Phenylene-bridged Cp/carboxamide ligands for titanium complexes of various binding modes and their ethylene/1-octene copolymerization

Article abstract of DOI:10.1021/om060604x

o-Phenylene-bridged or substituted o-phenylene-bridged di- or trimethylcyclopentadienyl/carboxamide ligands 2-(RMe₂C ₅H₂)-4,6-R′₂C₆H ₂NHC(O)^tBu (R = Me or H; R′ = Me, H, or F) are prepared. When R′ is methyl or H, unbridged trichlorotitanium complexes containing a chloroimine unit as a pendant group, 2-[(η⁵-RMe ₂C₅H)TiCl₃]-4,6-R′₂C ₆H₂N=C(Cl)^tBu (7, R = H, R′ = H; 8, R = Me, R′ = H; 9, R = H, R′ = Me; 10, R = Me, R′ = Me), are unexpectedly afforded through the successive addition of Ti(NMe ₂)₄ and SiCL₄ to the ligands. The same treatment to the ligands where R′ = F affords oxygen-coordinated bridged complexes [2-(η⁵-RMe₂C₅H)-4,6-F ₂C₆H₂N=C(O)^tBu-κO]TiCl ₂ (11, R = H; 12, R = Me). The desired nitrogen-coordinated bridged complexes [2-(η⁵-RMe₂C₅H)C ₆H₄NC(O)^tBu-κ²N,O]-TiMe ₂ (13, R = H; 14, R = Me) are obtained by reacting the corresponding dilithium compound with Me₂TiCl₂. The binding modes of 7, 8, 9, 11, and 14 are confirmed by X-ray crystallography. Trichlorotitanium complex 8 shows high activity in ethylene/1-octene copolymerization (activity, 100 × 10⁶ g/molTi·h at 13 bar ethylene). Trimethylcyclopentadienyl complexes show higher activity than the dimethylcyclopentadienyl analogues, and the activities of 12 and 14 reach ～65 × 10⁶g/molTi·h. Complex 12 is excellent in incorporating 1-octene.

Full text of DOI:10.1021/om060604x

5122
Organometallics 2006, 25, 5122-5130
Phenylene-Bridged Cp/Carboxamide Ligands for Titanium
Complexes of Various Binding Modes and Their Ethylene/1-Octene
Copolymerization
Ui Gab Joung,† Chun Ji Wu,† Sang Hoon Lee,† Choong Hoon Lee,‡ Eun Jung Lee,‡
Won-Sik Han,§ Sang Ook Kang,§ and Bun Yeoul Lee*,†
Department of Molecular Science and Technology, Ajou UniVersity, Suwon 443-749, Korea, LG Chem
Ltd./Research Park, 104-1, Munji-dong, Yuseong-gu, Daejon 305-380, Korea, and Department of
Chemistry, Korea UniVersity, 208 Seochang, Chochiwon, Chung-nam 339-700, Korea
ReceiVed July 4, 2006
o-Phenylene-bridged or substituted o-phenylene-bridged di- or trimethylcyclopentadienyl/carboxamide
ligands 2-(RMe2C5H2)-4,6-R′2C6H2NHC(O)tBu (R ) Me or H; R′ ) Me, H, or F) are prepared. When
R′ is methyl or H, unbridged trichlorotitanium complexes containing a chloroimine unit as a pendant
group, 2-[(η5-RMe2C5H)TiCl3]-4,6-R′2C6H2NdC(Cl)tBu (7, R ) H, R′ ) H; 8, R ) Me, R′ ) H; 9, R
) H, R′ ) Me; 10, R ) Me, R′ ) Me), are unexpectedly afforded through the successive addition of
Ti(NMe2)4 and SiCl4 to the ligands. The same treatment to the ligands where R′ ) F affords oxygen-
coordinated bridged complexes [2-(η5-RMe2C5H)-4,6-F2C6H2NdC(O)tBu-κO]TiCl2 (11, R ) H; 12, R
) Me). The desired nitrogen-coordinated bridged complexes [2-(η5-RMe2C5H)C6H4NC(O)tBu-κ2N,O]-
TiMe2 (13, R ) H; 14, R ) Me) are obtained by reacting the corresponding dilithium compound with
Me2TiCl2. The binding modes of 7, 8, 9, 11, and 14 are confirmed by X-ray crystallography.
Trichlorotitanium complex 8 shows high activity in ethylene/1-octene copolymerization (activity, 100 ×
106 g/molTi‚h at 13 bar ethylene). Trimethylcyclopentadienyl complexes show higher activity than the
dimethylcyclopentadienyl analogues, and the activities of 12 and 14 reach ∼65 × 106g/molTi‚h. Complex
12 is excellent in incorporating 1-octene.
preparation route for the o-phenylene-bridged (dimethyl or
trimethylcyclopentadienyl)/(amide or sulfonamide) ligand sys-
tem.7 The Suzuki coupling reaction of 2-bromoaniline com-
pounds with 2-dihydroxyboryl-3,4-dimethyl-2-cyclopenten-1-
one or 2-dihydroxyboryl-3-methyl-2-cyclopenten-1-one, which
can be easily prepared on a 30 g scale in a laboratory, is a key
step in the route (eq 1). The replacement of the silylene bridge
with the o-phenylene group leads to a structural change in terms
of a narrower Cp(cent)-Ti-N angle, which is indicative of a
more “constrained feature” in the o-phenylene-bridged com-
plexes. While the silicon atom in the CGC is severely deviated
from the cyclopentadienyl plane,8 the elements constituting the
chelation in the o-phenylene-bridged complexes are not situated
in a severely strained position. Some complexes are superior
Introduction
The CGC (constrained-geometry catalyst) [Me2Si(η5-Me4C5)(Nt-
Bu)]TiCl2 is a typical representative among homogeneous
1
Ziegler-Natta catalysts.2,3 Its activated complex is thermally
stable and provides a high molecular weight polymer with high
content of R-olefin in ethylene/R-olefin copolymerizations,
which enable its use in commercial processes. Various modi-
fications have been successfully carried out either by the
replacement of the Me4C5 unit with other π-donor ligands4 or
by the replacement of the NtBu unit with other amides or
phosphides,5 but the modification of the bridge has not been so
abundant and successful.6 Recently, we disclosed a novel
* Corresponding author. E-mail: bunyeoul@ajou.ac.kr.
† Ajou University.
(4) (a) Irwin, L. J.; Miller, S. A. J. Am. Chem. Soc. 2005, 127, 9972. (b)
Grandini, C.; Camurati, I.; Guidotti, S.; Mascellani, N.; Resconi, L.;
Nifant’ev, I. E.; Kashulin, I. A.; Ivchenko, P. V.; Mercandelli, P.; Sironi,
A. Organometallics 2004, 23, 344. (c) De Rosa, C.; Auriemma, F.; Ruiz
de Ballesteros, O.; Resconi, L.; Fait, A.; Ciaccia, E.; Camurati, I. J. Am.
Chem. Soc. 2003, 125, 10913. (d) Klosin, J.; Kruper, W. J., Jr.; Nickias, P.
N.; Roof, G. R.; De Waele, P.; Abboud, K. A. Organometallics 2001, 20,
2663.
‡ LG Chem Ltd./Research Park.
§ Korea University.
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(b) Gibson, V. C.; Spitzmesser, S. K. Chem. ReV. 2003, 103, 283.
(2) Review: (a) Brintzinger, H. H.; Fischer, D.; Mu¨lhaupt, R.; Rieger,
B.; Waymouth, R. M. Angew. Chem., Int. Ed. Engl. 1995, 34, 1143. (b)
Britovsek, G. J. P.; Gibson, V. C.; Wass, D. F. Angew. Chem., Int. Ed.
1999, 38, 429. (c) Alt, H. G.; Ko¨pple, A. Chem. ReV. 2000, 100, 1205. (d)
Coates, G. W. Chem. ReV. 2000, 100, 1223. (e) Resconi, L.; Cavallo, L.;
Fait, A.; Piemontesi, F. Chem. ReV. 2000, 100, 1253. (f) Chen, E. Y.-X.;
Marks, T. J. Chem. ReV. 2000, 100, 1391. (g) Alt, H. G. Dalton Trans.
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(3) Recent progress: (a) Arriola, D. J.; Carnahan, E. M.; Hustad, P. D.;
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B.; Keaton, R. J.; Fettinger, J. C.; Sita, L. R. J. Am. Chem. Soc. 2006, 128,
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4524. (d) Amin, S. B.; Marks, T. J. J. Am. Chem. Soc. 2006, 128, 4506. (e)
Arndt, P.; Ja¨ger-Fiedler, U.; Klahn, M.; Baumann, W.; Spannenberg, A.;
Burlakov, V. V.; Rosenthal, U. Angew. Chem., Int. Ed. 2006, 45, 4195. (f)
Starzewski, K. A. O.; Xin, B. S.; Steinhauser, N.; Schweer, J.; Benet-
Buchholz, J. Angew. Chem., Int. Ed. 2006, 45, 1799.
(5) Altenhoff, G.; Bredeau, S.; Erker, G.; Kehr, G.; Kataeva, O.; Frohlich,
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Chem. Soc. 2001, 123, 6181. (b) Wang, C.; Erker, G.; Kehr, G.; Wedeking,
K.; Frohlich, R. Organometallics 2005, 24, 4760. (c) Kim, T. H.; Won, Y.
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Organometallics 2006, 25, 2133. (b) Cho, D. J.; Wu, C. J.; Bok, T.; Lee,
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10.1021/om060604x CCC: $33.50 © 2006 American Chemical Society
Publication on Web 09/14/2006

Phenylene-Bridged Cp/Carboxamide Ligands
Organometallics, Vol. 25, No. 21, 2006 5123
a
Scheme 1
Reaction of 1-6 with an equimolar amount of Ti(NMe2)4 at
80 °C for 1 day affords a bis(dimethylamido)titanium complex.
