Xu,‡ Linda Koch,‡
Xiaoliang Gao,‡ and Daryll G. Harrison‡
School of Physical Sciences, Chemistry and Biochemistry, University of Windsor,
Windsor, Ontario, Canada N9B 3P, and NOVA Chemicals Corporation, Research &
Technology Center, 2928 16 Street N.E., Calgary, Alberta, Canada T2E 7K7
Received November 19, 2002
A strategy for polymerization catalyst design has been developed based on the steric and
electronic analogy of bulky phosphinimides to cyclopentadienyl ligands. To this end, the
family of complexes of the form (Cp†)TiCl2(NPR3) has been prepared and characterized. Alkyl
and aryl derivatives of these species have also been synthesized, and a number have been
evaluated for use as catalyst precursors in olefin polymerization. The polymerization of
ethylene has been examined employing several types of cocatalyst activators. Trends and
patterns in the structure-activity relationship are discussed, and the implications for catalyst
design are evaluated.
In tr od u ction
lide,25,26 boratabenzene,27,28 pendant cyclopentadienyl
borane ligands,29 trimethylene,28 cyclopentadienylbo-
rate,30 diketimine,31 tropidinyl,32 tridentate,33 and mac-
rocyclic ligands34 have been shown to exhibit appre-
ciable catalytic activities. Nonetheless, perhaps the most
commercially significant development since the advent
of metallocene catalysts has been systems based on the
so-called “constrained geometry catalyst” (CGC).35-43
This catalyst system evolved from a strategy of increas-
Strategies for the development of new homogeneous
olefin polymerization catalysts have resulted in the
synthesis and exploration of a variety of new and
interesting early transition metal complexes.1-3 For
example, Ti and Zr complexes containing amido,4-6
diamido,7-12 amidinates,13-15 imidophosphonamides,16
pyridine-alkoxides,17 aryloxides,18-22 ketimides,23,24 borol-
* Corresponding author. Fax: 519-973-7098. E-mail: stephan@
uwindsor.ca.
(18) Nomura, K; Naga, N.; Miki, M.; Yanagi, K.; Imai, A. Organo-
metallics 1998, 17, 2152-2154.
† University of Windsor.
(19) Tsukahara, T.; Swenson, D. C.; J ordan, R. F. Organometallics
1997, 16, 3303-3313.
‡ NOVA Chemicals Corporation.
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10.1021/om020954t CCC: $25.00 © 2003 American Chemical Society
Publication on Web 04/03/2003

1938 Organometallics, Vol. 22, No. 9, 2003
Stephan et al.
Avance-300 and are referenced to 85% H3PO4, saturated
NaBH4/H2O, and 80% CFCl3 in CDCl3, respectively. Unless
otherwise stated, all spectra were recorded at 25 °C in
d6-benzene. Guelph Chemical Laboratories performed combus-
tion analyses. In a very few cases, despite repeated analyses
and the use of added oxidant, C analyses yielded deviations
from calculated values. We attribute this to partial formation
of TiC during combustion of the Ti-organometallic derivatives.
The compounds R3PNSiMe3, CpTiCl3, Cp*TiCl3, (indenyl)TiCl3,
(t-BuC5H4)TiCl3, (n-BuC5H4)TiCl3, (indenyl)Ti(NPt-Bu3)Cl2 (24),
and (Indenyl)Ti(NPt-Bu3)Me2 (41) were prepared via published
methods.46,51,52 The precursor phosphines and N3SiMe3 were
purchased from either the Strem Chemical or Aldrich Chemi-
cal Companies.
ing the exposure of the metal center by the incorporation
of a constrained chelating cyclopentadienyl-amide ligand.
In developing our own approach to catalyst design,
we noted the work of Wolczanski et al.,44 who described
the steric analogy between the tri-tert-butylmethoxide
(tritox) and cyclopentadienyl ligands. In addition, we
took notice of the electronic analogy between phosphin-
imide and cyclopentadienyl ligands described by Deh-
nicke et al.45-48 As phosphinimide ligands are structur-
ally related to Wolczanski’s “tritox”, we recognized that
bulky phosphinimides offer both steric and electronic
analogies to the cyclopentadienyl ligand. Moreover,
these ligands are easily modified, providing the op-
portunity for systematic studies of structure-activity
relationships and they provide the powerful probe
associated with 31P NMR spectroscopy.49 In this article,
we detail the synthesis and characterization of a family
of complexes of the form Cp†TiCl2(NPR3) that include
such phosphinimide ligands. In addition, a number of
alkyl and aryl derivatives are described. These species
are shown to act as precursors to effective ethylene
polymerization catalysts. This family of compounds
yields active catalysts, although the levels of activity
depend both on the precise details of the ligands and
on the mode of activation. Trends in the structure-
property-activity relationships are evaluated and dis-
cussed. A preliminary account of some of the results
presented herein has previously been published.50
Syn th esis of R3P NSiMe3 (R ) Et 1, Cy 2, i-P r 3, t-Bu 4,
P h 5, p-MeC6H4 6, p-CF 3C6H4 7, p-F C6H4 8, p-MeOC6H4 9).
These compounds were prepared in a fashion similar to that
described in the literature for 5 with only minor modifications
to the published procedure, other than substitution of the
appropriate phosphine precursor. Thus, a single preparation
is detailed. Me3SiN3 (2.95 g, 10.7 mmol) was added to 3.00 g
(10.7 mmol) of Et3P to give an off-white slush. Heating with
stirring for 5 h at 80 °C initially produced a bubbling, light
yellow liquid, which became a darker yellow, clear liquid after
20 min. Cooling yielded a light brown, waxy solid, which was
recrystallized at -35 °C from MeCN (50 mL) to give 1.75 g
(80%) of the cream-colored solid product 1. 31P{1H} NMR: 15.0.
1H NMR: 1.12 (m, 6H, CH2); 0.84 (m, 9H, Me); 0.34 (s, 9H,
1
SiMe3). 13C{1H} NMR: 21.9 (d, J PC ) 67 Hz, PCH2); 6.4
1
(CH2Me), 5.0 (SiMe3). 2 (93%): 31P{1H} NMR: 17.0. H NMR:
1.88-1.09 (m, 33H, Cy); 0.43 (s, 9H, SiMe3). 13C{1H}: 37.1 (d,
2
1J PC ) 48 Hz, PCH); 27.4 (d, J PC ) 12 Hz, CH2), 27.3, 26.9
(CH2); 5.3 (SiMe3). 3 (87%): 31P{1H} NMR: 24.6. 1H NMR: 1.62
(m, 3H, CHMe2); 0.93 (m, 18H, CHMe2); 0.34 (s, 9H, SiMe3).
13C{1H} NMR: 26.1 (d, 1J PC ) 63 Hz, PCHMe2); 17.2 (PCHMe2);
Exp er im en ta l Section
Gen er a l Da ta . All preparations were done under an
atmosphere of dry, O2-free N2 employing both Schlenk line
techniques and Innovative Technologies, Braun, or Vacuum
Atmospheres inert atmosphere gloveboxes. Solvents were
purified employing Grubbs’ type column systems manufac-
tured by Innovative Technology. 1H and 13C{1H} NMR spectra
were recorded on Bruker Avance-300 and -500 spectrometers
operating at 300 and 500 MHz, respectively. Trace amounts
of protonated solvents were used as references, and chemical
shifts in ppm are reported relative to SiMe4. 31P{1H} NMR,
11B{1H} NMR, and 19F NMR spectra were recorded on a Bruker
1
5.0 (SiMe3). 4 (86%): 31P{1H} NMR: 32.4. H NMR: 1.17 (d,
3J PH ) 13 Hz, 27H, PCMe3); 0.4 (s, 9H, SiMe3). 13C{1H} NMR:
39.9 (d, 1J PC ) 55 Hz, PCMe3); 29.6 (PCMe3); 4.8 (SiMe3). Anal.
Calcd for C15H36NPSi: C, 62.21; H, 12.56; N, 4.84. Found: C,
62.12; H, 12.40; N, 4.85. 5: 31P{1H} NMR: -0.5. 1H NMR: 7.72
(m, 6H, Ph); 7.03 (m, 9H, Ph); 0.36 (s, 9H, SiMe3). 13C{1H}
2
3
NMR: 136.7, 135.4, 132.3 (d, J PC ) 9 Hz, Ph); 128.8 (d, J PC
) 6 Hz, Ph); 4.43 (SiMe3). 6 (93%): 31P{1H} NMR: 0.04. 1H
NMR: 7.75 (dd, 3J HH ) 8 Hz, 3J PH ) 12 Hz, 6H, C6H4Me); 6.92
3
(d, J HH ) 8 Hz, 6H, C6H4Me); 1.99 (s, 9H, C6H4Me); 0.42 (s,
9H, SiMe3). 13C{1H} NMR: 140.9, 134.2 (C6H4Me); 132.4 (d,
3J PC ) 11 Hz, C6H4Me); 129.1 (d, 2J PC ) 13 Hz, C6H4Me); 21.2
(C6H4Me); 4.5 (SiMe3). Anal. Calcd for C24H30NPSi: C, 73.62;
H, 7.72; N, 3.58. Found: C, 72.90; H, 7.93; N, 3.88. 7 (92%):
(35) Shapiro, P. J .; Bunel, E.; Schaefer, W. P.; Bercaw, J . E.
Organometallics 1990, 9, 867-869.
(36) Chen, Y.-X.; Marks, T. J . Organometallics 1997, 16, 3649-3657.
(37) Tian, S.; Arredondo, V. M.; Stern, C. L.; Marks, T. J . Organo-
metallics 1999, 18, 2568-2570.
1
3
3
31P{1H} NMR: -5.5. H NMR: 7.38 (dd, J HH ) 8 Hz, J PH
)
12 Hz, 6H, C6H4CF3); 7.25 (d, 3J HH ) 8 Hz, 6H, C6H4CF3); 0.27
(s, 9H, SiMe3). 13C{1H} NMR: 139.3 (C6H4CF3), 137.9, 132.5
(38) Deck, P. A.; Beswick, C. L.; Marks, T. J . J . Am. Chem. Soc.
1998, 120, 1772-1784.
2
3
(39) Woo, T. K.; Margl, P. M.; Lohrenz, J . C. W.; Blochl, P. E.;
Ziegler, T. J . Am. Chem. Soc. 1996, 118, 13021-13030.
(40) Shapiro, P. J .; Cotter, W. D.; Schaefer, W. P.; Labinger, J . A.;
Bercaw, J . E. J . Am. Chem. Soc. 1994, 116, 4623-4640.
(41) Devore, D. D.; Timmers, F. J .; Hasha, D. L.; Rosen, R. K.;
Marks, T. J .; Deck, P. A.; Stern, C. L. Organometallics 1995, 14, 3132-
3134.
(C6H4CF3); 133.3 (d, J PC ) 35 Hz, p-C6H4CF3); 125.5 (d, J FC
) 13 Hz, m-C6H4CF3); 4.0 (SiMe3). 19F NMR: 14.8. Anal. Calcd
for C24H21F9NPSi: C, 65.59; H, 4.81; N, 3.19. Found: C, 65.23;
H, 4.55; N, 3.07. 8 (93%): 31P{1H} NMR: -3.8. 1H NMR: 7.41
(m, 6H, C6H4F); 6.69 (dd, 3J HH ) 8 Hz, 3J PH ) 2 Hz, 6H, C6H4F);
0.29 (9H, SiMe3). 13C{1H} NMR: 164.8 (d, J FC ) 253 Hz,
1
(42) Lindsay, K. F. Mod. Plast. 1993, 82.
