sp3-C1-bridged 1,3-Me2Cp/amido titanium and zirconium complexes and their reactivities towards ethylene polymerization

Article abstract of DOI:10.1002/ejic.200300703

sp³-C¹-Bridged Cp/amido titanium and zirconium complexes are synthesized by using novel fulvenes that have substituents in the 1-, 4-, and 6-positions only. Thus, the nucleophilic attack of lithium tert-butylamide on 1,4-dimethyl-6-p

Full text of DOI:10.1002/ejic.200300703

FULL PAPER
sp3-C1-Bridged 1,3-Me2Cp/Amido Titanium and Zirconium Complexes and
Their Reactivities towards Ethylene Polymerization
Tae Ho Kim,[a] Young Chul Won,[a] Bun Yeoul Lee,*[a] Dong Mok Shin,[b] and
Young Keun Chung[b]
Keywords: Cyclopentadienyl / Zirconium / Titanium / Polymerization / Homogeneous catalysis
sp3-C1-Bridged Cp/amido titanium and zirconium complexes
are synthesized by using novel fulvenes that have substitu-
M = Zr, R = 2-furyl, 14; M = Zr, R = cyclohexyl, 15). Complex
10 is very sensitive towards water, such that an oxo-bridged
ents in the 1-, 4-, and 6-positions only. Thus, the nucleophilic dimer,
(1,3-Me2C5H2−CHPh−NHtBu)ZrCl2−µO−ZrCl2(1,3-
attack of lithium tert-butylamide on 1,4-dimethyl-6-phenyl-
fulvene, 6-(2-furyl)-1,4-dimethylfulvene and 6-cyclohexyl-
1,4-dimethylfulvene, and subsequent aqueous workup,
yields tBuN(H)−CHR−C5H3Me2 (R = phenyl, 6; R = 2-furyl, 7;
R = cyclohexyl, 8) in 80, 88, and 60% yields, respectively. The
reactions of the ligands with M(NMe2)4 (M = Ti or Zr) afford
the desired bis(dimethylamido) complexes, which can be
transformed by treatment with Me2SiCl2 to the dichloride
complexes, (1,3-Me2C5H2−CHR−NtBu−κN)MCl2 (M = Ti, R =
Me2C5H2−CHPh−NHtBu) (12), is easily formed by the ab-
straction of water from the solvents. The solid structures of
(1,3-Me2C5H2−CHPh−NtBu−κN)Zr(NMe2)2, 10, 11, and 12
have been determined by X-ray crystallography. The com-
plexes are active towards the polymerization of ethylene
when activated with MAO. The activities are rather low and
the molecular weight distributions are broad (Mw/Mn
10−36).
=
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
phenyl, 10; M = Zr, R = phenyl, 11; M = Ti, R = 2-furyl, 13; Germany, 2004)
Introduction
bridged 1,3-Me2Cp/fluorenyl zirconium complex using the
fulvene.[7] Herein, we report on the syntheses and charac-
terizations of C1-bridged 1,3-Me2Cp/amido zirconium and
titanium complexes using fulvenes that have substituents in
the 1-, 4- and 6-positions only. The complexes are charac-
teristic since the methyl substituents on the cyclopen-
tadienyl ligand are located next to the bridge.[8] In these
complexes, the steric congestion at the reaction site is mini-
mized, while an electronic effect is imposed by the substitu-
ents.[9]
Various group 4 ansa-metallocene complexes, which have
drawn attention as homogeneous Ziegler catalysts, can be
synthesized from fulvenes. The C1-bridged Cp/fluorenyl and
C1-bridged Cp/indenyl complexes are typical examples.[1]
Some C1-bridged Cp/Cp,[2] C2-bridged Cp/Cp,[3] and C3-
bridged Cp/Cp complexes[4] are also obtained from fulv-
enes. Recently, Erker et al. reported on the syntheses of sp3-
C1-bridged Cp/amido titanium and zirconium complexes
using 6-tert-butylfulvene and 1,2,3,4-tetramethylfulvene.[5]
Fulvenes are conventionally synthesized by the base-me-
diated coupling of cyclopentadiene with aldehydes or ke-
tones.[6] If mono-substituted or 1,3-disubstituted cyclopen-
tadienes are used, the substituents are located mainly in the
2-position or the 1,3-positions in the resulting fulvenes due
Results and Discussion
Syntheses and Characterizations
6-(2-Furyl)-1,4-dimethylfulvene (4) and 6-cyclohexyl-1,4-
to steric reasons. Recently, we reported on a synthetic route dimethylfulvene (5) were synthesized by a similar method
for the preparation of 1,4-dimethyl-6-phenylfulvene, which using the same conditions as that developed for the syn-
is a novel product as it has substituents in the 1-, 4-, and 6-
positions only, and we demonstrated the synthesis of a C1-
[a]
Department of Molecular Science and Technology, Ajou
University, Suwon,
442-749, Korea
Fax: (internat.) ϩ 82-31-219-1844
E-mail: bunyeoul@ajou.ac.kr
[b]
School of Chemistry and Center for Molecular Catalysis, Seoul
National University,
Seoul 151-747, Korea
Scheme 1. i) nBuLi; ii) RC(O)H; iii) HCl; iv) dihydropyran,
p-TsOH; v) MeLi; vi) HCl; vii) NaOMe
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Titanium and Zirconium Complexes and Their Reactivities towards Ethylene Polymerization
FULL PAPER
thesis of 1,4-dimethy-6-phenylfulvene (Scheme 1). The over-
all yields from the starting material 1 were 31% and 42%
1
for 4 and 5, respectively. The H NMR spectra, 13C NMR
spectra, and the elemental analyses are in agreement with
the fulvene structures of 4 and 5.