A single Me2N signal is observed as a singlet at 2.9 ppm in the
1H NMR spectra of the symmetrically substituted Me2C5H2
complexes, but two Me2N signals are observed at 2.8 and 3.1
ppm for the Me3C5H complexes. When Me2SiCl2 is employed
as a chlorinating agent, replacement of only one Me2N ligand
occurs.12 The treatment of more powerful SiCl4 in excess to
the bis(dimethylamido)titanium complexes clearly provides one
complex. The 1H NMR spectra indicate that both Me2N ligands
are replaced with the chloride, but X-ray crystallographic studies
reveal unexpected structures. For phenylene- and dimethylphe-
nylene-bridged ligands, unbridged trichlorotitanium complexes
are afforded (Scheme 1 and Figures 1-3).13 The carboxamide
unit is transformed to a chloroimine unit that is not coordinated
with the titanium. A single Cp-H signal is observed at 6.03 in
the 1H NMR spectrum (C6D6) of the dimethylcyclopentadienyl
complex 7, but two abnormal Cp-H signals are observed at 5.90
and 6.18 ppm as doublets (J ) 2.8 Hz) in 1:1 ratio for 9. The
only difference between 7 and 9 is the presence of methyl
substituents on the phenylene bridge. This unexpected observa-
tion of the two Cp-H signals for 9 can be explained by the high
rotation barrier around the N-C(phenylene) bond. The methyl
group on the ortho-position of the phenylene bridge might block
the rotation as shown below.14 If the rotation is not allowed,
the two Cp-H protons are considered diastereotoptic to each
other, and two signals should be observed. For trimethyl
complex 10, the prohibited rotation gives rise to two isomers
and actually two sets of signals are observed in 0.57:0.43 ratio
in the 1H NMR spectrum. The CdN carbon signals are observed
at 156 ppm in the 13C NMR spectra of 7-10. In the case of
ligands 1-6, the carbonyl-carbon signals are observed at ∼176
ppm.
a Legend: (i) 2-BrC6H2(R′)2NH2, Na2CO3, Pd(PPh3)4 (1 mol %); (ii)
MeLi/CeCl3, then HCl (2 N); (iii) pivaloyl chloride, Et3N; (iv)
Ti(NMe2)4; (v) SiCl4.
to the CGC in ethylene/R-olefin copolymerization in terms of
activity, R-olefin incorporation, and molecular weight of the
obtained polymer. Herein, we report titanium complexes derived
from o-phenylene-bridged di- or trimethylcyclopentadienyl/
carboxamide ligands. By variation of the substituents on the
ligand system or by changing the metalation method, titanium
complexes of various coordination modes are provided and some
interesting polymerization results are observed with the com-
plexes in ethylene/1-octene copolymerization.
Results and Discussion
Synthesis and Characterization. Various aniline derivatives
containing the Me2H3C5 or Me3H2C5 unit at the 2-position are
prepared by the Suzuki coupling reaction of 2-bromoanilines
with 2-dihydroxyboryl-3,4-dimethyl-2-cyclopenten-1-one or 2-di-
hydroxyboryl-3-methyl-2-cyclopenten-1-one.7b The addition of
pivaloyl chloride (tBuC(O)Cl) to the aniline derivatives in the
presence of Et3N affords 1-6 in 70-93% yields (Scheme 1).
Usually, a mixture of isomers is obtained for substituted
cyclopentadiene compounds by the facile 1,5-sigmatropic rear-
rangement,9 but compounds 1-6 exist as a single isomer at room
temperature, showing only one set of signals in the 1H and 13
C
X-ray crystallographic studies reveal that an oxygen-
coordinated dichlorotitanium complex is afforded when the same
treatment is applied for the difluorophenylene-bridged ligand 5
NMR spectra. The isomer where two hydrogens are attached
on the sp3-carbon is thermodynamically more stable and is
predominant at room temperature. The preparation of the ortho-
lithiated compound of pivaloyl-protected aniline has already
been reported,10 but its reaction with 2,3,4,5-tetramethyl-2-
cyclopenten-1-one or sterically less hindered 3,4-dimethyl-2-
cyclopenten-1-one11 does not provide the desired compound (eq
2). Probably, the strong basicity of the lithium carboxamide
triggers the deprotonation of cyclopentenone, which blocks the
desired nucleophilic attack of the carbanion on the carbonyl.
Therefore, a synthetic route based on the Suzuki coupling
reaction is unique for the preparation of this kind of ligand
system.
1
(Scheme 1 and Figure 4). The H and 13C NMR spectra are in
agreement with the structure. The NdC(tBu)-O carbon signal
is observed at 168.3 ppm in the 13C NMR spectrum of 11. The
1
analysis of the H and 13C NMR spectra of 12 suggests that a
similar oxygen-coordinated complex is also afforded for the
trimethylcyclopentadienyl ligand 6. Especially, observation of
a 13C NMR signal at 168.7 strongly supports the -NdC(tBu)-
O-Ti structure.
(12) Lee, B. Y.; Han, J. W.; Lee, I. S.; Chung, Y. K. J. Organomet.
Chem. 2001, 627, 233.
(13) Qian, Y.; Huang, J.; Bala, M. D.; Lian, B.; Zhang, H.; Zhang, H.
Chem. ReV. 2003, 103, 2633.
(14) Won, Y. C.; Jeong, U. G.; Cho, E. S.; Lee, B. Y.; Lee, H.; Park,
Y.-W.; Song, K. H. Synthesis 2004, 1052. (b) Joe, D. J.; Lee, B. Y.; Shin,
D. M. Bull. Kor. Chem. Soc., 2005, 25, 233.
(9) Jutzi, P. Chem. ReV. 1986, 86, 983.
(10) Fuhrer, W.; Gschwend, H. W. J. Org. Chem. 1979, 44, 1133.
(11) Conia, J. M.; Leriverend, M. L. Bull. Soc. Chim. Fr. 1970, 2981.

5124 Organometallics, Vol. 25, No. 21, 2006
Joung et al.
Figure 1. Thermal ellipsoid plot (30% probability level) of 7.
Selected bond distances (Å) and angles (deg): N-C(7), 1.240(4);
C(7)-Cl(4), 1.785(3); Ti-Cp(c), 2.025; Ti(1)-Cl(1), 2.2352(11);
Ti(1)-Cl(2), 2.2170(12); Ti(1)-Cl(3), 2.2276(11); N-C(7)-C(14),
120.6(3); N-C(7)-C(8), 124.7(3); C(8)-C(7)-Cl(4), 114.6(2);
C(8)-C(7)-N-C(1), 0.8; Cl(4)-C(7)-N-C(1), 1.2; C(7)-N-
C(1)-C(2), 100.3; C(13)-C(12)-C(2)-C(1), 67.9.
Figure 2. Thermal ellipsoid plot (30% probability level) of 8.
Selected bond distances (Å) and angles (deg): N-C(7), 1.234(7);
C(7)-Cl(4), 1.770(6); Ti-Cp(c), 2.031; Ti-Cl(1), 2.2270(18); Ti-
Cl(2), 2.2359(17); Ti-Cl(3), 2.2428(18); N-C(7)-C(14), 121.9-
(5); N-C(7)-C(8), 124.0(6); C(8)-C(7)-Cl(4), 114.1(4); C(8)-
C(7)-N-C(1), 1.9; Cl(4)-C(7)-N-C(1), 0.6; C(7)-N-C(1)-
C(2), 86.6; C(13)-C(12)-C(2)-C(1), 61.9.
In the 13C NMR spectra of all the intermediate (NMe2)2Ti
complexes, the most downfield shifted signals are observed at
168-171 ppm. Because the chemical shifts are very close to
those observed for the oxygen-coordinated complexes 11 and
13 (168-171 ppm versus 168 ppm), it may be suggested that
the structure of the intermediate (NMe2)2Ti complexes is oxygen
coordinated, as shown in eq 3. For carboxamide compounds
1-6, the corresponding signals are observed at ∼176 ppm. The
titanium atom is so oxophilic that the formation of the oxygen-
coordinated complex may be more favorable than the formation
of the nitrogen-coordinated one. A plausible pathway for the
transformation of the (NMe2)2Ti complexes to the chloroimine
Cl3Ti complexes 7-10 is proposed in eq 3. For (NMe2)2Ti
complexes derived from 1-4, the oxygen ligand along with the
two Me2N ligands is replaced with chloride by the treatment of
SiCl4, affording the -NdC(tBu)OSiCl3 unit as a pendant group,
which is eventually transformed to -NdC(tBu)Cl.
1.46 (tBu), and 0.88 (Ti-Me) with the same integration ratio as
observed for the major isomer. In the 1H NMR spectrum of 14
(C6D6), two sets of signals are also observed in a 0.78:0.22 ratio.
The purification of the complexes by multiple recrystallization
does not eliminate the minor isomer, and even the ratio of the
two isomers is not altered by the recrystallization, which implies
that the two isomers are in equilibrium in solution. When the
temperature is raised to 90 °C, the two signal sets are collapsed
to a set of broad signals, strongly supporting the interconversion
between the two isomers. In the 13C NMR spectrum, the
tBuC(O)N-carbon signal is observed at 187-188 ppm for the
major isomer, while the corresponding signal is observed
dramatically upfield shifted at 165-166 ppm for the minor
isomer. Since the chemical shift observed for the minor isomer
is close to those observed for the oxygen-coordinated complexes
11 and 12 (165-166 ppm versus 168 ppm), we assume that
the minor isomer is the oxygen-coordinated one, as drawn in
eq 4.
X-ray Crystallographic Studies. Figure 1 shows the struc-
ture of 7 with the selective bond distances and angles revealed
by X-ray crystallography. The N-C(7) distance (1.240(4) Å)
is indicative of a double bond and the measured C(7)-Cl(4)
distance (1.785(3) Å) is in agreement with the tabulated carbon-
chlorine bond distance.16 The carbon (C(7)) attached to Cl and
N is perfectly trigonal (the sum of the bond angles around the
carbon, 360.0°). The double-bond character between the C(7)
and N atoms is further supported by the dihedral angles of C(8)-
C(7)-N-C(1) (0.8°) and Cl(4)-C(7)-N-C(1) (1.2°). These
metrical parameters clearly indicate the chloroimine structure
depicted in Scheme 1. The C(7), N, C(8), Cl(4), and C(1) atoms
are situated in a plane, and the plane is almost perpendicular to
the phenylene plane (the angle between the planes, 81.02(11)°).