2
3
C6H4-F); 134.4 (dd, J PC ) 12 Hz, J FC ) 8 Hz, o-C6H4); 131.5
(43) Stevens, J . C. In Catalyst Design for Taylor-made Polyolefins,
Studies in Surface Science and Catalysis; Soga, K., Terano, M., Eds.;
Elsevier: Amsterdam, 1994; Vol. 89, pp 277-284.
(44) Lubben, T. V.; Wolczanski, P. T.; Van Duyne, G. D. Organo-
metallics 1984, 3, 977-983.
(45) Anfang, S.; Harms, K.; Weller, F.; Borgmeier, O.; Lueken, H.;
Schilder, H.; Dehnicke, K. Z. Anorg. Allg. Chem. 1998, 624, 159-166.
(46) Dehnicke, K.; Weller, F. Coord. Chem. Rev. 1997, 158, 103-
169.
4
1
3
(dd, J FC ) 4 Hz, J PC ) 106 Hz, ipso-C6H4F); 115.7 (dd, J PC
2
3
) 13 Hz, J FC ) 21 Hz, m-C6H4F); 4.2 (d, J PC ) 4 Hz, SiMe3).
19F NMR: -30.6. Anal. Calcd for C21H21F3NPSi: C, 62.51; H,
5.26; N, 3.47. Found: C, 62.55; H, 5.32; N, 3.20. 9 (89%): 31P-
{1H} NMR: -0.7. H NMR: 7.75 (dd, J HH ) 8 Hz, J PH ) 12
1
3
3
3
4
Hz, 6H, C6H4); 6.71 (dd, J HH ) 8 Hz, J PH ) 2 Hz, 6H, C6H4);
3.21 (s, 9H, MeO); 0.45 (s, 9H, SiMe3). 13C{1H} NMR: 162.0
(d, 4J PC ) 4 Hz, p-C6H4); 134.1 (d, 3J PC ) 12 Hz, m-C6H4); 128.9,
(47) Dehnicke, K.; Krieger, M.; Massa, W. Coord. Chem. Rev. 1999,
182, 19-65.
2
113.9 (d, J PC ) 13 Hz); 54.7 (OMe); 4.64 (SiMe3).
(48) Dehnicke, K.; Straehle, J . Polyhedron 1989, 8, 707-726.
(49) Kickham, J . E.; Guerin, F.; Stephan, D. W. J . Am. Chem. Soc.
2002, 124, 11486-11494.
(51) Samuel, E.; Rausch, M. D. J . Am. Chem. Soc. 1973, 95, 6263.
(52) Guerin, F.; Beddie, C. L.; Stephan, D. W.; Spence, R. E. v. H.;
Wurz, R. Organometallics 2001, 20, 3466-3471.
(50) Stephan, D. W.; Stewart, J . C.; Guerin, F.; Spence, R. E. v. H.;
Xu, W.; Harrison, D. G. Organometallics 1999, 18, 1116-1118.

An Approach to Catalyst Design
Organometallics, Vol. 22, No. 9, 2003 1939
Syn th esis of Cp Ti(NP R3)Cl2 (R ) Et 10, Cy 11, i-P r 12,
t-Bu 13, P h 14, p-MeC6H4 15, p-CF 3C6H4 16, p-F C6H4 17,
p-MeOC6H4 18), (Cp ′)Ti(NP R3)Cl2 (Cp ′ ) Me3SiC5H4, R )
i-P r 19, t-Bu 20; Cp ′ ) Me5C5, R ) i-P r 21, t-Bu 22; Cp ′ )
in d en yl, R ) i-P r 23; Cp ′ ) t-Bu C5H4, R ) Cy 25, i-P r 26,
t-Bu 27; Cp ′ ) n -Bu C5H4, R ) t-Bu 28; Cp ′ ) P h 4C5H, R )
t-Bu 29). These compounds were prepared employing similar
procedures, and thus only one representative preparation is
detailed. To 515 mg (2.35 mmol) of CpTiCl3 and 820 mg (2.35
mmol) of 5 was added 50 mL of benzene to give a cloudy yellow
mixture. Heating for 4 h at 80 °C gave a clear, deep yellow
solution. Cooling and removal of volatiles gave 1.03 g (95%) of
14 as a deep yellow solid product. 10 (89%): 31P{1H} NMR:
Found: C, 50.72; H, 8.45; N, 2.95. 21 (93%): 31P{1H} NMR:
1
34.5. H NMR: 2.20 (s, 15H, C5Me5); 1.81 (m, 3H, PCHMe2);
0.97 (m, 18H, PCHMe2). 13C{1H} NMR: 125.5 (C5Me5); 26.2
(d, 1J PC ) 56 Hz, PCHMe2); 16.9 (PCHMe2); 13.1 (C5Me5). Anal.
Calcd for C19H36Cl2NPTi: C, 53.29; H, 8.47; N, 3.27. Found:
1
C, 53.45; H, 8.83; N, 3.14. 22 (73%): 31P{1H} NMR: 46.0. H
3
NMR: 2.18 (s, 15H, C5Me5); 1.26 (d, J PH ) 13 Hz, 27H,
1
PCMe3). 13C{1H} NMR: 125.2 (C5Me5); 41.8 (d, J PC ) 44 Hz,
PCMe3); 29.8 (PCMe3); 13.1 (C5Me5). Anal. Calcd for C22H42
-
Cl2NPTi: C, 56.18; H, 9.00; N, 2.98. Found: C, 56.39; H, 9.38;
N, 3.04. 23 (88%): 31P{1H} NMR: 37.1. 1H NMR: 7.78 (m,
2H, Ind); 7.18 (m, 2H, Ind); 6.79 (m, 1H, Ind); 6.61 (m, 2H,
Ind); 1.60 (m, 3H, CHMe2); 0.85 (m, 18H, CHMe2). 13C{1H}
1
1
NMR: 129.9, 125.7, 126.3, 115.8, 105.3 (Ind); 25.5 (d, J PC
)
26.4. H NMR: 6.42 (s, 5H, Cp); 0.95 (m, 6H, CH2); 0.72 (m,
1
9H, Me). 13C{1H} NMR: 114.9 (Cp), 18.9 (d, J PC ) 63 Hz,
56 Hz, PCHMe2); 16.5 (PCHMe2). Anal. Calcd for C18H28Cl2-
NPTi: C, 52.97; H, 6.91; N, 3.43. Found: C, 52.68; H, 6.49; N,
3.22. 25 (93%): 31P{1H} NMR: 29.4. 1H NMR: 6.55 (m, 2H,
Cp); 6.44 (m, 2H, Cp); 1.85 (br d, 6H, Cy); 1.67 (br s, 6H, Cy);
1.55 (br m, 6H, Cy); 1.49 (s, 9H, CMe3); 1.44 (br m, 6H, Cy);
1.16 (br m, 9H, Cy). 13C{1H} NMR: 142.5 (t-BuC5H4); 115.2,
111.7 (Cp); 35.9 (d, 1J PC ) 55 Hz, PCH); 26.9 (d, 2J PC ) 12 Hz,
CH2); 33.0 (CMe3), 31.5 (CMe3); 26.7, 26.6 (m, CH2). Anal. Calcd
for C27H46Cl2NPTi; C, 60.68; H, 8.68; N, 2.62. Found: C, 60.39;
H, 8.56; N, 2.52. 26 (95%): 31P{1H} NMR: 38.3. 1H NMR: 6.47
PCH2), 5.8 (CH2Me). Anal. Calcd for C11H20Cl2NPTi: C, 41.81;
H, 6.38; N, 4.43. Found: C, 41.52; H, 6.49; N, 4.02. 11 (94%):
31P{1H} NMR: 28.5. 1H NMR: 6.47 (s, 5H, Cp); 1.74-1.02 (m,
1
33H, Cy). 13C{1H} NMR: 114.9 (Cp); 35.8 (d, J PC ) 54 Hz,
P-CH); 27.0, 26.8, 26.7, 26.1 (Cy). Anal. Calcd for C23H36Cl2-
NPTi: C, 58.00; H, 7.62; N, 2.94. Found: C, 57.77; H, 7.35; N,
2.78. 12 (90%): 31P{1H} NMR: 36.9. 1H NMR: 6.42 (s, 5H,
3
2
Cp); 1.65 (m, 3H, CHMe2); 0.87 (dd, J HH ) 7 Hz, J PH ) 15
Hz, 18H, CHMe2). 13C{1H} NMR: 114.9 (Cp); 27.6 (d, J PC
)
1
3
(m, 2H, Cp); 6.36 (m, 2H, Cp); 1.81 (d of sept, J HH ) 7 Hz,
56 Hz, P-CH), 16.5 (CHMe2). Anal. Calcd for C14H26Cl2NPTi:
C, 46.95; H, 7.32; N, 3.91. Found: C, 46.45; H, 7.11; N, 3.76.
13 (92%): 31P{1H} NMR: 45.2. 1H NMR: 6.46 (s, 5H, Cp); 1.14
(d, 2J PH ) 14 Hz, 27H, PCMe3). 13C{1H} NMR: 115.0 (Cp); 41.9
2J PH ) 11 Hz, 3H, PCHMe2); 1.46 (s, 9H, CMe3); 0.99 (dd, 3J PH
3
) 16 Hz, J HH ) 7 Hz, 18H, PCHMe2). 13C{1H} NMR: 142.5
(t-BuC5H4); 115.1, 111.7 (C5H4); 33.0 (CMe3), 31.5 (CMe3), 25.8
1
(d, 1J PC ) 44 Hz, PCMe3); 29.4 (PCMe3). Anal. Calcd for C17H32
-
(d, J PC ) 56 Hz, PCHMe2), 16.7 (s, CHMe2). Anal. Calcd for
C
18H34Cl2NPTi: C, 52.19; H, 8.27; N, 3.38. Found: C, 52.09;
Cl2NPTi: C, 51.02; H, 8.06; N, 3.50. Found: C, 50.87; H, 7.89;
H, 8.19; N, 3.32. 27 (91%): 31P{1H} NMR: 45.8 (s). H NMR:
6.56 (m, 2H, Cp); 6.42 (m, 2H, Cp); 1.52 (s, 9H, CMe3); 1.19 (d,
3J PH ) 14 Hz, 27H, PCMe3). 13C{1H} NMR: 142.5 (t-BuC5H4);
116.0, 110.8 (C5H4); 42.0 (d, 1J PC ) 43 Hz, PCMe3); 33.1 (CMe3);
31.5 (CMe3); 29.6 (PCMe3). Anal. Calcd for C21H40Cl2NPTi; C,
55.28; H, 8.84; N, 3.07. Found: C, 55.35; H, 8.93; N, 2.91. 28
(91%): 31P{1H} NMR (C6D6): 45.0 (s). 1H NMR (C6D6): 6.44
1
1
N, 3.22. 14: 31P{1H} NMR: 2.7. H NMR: 7.67 (m, 6H, Ph);
6.98 (m, 9H, Ph); 6.19 (s, 5H, Cp). 13C{1H} NMR: 132.6, 130.4,
129.5 (Ph); 129.0 (d, 2J PC ) 12 Hz, Ph); 115.3 (Cp). Anal. Calcd
for C23H20NPCl2Ti: C, 60.03; H, 4.38; N, 3.04. Found: C, 59.70;
H, 4.38; N, 3.04. 15 (98%): 31P{1H} NMR: 3.7. 1H NMR: 7.71
3
3
4
(dd, J HH ) 8 Hz, J PH ) 13 Hz, 6H, C6H4); 6.86 (dd, J PH ) 3
Hz, 6H, C6H4); 6.27 (s, 5H, Cp); 1.92 (s, 9H, Me). 13C{1H}
NMR: 143.2, 126.5 (C6H4); 132.9 (d, 3J PC ) 11 Hz, C6H4), 129.8
(dd, 2H, C5H4, J H-H ) 3 Hz, 4J H-H ) 3 Hz), 6.31 (dd, 2H, C5H4,
3
3J H-H ) 3 Hz, J H-H ) 3 Hz), 2.90 (t, 2H, J H-H ) 8 Hz,
4
3
2
(d, J PC ) 13 Hz, C6H4), 115.2 (Cp); 21.3 (Me). Anal. Calcd for
3
3
CH2C5H4), 1.63 (tt, 2H, J H-H ) 8 Hz, J H-H ) 8 Hz, CH2CH2-
C
26H26NPCl2Ti: C, 62.18; H, 5.22; N, 2.79. Found: C, 61.85;
CH2), 1.33 (tq, 2H, 3J H-H ) 8 Hz, 3J H-H ) 7 Hz, CH3CH2), 1.17
H, 5.17; N, 2.60. 16 (89%): 31P{1H) NMR: -3.0. 1H NMR: 7.44
3
3
3
3
4
(t, 27H, J P-H ) 14 Hz, PCMe3), 0.87 (t, 3H, J H-H ) 7 Hz,
Me), 13C{1H} NMR: 135.4 (s, C4H4CR, I), 118.0 (s, C4H4CR),
113.4 (s, C4H4CR), 40.3 (d, J P-C ) 44 Hz, CMe3), 33.3 (s,
(dd, J HH ) 8 Hz, J PH ) 13 Hz, 6H, C6H4); 7.27 (dd, J PH ) 2
Hz, 6H, C6H4); 6.18 (s, 5H, Cp). 13C{1H} NMR: 133.6, 132.8,
1
3
2
128.5 (C6H4); 133.0 (d, J PC ) 11 Hz, C6H4); 126.2 (d, J FC
)
10 Hz, p-C6H4); 116.1 (Cp). 19F{1H} NMR: 14.6. Anal. Calcd
for C26H17Cl2F9NPTi: C, 47.02; H, 2.58; N, 2.11. Found: C,
46.70; H, 2.19; N, 2.40. 17: (91%). 31P{1H} NMR: -0.6. 1H
CH2C5H4), 31.0 (s, CH2CH2CH2), 29.9 (s, PCMe3), 23.3 (s, CH3-
CH2), 14.5 (s, CH3CH2) Anal. Calcd: C, 55.28; H, 8.84; N, 3.07.