The nucleophilic attack of lithium tert-butylamide on the
fulvenes in THF, followed by aqueous workup, afforded the
desired ligands 6, 7, and 8 in 80, 88, and 60% yields, respec-
tively (Scheme 2). Substituted cyclopentadienes are fre-
quently obtained as a set of isomers due to the rapid 1,5-
sigmatropic rearrangement.[10] However, compounds 6, 7,
and 8 were obtained as single isomers, as a result of the
symmetry of the substituents, and were characterized un-
1
ambiguously by H and 13C NMR spectroscopy. Compari-
son of the 13C NMR spectra of the three compounds assists
in the assignment of the signals. The signal at 125 ppm is
assigned to CpϪCH and the signals for CpϪC(CH3) are
observed at 140Ϫ144 ppm. The signals assigned to
CpϪC(bridgehead) and CpϪCH2 are observed at
136Ϫ138 ppm and 44 ppm, respectively.
Figure 1. Thermal ellipsoid plot (30% probability level) of the
structure of 9
Similar reactions of 7 and 8 with Zr(NMe2)4, and reac-
tions of 6 and 7 with Ti(NMe2)4, afforded the correspond-
ing bis(dimethylamido) complexes. The reaction of 8 with
Ti(NM2)4 was sluggish under identical conditions. The
bis(dimethylamido) complexes are oily and therefore could
1
not be purified by recrystallization; however, the H and
13C NMR spectra strongly support their formation. The
crude products have been used for the proceeding chlori-
nation reactions without further purification. The synthetic
method described here is complementary to that developed
by Erker, who obtained the Cp and tetramethylcyclopen-
tadienyl analogues by treating the corresponding dilithium
salts with TiCl2(NMe2) or ZrCl2(NEt2)2(THF)2.[5]
Scheme 2
The reaction of 6 with Zr(NMe2)4 at 100 °C for 2 days
afforded the desired C1-bridged 1,3-Me2Cp/amido zir-
conium complex 9 (Scheme 3).[11] The dimethylamine
formed was removed by a stream of nitrogen gas. When the
reaction was carried out by heating without the stream of
nitrogen, the reaction stops with the formation of un-
Erker attempted to convert (Me4CpϪCH2ϪNtBu)Zr-
(NEt2)2 to (Me4CpϪCH2ϪNtBu)ZrCl2 by treatment with
excess unpurified Me3SiCl.[5] He unexpectedly obtained an
µ-oxo complex, (Me4CpϪCH2ϪNtBu)ZrCl2ϪµOϪZrCl2-
(Me4CpϪCH2ϪNtBu). The yield of the µ-oxo complex was
relatively low (40%), and a complicated mixture of unidenti-
fied products was observed in the 1H NMR spectrum.
When the reaction of two equivalents of carefully dried Me-
3SiCl with the bis(dimethylamido) titanium complex of 6 in
bridged tris(dimethylamido)Cp complex. The H and 13C
NMR spectra support the structure shown in Scheme 3.
Signals for the Cp protons are observed as a pair of dou-
1
1
blets (J ϭ 2.8 ppm) at 5.88 ppm and 5.48 ppm in the H
NMR spectrum (C6D6), and the methyl signals of the di-
methylamido group are observed as a pair of singlets at 3.09
and 2.89 ppm. The signal for the bridgehead carbon on the
Cp moiety is observed at 105.76 ppm in the 13C NMR spec-
trum. Complex 9 is a solid, and single crystals suitable for
X-ray crystallography were obtained by recrystallization in
pentane at Ϫ30 °C. The X-ray crystallographic studies con-
firm the structure shown in Scheme 3. The thermal ellipsoid
plot is shown in Figure 1.
1
C6D6 was followed by H NMR spectroscopy, it was seen
that only one dimethylamido ligand was replaced by the
chloride ligand giving (1,3-Me2C5H2ϪCHPhϪNtBuϪκN)-
TiCl(NMe2). Complete chlorination is achieved using Me2-
SiCl2.[12] Addition of four equivalents of Me2SiCl2 in C6D6
resulted in the formation of the desired dichloride complex
1
10 (Scheme 4). The H and 13C NMR spectra are in agree-
ment with the structure of the dichloride complex. Single
crystals of 10 suitable for X-ray crystallography were ob-
tained in toluene at Ϫ30 °C and X-ray crystallographic
studies confirm the dichloride structure (Figure 2).
Addition of two equivalents of Me2SiCl2 to the bis(di-
methylamido)zirconium complex 9 in benzene and overnight
stirring, resulted in the precipitation of a white solid. The
1H and 13C NMR spectra of the precipitate strongly sup-
Scheme 3
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T. H. Kim, Y. C. Won, B. Y. Lee, D. M. Shin, Y. K. Chung
FULL PAPER
Since the 1H and 13C NMR spectra of the precipitate
strongly support the structure of the desired mononuclear
complex 11, the formation of 12 may be attributed to the
presence of water as an impurity in the recrystallization sol-
vents. Single crystals suitable for X-ray crystallography were
directly deposited when 9 and Me2SiCl2 were mixed in ben-
zene and reacted without stirring for several days at room
temperature. X-ray crystallographic studies of a single crys-
tal obtained by this procedure reveal the desired structure
of the mononuclear complex 11 (Figure 4). Complexes
13؊15 were synthesized in a similar manner, by the reac-
tions of two or three equivalents of Me2SiCl2 with the crude
bis(dimethylamido) complexes, which are obtained by the
reaction of 7 with Ti(NMe2)4 and reactions of 7 and 8 with
Zr(NMe2)4 (Scheme 4).