The cyclopentadienyl plane is skewed to the phenylene plane
The addition of the dilithium salt of 1 and 2 to in situ
generated Me2TiCl2 in diethyl ether affords the desired chelated
dimethyltitanium complexes 13 and 14 in 72% and 68% yields,
respectively (Scheme 2).15 The structure of 13 is confirmed by
X-ray crystallography. In the 1H NMR spectrum of 13 (C6D6),
two sets of signals are observed in a 0.87:0.13 ratio. A signal
set of the major isomer is composed of singlet signals at 6.46
(Cp-H), 1.62 (Cp-Me), 1.36 (tBu), and 1.09 (Ti-Me) in 2:6:9:6
integration ratios, which is in agreement with the structure drawn
in Scheme 2. Meanwhile, the signal set of the minor isomer is
also composed of singlet signals at 6.25 (Cp-H), 1.80 (Cp-Me),
(15) Park, J. T.; Woo, B. W.; Yoon, S. C.; Shim S. C. J. Organomet.
Chem. 1997, 535, 29.
(16) Weast, R. C. CRC Handbook of Chemistry and Physics, 70th ed.;
CRC Press: Boca Raton, 1990; p F-188.

Phenylene-Bridged Cp/Carboxamide Ligands
Organometallics, Vol. 25, No. 21, 2006 5125
Figure 3. Thermal ellipsoid plot (30% probability level) of 9.
Selected bond distances (Å) and angles (deg): N-C(9), 1.241(3);
Cl(4)-C(9), 1.790(2); Ti-Cp(c), 2.025; Ti(1)-Cl(1), 2.2329(7);
Ti(1)-Cl(2), 2.2306(7); Ti(1)-Cl(3), 2.2338(7); N-C(9)-C(10),
124.9(2); C(10)-C(9)-Cl(4), 113.86(17); N-C(9)-Cl(4) 121.24-
(17); C(10)-C(9)-N-C(1), 4.8; Cl(4)-C(9)-N-C(1), 2.4; C(9)-
N-C(1)-C(2), 98.6; C(15)-C(14)-C(2)-C(1), 103.4.
Figure 5. Thermal ellipsoid plot (30% probability level) of 14.
Selected bond distances (Å) and angles (deg): Ti-N, 2.1072(13);
Ti-O, 2.1446(12); Ti-C(20), 2.0952(17); Ti-C(21), 2.1523(18);
Ti-Cp(c), 2.056; N-C(7), 1.3262(19); O-C(7), 1.2822(18); Cp-
(c)-Ti-O, 151.00; C(20)-Ti-N, 100.86(6); N-Ti-C(21), 136.10-
(6); N-Ti-O, 60.78(5); C(20)-Ti-C(21), 99.45(8); O-C(7)-
N, 111.11(13); O-C(7)-C(16), 118.80(13); N-C(7)-C(16),
130.05(14); C(2)-C(1)-C(8), 116.39(12); C(1)-C(2)-N, 111.90-
(13); C(7)-N-C(2), 136.91(13); C(7)-N-Ti, 93.27(9); C(2)-N-
Ti, 126.61(10); C(7)-O-Ti, 92.85(9); Cp(c)-C(8)-C(1), 6.02;
C(8)-Cp(c)-Ti, 87.92; C(9)-C(8)-C(1)-C(2), 99.1.
(4)°) and the C(8)-C(9)-N(1) angle (129.7(4)°) are slightly
increased from the ideal value of 120°. The wide Ti-O-C angle
(149.53°) and relatively short Ti-O distance (1.802(3) Å) are
indicative of some π-donation from the oxygen ligand to the
titanium. The cyclopentadienyl plane and the phenylene plane
are not situated perpendicularly but are tilted at 51.97(15)°.
Figure 5 shows the structure of 14. Even though the Ti-N
and Ti-O distances (2.1072(13) and 2.1446(12) Å, respectively)
are relatively long, when compared with the Ti-N distance
observed for the standard CGC (1.907(4) Å)8 and the Ti-O
distances observed for 11 (1.802(3) Å) and the Me4Cp-phenoxy
complex (1.832(3) Å),17 the measured Ti-N and Ti-O dis-
tances clearly indicate a chemical bonding between the Ti and
N atoms and between the Ti and O atoms, respectively.
Coordination geometry around the titanium center may be
classified into a distorted trigonal bipyramidal with the oxygen
and the cyclopentadienyl ligands situated at the axial positions.
The C-O distance (1.2822(18) Å) is indicative of a double
bond, while tBuC-N distance (1.3262(19) Å) is indicative of a
shortened single bond. The Cp(cent)-Ti-N angle (101.36°) is
close to that observed for the o-phenylene-bridged Cp/sulfon
amido complex [2-(η5-Me3C5H)C6H4NSO2C6H4CH3)]TiCl2
(100.91°),7b but it is substantially smaller than those observed
for the standard CGC (107.6°) and the o-phenylene-bridged Cp/
amido complex [2-(η5-Me3C5H)C6H3NC6H11]TiCl2 (104.8°).7a
The Cp(cent)-Ti-O angle is 151.00°. The Ti-Cp(cent)-
C(bridgehead) angle (87.92°) and the Cp(cent)-C(bridgehead)-
C(phenylene) angle (6.02°) are slightly deviated from the ideal
values of 90° and 0°, respectively. The C(8)-C(1)-C(2) and
C(1)-C(2)-N angles are also slightly contracted to 116.39-
(12)° and 111.90(13)° from the ideal 120°. The nitrogen atom
is not perfectly trigonal (sum of the bond angles around nitrogen,
356.79°), but the sum of the angles is closer to the trigonal value
(360°) rather than to the tetrahedral value (329.1°). The
Figure 4. Thermal ellipsoid plot (30% probability level) of 11.
Selected bond distances (Å) and angles (deg): N(1)-C(14), 1.260-
(6); O(1)-C(14), 1.343(5); Ti-O(1), 1.802(3); Ti-Cl(1), 2.2434-
(15); Ti-Cl(2), 2.257(2); Ti-Cp(c), 2.016; Cl(1)-Ti-Cl(2),
103.98(7); Cp(c)-Ti-O(1), 112.66; O(1)-Ti-Cl(1), 102.89(11);
O(1)-Ti-Cl(2), 102.03(11); C(14)-O(1)-Ti, 149.5(3); C(14)-
N(1)-C(9), 128.9(4); N(1)-C(14)-O(1), 125.8(4); N(1)-C(14)-
C(15), 120.6(4); O(1)-C(14)-C(15), 113.5(4); C(8)-C(9)-N(1),
129.7(4); C(9)-C(8)-C(1), 126.7(4); C(2)-C(1)-C(8)-C(9), 53.1.
Scheme 2
with an angle of 69.62(11)°. Figures 2 and 3 show the structure
of 8 and 9, respectively. The metrical parameters around the
nitrogen atom are the same as those observed for 7, confirming
the chloroimine structure.
Figure 4 shows the structure of 11 with selected bond
distances and angles. The N-C(O) distance (1.260(6) Å) is
indicative of a double bond, while the NC-O distance (1.343-
(5) Å) is indicative of a shortened single bond. The Cp(cent)-
Ti-O angle (112.66°) is bigger than those observed for Me4Cp-
phenoxy titanium complexes [2-(η5-Me4C5)C6H4O-κ,O]TiCl2
(∼107°)17 and the Cp(cent)-Ti-N angle observed for the
standard CGC (107.4°).8 The C(1)-C(8)-C(9) angle (126.7-
(17) (a) Zhang, Y.; Mu, Y.; Lu, C.; Li, G.; Xu, J.; Zhang, Y.; Zhu, D.;
Feng, S. Organometallics 2004, 23, 540. (b) Zhang, Y.; Wang, J.; Mu, Y.;
Shi, Z.; Lu, C.; Zhang, Y.; Qiao, L.; Feng, S. Organometallics 2003, 22,
3877. (c) Chen, Y.-X.; Fu, P.-F.; Stern, C. L.; Marks, T. J. Organometallics
1997, 16, 5958.

5126 Organometallics, Vol. 25, No. 21, 2006
Table 1. Ethylene/1-Octene Copolymerization Resultsa
Joung et al.
entry
catalyst
yield (g)
Ab
Tm (°C)
density
[Oct]c
MId
Mw
Mw/Mn
1
2
3
4
5
6
7
8
7
8
9
64
85
8.2
10
17
54
35
56
23
76
100
9.9
12
20
63
42
67
28
62
60
0.863
0.860
22
23
1.6
6.3
0
114 000
73 000
2.8
2.9
4.6
5.3
4.0
6.9
6.9
4.6
6.6
111.8
111.0
62
broad
74
124 000
155 000
186 000
123 000
209 000
154 000
216 000
10
11
12
13
14
16
19
CGC
0
0.861
0.858
0.877
0.872
0.873
23
31
20
20
0.26
4.9
0.13
0.64
0.13
63
77
9
10
11
trace
130
160
89
0.871
19
20
56 000
2.8
a Polymerization conditions: 1000 mL of a toluene solution of 1-octene (0.8 M), 5 µmol of complex, 15 µmol of (Ph3C)[B(C6F5)4], 0.125 mmol of
iBu3Al, 13 bar of ethylene, 10 min, temperature 90 °C. b Activity in units of 106 g/molTi‚h. c 1-Octene content in the copolymer measured by the 1H NMR.
d Melt index, which is the melt flow rate (g/10 min) at 190 °C and using a load of 2160 g.
cyclopentadienyl plane and the phenylene plane are slightly tilted
(the angle between the planes, 76.10(5)°).
same position, are prepared according to the route shown in
eqs 5 and 6, respectively. As expected, complex 19 shows
negligible activity, while the complex containing aldimine group
16 exhibits low activity (28 × 106 g/molTi‚h).