Found: C, 55.42; H, 9.06; N, 3.23. 29 (63%): 31P{1H} NMR:
48.1. 1H NMR: 7.84 (m, 8H, Ph); 7.56 (s, 1H, Cp); 7.09 (m,
4H, Ph); 6.95 (m, 6H, Ph); 6.90 (m, 2H, Ph); 0.91 (d, 3J PH ) 14
Hz, 27H, PCMe3). 13C{1H} NMR (partial): 135.1, 134.9, 132.9,
130.4, 129.1, 128.5, 127.9, 127.2, 105.9 (Cp and Ph); 42.2 (d,
3
3
NMR: 7.40 (m, 6H, C6H4); 6.66 (td, J HH ) 8 Hz, J PH ) 2 Hz,
2J FH ) 8 Hz, 6H, C6H4); 6.18 (s, 5H, Cp). 13C{1H} NMR: 165.6
1
2
3
(d, J CF ) 252 Hz, C6H4-F); 135.1 (dd, J PC ) 11 Hz, J FC
)
10 Hz, o-C6H4); 125.6 (d, 1J PC ) 107 Hz, ipso-C6H4); 116.5 (dd,
1J PC ) 43 Hz, PCMe3); 29.4 (PCMe3). Anal. Calcd for C41H48
-
3J PC ) 13 Hz, J FC ) 21 Hz, m-C6H4F); 115.5 (Cp). 19F{1H}
2
Cl2NPTi: C, 69.89; H, 6.87; N, 1.99. Found: C, 69.62; H, 6.52;
N, 1.75.
NMR: -26.7. Anal. Calcd for C23H17F3NPTiCl2: C, 53.73; H,
3.33; N, 2.72. Found: C, 53.58; H, 3.37; N, 2.41. 18 (90%): 31P-
3
3
{1H} NMR: 3.4. 1H NMR: 7.73 (dd, J HH ) 8 Hz, J PH ) 12
Syn th esis of Cp Ti(NP R3)Me2 (R ) Cy 30, i-P r 31, t-Bu
32, P h 33, p -MeC6H 4 34, p -CF 3C6H 4 35, p -F C6H 4 36,
p-MeOC6H4 37), Cp ′Ti(NP R3)Me2 (Cp ′ ) Me5C5, R ) i-P r
38, t-Bu 39; Cp ′ ) In d en yl, R ) i-P r 40; Cp ′ t-Bu C5H4, R
) Cy 42, i-P r 43, t-Bu 44; Cp ′ ) P h 4C5H, R ) t-Bu 45),
Cp Ti(NP R 3)Bn 2 (R ) Cy 46, i-P r 47, t-Bu 48, P h 49,
p-MeC6H4 50, p-CF 3C6H4 51, p-F C6H4 52, p-MeOC6H4 53),
Cp Ti(NP R3)P h 2 (R ) Cy 54, i-P r 55, t-Bu 56, P h 57), Cp Ti-
(NP R3)(C6H33,5-(CF 3)2)2 (R ) Cy 58, P h 59), a n d Cp Ti-
(NP P h 3)(C6H-2,3,4,5-F 4)2 (60). These compounds were pre-
pared employing similar procedures using the appropriate
starting material and the corresponding alkyl/arylating agent.
Thus only one representative preparation is detailed. To a
slightly cloudy, yellow 5 mL benzene solution of 150 mg (0.326
mmol) of 14 was added 0.47 mL (0.658 mmol) of a 1.4 M ether
solution of MeLi. After stirring for 20 min, the mixture became
more cloudy and dark yellow-gray in color. Removal of benzene
4
Hz, 6H, C6H4); 6.69 (dd, J PH ) 2 Hz, 6H, C6H4); 6.30 (s, 5H,
Cp); 3.19 (s, 9H, OMe). 13C{1H} NMR: 163.3 (C6H4-OMe);
134.7 (d, 1J PC ) 11 Hz, ipso-C6H4); 120.8 (C6H4); 114.7 (d, 2J PC
) 13 Hz, C6H4); 115.1 (Cp); 54.9 (OMe). Anal. Calcd for
C
26H26O3NPCl2Ti: C, 56.75; H, 4.76; N, 2.55. Found: C, 56.82;
H, 5.25; N, 2.52. 19: 31P{1H} NMR: 36.6. H NMR: 6.81 (s,
2H, C5H4); 6.55 (s, 2H, C5H4); 1.66 (m, 3H, PCHMe2); 0.88 (dd,
3J HH ) 7 Hz, 3J PH ) 12 Hz, 18H, PCHMe2); 0.50 (s, 9H, SiMe3).
13C{1H} NMR: 126.6, 124.0, 115.1 (Cp); 25.6 (d, 1J PC ) 54 Hz,
1
PCHMe2); 16.6 (PCHMe2); 0.05 (SiMe3). Anal. Calcd for C17H34
-
Cl2NPSiTi: C, 47.45; H, 7.96; N, 3.26. Found: C, 47.23; H,
1
7.79; N, 3.04. 20 (91%): 31P{1H} NMR: 45.4. H NMR: 6.83
3
(s, 2H, Cp); 6.58 (s, 2H, Cp); 1.15 (d, J PH ) 14 Hz, 27H,
PCMe3); 0.52 (s, 9H, SiMe3). 13C{1H} NMR: 126.6, 124.5, 114.4
(Cp); 41.9 (d, 1J PC ) 44 Hz, PCMe3); 29.5 (PCMe3); 0.05 (SiMe3).
Anal. Calcd for C20H40NPSiTiCl2: C, 50.85; H, 8.54; N, 2.97.

1940 Organometallics, Vol. 22, No. 9, 2003
Stephan et al.
gave a yellow-gray solid. The solid was extracted with 4 × 4
mL of hexane, and the extracts were filtered to give a clear,
deep yellow solution. Evaporation of hexane gave 82 mg (60%)
of 33 as a deep yellow solid product. 30 (95%): 31P{1H} NMR:
14.8. 1H NMR: 6.24 (s, 5H, Cp); 1.92-1.05 (br m, 33H, Cy);
0.70 (s, 6H, TiMe). 13C{1H} NMR: 110.5 (Cp), 39.5 (TiMe), 36.8
(m, 2H, Cp); 6.16 (m, 2H, Cp); 2.04 (br d, 6H, Cy); 1.81 (br s,
6H, Cy); 1.69 (br m, 6H, Cy); 1.64 (br m, 6H, Cy); 1.50 (s, 9H,
CMe3); 1.23 (br m, 9H, Cy), 0.77 (s, 6H TiMe). 13C{1H} NMR:
138.9 (ipso-C5H4); 109.4 (C5H4); 108.0 (C5H4); 39.8 (TiMe); 37.1
1
3
(d, J PC ) 57 Hz, PCH); 27.3 (d, J PC ) 13 Hz, CH2); 32.1
(CMe3); 31.9(CMe3); 27.2, 26.5 (CH2). Anal. Calcd for C29H52
-
1
(d, J PC ) 57 Hz, PCMe3); 27.3, 27.1, 26.5. Anal. Calcd for
NPTi; C, 70.57; H, 10.62; N, 2.84. Found: C, 70.26; H, 10.33;
C
25H44NPTi: C, 68.64; H, 10.14; N, 3.20. Found: C, 68.32; H,
N, 2.65. 43 (91%): 31P{1H} NMR: 22.3. 1H NMR: 6.21 (m,
1
2
9.79; N, 3.12. 31 (91%): 31P{1H} NMR: 22.5. H NMR: 6.20
2H, Cp); 5.99 (m, 2H, Cp); 1.81 (d of sept, J PH ) 11 Hz, 3H,
3
3
3
(s, 5H, Cp); 1.67 (m, 3H, PCHMe2); 0.93 (dd, J PH ) 14 Hz,
PCHMe2); 1.39 (s, 9H, CMe3); 0.99 (dd, J PH ) 16 Hz, J HH )
3J HH ) 7 Hz, 18H, PCHMe2); 0.96 (s, 6H, TiMe). 13C{1H}
NMR: 110.5 (Cp); 39.6 (TiMe); 26.2 (d, 1J PC ) 57 Hz, PCHMe2);
16.9 (PCHMe2). Anal. Calcd for C16H32NPTi: C, 60.57; H,
10.17; N, 4.41. Found: C, 60.11; H, 9.82; N, 4.17. 32: (97%).
7 Hz, 18H, PCHMe2); 0.64 (s, 6H, TiMe). 13C{1H} NMR: 139.5
(ipso-C5H4); 109.3, 108.1 (C5H4); 39.8 (TiMe); 32.9 (CMe3); 32.1
(CMe3); 26.5 (d, 1J PC ) 58 Hz, PCHMe2); 17.1 (PCHMe2). Anal.
Calcd for C20H40NPTi: C, 64.34; H, 10.80; N, 3.75. Found: C,
64.19; H, 10.66; N, 3.66. 44 (87%): 31P{1H} NMR: 32.2. 1H
NMR: 6.27 (m, 2H, Cp); 5.79 (m, 2H, Cp); 1.47 (s, 9H, CMe3);
31P{1H} NMR: 31.3. H NMR: 6.22 (s, 5H, Cp); 1.20 (d, J PH
) 13 Hz, 27H, PCMe3); 0.67 (s, 6H, TiMe). 13C{1H} NMR: 110.8
(Cp); 41.3 (d, 1J PC ) 47 Hz, PCMe3); 39.9 (TiMe); 29.6 (PCMe3).