Scheme 4
Figure 2. Thermal ellipsoid plot (30% probability level) of the
structure of 10
port the formation of the desired dichloride complex 11
(Scheme 4). The main features of the NMR spectra are al-
most identical to those observed for titanium complex 10.
However, X-ray crystallographic studies of a single crystal,
which was obtained by dissolving the precipitate in benzene
and by the slow addition of pentane vapor at room tem-
perature, reveal the structure of an unexpected dinuclear µ-
oxo complex, 12 (Figure 3). A similar dinuclear µ-oxo com-
plex was observed by Erker when (Me4CpϪ
CH2ϪNtBu)Zr(NEt2)2 was treated with excess unpurified
Me3SiCl.[5]
Figure 4. Thermal ellipsoid plot (30% probability level) of the
structure of 11
Crystal Structures of 9, 10, 11, and 12
The thermal ellipsoid plots of 9, 10, and 11 are shown in
Figures 1, 2, and 4, respectively, and the selected bond
lengths and angles are tabulated in Table 1. The crystal
structures show the tetrahedral coordination geometry of
the central zirconium or titanium atoms. The cyclopen-
tadienyl ligands are η5-coordinated, with a systematic in-
crease in the ZrϪC bond lengths on moving from the
bridgehead carbon atom to the peripheral carbon atoms.
The MϪC distances observed for the titanium complex 10
are shorter than the corresponding distances observed for
the zirconium complexes 9 and 11, and the MϪC distances
observed for the bis(dimethylamido) complex 9 are longer
than those observed for the dichloride complex 11. A simi-
lar trend is observed for the MϪNtBu distances of 9, 10,
and 11. The ClϪMϪCl angle observed for the zirconium
complex 11 [123.27(5)°] is greater than that observed for the
titanium complex 10 [104.11(7)°], as well as for the
NϪZrϪN angle observed for 9 [104.56(16)°]. The bridge
carbon atoms are out of the Cp planes, and consequently
the CpcentroidϪCbridgeheadϪCbridge bond angles deviate from
the ideal value of 180°. The CpcentroidϪCbridgeheadϪCbridge
angle observed for the titanium complex 10 (152.1°) is
smaller than those observed for the zirconium complexes 9
and 11 (156.2 and 155.8°, respectively), indicating that the
bridge carbon atom is further out of the Cp plane in the
Figure 3. Thermal ellipsoid plot (30% probability level) of the
structure of 12
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Titanium and Zirconium Complexes and Their Reactivities towards Ethylene Polymerization
FULL PAPER
˚
Table 1. Selected bond lengths (A) and angles (°)
9
10
11
12
MϪCl(or N)[a]
MϪCl(or N)
2.033(4)
2.061(4)
2.106(3)
2.420(4)
2.466(4)
2.557(4)
2.525(4)
2.587(4)
2.206
2.2801(15)
2.2653(16)
1.924(4)
2.256(4)
2.338(5)
2.315(5)
2.360(5)
2.373(5)
1.992
1.543(6)
1.469(5)
97.1
152.1
104.11(7)
97.3(3)
2.5292(18)
2.4310(15)
2.076(3)
2.390(4)
2.484(4)
2.462(4)
2.508(4)
2.503(4)
2.156
1.529(5)
1.469(4)
91.0
155.8
123.27(5)
99.3(3)
2.4688(13)
2.4265(14)
2.536(4)[b]
2.444(4)
2.521(5)
2.483(4)
2.549(5)
2.514(4)
2.199
MϪNCbridge
MϪCbridgehead
MϪCcp(CH3)[a]
MϪCcp(CH3)
M-CcpHa
MϪCcpH
MϪCpcentroid
CbridgeheadϪCbridge
CbridgeϪN
1.543(5)
1.470(5)
90.7
1.513(6)
1.485(5)
CpcentroidϪMϪNCbridge
Cpcentroid-Cbridgehead-Cbridge
Cl(or N)ϪMϪCl (or N)
CbridgeheadϪCbridgeϪN
CbridgeϪNϪM
156.2
164.8
104.56(16)
100.9(3)
106.7(2)
118.2(3)
127.9(3)
87.04(5)
103.3(3)
98.1(3)
117.9(4)
129.8(3)
107.1(3)
120.4(3)
129.5(3)
107.5(2)
119.4(3)
131.0(2)
CbridgeϪNϪCMe3
MϪNϪCMe3
[a]
[b]
˚
Bond length with respect to the side to which the phenyl group is located. ZrϪO distance, 1.9526(5) A.
titanium complex 10. The CbridgeheadϪCbridgeϪN angles
Table 2. Ethylene polymerization results
(100.9(3), 97(3) and 99.3(3) ° for 9, 10, and 11, respectively)
Entry Compound[a] Time Activity
Mw
Mw/Mn
[c]
[c]
deviate from the ideal sp3-tetrahedral angle (109.5°). The
CpcentroidϪMϪNCbridge angles observed for 9, 10, and
11 are smaller than that observed for the related
(min) (kg/mol·h)
1
2
3
4
5
6
10[b]
11
13
14
15
9
30
30
10
20
30
30
92
16
318
150
71
34000 14
361000 36
610000 32
198000 29
348000 10
150000 24
complex (Me4CpSiN)Zr(NR2)2 (100.2°).[13] The Cpcentroid
Ϫ
MϪNCbridge angles observed for the zirconium complexes
9 and 11 (90.7 and 91.0°, respectively) are smaller than that
observed for the titanium complex 10 (97.1°), reflecting that
the constraint imposed by the CpϪCbridgeϪNϪM frame is
larger in the zirconium complexes than in the titanium com-
122
[a]
Polymerization conditions: 30 mL toluene, 60 °C, 10 µmol cata-
[b]
plex. The nitrogen atoms on the dimethylamido ligand in lyst, Al/Zr or Ti ϭ 500, 100 psig ethylene. 5.0 µmol catalyst, Al/
10 form a perfect trigonal planar structure (sum of the
bond angles are 359.1° and 359.9°). The nitrogen atoms
[c]
Zr or Ti ϭ 1000. Determined by GPC in 1,2,4-trichlorobenzene
at 140 °C against polystyrene standards.