Polymerization Studies. The newly prepared complexes are
tested for ethylene/1-octene copolymerization after activation
with (Ph3C)[B(C6F5)4] and iBu3Al. The triisobutylaluminum is
added both as a scavenger and as an alkylating agent. The
polymerization conditions and the results are summarized in
Table 1. Interestingly, the unbridged complexes 7 and 8 exhibit
fairly good activity, and the activity of the Me3C5H complex 8
reaches 100 × 106 g/molTi‚h. Under the same conditions, the
standard CGC shows activity of 160 × 106 g/molTi‚h. By
replacing one methyl group on the cyclopentadienyl ligand with
hydrogen, the activity is reduced to 76 × 106 g/molTi‚h. The
melting temperature of the polymer (Tm) and the density of the
resin are mainly dependent on the 1-octene content in the
copolymer. The lower the melting temperature or the lower the
density, the higher the 1-octene content. A comparison of the
densities (0.863, 0.860, 0.871 g/cm3 for 7, 8, and the CGC,
respectively) and the melting temperatures (62.2, 60.3, and 89.4
°C for 7, 8, and the CGC, respectively) of the polymers indicates
that 7 and 8 are slightly superior to the CGC in incorporating
1-octene (entries 1, 2, and 11), which is also confirmed by the
analysis of the 1H NMR spectra of the polymers.8b The
molecular weights of the polymers obtained by 7 and 8 (Mw,
114 000 and 73 000, respectively) are higher than that of the
polymer obtained with the CGC (Mw, 56 000). The melt flow
rate is mainly dependent on the molecular weight, and the
molecular weight data obtained on the GPC are in agreement
with the data of the melt flow rate (MI) of the resins (1.6, 6.3,
and 20 g/10 min for 7, 8, and the CGC, respectively). Rather
narrow molecular weight distributions (Mw/Mn, 2.8-2.9) are
observed, indicating a single active species in the polymerization
reaction.
The bridged complexes 11-14 exhibit moderate or good
activity. The general trend observed in this work is that the
activity of the trimethylcyclopentadienyl complex is higher than
that of the corresponding dimethylcyclopentadienyl analogue.
The activities of the trimethylcyclopentadienyl complexes 12
and 14 are 63 × 106 and 56 × 106 g/molTi‚h, respectively.
Interestingly, the oxygen-coordinated complex 12 is excellent
in incorporating 1-octene, and the 1-octene content of the
polymer (31 mol %) is significantly higher than that of the
polymer obtained with the CGC (19 mol %). The bridged
complexes 11-14 provide polymers of significantly higher
molecular weight (Mw, 120 000-200 000) than the CGC (Mw,
56 000). Rather broad molecular weight distributions (Mw/Mn,
4-7) are observed even though the GPC traces are monomodal.
The broadening of the molecular weight distribution might be
ascribed to the binding mode change described in eq 3.
Summary. Phenylene-bridged or substituted phenylene-
bridged di- or trimethylcyclopentadienyl/carboxamide ligands
2-(RMe2C5H2)-4,6-R′2C6H2NHC(O)tBu are prepared, from
which titanium complexes of various binding modes are
afforded. Unbridged trichlorotitanium complexes bearing a
chloroimine unit as a pendant group, 2-[(η5-RMe2C5H)TiCl3]-
4,6-R′2C6H2NdC(Cl)tBu (7, R ) H, R′ ) H; 8, R ) Me, R′ )
H; 9, R ) H, R′ ) Me; 10, R ) Me, R′ ) Me), are unexpectedly
obtained by the successive treatment of Ti(NMe2)4 and SiCl4
to the phenylene-bridged or dimethylphenylene-bridged ligands,
but the same treatment on the difluorophenylene-bridged ligands
provides oxygen-coordinated bridged complexes [2-(η5-RMe2-
C5H)-4,6-F2C6H2NdC(O)tBu-κO]TiCl2 (11, R ) H; 12, R )
Placing methyl groups on the phenylene bridge dramatically
reduces the activity. The activity of 9 and 10 is almost 1/10 of
those observed for 7 and 8 (entries 1/2 versus entries 3/4).
Furthermore, the melting temperatures of the polymers (111.8
and 111.0 °C) indicate that complexes 9 and 10 are significantly
inferior to 7, 8, and the CGC in incorporating 1-octene. We
suspect that the fairly high activity and the excellent 1-octene
incorporation ability of 7 and 8 might be attributed to the
formation of nitrogen-coordinated active species during the
activation process. For less active 9 and 10, the rotation around
the C(phenylene)-N bond is blocked by the presence of the
methyl group on the phenylene bridge, possibly hampering the
formation of the nitrogen-coordinated active species. To prove
the critical role of the pendant chloroimine unit in affording
the high activities, complex 16, containing the aldimine group,
and complex 19, not containing any functional group on the

Phenylene-Bridged Cp/Carboxamide Ligands
Organometallics, Vol. 25, No. 21, 2006 5127
118.94, 122.96, 126.21, 127.78, 129.13, 134.27, 134.63, 135.91,
137.91, 138.67, 175.75 ppm. Anal. Calc (C19H25NO): C, 80.52;
H, 8.89; N, 4.94. Found: C, 80.41; H, 8.78; N, 4.64.
Me). The desired nitrogen-coordinated bridged complexes,
[2-(η5-RMe2C5H)C6H4NC(O)tBu-κ2N,O]TiMe2 (13, R ) H; 14,
R ) Me), are obtained by reacting the dilithium compound with
Me2TiCl2, but X-ray crystallographic studies show that both the
nitrogen and the oxygen coordinate with the titanium. Con-
nectivity and the binding modes of 7, 8, 9, 11, and 14 are
confirmed by X-ray crystallography.
Interestingly, the unbridged complexes 7 and 8, when
activated with (Ph3C)[B(C6F5)4] and Al(iBu)3, exhibit fairly good
activity in ethylene/1-octene copolymerization, while the com-
plexes 9 and 10, which have dimethyl substituents on the
phenylene bridge, are negligible. Complexes 7 and 8 are slightly
superior to the CGC in incorporating 1-octene. The chloroimine
unit (-NdC(Cl)tBu) plays a critical role in affording high
activity. Very low activity is observed not only in the complex
containing the aldimine group, 2-[(η5-Me3C5H)TiCl3]C6H4Nd
C(H)tBu (16), but also in the complex not having any pendant
group, (η5-Me3PhC5H)TiCl3 (19). The bridged complexes 11-
14 also exhibit moderate or good activity. The trimethylcyclo-
pentadienyl complex shows higher activity than the correspond-
ing dimethylcyclopentadienyl analogue, and the oxygen-
coordinated complex 12 is excellent in incorporating 1-octene.
Compound 3. The compound was synthesized from 2-(Me2C5H3)-
4,6-Me2C6H2NH2 using the same conditions and procedures as for
1. A white solid was obtained (yield, 70%). Mp: 136 °C. IR
(neat): 3317 (N-H), 1650 (CdO) cm-1. 1H NMR (CDCl3): δ 1.17
(s, 9H, C(CH3)3), 1.69 (s, 3H, CH3), 1.85 (s, 3H, CH3), 2.24 (s,
3H, Ph-CH3), 2.34 (s, 3H, Ph-CH3), 2.97 (br d, J ) 1.2 Hz, 2H,
Cp-CH2), 5.94 (s, 1H, Cp-CH), 6.75 (s, 1H, NH), 6.78 (s, 1H, Ph-
H), 7.03 (s, 1H, Ph-H) ppm. 13C{1H} NMR (CDCl3): δ 14.54,
14.58, 18.74, 21.08, 27.50, 44.19, 123.88, 127.76, 130.41, 130.53,
131.19, 132.90, 134.94, 135.59, 140.14, 143.35, 175.85 ppm. Anal.
Calc (C20H27NO): C, 80.76; H, 9.15; N, 4.71. Found: C, 80.57;
H, 8.92; N, 5.11.
Compound 4. The compound was synthesized from 2-(Me3C5H2)-
4,6-Me2C6H2NH2 using the same conditions and procedures as for
1. A white solid was obtained (yield, 89%). Mp: 134 °C. IR
(neat): 3332 (N-H), 1650 (CdO) cm-1. 1H NMR (CDCl3): δ 1.16
(s, 9H, C(CH3)3), 1.54 (s, 3H, CH3), 1.80 (s, 3H, CH3), 1.94 (s,
3H, CH3), 2.23 (s, 3H, Ph-CH3), 2.33 (s, 3H, Ph-CH3), 2.84-2.97
(m, 2H, Cp-CH2), 6.76 (s, 2 H, Ph-H), 7.02 (s, 1 H, NH) ppm.
13C{1H} NMR (CDCl3): δ 11.63, 13.50, 14.23, 18.79, 21.09, 27.46,
39.13, 48.64, 127.68, 130.28, 131.18, 132.85, 133.22, 134.79,
135.34, 135.47, 135.62, 140.51, 175.77 ppm. Anal. Calc (C21H29-
NO): C, 80.98; H, 9.38; N, 4.50. Found: C, 80.72; H, 9.60; N,
4.90.
Experimental Section
General Remarks. All manipulations were performed under an
inert atmosphere using standard glovebox and Schlenk techniques.
Toluene, pentane, THF, and C6D6 were distilled from benzophenone
ketyl. Pyridine-d5 and SiCl4 were dried over CaH2 and transferred
under vacuum to reservoirs. NMR spectra were recorded on a
Varian Mercury plus 400. Elemental analyses were carried out at
the Inter-University Center Natural Science Facilities, Seoul
National University. Gel permeation chromatograms (GPC) were
obtained at 140 °C in trichlorobenzene using a Waters Model 150-
C+ GPC, and the data were analyzed using a polystyrene analyzing
curve. Differential scanning calorimetry (DSC) was performed on
a Thermal Analysis 3100.
Compound 5. The compound was synthesized from 2-(Me2C5H3)-
4,6-F2C6H2NH2 using the same conditions and procedures as for
1. A white solid was obtained (yield, 76%). Mp: 144 °C. IR
1
(neat): 3317 (N-H), 1666 (CdO) cm-1. H NMR (C6D6): δ 1.01
(s, 9H, C(CH3)3), 1.66 (s, 3H, CH3), 1.72 (q, J ) 2.0 Hz, 3H, CH3),
2.66 (quintet, J ) 1.6 Hz, 2H, Cp-CH2), 5.79 (d, J ) 2.0 Hz, 1H,
Cp-CH), 6.36 (s, 1H, NH), 6.52 (s, IH, Ph-H), 6.54 (s, 1H, Ph-H)
ppm. 13C{1H} NMR (CDCl3): δ 14.60 (CH3), 14.63 (CH3), 27.57
(C(CH3)3), 39.28 (C(CH3)3), 44.53 (Cp-CH2), 103.58 (t, 2JCF ) 25.1
2
4
Hz, CH), 112.41 (dd, JCF ) 21.2, JCF ) 3.8 Hz, CH), 120.89
(dd, J ) 14, 6.0 Hz), 124.60 (dCH), 137.72 (dd, J ) 11.0, 3.0
Hz), 138.56 (dC-C6), 141.70 (dCCH3), 142.95(dCCH3), 158.48
(dd, 1JCF ) 228, 3JCF ) 12.9 Hz, CF), 161.00 (dd, 1JCF ) 223, 3JCF
) 12.2 Hz, CF), 175.52 (CO) ppm. Anal. Calc (C18H21F2NO): C,
70.80; H, 6.93; N, 4.59. Found: C, 70.85; H, 7.10; N, 4.82.