Anal. Calcd for C19H38NPTi: C, 63.50; H, 10.66; N, 3.90.
Found: C, 63.12; H, 10.54; N, 3.93. 33: 31P{1H} NMR: -7.4.
1H NMR: 7.77 (m, 6H, Ph); 7.03 (m, 9H, Ph); 6.03 (s, 5H, Cp);
1
3
1.21 (d, J PH ) 13 Hz, 27H, PCMe3); 0.60 (s, 6H, TiMe). 13C-
3
{1H} NMR: 139.4 (ipso-C5H4); 108.9, 108.0 (C5H4); 41.5 (d, 1J PC
) 46 Hz, CMe3); 39.6 (TiMe); 33.1 (CMe3); 32.1 (CMe3); 29.7
(PCMe3). Anal. Calcd for C23H46NPTi: C, 66.49; H, 11.16; N,
3.37. Found: C, 66.32; H, 11.07; N, 3.23. 45: 31P{1H} NMR:
34.4. 1H NMR: 7.74 (d, 4H, Ph); 7.48 (d, 4H, Ph); 7.0 (m, 12H,
Ph); 6.49 (s, 1H, Cp); 1.12 (s, 6H, TiMe); 1.05 (d, 3J PH ) 13 Hz,
27H, PCMe3). 13C{1H} NMR: 137.1, 136.4, 132.8, 129.6, 129.2,
127.8, 126.7, 126.2, 125.1, 109.8, 102.6 (C5(C6H5)4H); 46.9
0.94 (s, 6H, TiMe). 13C{1H} NMR: 133.3, 131.5, 132.4 (d, J PC
3
) 9 Hz); 128.6 (d, 2J PC ) 12 Hz); 111.2 (Cp); 43.2 (TiMe). Anal.
Calcd for C25H26NPTi: C, 71.60; H, 6.25; N, 3.34. Found: C,
70.92; H, 6.26; N, 3.31. 34 (80%): 31P{1H} NMR: -7.3. 1H
3
2
NMR: 7.79 (dd, J HH ) 8 Hz, J PH ) 12 Hz, 6H, Ph); 6.91 (dd,
3J PH ) 2 Hz, 6H, Ph); 6.10 (s, 5H, Cp); 1.96 (s, 9H, Me); 0.96
(TiMe); 41.6 (d, J PC ) 45 Hz, PCMe3); 29.6 (PCMe3). Anal.
1
(s, 6H, TiMe). 13C{1H} NMR: 141.8, 132.5 (d, J PC ) 11 Hz,
Calcd for C43H54NPTi: C, 77.81; H, 8.20; N, 2.11. Found: C,
77.54; H, 8.01; N, 1.97. 46 (76%): 31P{1H} NMR: 18.9. 1H
3
2
C6H4); 131.2, 129.3 (d, J PC ) 12 Hz, C6H4); 111.0 (Cp), 42.5
3
3
(s, TiMe); 21.2 (Ph-Me). Anal. Calcd for C28H32NPTi: C, 72.89;
H, 6.99; N, 3.04. Found: C, 73.11; H, 7.15; N, 3.02. 35 (71%):
NMR: 7.23 (t, J HH ) 8 Hz, 4H, o-C6H5); 7.11 (d, 4H, J HH )
3
7 Hz, m-C6H5); 6.89 (t, 2H, J HH ) 7 Hz, p-C6H5); 5.95 (s, 5H,
1
3
2
2
31P{1H} NMR: -13.2. H NMR: 7.46 (dd, J HH ) 8 Hz, J PH
)
Cp); 2.91 (d, J HH ) 9 Hz, 2H, CH2Ph); 2.61 (d, 2H, CH2Ph);
3
3
12 Hz, 6H, C6H4); 7.26 (dd, J HH ) 8 Hz, J PH ) 2 Hz, 6H,
1.81-1.05 (bm, 33H, Cy). 13C{1H} NMR: 153.1 (ipso-C6H5);
128.1, 126.5, 120.4 (C6H5); 112.8 (Cp); 69.7 (CH2Ph); 36.4 (d,
1J PC ) 56 Hz, PCH); 27.2, 27.1, 26.4 (CH2). Anal. Calcd for
C6H4); 6.00 (s, 5H, Cp); 0.89 (s, 6H, TiMe). 13C{1H} NMR: 136.8
1
2
(d, J PC ) 98 Hz, ipso-C6H4); 133.8 (d, J PC ) 34 Hz, o-C6H4);
3
1
132.5 (d, J PC ) 9 Hz, m-C6H4); 125.7 (q, J FC ) 271 Hz, Ph-
CF3); 122.3 (p-C6H4), 111.6 (Cp); 46.0 (TiMe). 19F NMR: 14.8.
Anal. Calcd for C28H23F9NPTi: C, 53.95; H, 3.72; N, 2.25.
Found: C, 53.52; H, 3.41; N, 2.04. 36 (71%): 31P{1H} NMR:
C37H52NPTi: C, 75.37; H, 8.89; N, 2.38. Found: C, 75.12; H,
8.43; N, 2.09. 47 (65%): 31P{1H} NMR: 26.6. H NMR: 7.23
1
(t, 3J HH ) 8 Hz 4H, o-C6H5); 7.09 (d, 3J HH ) 7 Hz, 4H, m-C6H5);
3
6.90 (t, J HH ) 7 Hz, 2H, p-C6H5); 5.89 (s, 5H, Cp); 2.85 (d,
1
3
-10.9. H NMR: 7.47 (m, 6H, C6H4); 6.70 (ddd, J HH ) 8 Hz,
2J HH ) 9 Hz, 2H, CH2Ph); 2.62 (d, 2H, CH2Ph); 1.63 (m, 3H,
PCHMe2); 0.86 (dd, 3J PH ) 13 Hz, 3J HH ) 5 Hz, 18H, PCHMe2).
13C{1H} NMR: 153.0 (ipso-C6H5); 128.1, 126.5, 120.4 (C6H5);
112.9 (Cp); 69.9 (CH2Ph); 26.7 (d, 1J PC ) 57 Hz, PCHMe2); 16.9
(PCHMe2). Anal. Calcd for C28H40NPTi: C, 71.63; H, 8.59; N,
2.98. Found: C, 71.38; H, 8.42; N, 2.71. 48 (94%): 31P{1H}
2J PH ) 2 Hz, J FH ) 8 Hz, 6H, C6H4); 6.02 (s, 5H, Cp); 0.86 (s,
3
6H, TiMe). 13C{1H} NMR: 165.1 (d, J FC ) 250 Hz, C6H4-F);
1
2
3
134.7 (dd, J PC ) 10 Hz, J FC ) 9 Hz, C6H4); 129.4, 116.0 (dd,
2J FC ) 21 Hz, 3J PC ) 12 Hz, C6H4); 111.2 (Cp); 44.1 (TiMe). 19
F
NMR: -29.1. Anal. Calcd for C25H23F3NPTi: C, 63.44; H, 4.90;
N, 2.96. Found: C, 63.26; H, 4.67; N, 2.79. 37 (73%): 31P{1H}
NMR: 36.1. H NMR: 7.25 (t, J HH ) 8 Hz, 4H, o-C6H5); 7.05
1
3
3
2
NMR: -7.9. 1H NMR: 7.79 (dd, J HH ) 7 Hz, J PH ) 12 Hz,
(d, 3J HH ) 7 Hz 4H, m-C6H5); 6.92 (t, 3J HH ) 7 Hz, 2H, p-C6H5);
3
2
6H, C6H4); 6.71 (dd, J PH ) 2 Hz, 6H, C6H4); 6.15 (s, 5H, Cp);
5.93 (s, 5H, Cp); 2.88 (d, J HH ) 9 Hz, 2H, CH2Ph); 2.71 (d,
3.18 (s, 9H, OMe); 0.99 (s, 6H, TiMe). 13C{1H} NMR: 162.5
(OC6H4); 134.3 (d, 2J PC ) 11 Hz, o-C6H4); 125.7 (m-C6H4); 114.2
2H, CH2Ph); 1.16 (d, J PH ) 13 Hz, 27H, PCMe3). 13C{1H}
3
NMR: 153.4 (ipso-C6H5); 128.5, 126.1, 120.7 (C6H5) 113.6 (Cp);
70.0 (CH2Ph); 41.3 (d, J PC ) 45 Hz, PCMe3); 29.6 (PCMe3).
1
1
(d, J PC ) 13 Hz, ipso-C6H4); 110.9 (Cp); 54.8 (OMe); 41.9
(TiMe). Anal. Calcd for C28H32NO3PTi: C, 66.02; H, 6.33; N,
2.75. Found: C, 65.67; H, 6.27; N, 2.82. 38 (83%): 31P{1H}
NMR: 20.7. 1H NMR: 2.04 (s, 15H, C5Me5); 1.85 (m, 3H,
PCHMe2); 1.06 (dd, 3J PH ) 14 Hz, 3J HH ) 7 Hz, 18H, PCHMe2);
0.29 (s, 6H, TiMe). 13C{1H} NMR: 118.1 (C5Me5); 41.6 (TiMe);
26.9 (d, 1J PC ) 57.5 Hz, PCHMe2); 17.3 (PCHMe2); 12.2 (C5Me5).
Anal. Calcd for C21H42NPTi: C, 65.11; H, 10.93; N, 3.62.
Found: C, 64,67; H, 11.00; N, 3.74. 39 (87%): 31P{1H} NMR:
Anal. Calcd for C31H46NPTi: C, 72.79; H, 9.06; N, 2.74.
Found: C, 71.91; H, 9.70; N, 2.78. 49: 31P{1H} NMR: -2.8.