bonded to the tert-butyl group in the dichloride complexes
10 and 11 also almost form a trigonal planar structure (sum
of bonding angles, 357.0° and 357.9°, respectively), how-
of Cp2ZrCl2, but are similar to those of the cyclopen-
ever, the corresponding nitrogen atoms in the bis(dimethyla-
tadienyl or tetramethylcyclopentadienyl analogues pre-
viously prepared by Erker.[5] The titanium complexes show
higher activities relative to the zirconium complexes (entry
1 and 3 versus entry 2 and 4). The activity depends strongly
on the substituent attached to the bridge carbon atom. The
complexes that have the 2-furyl group show the highest ac-
tivity (entry 3 and 4), and the activity of the zirconium com-
plex that has the 2-furyl substituent is 10 times higher than
the complex that has a phenyl substituent (entry 2 and 4).
The complex rac-(EBI)Zr(NMe2)2 was reported to be less
active than the corresponding dichloride complex when ac-
tivated with MAO.[14] However, in this case, the bis(dime-
thylamido) complex 9 shows a higher activity than the cor-
responding dichloride complex 11 (entry 2 and 6). The ti-
tanium complex 13, which shows the highest activity, pro-
duces a polymer with the highest molecular weight (Mw,
mido) complex 9 deviate from the trigonal planar structure
(sum of the bond angles is 352.8°).
The thermal ellipsoid plot of 12 is shown in Figure 3
and the selected bond lengths and angles are tabulated
in Table 1. The metrical parameters observed for 12 are
very similar to those observed for [Me4CpϪ
CH2ϪN(H)tBu]ZrCl2ϪOϪZrCl2[Me4CpϪCH2ϪN(H)tBu],
with the exception of the ZrϪOϪZr angle. A strictly linear
ZrϪOϪZr arrangement (180°) is observed for complex 12,
while
a
somewhat bent structure is observed for
[Me4CpϪCH2ϪN(H)tBu]ZrCl2ϪOϪZrCl2[Me4CpϪCH2Ϫ
N(H)tBu] (the ZrϪOϪZr angle is 168.2°).
Ethylene Polymerization Studies
The dichloride complexes 10, 11, and 13؊15 are active 610,000). The molecular weight distributions are very broad
towards the polymerization of ethylene when activated with (Mw/Mn ϭ 10Ϫ36), indicating that there are several types
MAO (Table 2). The activities are low compared with that of active species in the polymerization solution.
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T. H. Kim, Y. C. Won, B. Y. Lee, D. M. Shin, Y. K. Chung
FULL PAPER
IR (neat): ν˜ ϭ 1635 and 1673 (CϭCϪCϭO), 3315 (br., OH) cmϪ1
C11H12O3 (192.21): calcd. C 68.7, H 6.31; found C 68.8, H 6.50.
.
Conclusion
sp3ϪC1Ϫbridged Cp/amido CGC complexes (1,3-
Me2C5H2ϪCHRϪNtBuϪκN)MCl2 (M ϭ Ti, Zr; R ϭ phe-
nyl, 2-furyl, cyclohexyl) have been synthesized using novel
fulvenes that have substituents in the 1-, 4-, and 6-positions
only. The bis(dimethylamido) complexes, which have
been prepared by the reaction of M(NMe2)4 with
tBuN(H)ϪCHRϪC5H3Me2, can be transformed to the di-
chloride complexes by treatment with Me2SiCl2. The com-
plexes are active towards the polymerization of ethylene
when activated with MAO. The titanium complexes show
higher activities relative to the zirconium complexes, and
the titanium complex that has a 2-furyl group on the bridge
carbon atom shows the highest activity. The molecular
weight distributions are broad (Mw/Mn, 10Ϫ36).
Compound 3: This compound was synthesized according to a pro-
cedure similar to that of 2. It was purified by column chromatogra-
phy on silica gel eluting with hexane and ethyl acetate (v/v, 2:1)
(oil, 82%). 1H NMR (400 MHz, CDCl3, 25 °C): δ ϭ 0.19 (td,
JH,H ϭ 12.0, JH,H ϭ 3.2 Hz, 1 H, Cy-H), 1.00 (td, JH,H ϭ 12.0,
JH,H ϭ 3.2 Hz, 1 H, Cy-H), 1.08Ϫ1.84 (m, 9 H, Cy-H), 2.05 (s, 3
H, CH3), 2.38Ϫ2.43 (m, 2 H, CH2), 2.52Ϫ2.62 (m, 2 H, CH2), 3.66
3
3
3
(d, JH,H ϭ 10.0 Hz, 1 H, OH), 4.10 (dd, JH,H ϭ 10.0, JH,H
ϭ
8.4 Hz, 1 H, OCH) ppm. 13C{1H} NMR (100 MHz, CDCl3, 25
°C): δ ϭ 17.72 (CH3), 25.93 (Cy-CH2), 26.10 (Cy-CH2), 26.46 (Cy-
CH2), 29.30 (Cy-CH2), 29.46 (Cy-CH2), 31.94 (CH2), 34.64 (CH2),
43.79 (Cy-CH), 73.14 (COH), 139.49 (CϭC), 171.91 (CϭC), 210.88
(carbonyl) ppm. IR (neat): ν˜ ϭ 2850 and 2923 (CϭCϪCϭO), 3446
(br., OH) cmϪ1. C13H20O2 (208.30): calcd. C 75.0, H 9.70; found
C 75.3, H 9.52.