Compound 1. To a flask containing 2-(Me2C5H3)C6H4NH2
(0.263 g, 1.42 mmol)7b in methylene chloride (10 mL) were added
triethylamine (0.130 g, 1.29 mmol) and pivaloyl chloride (0.155 g,
1.29 mmol). After the solution was stirred for 1 h at room
temperature, it was transferred to a separatory funnel containing
aqueous HCl (2 N, 5 mL). After the mixture was vigorously shaken,
the organic phase was collected and rapidly washed with aqueous
saturated NaHCO3 (5 mL). After the organic phase was dried over
anhydrous MgSO4, solvent was removed with a rotary evaporator
to give a residue, which was purified by column chromatography
on silica gel eluting with hexane and ethyl acetate (v/v, 10:1). A
colorless oil was obtained (0.355 g, 93%). IR (neat): 3409 (N-
H), 1681(CdO) cm-1. 1H NMR (CDCl3): δ 1.18 (s, 9H, C(CH3)3),
1.73 (q, J ) 1.6 Hz, 3H, CH3), 1.89 (s, 3H, CH3), 3.06-3.11 (m,
2H, Cp-CH2), 6.05 (d, J ) 2.0 Hz, 1H, Cp-CH), 7.07 (dd, J ) 7.6,
2.0 Hz, 1H, H3 or 6), 7.11 (td, J ) 7.2, 1.2 Hz, 1H, H4 or 5), 7.33 (td,
J ) 8.4, 2.0 Hz, 1H, H4 or 5), 7.54 (s, 1H, NH), 8.44 (d, J ) 8.0 Hz,
1H, H3 or 6) ppm. 13C{1H} NMR (CDCl3): δ 14.47, 14.64, 27.42,
44.59, 119.15, 123.14, 125.27, 125.74, 128.07, 129.28, 136.02,
138.36, 142.64, 142.76, 175.93 ppm. Anal. Calc (C18H23NO): C,
80.26; H, 8.61; N, 5.20. Found: C, 80.41; H, 8.45; N, 5.24.
Compound 2. The compound was synthesized from 2-
(Me3C5H2)C6H4NH2 using the same conditions and procedures as
for 1. A light yellow oil was obtained (yield, 89%). IR (neat): 3409
Compound 6. The compound was synthesized from 2-(Me3C5H2)-
4,6-F2C6H2NH2 using the same conditions and procedures as for
1. A white solid was obtained (yield, 64%). Mp: 138 °C. IR
(neat): 3301 (N-H), 1666 (CdO) cm-1. 1H NMR (CDCl3): δ 1.18
(s, 9H, C(CH3)3), 1.58 (s, 3H, CH3), 1.82 (s, 3H, CH3), 1.94 (s,
3H, CH3), 2.92 (s, 2H, Cp-CH2), 6.61 (s, 1H, NH), 6.67 (ddd, J )
8.4, 2.4, 1.2 Hz, 1H, H5), 6.86 (ddd, J ) 11.2, 9.2, 2.4 Hz, 1H, H3)
ppm. 13C{1H} NMR (CDCl3): δ 11.57 (CH3), 13.48 (CH3), 14.28
(CH3), 27.45 (C(CH3)3), 39.30 (C(CH3)3), 48.86 (Cp-CH2), 103.26
2
2
4
(t, JCF ) 25.0 Hz, CH), 112.00 (dd, JCF ) 22.0, JCF ) 3.1 Hz,
CH), 119.61 (dd, J ) 12.0, 3.0 Hz), 133.70, 134.31, 136.65 (d, J
1
3
) 9.1 Hz), 137.47, 138.02, 157.50 (dd, JCF ) 250, JCF ) 12.9
1
3
Hz, CF), 160.55 (dd, JCF ) 246, JCF ) 12.9 Hz, CF), 176.00
(CO) ppm. Anal. Calc (C19H23F2NO): C, 71.45; H, 7.26; N, 4.39.
Found: C, 71.41; H, 7.38; N, 4.73.
Compound 7. Compound 1 (2.06 g, 7.65 mmol), Ti(NMe
)
2 4
(1.72 g, 7.65 mmol), and toluene (20 mL) were added into a Schlenk
flask. The solution was stirred for 1 day at 80 °C. Removal of
solvent gave a red oil. 1H NMR (C6D6): δ 1.43 (s, 9H, C(CH3)3),
1.94 (s, 6H, CH3), 2.97 (s, 12H, NCH3), 5.88 (s, 2H, Cp-H), 7.01
(td, J ) 8.4, 1.2 Hz, 1H, H4 or 5), 7.26 (td, J ) 8.4, 1.6 Hz, 1H,
H4 or 5), 7.30 (d, J ) 8.0 Hz, 1H, H3 or 6), 7.66 (d, J ) 8.0 Hz, 1H,
H3 or 6) ppm. 13C{1H} NMR(C6D6): δ 14.73 (Cp-CH3), 29.14
(C(CH3)3), 39.77 (C(CH3)3), 48.35 (N-C), 112.35, 122.81, 123.10,
125.21, 125.55, 128.54, 131.55, 132.86, 144.65, 168.49 ppm. To a
1
(N-H), 1681 (CdO) cm-1. H NMR (CDCl3): δ 1.17 (s, 9H,
C(CH3)3), 1.58 (s, 3H, CH3), 1.83 (s, 3H, CH3), 1.98 (s, 3H, CH3),
3.01 (s, 2H, Cp-CH2), 7.05 (dd, J ) 7.6, 2.0 Hz, 1H, H3 or 6), 7.08
(td, J ) 7.6, 1.2 Hz, 1H, H4 or 5), 7.30 (td, J ) 7.6, 1.6 Hz, 1H,
H4 or 5), 7.60 (s, 1H, NH), 8.44 (d, J ) 8.4 Hz, 1H, H3 or 6) ppm.
13C{1H} NMR (CDCl3): δ 11.46, 13.51, 14.17, 27.29, 39.71, 48.87,

5128 Organometallics, Vol. 25, No. 21, 2006
Joung et al.
flask containing the resulting bis(dimethylamido)titanium complex
in toluene (20 mL) was added SiCl4 (5.20 g, 30.6 mmol). After the
solution was stirred 4 h at room temperature, all volatiles were
removed under vacuum to give a yellow residue, which was
triturated in pentane (30 mL) (1.77 g, 53%). Single crystals were
obtained by vapor-phase addition of pentane to a benzene solution.
1H NMR (C6D6): δ 0.93 (s, 9H, C(CH3)3), 2.21 (s, 6H, CH3), 6.03
(s, 2H, Cp-H), 6.65 (d, J ) 8.4 Hz, 1H, H3or 6), 6.89 (t, J ) 7.6 Hz,
1H, H4 or 5), 7.03 (t, J ) 8.0 Hz, 1H, H4 ×c1fr 5), 7.67 (d, J ) 7.6
Hz, 1H, H3 or 6) ppm. 13C{1H} NMR(C6D6): δ 17.19, 28.12, 43.89,
119.74, 123.05, 123.65, 125.28, 130.03, 131.89, 140.15, 140.79,
147.23, 155.97 ppm. Anal. Calc (C18H21Cl4NTi): C, 49.02; H, 4.80;
N, 3.18. Found: C, 49.18; H, 4.42; N, 3.24.
Ph-CH3), 2.25 (s, 1.3H, CH3), 2.27 (s, 1.7H, CH3), 2.32 (s, 1.7H,
CH3), 2.34 (s, 1.3H, CH3), 5.85 (s, 0.43H, Cp-H), 6.12 (s, 0.57H,
Cp-H), 6.81 (s, 1H, Ph-H), 7.51 (s, 0.57H, Ph-H), 7.55 (s, 0.43H,
Ph-H) ppm. 13C{1H} NMR (C6D6): δ 15.15, 15.80, 16.14, 16.81,
17.34, 17.70, 17.97, 21.07, 28.13, 43.76, 122.53, 122.60, 123.98,
124.03, 125.98, 126.57, 130.04, 130.20, 132.37, 134.28, 134.35,
136.96, 137.84, 138.59, 138.63, 139.38, 139.83, 142.27, 143.31,
143.80, 143.96, 155.80, 155.89 ppm. Anal. Calc (C21H27Cl4NTi):
C, 52.21; H, 5.63; N, 2.90. Found: C, 52.08; H, 5.35; N, 3.24.