1H NMR: 7.48 (m, 6H, Ph); 7.02 (m, 17H, Ph); 6.83 (t, 2H,
2
3J HH ) 6 Hz, p-C6H5CH2); 5.82 (s, 5H, Cp); 3.16 (d, J HH ) 9
Hz, 2H, CH2Ph); 2.60 (d, 2H, CH2Ph). 13C{1H} NMR: 151.9
2
2
(ipso-CH2C6H5); 132.6 (d, J PC ) 10 Hz, Ph); 128.7 (d, J PC
)
12 Hz, Ph); 133.4, 132.0, 131.7 (PC6H5); 128.1, 120.4 (CH2C6H5);
113.2 (Cp); 73.1 (CH2Ph). Anal. Calcd for C37H34NPTi; C, 77.76;
H, 6.00; N, 2.45. Found: C, 77.41; H, 5.49; N, 2.09. 50 (61%):
1
3
31.9. H NMR: 2.05 (s, 15H, C5Me5); 1.29 (d, J PH ) 12.8 Hz,
27H, PCMe3); 0.41 (s, 6H, TiMe). 13C{1H} NMR: 118.0 (C5-
31P{1H} NMR: -2.7. H NMR: 7.52 (dd, J HH ) 8 Hz, J PH
)
1
3
2
1
3
Me5); 43.0 (TiMe), 41.5 (d, J PC ) 46.6 Hz, PCMe3); 29.9
12 Hz, 6H, C6H4); 7.10 (m, 8H, C6H4); 6.92 (dd, J PH ) 2 Hz,
6H, C6H4); 6.85 (m, 2H, C6H4); 5.89 (s, 5H, Cp); 3.24 (d, 2H,
2J HH ) 9 Hz, CH2Ph); 2.62 (d, 2H, CH2Ph); 2.04 (s, 9H,
(PCMe3), 11.0 (C5Me5). Anal. Calcd for C24H48NPTi: C, 67.12;
H, 11.26; N, 3.26. Found: C, 67.09; H, 11.56; N, 3.26. 40
1
3
(72%): 31P{1H} NMR: 22.6. H NMR: 7.69 (m, 2H, indenyl);
C6H4Me). 13C{1H} NMR: 152.1 (ipso-CH2C6H5), 145.1 (d, J PC
2
7.19 (m, 2H, indenyl); 6.34 (m, 2H, indenyl); 6.03 (m, 1H,
) 3 Hz, m-PC6H4); 132.7 (d, J PC ) 10 Hz, o-PC6H4); 129.9,
3
3
indenyl); 1.68 (m, 3H, PCHMe2); 0.94 (dd, J PH ) 14 Hz, J HH
) 7 Hz, 18H, PCHMe2); 0.22 (s, 6H, TiMe). 13C{1H} NMR:
126.4, 125.0, 123.5, 112.5, 100.5 (Indenyl); 42.6 (TiMe); 26.2
129.4 (d, 1J PC ) 12 Hz, ipso-PC6H4); 127.9, 127.1, 120.3 (C6H5);
113.1 (Cp); 75.5 (CH2Ph); 21.3 (Ph-Me). Anal. Calcd for C40H40
-
NPTi; C, 78.30; H, 6.57; N, 2.28. Found: C, 78.05; H, 6.36; N,
1
1
3
(d, J PH ) 58 Hz, PCHMe2); 16.9 (s, PCHMe2). Anal. Calcd for
1.98. 51 (86%): 31P{1H} NMR: -9.1. H NMR: 7.30 (dd, J HH
3
3
2
C
20H34NPTi: C, 65.39; H, 9.33; N, 3.81. Found: C, 65.02; H,
) 8 Hz, J PH ) 2 Hz, 6H, PC6H4); 7.19 (dd, J HH ) 8 Hz, J PH
) 12 Hz, 6H, PC6H4); 6.95 Ph(t, 3J HH ) 7 Hz, 4H, m-CH2C6H5);
1
9.04; N, 3.42. 42 (94%): 31P{1H} NMR: 14.3. H NMR: 6.33

An Approach to Catalyst Design
Organometallics, Vol. 22, No. 9, 2003 1941
3
3
3
4
6.88 (d, J HH ) 7 Hz, 4H, o-CH2C6H5); 6.75 (t, J HH ) 7 Hz,
114.0 (Cp). 19F NMR: -36.0 (dd, J FF ) 30 Hz, J HF ) 16 Hz,
2-C6HF4); -63.7 (m, 5-C6HF4); -80.6 (m, 3,4-C6HF4). Anal.
Calcd for C35H22F8NPTi: C, 61.16; H, 3.22; N, 2.04. Found:
C, 61.00; H, 2.98; N, 1.87.
2
2H, p-CH2C6H5); 5.78 (s, 5H, Cp); 3.01 (d, J HH ) 9 Hz, 2H,
CH2Ph); 2.61 (d, 2H, CH2Ph). 13C{1H} NMR: 151.3 (ipso-
1
2
CH2C6H5), 135.7 (d, J PC ) 97 Hz, ipso-PC6H5); 133.9 (d, J PC
3
) 32 Hz, o-PC6H5); 132.7 (d, J PC ) 11 Hz, m-PC6H5); 128.2,
Syn th esis of Cp Ti(NP R3)(CH2SiMe3)2 (R ) t-Bu 3 61, P h
62). These compounds were prepared employing similar
procedures using the appropriate starting material. A solution
of Me3SiCH2Li (1.8 mmol, 1.0 M in pentane) in Et2O was added
dropwise at 25 °C to a slurry of 13 (0.32 g, 0.80 mmol) in the
same solvent (30 mL). The heterogeneous mixture was stirred
for 15 h, after which time the solvent was removed in vacuo.
The product was extracted with hexanes (3 × 20 mL) and
filtered through Celite. Removal of the solvent afforded a white
126.9, 125.8, 121.1 (Ar); 113.6 (Cp), 75.9 (CH2Ph). 19F NMR:
14.8. Anal. Calcd for C40H31F9NPTi: C, 61.95; H, 4.03; N, 1.81.
Found: C, 61.56; H, 3.94; N, 1.71. 52 (50%): 31P{1H} NMR:
-6.6. 1H NMR: 7.15 (m, 8H, Ar); 6.98 (m, 8H, Ar); 7.16 (m,
2
6H, Ar); 5.80 (s, 5H, Cp); 3.02 (d, J HH ) 9 Hz, 2H, CH2Ph);
2
2.57 (d, J HH ) 9 Hz, 2H, CH2Ph). 13C{1H} NMR: 165.2 (d,
1J FC ) 255 Hz, C6H4F); 151.8 (ipso-CH2C6H5); 134.8 (dd, J PC
2
) 12 Hz, 3J FC ) 9 Hz, o-PC6H4F); 128.4, 126.9, 120.7 (Ar); 116.1
3
2
solid (0.34 g, 83%). 61: 31P{1H} NMR: 32.5. H NMR: 6.31 (s,
5H, Cp); 1.19 (d, J PH ) 13 Hz, 27H, PCMe3); 1.12 (d, J HH
1
(dd, J PC ) 14 Hz, J FC ) 22 Hz, m-PC6H4F); 113.2 (Cp); 74.0
(CH2C6H5). 19F NMR: -28.5. Anal. Calcd for C37H31F3NPTi:
C, 71.05; H, 5.00; N, 2.24. Found: C, 70.76; H, 4.73; N, 2.07.
53 (71%): 31P{1H} NMR: -3.4. H NMR: 7.52 (dd, J HH ) 8
Hz, J PH ) 12 Hz, 6H, o-PC6H4OMe); 7.10 (d, J HH ) 7 Hz,
4H, o-CH2C6H5); 6.84 (m, 6H, CH2C6H5); 6.72 (dd, J HH ) 8
3
2
)
2
11 Hz, 2H, CH2Si); 0.90 (d, J HH ) 11 Hz, 2H, CH2Si); 0.25 (s,
18H, SiMe3). 13C{1H} NMR: 109.5 (Cp); 42.5 (CH2Si); 40.4 (d,
1J PC ) 47 Hz, PCMe3); 29.6 (PCMe3); 4.3 (SiMe3). Anal. Calcd
for C25H54NPSi2Ti: C, 59.61; H, 10.81; N, 2.78. Found: C,
59.23; H, 10.50; N, 2.09. 62 (98%, red oil): 31P{1H} NMR: -5.7.
1H NMR: 7.71 (m, 6H, Ph); 7.05 (m, 9H, Ph); 6.09 (s, 5H, Cp);
1.32 (s, 1 H, CH2SiMe3); 0.21 (s, 18 H, CH2SiMe3). 13C{1H}
NMR: 134.0 (s, C6H5); 129.0 (d, 1J CP ) 15 Hz, C6H5); 132.1 (s,
C6H5); 129.0 (s, C6H5); 128.9 (s, C6H5), 111.2 (Cp); 61.6 (s, CH2-
SiMe3); 3.6 (s, CH2SiMe3). Anal. Calcd for C31H45NPSi2Ti: C,
65.70; H, 8.00; N, 2.47. Found: C, 65.41; H, 7.80; N, 2.13.
Syn th esis of Cp Ti(NP t-Bu 3)Cl(O-2,6-i-P r 2C6H3) (63). To
1 g (2.5 mmol) of 13 was added 600 mg (2.8 mmol) of Na[O-
2,6-(i-Pr)2C6H3] and 50 mL of benzene. The dark yellow-orange
mixture was stirred for 2 days at room temperature, after
which the NaCl was filtered off, yielding a dark yellow-orange
solution. Removal of volatiles in vacuo gave 1.30 g (96%) of
1
3
3
3
3
4
Hz, J PH ) 2 Hz, 6H, m-PC6H4OMe); 5.93 (5H, Cp); 3.26 (d,
2J HH ) 9 Hz, 2H, CH2Ph); 3.19 (9H, OMe); 2.65 (d, J HH ) 9
2
Hz, 2H, CH2Ph). 13C{1H} NMR: 162.6 (p-PC6H4OMe), 152.2
3
(ipso-CH2C6H5); 134.5 (d, J PC ) 12 Hz, m-C6H4OMe); 128.1,
127.1, 124.5, 120.3 (Ar); 114.3 (d, J PC ) 13 Hz, o-CH2C6H5);
113.1 (Cp); 72.1 (s, CH2Ph); 54.9 (OMe). Anal. Calcd for C40H40
NO3PTi: C, 72.62; H, 6.09; N, 2.12. Found: C, 72.27; H, 5.79;
N, 2.01. 54 (56%): 31P{1H} NMR: 18.9. 1H NMR: 7.80 (d, 3J HH
2
-
3
) 7 Hz, 4H, o-C6H5); 7.22 (t, J HH ) 7 Hz, 4H, m-C6H5); 7.13
(t, 3J HH ) 7 Hz, 2H, Ph); 6.40 (s, 5H, Cp); 1.82-1.00 (bm, 33H,
Cy). 13C{1H} NMR: 190.6 (s, ipso-C6H5); 136.7, 126.2, 125.7
(s, Ph); 112.6 (Cp); 36.4(d, 1J PC ) 56 Hz, PCH), 27.1, 26.9, 26.3
(Cy). Anal. Calcd for C35H48NPTi: C, 74.85; H, 8.61; N, 2.49.
Found: C, 74.32; H, 8.39; N, 2.22. 55 (94%): 31P{1H} NMR:
26.3. 1H NMR: 7.78 (dd, 3J HH ) 7 Hz, 4J HH ) 2 Hz, 4H, o-C6H5);
the dark yellow product. 31P{1H} NMR: 40.1. H NMR: 7.22
1
(d, 2H, 3J HH ) 7 Hz, m-C6H3); 7.05 (t, 3J HH ) 7 Hz, 1H, p-C6H3);
3
3
6.35 (s, 5H, Cp); 3.92 (sept, 2H, CHMe2); 1.41 (d, 3J HH ) 7 Hz,
7.22 (t, J HH ) 7 Hz, 4H, m-C6H5); 7.13 (t, J HH ) 7 Hz, 2H,
p-C6H5); 6.35 (s, 5H, Cp); 1.60 (m, 3H, PCHMe2); 0.80 (dd, 3J HH
3
2
6H, CHMe2); 1.35 (d, J HH ) 7 Hz, 6H, CHMe2); 1.18 (d, J PH
) 13 Hz, 27H, PCMe3). 13C{1H} NMR (partial): 163.7 (OC6H3);
123.5, 120.6 (C6H3); 113.8 (Cp); 41.6 (d, 1J PC ) 45 Hz, PCMe3);
29.4 (PCMe3); 26.3 (CHMe2); 24.6 (CHMe2). Anal. Calcd for
3
) 7 Hz, J PH ) 14 Hz, 18H, PCHMe2). 13C{1H} NMR: 190.5
(ipso-C6H5); 136.6, 126.2, 125.8 (C6H5); 112.6 (s, Cp); 25.8 (d,
1J PC ) 51 Hz, PCHMe2); 16.8 (PCHMe2). Anal. Calcd for C26H36
NPTi: C, 70.75; H, 8.22; N, 3.17. Found: C, 70.29; H, 8.14; N,
3.11. 56 (80%): 31P{1H} NMR: 35.9. H NMR: 7.75 (d, J HH
) 8 Hz, 4H, o-C6H5); 7.23 (t, J HH ) 8 Hz, 4H, m-C6H5); 7.13
-
C
29H49ClNOPTi: C, 64.26; H, 9.11; N, 2.58. Found: C, 63.88;
1
3
H, 8.95; N, 2.55.