6-(2-Furyl)-1,4-dimethylfulvene (4): Compound
2
(1.44 g,
7.50 mmol) was dissolved in CH2Cl2 (10 mL). Dihydropyran
(0.95 g, 11 mmol) and pyridinium p-toluenesulfonate (PPTS)
(0.19 g, 0.75 mmol) were then added at room temperature. The
solution was stirred for 4 hours and then diluted with diethyl ether
(50 mL). The solution was washed with saturated aqueous NaCl
solution. The organic phase was collected and dried over anhydrous
MgSO4. Removal of the solvent using a rotary evaporator gave a
residue that was purified by column chromatography on silica gel
eluting with hexane and ethyl acetate (v/v, 2:1). Signals of two dia-
Experimental Section
General Remarks: All manipulations were performed under an inert
atmosphere using standard glove box and Schlenk techniques.
Toluene, pentane, THF, diethyl ether, and benzene were distilled
from benzophenone ketyl. Toluene used for the polymerization re-
action was purchased from Aldrich (anhydrous grade) and purified
further over Na/K alloy. Dichlorodimethylsilane was dried over
CaH2. Ethylene was purchased from Conley Gas (99.9%) and puri-
fied by contactwith molecular sieves and copper overnight under a
pressure of 150 psig. Methylaluminoxane (MAO) was purchased as
a solution in toluene from Akzo (7.6 weight% of Al, MMAO type
4). The NMR spectra were recorded on a Varian Mercury plus
400 spectrometer. Elemental analyses were carried out at the Inter-
University Center Natural Science Facilities, Seoul National Uni-
versity. Gel permeation chromatograms (GPC) were obtained at
140 °C in trichlorobenzene using a Waters Model 150-Cϩ GPC,
and the data were analyzed using a polystyrene analyzing curve.
1
stereomers are observed in the H NMR spectrum. The yield was
1.77 g (yield, 85%). The compound was dissolved in diethyl ether
(5 mL), and MeLi (6.4 mL, 1.5  in diethyl ether, 9.6 mmol) was
added dropwise at Ϫ78 °C. The solution was allowed to warm to
room temperature and stirred overnight. Water (10 mL) was then
added. The diethyl ether was removed using a rotary evaporator.
Ethyl acetate (30 mL) was added to the residue and the mixture
was poured into a separating funnel. The aqueous layer was re-
moved and aqueous HCl (2 , 30 mL) was added. The mixture was
shaken vigorously for 2.5 minutes. The aqueous layer was removed
and the organic layer was washed with saturated aqueous NaHCO3
solution (30 mL). The organic layer was collected and dried over
anhydrous MgSO4. The solvent was removed using a rotary evapor-
ator, thus giving a residue. NaH (0.23 g, 9.6 mmol) and anhydrous
THF (10 mL) was added to the residue under a nitrogen atmos-
phere. Methanol (1.0 mL) was added using a syringe, upon which
hydrogen gas was evolved and the solution became red. The solu-
tion was stirred for 20 minutes at room temperature under nitrogen.
The solution was poured into a separating funnel containing water
(20 mL), and the red compound was extracted with ethyl acetate
(50 mL). The organic layer was dried over anhydrous MgSO4. Re-
moval of the solvent gave a red residue that was purified by column
chromatography on silica gel eluting with hexane and ethyl acetate
(v/v, 20:1). The yield was 0.750 g (overall yield from 2, 58%). 1H
NMR (400 MHz, CDCl3, 25 °C): δ ϭ 2.09 (s, 3 H, CH3), 2.31 (s,
Compound 2: nBuLi (3.82 g, 2.5  in hexane, 13.8 mmol) at Ϫ78
°C was added dropwise to a Schlenk flask containing 1 (3.00 g,
13.8 mmol) in THF (5 mL), and the solution was stirred for 1 hour
at Ϫ78 °C. Furfural (1.32 g, 13.8 mmol) was added and the solu-
tion was stirred for 2 hours at Ϫ78 °C. The solution was poured
into a separating funnel containing water (20 mL), and the product
was extracted with ethyl acetate (10 mL ϫ 5). The combined or-