Compound 11. The complex was synthesized from 5 using the
same conditions and procedures as for 7. Overall yield from 5 was
78%. The NMR data for the intermediate bis(dimethylamido)-
titanium complex: 1H NMR (C6D6): δ 1.40 (s, 9H, C(CH3)3), 1.81
(s, 6H, CH3), 2.92 (s, 12H, NCH3), 5.79 (s, 2H, Cp-H), 6.69-6.68
(m, 2H) ppm. 13C{1H} NMR (C6D6): δ 14.51, 29.04, 48.29, 103.78
Compound 8. The complex was synthesized from 2 using the
same conditions and procedures as for 7. Overall yield from 2 was
73%. NMR data for the intermediate bis(dimethylamido)titanium
complex: 1H NMR (C6D6): δ 1.45 (s, 9H, C(CH3)3), 1.88 (s, 3H,
CH3), 1.94 (s, 3H, CH3), 2.03 (s, 3H, CH3), 2.81 (s, 6H, N-CH3),
3.14 (s, 6H, N-CH3), 5.86 (s, 1H, Cp-H), 7.03 (td, J ) 7.2, 1.2 Hz,
1H, H4 or 5), 7.27 (dd, J ) 7.6, 0.8 Hz, 1H, H3 or 6), 7.30 (td, J )
2
2
4
(t, JCF ) 27.0 Hz, Ph-CH), 112.59, 113.69 (dd, JCF ) 21.2, JCF
) 3.8 Hz, CH), 122.86, 123.08, 128.14, 130.61 (dd, J ) 9.0, 4.0
1
3
Hz), 157.49 (dd, JCF ) 240, JCF ) 12.8 Hz, CF), 159.31 (dd,
1JCF ) 246, 3JCF ) 12.1 Hz, CF), 170.32 (CO) ppm. Single crystals
of 11 were obtained in toluene solution at -30 °C. Analytical data
for 11: 1H NMR (C6D6): δ 1.33 (s, 9H, C(CH3)3), 1.81 (s, 6H,
CH3), 6.08 (s, 2H, Cp-H), 6.16 (ddd, J ) 9.2, 6.4, 1.6 Hz, 1H, H5),
6.54 (ddd, J ) 9.6, 8.0, 3.6 Hz, 1H, H3) ppm. 13C{1H} NMR
(C6D6): δ 16.42 (CH3), 28.64 (C(CH3)3), 42.10 (C(CH3)3), 105.47
7.6, 1.2 Hz, 1H, H4 or 5), 7.70 (dd, J ) 8.0, 0.8 Hz, 1H, H3 or 6
)
ppm. 13C{1H} NMR(C6D6): δ 12.79, 13.06, 14.13, 29.12, 39.76,
47.12, 49.85, 115.52, 120.22, 121.21, 121.31, 122.78, 125.59,
125.95, 128.48, 131.52, 132.95, 144.69, 168.90 ppm. Single crystals
of 8 were obtained by vapor-phase addition of pentane to a benzene
solution. Analytical data for 8: 1H NMR (C6D6): δ 0.91 (s, 9H,
C(CH3)3), 2.00 (s, 3H, CH3), 2.17 (s, 3H, CH3), 2.25 (s, 3H, CH3),
5.99 (s, 1H, Cp-H), 6.66 (d, J ) 8.0 Hz, 1H, H3 or 6), 6.91 (tt, J )
8.4, 1.2 Hz, 1H, H4 or 5), 7.04 (tt, J ) 8.0, 1.2 Hz, 1H, H4 or 5), 7.73
(d, J ) 8.0 Hz, 1H, H3 or 6) ppm. 13C{1H} NMR (C6D6): δ 15.19,
16.39, 17.49, 28.08, 43.85, 119.64, 123.63, 124.79, 125.22, 129.96,
132.13, 137.78, 138.85, 139.28, 141.78, 147.20, 155.74 ppm. Anal.
Calc (C19H23Cl4NTi): C, 50.15; H, 5.09; N, 3.08. Found: C, 50.24;
H, 5.12; N, 3.24.
2
2
4
(t, JCF ) 25.8 Hz, Ph-CH), 113.85 (dd, JCF ) 23.0, JCF ) 3.8
Hz, Ph-CH), 122.46 (Cp-CH), 126.70 (d, J ) 9.1 Hz), 127.05 (dd,
J ) 8.0, 4.0 Hz), 129.90, 132.43, 133.86, 158.99 (dd, 1JCF ) 247,
3JCF ) 13.7 Hz, CF), 159.91 (dd, 1JCF ) 250, 3JCF ) 12.9 Hz, CF),
168.29 (CdO) ppm. 19F NMR (C6D6): δ -109.93 (q, J ) 7.5 Hz),
-118.22 (t, J ) 7.5 Hz) ppm. Anal. Calc (C18H19Cl2F2NOTi): C,
51.22; H, 4.54; N, 3.32. Found: C, 51.41; H, 4.25; N, 3.24.
Compound 12. The complex was synthesized from 7 using the
same conditions and procedures as for 7. Overall yield from 6 was
89%. The NMR data for the intermediate bis(dimethylamido)-
titanium complex: 1H NMR (C6D6): δ 1.41 (s, 9H, C(CH3)3), 1.72
(s, 3H, CH3), 1.84 (s, 3H, CH3), 1.96 (s, 3H, CH3), 2.77 (s, 6H,
NCH3), 3.09 (s, 6H, NCH3), 5.80 (s, 1H, Cp-H), 6.70-6.82 (m,
2H, Ph-H) ppm. 13C{1H} NMR (C6D6): δ 12.67 (CH3), 12.80
(CH3), 14.01 (CH3), 29.04 (C(CH3)3), 40.28 (C(CH3)3), 47.11 (NC),
Compound 9. The complex was synthesized from 3 using the
same conditions and procedures as for 7. Overall yield from 3 was
55%. NMR data for the intermediate bis(dimethylamido)titanium
complex: 1H NMR (C6D6): δ 1.45 (s, 9H, C(CH3)3), 1.99 (s, 6H,
N-CH3), 2.26 (s, 3H, Ph-CH3), 2.66 (s, 3H, Ph-CH3), 2.99 (s, 12H,
N-CH3), 5.88 (s, 2H, Cp-H), 7.01 (s, 1H, Ph-H), 7.10 (s, 1H, Ph-
H) ppm. 13C{1H} NMR (C6D6): δ 14.95, 21.13, 21.62, 29.27, 40.31,
48.41, 112.42, 122.68, 124.75, 125.76, 130.97, 131.25, 131.40,
137.03, 140.39, 167.26 ppm. Single crystals of 9 were obtained in
toluene solution at -30 °C. Analytical data for 9: 1H NMR
(C6D6): δ 0.95 (s, 9H, C(CH3)3), 1.95 (s, 3H, CH3), 2.09 (s, 3H,
CH3), 2.28 (s, 3H, Ph-CH3), 2.30 (s, 3H, Ph-CH3), 5.90 (d, J ) 2.8
Hz, 1H, Cp-H), 6.18 (d, J ) 2.8 Hz, 1H, Cp-H), 6.79 (s, 1H, Ph-
H), 7.45 (s, 1H, Ph-H) ppm. 13C{1H} NMR (C6D6): δ 17.09 (br),
17.69, 17.75, 21.04 (br), 28.19, 43.81, 121.94, 123.06 (d, J ) 9.1
Hz), 124.39, 126.66, 129.88 (d, J ) 9.1 Hz), 132.48 (d, J ) 6.8
Hz), 134.36, 139.26, 140.70, 141.67, 143.93, 156.11 ppm. Anal.
Calc (C20H25Cl4NTi): C, 51.21; H, 5.37; N, 2.99. Found: C, 51.01;
H, 5.25; N, 3.14.
2
2
49.82 (NC), 103.67 (t, JCF ) 25.7 Hz, Ph-CH), 112.75 (dd, JCF
) 21.2, 4JCF ) 3.8 Hz, CH), 115.74 (Cp-CH), 123.17 (br), 120.08
(Cp-CCH3), 121.24 (Cp-CCH3), 121.74 (Cp-CCH3), 128.57 (d, J
1
) 9.1 Hz), 130.64 (dd, J ) 8.0, 4.1 Hz), 157.51 (dd, JCF ) 261,
3JCF ) 13.6 Hz, CF), 159.35 (dd, 1JCF ) 246, 3JCF ) 12.9 Hz, CF),
170.67 (CO) ppm. Analytically pure crystals of 12 were obtained
in toluene solution at -30 °C. Analytical data for 12: 1H NMR
(C6D6): δ 1.34 (s, 9H, C(CH3)3), 1.74 (s, 3H, CH3), 1.89 (s, 3H,
CH3), 2.03 (s, 3H, CH3), 5.91 (s, 1H, Cp-H), 6.24 (ddd, J ) 11.6,
4.8, 2.4 Hz, 1H, H5), 6.57 (ddd, J ) 13.2, 8.8, 3.6 Hz, 1H, H3)
ppm. 13C{1H} NMR (C6D6): δ 14.12 (CH3), 15.58 (CH3), 16.69
2
(CH3), 28.66 (C(CH3)3), 42.04 (C(CH3)3), 105.39 (t, JCF ) 25.8
2
4
Hz, Ph-CH), 113.76 (dd, JCF ) 22.0, JCF ) 4.5 Hz, Ph-CH),
123.83 (Cp-CH), 128.57 (d, J ) 9.1 Hz), 130.64 (dd, J ) 8.0, 4.1
Hz), 130.39 (br), 130.68 (Cp-CCH3), 131.35 (Cp-CCH3), 135.90
Copmpound 10. The complex was synthesized from 4 using
the same conditions and procedures as for 7. Overall yield from 4
was 57%. The NMR data for the intermediate bis(dimethylamido)-
titanium complex: 1H NMR (C6D6): δ 1.45 (s, 9H, C(CH3)3), 1.92
(s, 3H, CH3), 1.99 (s, 3H, CH3), 2.06 (s, 3H, CH3), 2.27 (s, 3H,
Ph-CH3), 2.67 (s, 3H, Ph-CH3), 2.83 (s, 6H, N-CH3), 3.17 (s, 6H,
N-CH3), 5.89 (s, 1H, Cp-H), 7.00 (s, 1H, Ph-H), 7.11 (s, 1H, Ph-
H) ppm. 13C{1H} NMR (C6D6): δ 12.85, 13.30, 14.38, 21.18, 21.57,
29.26, 40.30, 47.22, 49.98, 115.62, 119.83, 120.80, 121.35, 125.15,
126.13, 130.91, 131.16, 131.47, 136.99, 140.40, 167.63 ppm. Two
signal sets are observed for 10 in a 0.57:0.43 ratio in the NMR
spectra. The minor signals are marked in italics. Analytical data
for 10: 1H NMR (C6D6): δ 0.93 (s, 3.9H, C(CH3)3), 0.94 (s, 5.1H,
C(CH3)3), 1.95 (s, 1.3H, CH3), 1.96 (s, 1.7H, CH3), 2.11 (s, 6H,
1
3
(Cp-CCH3), 158.96 (dd, JCF ) 246, JCF ) 13.7 Hz, CF), 159.98
(dd, JCF ) 250, JCF ) 12.9 Hz, CF), 168.68 ppm. 19F NMR
(C6D6): δ -108.11 (t, J ) 7.9 Hz), -113.76 (q, J ) 7.9 Hz) ppm.