3
Eth ylen e P olym er iza tion . (i) Schlenk line polymeriza-
tion: A solution of 6-10 µmol of catalyst precursor in 2.0 mL
of dry toluene was added to a flask containing 2.0 mL of dry
toluene. Five hundred equivalents of a 10 wt % toluene
solution of MAO was added to the flask. Alternatively, the
catalyst precursors were combined with [Ph3C][B(C6F5)4] under
an ethylene atmosphere at 25 °C. The flask was attached to a
Schlenk line with a cold trap, a stopwatch was started, and
the flask was evacuated three times for 5 s and refilled with
predried 99.9% ethylene gas. The solution was rapidly stirred
under 1 atm of ethylene at room temperature. The polymer-
ization was quenched by the injection of a 1.0 M HCl/MeOH
solution. The total reaction time was noted, and the polymer
was isolated. (ii) Bu¨chi reactor: A typical experiment is as
follows: a 1 L autoclave was dried under vacuum (10-2 mmHg)
for several hours. Toluene (500 mL) was transferred into the
vessel under a positive pressure of N2 and was heated to 30
°C. The temperature was controlled (to ca. (2 °C) with an
external heating/cooling bath and was monitored by a ther-
mocouple that extended into the polymerization vessel. A
solution of MAO (500 equiv) in toluene was injected, and the
mixture was stirred for 3 min at 150 rpm. The precatalyst in
a solution of toluene was then injected, and the reaction
mixture was stirred for an additional 3 min at the same rate.
The rate of stirring was increased to 1000 rpm, and the vessel
was vented of N2 and pressurized with ethylene (33 psi). Any
recorded exotherm was within the allowed temperature dif-
ferential of the heating/cooling system. The solution was
stirred for 1 h, after which time the reaction was quenched
with 1 M HCl in MeOH. The precipitated polymer was
3
3
(t, J HH ) 7 Hz, 2H, p-C6H5); 6.35 (s, 5H, Cp); 1.06 (d, J PH
)
13 Hz, 27H, PCMe3). 13C{1H} NMR: 190.2 (ipso-C6H5); 136.1,
126.3, 125.5 (C6H5); 113.1 (Cp); 41.8 (d, 1J PC ) 46 Hz, PCMe3);
29.5 (PCMe3). Anal. Calcd for C29H42NPTi: C, 72.04; H, 8.76;
N, 2.90. Found: C, 71.65; H, 8.65; N, 2.91. 57: 31P{1H} NMR:
-4.6. 1H NMR: 7.93 (dd, J HH ) 7 Hz, J PH ) 2 Hz, 6H,
3
3
3
o-PC6H5); 7.70 (m, 4H, o-C6H5); 7.13 (t, J HH ) 7 Hz, 4H,
m-C6H5); 6.96 (m, 11H, Ar); 6.23 (s, 5H, Cp). 13C{1H} NMR:
1
192.4 (ipso-C6H5); 137.0, 132.7 (C6H5); 132.1 (d, J PC ) 60 Hz,
ipso-PC6H5); 128.7 (d, J PC ) 11 Hz, o-C6H5); 128.5, 128.3
2
(C6H5), 126.4 (d, 3J PC ) 9 Hz, m-PC6H5); 113.0 (Cp). Anal. Calcd
for C35H30NPTi: C, 77.35; H, 5.56; N, 2.58. Found: C, 77.22;
H, 5.38; N, 2.32. 58 (73%): 31P{1H} NMR: 25.4. 1H NMR: 8.13
(4H, o-C6H3); 7.70 (2H, p-C6H3); 6.09 (5H, Cp); 1.64-1.00 (m,
33H, Cy). 13C{1H} NMR: 188.1 (ipso-C6H3); 136.5, 128.7 (C6H3);
121.4 (q, 1J FC ) 287 Hz, PhCF3); 113.7 (Cp); 36.0 (d, 2J PC ) 55
Hz, PCH); 26.8, 26.3, 25.9 (Cy). 19F{1H} NMR: 15.4. Anal.
Calcd for C39H44F12NPTi: C, 56.19; H, 5.32; N, 1.68. Found:
C, 55.87; H, 5.19; N, 1.32. 59 (80%): 31P{1H} NMR: 2.08. H
NMR: 8.22 (s, 4H, o-C6H3); 7.65 (s, 2H, p-C6H3); 7.47 (m, 6H,
o-PC6H5); 7.01 (m, 9H, PC6H5); 5.95 (s, 5H, Cp). 13C{1H}
1
2
NMR: 188.6 (ipso-C6H5); 132.4 (d, J PC ) 30 Hz, o-PC6H5);
1
136.7, 132.1, 130.9, 129.6, 129.1, 119.9 (C6H5); 124.9 (q, J FC
) 273 Hz, PhCF3); 114.2 (Cp). 19F{1H} NMR: 15.4. Anal. Calcd
for C39H26F12NPTi: C, 57.44; H, 3.21; N, 1.72. Found: C, 56.98;
H, 3.07; N, 1.74. 60 (82%): 31P{1H} NMR: 2.9. 1H NMR: 7.51
3
3
3
(dd, J HH ) 8 Hz, J PH ) 2 Hz, 6H, o-PC6H5); 7.21 (dd, J HF
)
4
15 Hz, J HF ) 2 Hz, 2H, C6F4H); 6.97 (m, 9H, PC6H5); 6.16
(5H, Cp). 13C{1H} NMR (partial): 132.7-127.5 (br-m, Ar);

1942 Organometallics, Vol. 22, No. 9, 2003
Stephan et al.
Ta ble 1. Com p ou n d Nu m ber in g
Cp′
compound type
R3PNSiMe3
R
Et 1, Cy 2, i-Pr 3, t-Bu 4, Ph 5, p-MeC6H4 6, p-CF3C6H4 7,
p-FC6H4 8, p-CH3OC6H4
9
Cp′Ti(NPR3)Cl2
C5H5
Et 10, Cy 11, i-Pr 12, t-Bu 13, Ph 14, p-MeC6H4 15,
p-CF3C6H4 16, p-FC6H4 17, p-CH3OC6H4 18
Me3SiC5H4
C5Me5
i-Pr 19, t-Bu 20
i-Pr 21, t-Bu 22
Indenyl
t-BuC5H4
n-BuC5H4
Ph4C5H
C5H5
i-Pr 23, t-Bu 24
Cy25, i-Pr 26, t-Bu 27
t-Bu 28
t-Bu 29
Cp′Ti(NPR3)Me2
Cy30, i-Pr 31, t-Bu 32, Ph 33, p-MeC6H4 34, p-CF3C6H4 35,
p-FC6H4 36, p-CH3OC6H4 37
C5Me5
i-Pr 38, t-Bu 39
Indenyl
t-BuC5H4
Ph4C5H
i-Pr 40, t-Bu 41
Cy42, i-Pr 43, t-Bu 44
t-Bu 45
CpTi(NPR3)Bn2
Cy46, i-Pr 47, t-Bu 48, Ph 49, p-MeC6H4 50, p-CF3C6H4 51,
p-FC6H4 52, p-CH3OC6H4 53
Cy54, i-Pr 55, t-Bu 56, Ph 57
Cy 58, Ph 59
Ph 60
t-Bu 61 Ph 62
CpTi(NPR3)Ph2
CpTi(NPR3)(C6H3-3,5-(CF3)2)2
CpTi(NPR3)(C6H-2,3,4,5-F4)2
CpTi(NPR3)(CH2Si(CH3)3)2
CpTi(NPR3)Cl(O-2,6-i-Pr2C6H3)
t-Bu 63
Sch em e 1
subsequently washed with MeOH and dried at 100 °C for at
least 24 h prior to weighing.
X-r a y Da ta Collection a n d Red u ction . X-ray quality
crystals were obtained directly from the preparations as
described above. The crystals were manipulated and mounted
in capillaries in a glovebox, thus maintaining a dry, O2-free
environment for each crystal. Diffraction experiments were
performed on a Siemens SMART System CCD diffractometer.
The data were collected for a hemisphere of data in 1329
frames with 10 s exposure times. Crystal data are summarized
in Table 2. The observed extinctions were consistent with the
space groups in each case. 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 no
statistically significant change over the duration of the data
collections. An empirical absorption correction based on re-
dundant data was applied to each data set. Subsequent
solution and refinement was performed using the SHELXTL
solution package.
Resu lts a n d Discu ssion
Syn th esis a n d Ch a r a cter iza tion . Numerous phos-
phines can be oxidized to the corresponding phosphin-
imine derivative by reaction with Me3SiN3.46 In this
manner, the series of compounds R3PNSiMe3 (Table 1)
have been prepared. Several of these phosphinimines
have been previously prepared,46 although the present
report provides full NMR spectroscopic data for these
ligand precursors. Subsequent reaction with CpTiCl3
provides facile access to the corresponding series of
complexes of the form CpTi(NPR3)Cl2 (Table 1). Em-
ploying the appropriate precursors, this family of com-
pounds can be readily extended to include substitution
on the cyclopentadienyl ligand or Cp alternatives. In
this fashion the species (Cp′)Ti(NPR3)Cl2 (Table 1) were
also readily prepared. The synthetic routes are general-
ized in Scheme 1. All of these species are obtained in
high yield and are readily purified by recrystallization.
Compounds 11-13, 21-23, 27, and 28 have been
characterized crystallographically. Representative struc-
tures of the dichloride derivatives are presented in
Figures 1-5. In all cases the Ti adopts a pseudo-
tetrahedral geometry with the cyclopentadienyl ligand
or its analogue, the two chlorides and the phosphinimide
nitrogen completing the coordination sphere. It is
noteworthy that the indenyl group in 23 and the
St r u ct u r e Solu t ion a n d R efin em en t . Non-hydrogen
atomic scattering factors were taken from the literature
tabulations.53 The heavy atom positions were determined using
direct methods. 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 w(Fo - Fc)2
where the weight w is defined as 4Fo2/2σ(Fo2) and Fo and Fc
are the observed and calculated structure factor amplitudes.
For non-centrosymmetric space groups, the correct enantio-
morph was confirmed by data inversion and refinement. 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 Å. 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 final values
of refinement parameters are given in Table 2. Positional
parameters, hydrogen atom parameters, thermal param-
eters, and bond distances and angles have been deposited as
Supporting Information.
(53) Cromer, D. T.; Mann, J . B. Acta Crystallogr. A 1968, A24, 321-
324.