ganic layer was shaken with aqueous HCl (1 , 20 mL) for about
30 seconds, in which step the ketal group was deprotected to give
a carbonyl compound. The organic layer was washed with concen-
trated aqueous NaHCO3 solution (20 mL). The organic layer was
collected and dried over anhydrous MgSO4. The solvent was re-
moved to give a residue, which was purified by column chromatog-
raphy on silica gel eluting with hexane and ethyl acetate (v/v, 2:1) 3 H, CH3), 5.97 [s, 1 H, fulvene-C(2 or 3)-H], 6.11 [quadruplet,
(white solid, 1.44 g, 54%). M.p. 74 °C. 1H NMR (400 MHz, CDCl3, 4JH,H ϭ 1.2 Hz, 1 H, fulvene-C(2 or 3)ϪH)], 6.51 [dd, 3JH,H ϭ 3.2,
3
25 °C): δ ϭ 2.10 (s, 3 H, CH3), 2.44Ϫ2.48 (m, 2 H, CH2), 2.58Ϫ2.63
3JH,H ϭ 1.6 Hz, 1 H, furyl-C(4)ϪH], 6.73 [d, JH,H ϭ 3.2 Hz, 1 H,
(m, 2 H, CH2), 4.64 (d, 3JH,H ϭ 8.8 Hz, 1 H, OH), 5.60 (d, 3JH,H ϭ furyl-C(3)ϪH], 6.80 [(s, 1 H, fulvene-C(6)ϪH)], 7.56 [dd, JH,H
ϭ
3
3
3
4
8.8 Hz, 1 H, OCH), 6.22 [dd, JH,H ϭ 3.2, JH,H ϭ 0.8 Hz, 1 H,
1.6, JH,H ϭ 0.4 Hz, 1 H, furyl-C(5)ϪH)] ppm. 13C{1H} NMR
3
4
furyl-C(4)ϪH], 6.31 [dd, JH,H ϭ 3.2, JH,H ϭ 2.0 Hz, 1 H, furyl-
(100 MHz, CDCl3, 25 °C): δ ϭ 13.09 (CH3), 17.42 (CH3), 112.22
4
3
C(5)ϪH], 7.34 [dd, JH,H ϭ 2.0, JH,H ϭ 0.8 Hz, 1 H, furyl- (furyl-CH), 116.84 (furyl-CH), 119.38 (furyl-CH), 126.29 [fulvene-
C(3)ϪH] ppm. 13C{1H} NMR (100 MHz, CDCl3, 25 °C): δ ϭ
17.41 (CH3), 32.18 (CH2), 34.65 (CH2), 64.28 (COH), 106.26 [furyl-
C(3 or 4)], 110.23 [furyl-C(3 or 4)], 137.27 (CϭC), 142.04 [furyl-
C(2 or 3)], 129.38 [fulvene-C(1 or 4)], 131.68 [fulvene-C(2 or 3)],
134.05 [fulvene-C(1 or 4)], 141.77 [fulvene-C(5)], 144.49 [fulvene-
C(6)], 151.28 [furyl-C(2)] ppm. C12H12O1 (172.22): calcd. C 83.7,
C(5)], 154.57 [furyl-C(2)], 173.18 (CϭC), 210.05 (carbonyl) ppm. H 7.04; found C 83.6, H 7.00.
1526  2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www.eurjic.org
Eur. J. Inorg. Chem. 2004, 1522Ϫ1529

Titanium and Zirconium Complexes and Their Reactivities towards Ethylene Polymerization
FULL PAPER
6-Cyclohexyl-1,4-dimethylfulvene (5): This compound was synthe-
sized according to a procedure similar to that for 4. It was purified
by column chromatography on silica gel eluting with hexane and
ethyl acetate (v/v, 50:1). A yellow oily compound was obtained in
a 51% overall yield from 3. 1H NMR (400 MHz, CDCl3, 25 °C):
δ ϭ 1.12Ϫ1.44 (m, 5 H, Cy-CH2), 1.68Ϫ1.90 (m, 5 H, Cy-CH2),
142.73 [Cp-C(CH3)], 143.73 [Cp-C(CH3)] ppm. C18H31N1 (261.45):
calcd. C 82.7, H 12.0, N 5.35; found C 82.9, H 12.1, N 5.40.
(1,3-Me2C5H2-CHPh؊NtBu؊κN)Zr(NMe2)2 (9): Compound
6
(0.511 g, 2.00 mmol) and Zr(NMe2)4 (0.535 g, 2.00 mmol) were
weighed in a flask and toluene (30 mL) was added. The solution
was stirred for 2 days at 100 °C under a weak stream of nitrogen
gas. The volatiles were removed to give a white oil, which was quite
pure (analyzed by 1H and 13C NMR spectroscopy) (crude yield,
97%). Analytically pure single crystals suitable for X-ray crystal-
lography were obtained in pentane at Ϫ30 °C. M.p. 135 °C. 1H
NMR (400 MHz, C6D6, 25 °C): δ ϭ 1.24 (s, 9 H, tBu-H), 1.54 (s,
3 H, CH3), 2.19 (s, 3 H, CH3), 2.89 (s, 6 H, NCH3), 3.09 (s, 6 H,
3
2.01 (s, 3 H, CH3), 2.22 (s, 3 H, CH3), 2.93 (qt, JH,H ϭ 10.4,
3JH,H ϭ 3.2 Hz, 1 H, Cy-CH), 5.92 [s, 1 H, fulvene-C(2 or 3)ϪH],
4
6.03 [quadruplet, JH,H ϭ 1.2 Hz, 1 H, fulvene-C(2 or 3)ϪH], 6.11
3
[d, JH,H ϭ 10.4 Hz, 1 H, fulvene-C(6)ϪH] ppm. 13C{1H} NMR
(100 MHz, CDCl3, 25 °C): δ ϭ 12.68 (CH3), 16.95 (CH3), 25.79
(Cy-CH2), 25.98 (Cy-CH2), 33.12 (Cy-CH2), 37.55 (Cy-CH), 125.34
[fulvene-C(2 or 3)], 130.03 [fulvene-C(1 or 4)], 130.28 [fulvene-C(2
or 3)], 133.43 [fulvene-C(1 or 4)], 142.65 [fulvene-C(5)], 144.10 [ful-
vene-C(6)] ppm. C14H20 (188.31): calcd. C 89.3, H 10.7; found C
89.0, H 10.5.