Anal. Calc (C19H21Cl2F2NOTi): C, 52.32; H, 4.85; N, 3.21.
Found: C, 52.41; H, 4.75; N, 3.24.
1
3
Compound 13. To a stirred solution of 1 (1.31 g, 4.86 mmol)
in cold diethyl ether (25 mL, -30 °C) was added n-BuLi (3.9 mL,
9.73 mmol, 2.5 M in hexane) dropwise. The solution was stirred
for 6 h to give a light yellow solid, which was filtered and washed
1
with diethyl ether (1.34 g, 89%). The H and 13C NMR spectra
indicated that the dilithium salt was cleanly formed and 0.39 equiv
1
of diethyl ether was incorporated. H NMR (pyridine-d5): δ 1.35
(s, 9H, C(CH3)3), 2.26 (s, 6H, CH3), 6.28 (s, 2H, Cp-H), 6.90 (td,

Phenylene-Bridged Cp/Carboxamide Ligands
Organometallics, Vol. 25, No. 21, 2006 5129
J ) 6.8, 1.6 Hz, 1H, H4 or 5), 7.01 (td, J ) 7.2, 1.6 Hz, 1H, H4 or 5),
7.76 (dd, J ) 7.6, 2.4 Hz, 1H, H3 or 6), 7.89 (d, J ) 8.0 Hz, 1H,
H3 or 6) ppm. 13C{1H} NMR (pyridine-d5): δ 15.57, 29.86, 39.81,
103.50, 113.58, 115.13, 119.70, 123.99, 126.33, 131.13, 137.79,
153.18, 178.54 ppm. Diethyl ether (16 mL) and TiCl4‚DME (0.361
g, 1.29 mmol) were added into a flask. After the solution was cooled
to -30 °C, MeLi (1.18 g, 2.58 mmol, 1.6 M in diethyl ether) was
added dropwise and the mixture was stirred for 15 min. The
dilithium salt (0.40 g, 1.29 mmol) was added as a solid, and the
resulting solution was stirred for 3 h at room temperature. Solvent
was removed under vacuum, and the product was extracted with
pentane (15 mL). Removal of pentane gave a greenish-yellow solid
1H, Ph3 or 6), 7.27 (s, 1H, NdC-H) ppm. 13C{1H} NMR(C6D6): δ
12.37, 13.72, 14.78, 26.66, 36.83, 48.85, 120.62, 124.32, 127.81,
129.24, 131.00, 131.71, 135.18, 136.50, 141.77, 152.31, 172.69
ppm.
Complex 16. The imine compound (0.600 g, 2.17 mmol), Ti-
(NMe2)4 (0.487 g, 2.17 mmol), and toluene (12 mL) were added
into a Schlenk flask. The solution was stirred for 12 h at 100 °C.
Removal of solvent gave a red oil, which was extracted with pentane
(10 mL). Removal of solvent gave the desired tris(dimethylamido)-
titanium complex (0.783 g, 81%). 1H NMR (C6D6): δ 0.96 (s, 9H,
C(CH3)3), 1.89 (s, 3H, CH3), 2.03 (s, 3H, CH3), 2.12 (s, 3H, CH3),
3.13 (s, 18H, N-CH3), 5.56 (s, 1H, Cp-CH), 7.01 (dd, J ) 7.2, 1.6
Hz, 1H, Ph3 or 6), 7.10 (s, 1H, NdC-H), 7.12-7.19 (m, 2H, Ph4 and 5),
7.44 (dd, J ) 6.0, 1.2 Hz, 1H, Ph3 or 6) ppm. 13C{1H} NMR(C6D6):
δ 13.04, 13.27, 15.10, 26.75, 44.25, 49.63, 110.30, 119.16, 120.91,
121.05, 122.20, 124.08, 124.26, 127.77, 128.71, 134.04, 154.02,
172.66 ppm. To a flask containing the resulting tris(dimethylamido)-
titanium complex (0.783 g, 1.75 mmol) in toluene (10 mL) was
added Me2SiCl2 (0.679 g, 5.261 mmol). After the solution was
stirred for 1 h at 50 °C, all volatiles were removed under vacuum
to give a red residue, which was extracted with toluene (10 mL).
Removal of solvent gave the desired trichloride complex (0.691 g,
94%). Analytical data for 16: 1H NMR (C6D6): δ 0.79 (s, 9H,
C(CH3)3), 2.02 (s, 3H, CH3), 2.11 (s, 3H, CH3), 2.21 (s, 3H, CH3),
6.10 (s, 1H, Cp-CH), 6.67 (d, J ) 8.0 Hz, 1H, Ph3 or 6), 6.97 (td, J
) 7.2, 1.2 Hz, 1H, Ph4 or 5), 7.09 (td, J ) 7.6, 1.2 Hz, 1H, Ph4 or 5),
7.11 (s, 1H, NdC-H), 7.70 (dd, J ) 8.0, 1.2 Hz, 1H, Ph3 or 6) ppm.
13C{1H} NMR(C6D6): δ 15.27, 16.53, 17.71, 26.55, 36.99, 118.85,
124.97, 125.38, 125.69, 130.26, 132.00, 137.97, 139.19, 139.51,
143.15, 152.03, 172.69 ppm. Anal. Calc (C19H24Cl3NTi): C, 54.25;
H, 5.75; N, 3.33. Found: C, 54.41; H, 5.65; N, 3.24.
1
(yield, 72%) that is pure by the analysis of the H and 13C NMR
spectra. Analytically pure single crystals were obtained in pentane
solution at -30 °C. Two signal sets are observed in the NMR
spectra in a 0.87:0.13 ratio. The signals of the minor signals are
1
marked in italics. H NMR (C6D6, 25 °C): δ 0.89 (s, 0.78H, Ti-
CH3), 1.12 (s, 5.22H, Ti-CH3), 1.36 (s, 7.83H, C(CH3)3), 1.47 (s,
1.17H, C(CH3)3), 1.62 (s, 5.22H, CH3), 1.80 (s, 0.78H, CH3), 6.23
(s, 0.26H, Cp-H), 6.46 (s, 1.74H, Cp-H), 6.85 (td, J ) 7.2, 1.2 Hz,
1H, H4 or 5), 6.98 (td, J ) 7.2, 1.6 Hz, 1H, H4 or 5), 7.01-7.05 (m,
2H, H3and6) ppm. 13C{1H} NMR (C6D6): δ 13.59, 15.26, 27.06,
29.04, 39.53, 40.67, 58.55, 59.84, 115.27, 115.89, 119.88, 123.23,
123.57, 123.97, 124.21, 125.42, 127.85, 127.97, 128.21, 128.68,
129.68, 129.96, 131.56, 133.25, 142.18, 149.63, 165.16, 187.45
ppm. Anal. Calc (C20H27NOTi): C, 69.57; H, 7.88; N, 4.06.
Found: C, 69.27; H, 7.81; N, 4.34.
Compound 14. The compound was synthesized from 2 using
the same conditions and procedures as for 15 (overall yield, 68%).
The 1H and 13C NMR spectra indicated that the dilithium salt was
cleanly formed and 0.29 equiv of diethyl ether was incorporated.
NMR data for the dilithium compound: 1H NMR (pyridine-d5): δ
1.35 (s, 9H, C(CH3)3), 2.12 (s, 3H, CH3), 2.28 (s, 3H, CH3), 2.45
(s, 3H, CH3), 6.11 (s, 1H, Cp-H), 6.90 (t, J ) 6.8 Hz, 1H, H4 or 5),
7.02 (t, J ) 7.2 Hz, 1H, H4 or 5), 7.76 (d, J ) 7.6 Hz, 1H, H3 or 6),
7.89 (d, J ) 7.6 Hz, 1H, H3 or 6) ppm. 13C{1H} NMR (pyridine-d5):
δ 12.90, 14.73, 15.38, 29.86, 39.77, 104.54, 110.31, 110.73, 111.16,
114.19, 119.61, 123.79, 126.32, 131.23, 138.08, 153.28, 178.48
ppm. Analytically pure crystals were obtained in pentane solution
at -30 °C. Two signal sets are observed in the NMR spectra in a
0.78:0.22 ratio. Signals for the minor isomer are marked in italics.
Analytical data for 14: 1H NMR (C6D6, 25 °C): δ 0.75 (s, 0.66H,
Ti-CH3), 0.88 (s, 0.66H, Ti-CH3), 0.89 (s, 2.34H, Ti-CH3), 1.23
(s, 2.34H, Ti-CH3), 1.36 (s, 7.02H, C(CH3)3), 1.48 (s, 1.98H,
C(CH3)3), 1.51 (s, 2.34H, CH3), 1.66 (s, 2.34H, CH3), 1.76 (s,
0.66H, CH3), 1.79 (s, 0.66H, CH3), 2.00 (s, 0.66H, CH3), 2.16 (s,
2.34H, CH3), 6.00 (s, 0.22H, Cp-H), 6.25 (s, 0.78H, Cp-H), 6.87
(t, J ) 7.2, 0.78H, H4 or 5), 6.92 (t, J ) 7.2, 0.22H, H4 or 5), 6.99 (t,
J ) 8.4 Hz, 1H, H4 or 5), 7.04 (d, J ) 8.0 Hz, 0.78H, H3 or 6), 7.08
(d, J ) 0.78 Hz, 2H, H3 or 6), 7.12 (d, J ) 6.4 Hz, 0.22H, H3 or 6),
7.48 (d, J ) 8.0 Hz, 0.22H, H3 or 6) ppm. 13C{1H} NMR (C6D6): δ
11.85, 13.19, 13.54, 14.12, 14.56, 14.89, 27.16, 29.10, 39.66, 40.64,
55.87, 57.57, 60.29, 62.66, 116.87, 117.05, 120.10, 121.11, 122.48,
123.06, 123.25, 123.98, 124.18, 124.38, 124.66, 125.80, 126.75,
128.02, 128.63, 129.84, 130.32, 130.54, 131.69, 133.26, 142.49,
149.83, 165.50, 187.89 ppm. Anal. Calc (C21H29NOTi): C, 70.19;
H, 8.13; N, 3.90. Found: C, 70.41; H, 8.25; N, 3.84.