An Approach to Catalyst Design
Organometallics, Vol. 22, No. 9, 2003 1943
Ta ble 2. Cr ysta llogr a p h ic P a r a m eter sa
11
12
13
21
formula
fw
a (Å)
b (Å)
c (Å)
C
23H38Cl2NPTi
C14H26Cl2NPTi
358.13
C20.5H35.5Cl2NPTi
445.77
33.537(10)
8.532(3)
17.963(5)
110.349(7)
monoclinic
C2/c
C19H36Cl2NPTi
428.26
13.064(3)
12.971(3)
13.928(3)
102.29(2)
monoclinic
P2(1)/n
2306.1(9)
1.234
478.31
8.8309(6)
18.8687(12)
14.8404(10)
90.7500(10)
monoclinic
P2(1)/c
2472.6(3)
1.285
14.4159(8
16.1783(9)
15.8076(9)
91.4547(11)
monoclinic
P2(1)/c
3685.5(4)
1.291
â (deg)
cryst syst
space group
vol (Å3)
4819(2)
1.229
Dcalcd (g cm-1
)
Z
4
8
8
4
abs coeff, µ, mm-1
0.636
9328
3524
253
0.0462
0.1110
1.036
0.830
14139
6258
343
0.0472
0.0902
0.832
0.648
1695
1634
215
0.1239
0.2727
1.341
0.674
1862
1262
217
0.0363
0.0938
0.757
no. of data collected
2
2
no. of data Fo > 3σ(Fo
no. of variables
R (%)
Rw (%)
goodness of fit
)
22
22H42Cl2NPTi
23
27
formula
fw
a (Å)
b (Å)
c (Å)
C
C18H28Cl2NPTi
408.18
17.160(2)
13.119(2)
18.646(4)
C21H40Cl2NPTi
470.34
11.6734(6)
16.6150(9)
13.614(7)
98.2953(11)
monoclinic
P2(1)/n
2612.9(14)
1.196
456.31
8.4136(2)
15.8989(2)
19.3131(4)
96.8610(10)
monoclinic
P2(1)/c
2564.95(9)
1.182
â (deg)
cryst syst
space group
vol (Å3)
orthorhombic
Pca2(1)
4197.5(12)
1.292
Dcalcd (g cm-1
)
Z
4
8
4
abs coeff, µ, mm-1
0.601
12 914
4553
0.738
20 359
7302
0.610
12 749
4447
no. of data collected
2
2
data Fo > 3σ(Fo
no. of variables
R (%)
Rw (%)
goodness of fit
)
244
415
235
0.0598
0.1604
1.061
0.0394
0.0620
0.764
0.0530
0.1531
1.030
28
56
62
63
formula
fw
a (Å)
b (Å)
C
21H40Cl2NPTi
C29H42NPTi
483.51
18.54800
15.0094
C31H42NPSi2Ti
563.71
11.069(5)
12.798(6)
12.887(6
100.195(9)
100.894(9)
105.726(9)
triclinic
P1h
C29H49ClNOPTi
542.01
17.777(6)
10.7647(15)
32.068(7)
456.31
15.472(4)
8.5317(13)
18.928(4)
c (Å)
19.65940(10)
R (deg)
â (deg)
γ (deg)
cryst syst
space group
vol (Å3)
Dcalcd (g cm-1
Z
100.973(12)
monoclinic
P2(1)/n
2452.8(8
1.236
orthorhombic
Pbca
5473.07(8)
1.174
orthorhombic
Pca2(1)
6136(3)
1.173
1674.5(14
1.118
)
4
8
2
8
abs coeff, µ, mm-1
no. of data collected
no. of data Fo > 3σ(Fo
no. of variables
R (%)
0.638
12 066
4284
0.387
25 063
4794
0.393
7166
4749
325
0.0412
0.1078
1.029
0.439
11 100
6168
2
2
)
235
289
608
0.0375
0.0980
1.057
0.0874
0.2115
1.022
0.0655
0.1515
0.945
Rw (%)
goodness of fit
All data collected at 24 °C with Mo KR radiation (λ ) 0.71069 Å), R ) ∑||Fo| - |Fc||/∑|Fo|, Rw ) [∑[w(Fo - Fc2)2]/∑[wFo2)2]]0.5
.
a
2
cyclopentadienyl substitutents in 27 and 28 are oriented
vary only slightly, averaging 102.6(10)° and 102.4(8)°,
away from the phosphinimide ligand, presumably re-
flecting a preferred geometry in which steric conflicts
are minimized.
The key metric parameters for these structures are
presented in Table 3. In each case, the geometry about
the N atom is approximately linear with the P-N-Ti
angles ranging between 159.6(2)° and 176.6(4)°. The
P-N and Ti-N distances are very similar in all these
compounds, averaging 1.606(7) and 1.758(14) Å, respec-
tively. Similarly, the Cl-Ti-Cl and N-Ti-Cl angles
respectively. The angles at Ti between the centroid of
the η5-carbons of the Cp-type ligands and N appear to
reflect the steric demands of both ligands. For com-
pounds 11-13 the N-Ti-Cp angles range from 116.1°
for the i-Pr3PN derivative to 122.0° for the t-Bu3PN
species. For compounds 27 and 28 this angle is similar
to that seen for 13; however it increases to 125.3° for
compound 22, consistent with the steric influence of the
substituted cyclopentadienyl ligand. Similarly, the
N-Ti-Cp angle in 23 of 120.3° is significantly higher

1944 Organometallics, Vol. 22, No. 9, 2003
Stephan et al.
F igu r e 1. ORTEP drawing of 13, 30% thermal ellipsoids,
H atoms omitted for clarity.
F igu r e 5. ORTEP drawing of 28, 30% thermal ellipsoids,
H atoms omitted for clarity.
F igu r e 2. ORTEP drawing of 21, 30% thermal ellipsoids,
H atoms omitted for clarity.
F igu r e 6. ORTEP drawing of 56, 30% thermal ellipsoids,
H atoms omitted for clarity. Ti(1)-N(1) 1.783(3) Å, Ti(1)-
C(24) 2.128(5) Å, Ti(1)-C(18) 2.170(5) Å, N(1)-P(1)
1.602(4) Å; Ti(1)-N(1)-P(1) 169.4(3)°, N(1)-Ti(1)-C(24)
105.27(18)°, N(1)-Ti(1)-C(18) 99.87(18)°.
F igu r e 3. ORTEP drawing of 23, 30% thermal ellipsoids,
H atoms omitted for clarity.
F igu r e 7. ORTEP drawing of 62, 30% thermal ellipsoids,
H atoms omitted for clarity. Ti(1)-N(1) 1.814(2) Å, Ti(1)-
C(5) 2.128(3) Å, Ti(1)-C(1) 2.139(3) Å, P(1)-N(1) 1.581(2)
Å,
N(1)-Ti(1)-C(1)
104.05(11)°,
C(5)-Ti(1)-C(1)
97.34(12)°, P(1)-N(1)-Ti(1) 160.44(15)°.
(Table 1, Scheme 1). As a final example, the species
CpTi(NPR3)(CH2SiMe3)2 (R ) t-Bu3 61, Ph 62) was
readily obtained in 83% yield via the reaction of 13 and
14 with the alkylating agent (CH3)3SiCH2MgCl. For all
of alkyl/aryl derivatives, full spectroscopic characteriza-
tions were consistent with the formulations.
X-ray crystallographic data were also obtained for
compounds 56 (Figure 6) and 61 (Figure 7). The
structures of compounds 56 and 62 are as expected. The
Ti-N distance in 56 of 1.783(3) Å is only slightly longer
than that seen in 13, whereas the corresponding dis-
tance in 62 is significantly longer (1.814(2) Å). This
reflects the differing donor abilities of both the alkyl and
aryl groups as well as that of the phosphinimide ligands.
The P-N-Ti angle in 56, 169.4(2)°, falls in the range
observed for the complexes above. On the other hand,
the smaller P-N-Ti angle (160.44(15)°) and the shorter
P-N distance (1.581(2) Å) in 62 reflect the poorer donor
F igu r e 4. ORTEP drawing of 27, 30% thermal ellipsoids,
H atoms omitted for clarity.
than that found in 12 (116.1°), again reflecting what is
predominantly a steric influence of indenyl versus
cyclopentadienyl ligands.
The reactions of the above precursors with 2 equiv of
MeLi proceed, in general, in high yields, providing a
facile route to the series of compounds of the form CpTi-
(NPR3)Me2 and Cp†Ti(NPR3)Me2 (Table 1). In a similar
fashion, reactions with benzyl-Grignard reagents afford
bis-benzyl derivatives, CpTi(NPR3)Bn2 (R ) Cy 46, i-Pr
47, t-Bu 48, Ph 49, p-MeC6H4 50, p-CF3C6H4 51,
p-FC6H4 52, p-MeOC6H4 53) in high yield. Arylation
using PhLi or related substituted Grignard reagents
also proceeds efficiently to give the compounds 54-60

An Approach to Catalyst Design
Organometallics, Vol. 22, No. 9, 2003 1945
Ta ble 3. Metr ic P a r a m eter sa for Com p ou n d s of th e F or m (Cp ′)Ti(NP R3)Cl2
cmpd
Ti-Cl
Ti-N
N-P
Cl-Ti-Cl
N-Ti-Clav
Ti-N-P
N-Ti-Cpb
11
2.3074(9)
2.3098(9)
2.2928(14)
2.3015(13)
2.2945(13)
2.3020(12)
2.309(3)
2.313(12)
2.299(3)
2.314(2)
2.3050(18)
2.3204(15)
2.2932(14)
2.3067(12)
2.2968(13)
2.3021(13)
2.3096(10)
2.3148(11)
2.3114(8)
2.3162(9)
1.755(2)
1.606(2)
102.12(4)
103.43(8)
102.55(8)
102.79(10)
102.67(10)
103.39(10)
103.73(10)
102.6(2)
172.02(15)
121.3
12
1.750(3)
1.750(3)
1.775(11)
1.759(4)
1.794(3)
1.741(4)
1.746(4)
1.761(2)
1.7587(18)
1.609(3)
1.616(3)
1.593(10)
1.608(4)
1.595(3)
1.611(4)
1.600(4)
1.612(2)
1.6033(19)
102.07(6)
101.66(5)
102.69(12)
102.14(10)
100.70(7)
102.96(6)
103.68(5)
103.42(5)
102.13(3)
169.84(19)
167.24(19)
176.6(4)
116.1
13
21
22
23
122.0
122.6
125.3
120.3
102.7(2)
102.8(2)
167.8(4)
101.86(17)
101.68(11)
102.56(10)
104.20(13)
101.61(11)
103.73(12)
101.31(11)
101.72(8)
101.84(8)
101.65(6)
102.55(7)
165.5(2)
159.6(2)
163.9(2)
27
28
176.28(15)
175.91(12)
122.3
122.3
a
Where two set of parameters are reported, the structural data reveal two molecules in the asymmetric unit; errors in parentheses are
b
the standard deviations computed on the basis of the five bond lengths. N-Ti-Cp angles refer to the angle at Ti between N and the
centroid of the five η5-carbons.
structure-activity correlations in olefin polymerization.
Polymerization of ethylene was examined initially in
small-scale Schlenk line catalyst screening experiments.
Compounds 11-31 were employed as catalyst precur-
sors using 500 equiv of methylalumoxane (MAO) as the
activator (Table 4). In general, these catalysts exhibit
single site activity, as evidenced by the relatively narrow
polydispersities of the resulting polyethylene (PE).
However, the PE derived from compounds 11, 12, 25,
and 26 show bimodal distributions of molecular weights,
suggesting the presence of more than one active site. It
is noteworthy that in these cases although these cata-
lysts have reduced activity, Mw’s of PE as high as 9 ×
105 g/mol were observed.
F igu r e 8. ORTEP drawing 63 (one of the two molecules
in the asymmetric unit), 30% thermal ellipsoids, H atoms
omitted for clarity. Ti(1)-N(1) 1.775(9) Å, Ti(1)-O(1)
1.846(8) Å, Ti(1)-Cl(1) 2.339(4) Å, P(1)-N(1) 1.588(10) Å,
N(1)-Ti(1)-O(1) 104.1(4)°, N(1)-Ti(1)-Cl(1) 101.5(3)°,
O(1)-Ti(1)-Cl(1) 101.9(3)°, P(1)-N(1)-Ti(1) 170.9(7)°, C(6)-
O(1)-Ti(1) 153.3(8)°.
The catalysts derived from compounds 14-18 permit
examination of electronic factors, as these species are
essentially isosteric. The observed differences in activity
are relatively small, but the trend suggests that electron-
donating substituents favor somewhat higher activities.
On the other hand, the catalysts derived from 10-13
are electronically similar, although the steric demands
of the ancillary phosphinimide ligand vary significantly.