3
NCH3), 5.48 (d, JH,H ϭ 2.8 Hz, 1 H, Cp-H), 5.85 (s, 1 H, bridge-
3
3
CH), 5.88 (d, JH,H ϭ 2.8 Hz, 1 H, Cp-H), 7.13 [t, JH,H ϭ 7.6 Hz,
1 H, Ph-C(para)ϪH], 7.25 [t, 3JH,H ϭ 7.6 Hz, 2 H, Ph-C(meta)ϪH],
7.61 [d, 3JH,H ϭ 7.6 Hz, 2 H, Ph-C(ortho)ϪH] ppm. 13C{1H} NMR
(100 MHz, C6D6, 25 °C): δ ϭ 13.52 (CH3), 14.79 (CH3), 32.24
[C(CH3)3], 43.58 [N(CH3)2], 47.37 [N(CH3)2], 56.20 [NC(CH3)3],
Substituted Cyclopentadiene (6): 1,4-Dimethyl-6-phenylfulvene
(0.95 g, 5.21 mmol) was dissolved in cold THF (Ϫ30 °C, 40 mL)
and lithium tert-butylamide (0.41 g, 5.21 mmol) was added. The 59.33 (bridge-CH), 105.76 [Cp-C(bridgehead)], 107.74 (Cp-CH),
solution was stirred overnight at room temperature. Water (20 mL) 112.60 (Cp-CH), 123.77 [Cp-C(CH3)], 125.43 [Cp-C(CH3)], 126.45
was added and the product was extracted with hexane (50 mL). It (Ph-C), 127.64 (Ph-C), 128.45 (Ph-C), 147.10 [Ph-C(ipso)] ppm.
was purified by column chromatography on silica gel eluting with
C22H35N3Zr (432.76): calcd. C 61.1, H 8.15, N 9.71; found C 61.3,
hexane and ethyl acetate (v/v, 10:1). The yield was 80% (1.06 g). 1H H 8.23, N 9.65.
NMR (400 MHz, CDCl3, 25 °C): δ ϭ 1.13 (s, 9 H, tBu-H), 1.82
(1,3-Me2C5H2؊CHPh؊NtBu؊κN)TiCl2 (10): The bis(dimethyl-
(quadruplet, JH,H ϭ 2.0 Hz, 3 H, CH3), 2.14 (s, 3 H, CH3), 2.80
(quintet, JH,H ϭ 2.0 Hz, 2 H, CH2), 4.98 (s, 1 H, bridge-CH), 5.78
amido) complex was synthesized according to a procedure similar
to that of 9, however, 6 (0.511 g, 2.00 mmol) and Ti(NMe2)4
(0.450 g, 2.00 mmol) were used. A deep red oil was obtained, which
3
(d, JH,H ϭ 2.0 Hz, 1 H, Cp-CH), 7.14 [t, JH,H ϭ 8 Hz, 1 H, Ph-
3
C(para)ϪH], 7.25 [t, JH,H ϭ 8 Hz, 2 H, Ph-C(meta)ϪH], 7.46 [d,
1
1
was quite pure (analyzed by H and 13C NMR spectroscopy). H
NMR (400 MHz, C6D6, 25 °C): δ ϭ 1.28 (s, 9 H, tBu-H), 1.44 (s,
3 H, CH3), 2.13 (s, 3 H, CH3), 3.01 (s, 6 H, NCH3), 3.27 (s, 6 H,
3JH,H
ϭ 8 Hz, 2
H, Ph-C(ortho)ϪH] ppm. 13C{1H} NMR
(100 MHz, CDCl3, 25 °C): δ ϭ 14.65 (CH3), 15.92 (CH3), 30.12
[C(CH3)3], 44.12 (CH2), 51.41 [NC(CH3)3], 52.98 (NCH), 125.09
(Cp-CH), 125.69 [Ph-C(para)], 127.07 [Ph-C(ortho or meta)], 127.63
[Ph-C(ortho or meta)], 137.05 [Cp-C(bridgehead)], 143.02 [Cp-
C(CH3)], 143.11 [Cp-C(CH3)], 145.66 [Ph-C(ipso)] ppm. C18H25N1
(255.40): calcd. C 84.7, H 9.89, N 5.48; found C 84.6, H 10.1,
N 5.15.