Compound 17. 2-(Dihydroxyboryl)-3-methyl-2-cyclopenten-1-
one (1.00 g, 6.49 mmol), Na2CO3 (0.98 g, 9.3 mmol), and Pd-
(PPh3)4 (0.215 g, 0.186 mmol) were added into a Schlenk flask
inside a glovebox. The flask was brought out, and deoxygenated
DME (21 mL), deoxygenated water (7 mL), and bromobenzene
(0.971 g, 6.19 mmol) were added successively with a syringe. The
mixture was stirred for 12 h at 95 °C. After the solution was cooled
to room temperature, it was transferred to a separatory funnel
containing ethyl acetate (30 mL). Water (30 mL) was added, and
the organic phase was collected. The water phase was extracted
with additional ethyl acetate (20 mL × 2). The organic phase was
combined and dried over anhydrous MgSO4. The solvent was
removed with a rotary evaporator to give a residue, which was
purified by column chromatography on silica gel eluting with
hexane and ethyl acetate (v/v, 3:1) (1.07 g, 93%). IR (neat): 1695
(CdO) cm-1. 1H NMR (CDCl3): δ 1.18 (d, J ) 7.6 Hz, 3H, CH3),
2.02 (s, 3H, CH3), 2.07 (d, J ) 2.0 Hz, 1H, Cp-CH2), 2.68 (dd, J
) 18.0, 7.2 Hz, 1H, Cp-CH2), 2.73-2.79 (m, 1H, Cp-CH), 7.18
(d, J ) 8.0 Hz, 2H, H2 and 6), 7.19 (t, J ) 6.0 Hz, 1H, H4), 7.28 (t,
J ) 8.0 Hz, 2H, H3 and 5) ppm. 13C{1H} NMR(CDCl3): δ 15.94,
19.08, 37.26, 43.40, 127.27, 127.91, 128.84, 131.51, 139.45, 175.42,
206.24 ppm.
Compound 18. Compound 17 (1.05 g, 5.64 mmol) was dissolved
in THF (51 mL). The solution was cooled to -78 °C, and MeLi
(3.87 g, 8.46 mmol, 1.6 M solution in diethyl ether) was added
with a syringe. After the mixture was stirred for 2 h at -78 °C, it
was transferred to a separatory funnel containing H2O (100 mL)
and ethyl acetate (50 mL). The organic phase was collected, and
the water phase was extracted further with additional ethyl acetate
(20 mL × 2). The combined organic phase was shaken vigorously
with aqueous HCl (2 N, 40 mL) for 2 min. The organic phase was
collected and washed with saturated aqueous NaHCO3 solution.
After the organic phase was dried over anhydrous MgSO4, the
solvent was removed with a rotary evaporator to give a residue,
which was purified by column chromatography on silica gel eluting
Complex 15. Molecular sieves (1.60 g), 2 (1.05 g, 5.27 mmol),
pivaldehyde (0.68 g, 7.90 mmol), and toluene (10 mL) were added
into a Schlenk flask. The solution was stirred for 32 h at room
temperature. The volatiles were removed by vacuum to give a
residue, which was extracted with pentane (15 mL). Removal of
solvent gave a light yellow oil (1.39 g, 98%): 1H NMR (C6D6): δ
0.92 (s, 9H, C(CH3)3), 1.73 (s, 3H, CH3), 1.77 (s, 3H, CH3), 1.80
(s, 3H, CH3), 2.62 (dd, J ) 7.2, 1.6 Hz, 2H, Cp-CH2), 6.96 (td, J
) 7.6, 1.6 Hz, 1H, Ph4 or 5), 7.00 (dd, J ) 7.6, 0.8 Hz, 1H, Ph3 or 6),
7.09 (td, J ) 7.6, 1.2 Hz, 1H, Ph4 or 5), 7.13 (dd, J ) 7.2, 1.6 Hz,

5130 Organometallics, Vol. 25, No. 21, 2006
Table 2. Crystallographic Parameters of 7, 8, 9, 11, and 14
Joung et al.
7
8
9
11
14
formula
C18H21Cl4NTi
441.06
C19H23Cl4NTi
455.08
C26H25Cl4NTi
541.17
C18H19Cl2F2NOTi
422.13
C21H29NOTi
359.35
fw
size, mm3
a, Å
0.33 × 0.14 × 0.13
16.3487(9)
7.8575(4)
17.2294(9)
90
108.4470(10)
90
2099.56(19)
monoclinic
P2(1)/n
1.395
0.28 × 0.12 × 0.10
7.0671(17)
18.778(5)
16.371(4)
90
95.393(5)
90
2162.9(9)
monoclinic
P2(1)/c
1.398
0.37 × 0.21 × 0.14
10.4334(5)
12.0665(6)
12.1840(6)
69.9080(10)
71.3620(10)
83.7550(10)
1365.00(12)
triclinic
P1h
1.317
2
0.719
18 860
6761
296
0.45 × 0.35 × 0.29
9.538(5)
13.643(3)
15.072(13)
90
106.0120(10)
90
1885.2(19)
monoclinic
P2(1)/n
1.487
0.47 × 0.32 × 0.18
9.0860(4)
10.0478(5)
11.6051(5)
77.7360(10)
80.2020(10)
70.4210(10)
969.79(8)
triclinic
P1h
1.231
2
0.448
13 357
4793
225
0.0367
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
cryst syst
space group
D(calc), g cm-1
Z
4
4
4
µ, mm-1
no. of data collected
no. of unique data
no. of variables
R(%)
0.917
21 020
5213
222
0.892
19 639
5331
233
0.762
14 384
3946
226
0.0463
0.0684
0.0400
0.0801
Rw(%)
0.1128
0.1459
0.1091
0.1673
0.1021
goodness of fit
1.093
0.886
1.031
1.079
1.055
2
2
a Data collected at 233(2) K with Mo KR radiation (λ(KR) ) 0.7107 Å), R(F) ) ∑||Fo| - |Fc||/∑|Fo| with Fo > 2.0σ(I), Rw ) [∑[w(Fo - Fc )2]/
∑[w(Fo)2]2]1/2 with Fo > 2.0σ(I).
with hexane and ethyl acetate (v/v, 10:1). A colorless oil was
obtained (0.644 g, 62%). 1H NMR (CDCl3): δ 1.66 (s, 3H, CH3),
1.86 (s, 3H, CH3), 1.88 (s, 3H, CH3), 2.82 (s, 2H, Cp-CH2), 7.11
(dd, J ) 6.8, 1.6 Hz, 2H, H3 and 5), 7.17 (t, J ) 7.2 Hz, 1H, H4),
7.28 (t, J ) 7.6 Hz, 2H, H2 and 6) ppm. 13C{1H} NMR(CDCl3): δ
12.31, 13.62, 14.39, 48.96, 125.61, 126.08, 127.79, 128.39, 129.10,
133.47, 135.08, 135.48, 137.04, 142.37 ppm. Anal. Calc (C14H16):
C, 91.25; H, 8.75. Found: C, 91.41; H, 8.55.
the solution was heated to 90 °C, it was saturated with ethylene
gas (13 bar). An activated catalyst, which was prepared by mixing
the complex (5.0 µmol Ti), [CPh3][B(C6F5)4] (15 µmol), and
(iBu)3Al (0.125 mmol) for 2 min, was charged by pressurizing the
catalyst-feeding tank with N2 pressure. After the ethylene (13 bar)
was fed continuously for 10 min, the reaction mixture was drained
into a flask containing ethanol to give white precipitates, which
were collected by filtration and dried under vacuum.
Complex 19. The complex was synthesized from 18 using the
same conditions and procedures as for 16. Overall yield for the
trichloride complex from 18 was 81% (red solid). The NMR data
X-ray Crystallography. Crystals of 7-9, 11, and 14 were
mounted in thin-walled glass capillaries and sealed under argon.
The data sets were collected on a Bruker Smart CCD detector single
diffractometer. Mo KR radiation (λ ) 0.7107 Å) was used for all
structures. The structures were solved by the direct methods using
the SHELX-96 program and least-squares refinement using the
SHELXL-Plus (5.1) software package. All non-hydrogen atoms
were refined anisotropically. All hydrogen atoms were included in
the calculated positions. The crystal data and refinement results
are summarized in Table 2.
1
for the intermediate tris(dimethylamido)titanium complex: H NMR
(C6D6): δ 2.02 (s, 3H, CH3), 2.06 (s, 3H, CH3), 2.23 (s, 3H, CH3),
3.08 (s, 18H, N-CH3), 5.68 (s, 1H, Cp-H), 7.11 (tt, J ) 7.2, 1.6
Hz, 1H, H4) 7.29 (tt, J ) 7.2, 1.6 Hz, 2H, H3 or 5), 7.36 (dt, J )
6.8, 1.6 Hz, 2H, H2 or 6) ppm. 13C{1H} NMR (C6D6): δ 12.97, 13.16,
14.10, 49.40, 111.35, 119.49, 120.18, 120.85, 124.45, 126.06,
128.40, 131.01, 137.38 ppm. Analytical data for 19: 1H NMR
(C6D6): δ 1.95 (s, 3H, CH3), 2.09 (s, 3H, CH3), 2.17 (s, 3H, CH3),
6.02 (s, 1H, Cp-H), 7.06 (t, J ) 7.2 Hz, 1H, H4), 7.12 (t, J ) 7.2
Hz, 2H, H3 and 5), 7.25 (d, J ) 6.8 Hz, 2H, H2 and 6) ppm. 13C{1H}
NMR (C6D6): δ 14.97, 16.41, 17.46, 125.22, 128.55, 128.85,
130.48, 132.92, 136.49, 137.49, 139.29, 141.91 ppm. Anal. Calc
(C14H15Cl3Ti): C, 49.82; H, 4.48. Found: C, 49.79; H, 4.41.
Polymerization. To a 2.0 L Bu¨chi reactor were added 1.0 L of
toluene solution of 1-octene (0.80 M) and iBu3Al (0.5 mmol). After
Acknowledgment. The authors are grateful for financial
support from the Ministry of Commerce, Industry.
Supporting Information Available: Data in cif format for 7,
8, 9, 11, and 14. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM060604X