The observed activities in these cases infer marked
dependence on steric factors, as all of the tri-tert-
butylphosphimide complexes 13, 20, 27, 44, and 62
showed activities that are comparable to those observed
for Cp2ZrCl2 and the constrained geometry catalyst [(C5-
Me4SiMe2N-t-Bu)TiCl2 (CGC). Also, they are signifi-
cantly higher than those observed for Cp2TiCl2 or
CpTiCl3 using the same apparatus and conditions. In
contrast the catalysts derived from the smaller phos-
phinimide ligands exhibit markedly reduced activity.
GPC data for the PE derived for the active systems
reveal average Mw from 55 000 to 203 500 with poly-
dispersities of 1.6-2.4.
ability of the Ph3PN ligand. The C(18)-Ti-C(24) angle
of 101.48(19)° in 56 and the C(5)-Ti-C(1) angle of
97.34(12)° in 61 are smaller than the Cl-Ti-Cl angles
described above. The Ti-C bond lengths (2.128(5),
2.170(5) Å) in 56 are significantly shorter than those
seen in Cp2TiPh2 (2.272(14) Å)54 but similar to those
seen in 61 (2.128(3), 2.139(3) Å). This presumably
reflects the electron-deficient nature of the Ti center in
these compounds relative to that in the corresponding
titanocene.
Substitution of one of the chloride ligands of 13 was
also achieved by direct reaction with the bulky aryloxide
salt Na[O-2,6-(i-Pr)2C6H3]. In this manner, the species
CpTi(NP(t-Bu)3)Cl(O-2,6-i-Pr2C6H3), 63, was obtained in
96% yield. The spectroscopic data confirmed the formu-
lation as well as the diastereotopic nature of the
isopropyl methyl groups. A crystallographic study of 63
(Figure 8) revealed Ti-N and Ti-O distances of
1.775(9) and 1.846(8) Å, respectively, with P-N-Ti and
C-O-Ti angles of 170.9(7)° and 153.3(8)°, suggesting
that phosphinimide is a stronger π-donor than the
aryloxide.
Initial small-scale Schlenk line screenings were per-
formed employing dimethyl complexes 30-32 and 42-
44 as catalyst precursors and using [Ph3C][B(C6F5)4] as
the activator. These phosphinimide-based catalysts
rapidly generate high molecular weight, highly linear
(by NMR) polyethylene. The polymer generated from
complexes 30-32 range in Mw from 135 000 to 165 000
Eth ylen e P olym er iza tion . The synthetic chemistry
above provides facile access to a large series of related
Ti complexes. This offers an opportunity to probe
(54) Kocman, V.; Rucklidge, J . C. Chem. Commun. 1971, 1340.

1946 Organometallics, Vol. 22, No. 9, 2003
Ta ble 4. Eth ylen e P olym er iza tion Scr een in g Da ta
Stephan et al.
b
b
pre-cat.
co-cat.a
activitya
Mw
PDIe
pre-cat.
co-cat.a
activitya
Mw
PDIe
10
11
MAO/a
MAO/a
13
42
23
MAO/a
MAO/a
28
425
3590
336 000
18 700
578 500
89 900
1.8
2.2
2.8
2.4
1.6
24
25
26
12
13
MAO/a
MAO/a
49
MAO/a
MAO/a
46
16
7410
893 500
7580
910 200
65 400
2.1
3.4
1.9
2.5
2.4
652
14
15
16
17
18
19
20
21
22
30
31
32
32
32
MAO/a
MAO/a
MAO/a
MAO/a
MAO/a
MAO/a
MAO/a
MAO/a
MAO/a
TB/a
34
35
31
34
47
16
494
30
1400
231
225
401
830
<1
109 200
2.6
27
28
44
61
MAO/a
MAO/a
MAO/a
MAO/b
MAO/a
MAO/a
MAO/a
MAO/a
MAO/a
MAO/c
TB/a
881
2000
853
300
765
895
630
415
<10
670
1807
1193
1296
1485
55 600
81 400
203 500
116 353
2.3
3.6
1.9
2.8
62
Cp2ZrCl2
CGCd
Cp2TiCl2
CpTiCl3
Cp2ZrCl2
42
43
44
13
135 800
1.7
134 600
163 800
165 800
812 000
2.8
3.9
3.4
1.7
340 800
310 200
259 200
321 300
2.1
7.5c
TB/a
TB/a
MAO/c
TMA/c
TB/a
TB/a
MAO/c
9.9c
12.3c
a
MAO, methylalumoxane (500 equiv); TB, trityl tetrakispentafluorphenylborate (2 equiv); TMA, trimethylaluminum. Activity reported
in g/mmol/h/atm. Conditions: (a) Schlenk line, 1 atm pressure of ethylene and 25 °C, 5 min. (b) Schlenk line, 1 atm pressure of ethylene
and 25 °C, 30 min. (c) Buchi reactor, 1.8 atm pressure of ethylene, 30 °C, 30 min. b Molecular weight data were recorded against polyethylene
standards. c The high activity of these systems together with the observation of polydispersities in the range 7-12 suggest that these
d
polymerizations rapidly become diffusion-controlled reactions. CGC ) [(C5Me4SiMe2N-t-Bu)TiCl2. e Where two MWs are reported, GPC
curves were clearly bimodal and the quoted polydispersities were derived from a computational fit.
Sch em e 2
g/mol with polydispersities in the range of 2.4-3.8. The
catalysts derived from analogous tert-butylcyclopenta-
dienyl complexes 42-44 and trityl-borate activation
gave even higher molecular weight polyethylene
(Mw: 260-320 000). Moreover it was very encouraging
to note that the activities of the latter systems were as
much as twice that derived from Cp2ZrCl2 and three
times that derived from the CGC, under similar condi-
tions.
Selected cases were scaled up for testing on a Bu¨chi
reactor. In this system, typically 600-700 mL of solvent
imide ligands, though clearly this notion is fraught with
was employed with catalyst concentrations of approxi-
limitations. However, from the above structural data,
mately 50 µmol/L while the ethylene pressure was
around 1.8 atm. The trials reported here are 30 min,
and the active catalysts produce 10-20 g of PE. In this
manner, catalysts derived from compounds 13 and 32
the maximum angle subtended at Ti or the “cone
angle”59,60 for the phosphinimide ligand, t-Bu3PN, was
determined to be approximately 87°, similar to that
observed for a metal-bound cyclopentadienyl ligand (83°)
with MAO activation showed activity of 1485 and 830
(Scheme 2). This suggests that these ligands occupy
g PE/mmol/h/atm, respectively. Interestingly, changes
approximately similar volumes about the Ti center. On
to the Al activator had dramatic effects. Replacing MAO
the other hand, it is clear that the steric bulk of a
with AlMe3 results in a dramatic plummet in activity.
phosphinimide ligand is considerably removed from the
We have recently described reactions of CpTi(NPR3)-
metal as the Ti-P distance is over 3 Å, whereas the
Me2 with AlMe3 which proceed through a series of C-H
Ti-Cp-centroid distance is about 2.2 Å. The polymeri-
activation reactions, ultimately affording Ti-Al-carbide
zation data also suggest that steric factors play a
aggregates.49,55-58 This chemistry may account for the
significant role in determining the effectiveness of a
catalyst. For example, those catalysts incorporating tert-
butylphosphinimide ligands as in 13, 20, 22, 24, 27, and
28 are in general quite active. On the other hand, for
dramatic reduction in activity of these catalysts in the
presence of AlMe3.
Ca ta lyst Design Con sid er a tion s. The results above
demonstrate that the family of compounds of the form
the systems where additional substitution on the cyclo-
(Cp†)TiX2(NPR3) are effective catalyst precursors for
pentadienyl ligand contributes to the definition of the
olefin polymerization. The original concept on which
active site, sterically less demanding phosphinimide
these developments were based was the notion of a
ligands still provide for high activity. Examples of this
steric analogy between cyclopentadienyl and phosphin-
latter situation are the catalysts derived from com-
pounds 42 and 43. These polymerization data suggest
(55) Guerin, F.; Stephan, D. W. Angew. Chem., Int. Ed. 1999, 38,
3698-3701.
that the general strategy of employing ancillary ligands
with similar steric bulk to cyclopentadienyl ligands has
some viability. On the other hand, it also reveals
(56) Kickham, J . E.; Guerin, F.; Stewart, J . C.; Stephan, D. W.
Angew. Chem., Int. Ed. 2000, 39, 3263-3266.
(57) Kickham, J . E.; Guerin, F.; Stewart, J . C.; Urbanska, E.; Ong,
C. M.; Stephan, D. W. Organometallics 2001, 20, 1175-1182.
(58) Yue, N.; Hollink, E.; Gue´rin, F.; Stephan, D. W. Organometallics
2001, 20, 4424-4433.
(59) Tolman, C. A. J . Am. Chem. Soc. 1970, 92, 2956-2965.
(60) Tolman, C. A. Chem. Rev. 1977, 77, 313-348.

An Approach to Catalyst Design
Organometallics, Vol. 22, No. 9, 2003 1947
limitations of this approach, in that the very subtle
changes to the steric demands result in major changes
in activity. Although these subtleties are not well
understood, it is thought that the role of steric conges-
tion is to preclude deactivation pathways, includ-
ing cation dimerization and interaction with Lewis
acids leading to C-H activation. We have identified
these pathways in related phosphinimide complex sys-
tems.56,58,61,62
It is perhaps surprising that the complexes described
herein are highly effective catalysts, given the similar
success associated with the CGC. While both systems
provide a cyclopentadienyl- and N-based ligand to the
Ti center, the Cp-centroid-Ti-N angles (Table 3) in the
present phosphinimide complexes are significantly
greater than that found in the CGC (107.6°).43 This
seems to counter the notion that increased exposure of
the Ti center is required for heightened reactivity.
The electronic character of phosphinimide ligands has
been previously probed by Dehnicke and co-workers.45-48
The σ-π2 nature of the interaction with a metal center
suggests an electronic analogy to a cyclopentadienyl
ligand as well. Nonetheless the present polymerization
data demonstrate that minor perturbations to the donor
ability of the phosphinimide alter the activity of the
resulting catalysts to a small extent. However, it is
noteworthy that this comparison is made among cata-
lysts that operate in a low-activity regime. It may be
that electronic effects would be more dramatic for higher
activity systems. This aspect is the subject of ongoing
synthetic efforts.
In summary, the feasibility of an approach to catalyst
design based on the steric analogy between phosphin-
imide and cyclopentadienyl ligands is supported by the
family of titanium phosphinimide complexes (Cp†)TiX2-
(NPR3). Both the demonstrated activity of these species
in olefin polymerization and the metric parameters of
the titanium-phosphinimide complexes support the view
that such ligands provide a metal environment that
mimics metallocenes to some extent. Among the present
systems, it appears that steric rather than electronic
factors are key to the generation of highly active
systems. The optimization of the catalyst structure for
activity continues to be one focus of our efforts. Efforts
to apply these systems to a variety of other processes
are also the subjects of ongoing studies.
Ack n ow led gm en t . Financial support from the
NSERC of Canada and NOVA Chemicals Corporation
is gratefully acknowledged. Thanks to Keith Christall
for the synthesis of 28. D.W.S. is grateful to the
Alexander von Humboldt Stiftung for the award of a
Forschungpreis.
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
information tables as well as ORTEP drawings of all structures
reported herein. This material is available free of charge via
the Internet at http://pubs.acs.org.
(61) Yue, N. L. S.; Stephan, D. W. Organometallics 2001, 20, 2303-
2308.
(62) Kickham, J . E.; Guerin, F.; Stewart, J . C.; Urbanska, E.; Ong,
C. M.; Stephan, D. W. Organometallics 2001, 20, 3209.
OM020954T