3
NCH3), 5.44 (d, JH,H ϭ 2.8 Hz, 1 H, Cp-H), 5.80 (s, 1 H, bridge-
3
3
CH), 5.94 (d, JH,H ϭ 2.8 Hz, 1 H, Cp-H), 7.12 [t, JH,H ϭ 7.6 Hz,
1 H, Ph-C(para)ϪH], 7.24 [t, 3JH,H ϭ 7.6 Hz, 2 H, Ph-C(meta)ϪH],
7.55 [d, 3JH,H ϭ 7.6 Hz, 2 H, Ph-C(ortho)ϪH] ppm. 13C{1H} NMR
(100 MHz, C6D6, 25 °C): δ ϭ 13.76 (CH3), 14.59 (CH3), 32.11
[C(CH3)3], 48.42 [N(CH3)2], 52.65 [N(CH3)2], 59.95 [NC(CH3)3],
60.98 (bridge-CH), 103.29 [Cp-C(bridgehead)], 109.85 (Cp-CH),
115.62 (Cp-CH), 123.25 [Cp-C(CH3)], 126.37 (Ph-C), 128.35 (Ph-
C), 146.95 [Ph-C(ipso)] ppm. The crude residue was dissolved in
Substituted Cyclopentadiene 7: This compound was synthesized ac-
cording to a procedure similar to that for 6. It was purified by
column chromatography on silica gel eluting with hexane and ethyl
acetate (v/v, 50:1). The yield was 88%. 1H NMR (400 MHz, CDCl3, toluene (12 mL) and dichlorodimethylsilane (1.03 g, 8.00 mmol)
25 °C): δ ϭ 1.14 (s, 9 H, tBu-H), 1.99 (quadruplet, JH,H ϭ 2.0 Hz,
3 H, CH3), 2.10 (s, 3 H, CH3), 2.82 (quintet, JH,H ϭ 2.0 Hz, 2 H,
was added. The solution was stirred overnight. The volatiles were
removed under a vacuum. The complex was dissolved in toluene
CH2), 4.99 (s, 1 H, NCH), 5.83 (d, JH,H ϭ 1.6 Hz, 1 H, Cp-CH), and stored in a freezer (Ϫ30 °C) overnight to give red crystals
6.10 [d, 3JH,H ϭ 3.2 Hz, 1 H, furyl-C(3)ϪH], 6.28 [dd, 3JH,H ϭ 3.2,
which were suitable for X-ray crystallography (0.234 g, 37%). The
3
3JH,H ϭ 2.0 Hz, 1 H, furyl-C(4)ϪH], 7.32 [d, JH,H ϭ 2.0 Hz, 1 H, major constituent of the mother liquor was the desired complex,
furyl-C(5)ϪH] ppm. 13C{1H} NMR (100 MHz, CDCl3, 25 °C):
but further isolation of the clean complex from the mother liquor
δ ϭ 14.32 (CH3), 15.56 (CH3), 29.87 [C(CH3)3], 44.15 (CH2), 48.48 was not achieved. M.p. 163 °C. 1H NMR (400 MHz, C6D6, 25 °C):
(NCH), 51.30 [NC(CH3)3], 105.49 [furyl-C(3 or 4)], 109.95 [furyl- δ ϭ 1.37 (s, 9 H, tBu-H), 1.52 (s, 3 H, CH3), 1.88 (s, 3 H, CH3),
C(3 or 4)], 124.79 (Cp-CH), 138.36 [Cp-C(bridgehead)], 140.49 6.06 (d, 3JH,H ϭ 3.6 Hz, 1 H, Cp-H), 6.08 (s, 1 H, bridge-CH), 6.20
3
[Cp-C(CH3)], 140.75 [furyl-C(5)], 143.03 [Cp-C(CH3)], 157.78 [fu-
(d, JH,H ϭ 3.6 Hz, 1 H, Cp-H), 7.00Ϫ7.15 (m, 5 H, Ph-H) ppm.
ryl-C(2)] ppm. C16H23O1N1 (245.36): calcd. C 78.3, H 9.47, N 5.71; 13C{1H} NMR (100 MHz, C6D6, 25 °C): δ ϭ 15.12 (CH3), 17.88
found C 78.2, H 9.50, N 5.83.
(CH3), 30.83 [C(CH3)3], 62.45 (bridge-CH), 63.76 [NC(CH3)3],
102.13 [Cp-C(bridgehead)], 122.14 (Cp-CH), 122.78 (Cp-CH),
127.76 (Ph-C), 127.92 (Ph-C), 128.44 (Ph-C), 138.47 [Cp-C(CH3)],
138.79 [Cp-C(CH3)], 141.43 [Ph-C(ipso)] ppm. C18H23Cl2NTi
(372.15): calcd. C 58.1, H 6.24, N 3.76; found C 57.8, H 6.25,
N 3.93.
Substituted Cyclopentadiene 8: This compound was synthesized ac-
cording to a procedure similar to that for 6. It was purified by
column chromatography on silica gel eluting with hexane and ethyl
acetate (v/v, 30:1). The yield was 60%. 1H NMR (400 MHz, CDCl3,
25 °C): δ ϭ 0.7Ϫ2.2 (m, 11 H, Cy-H), 1.00 (s, 9 H, tBu-H), 1.94
(s, 3 H, CH3), 2.10 (s, 3 H, CH3), 2.65Ϫ2.82 (m, 2 H, Cp-CH2), (1,3-Me2C5H2؊CHPh؊NtBu؊κN)ZrCl2 (11): Compound
3.34 (d, JH,H ϭ 9.6 Hz, 1 H, NCH), 5.78 (s, 1 H, Cp-CH) ppm. (0.530 g, 1.22 mmol) was dissolved in toluene (20 mL) and dichloro-
13C{1H} NMR (100 MHz, CDCl3, 25 °C): δ ϭ 14.33 (CH3), 16.71 dimethylsilane (0.315 g, 2.44 mmol) was added. The solution was
(CH3), 26.66, 26.71, 26.83, 30.21 [C(CH3)3], 30.40, 32.11, 42.80, stirred overnight, upon which a white solid precipitated. The solid
43.62, 50.78, 55.89, 124.79 (Cp-CH), 136.70 [Cp-C(bridgehead)], was filtered and dried under vacuum. The yield was 44% (0.222 g).
9
Eur. J. Inorg. Chem. 2004, 1522Ϫ1529
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1527

T. H. Kim, Y. C. Won, B. Y. Lee, D. M. Shin, Y. K. Chung
FULL PAPER
The major constituent of the filtrate was the desired complex. The
1
dried under vacuum. The yield was 47%. M.p. 128 °C. H NMR
reaction for 4 days without stirring gave single crystals suitable for (400 MHz, C6D6, 25 °C): δ ϭ 1.23 (s, 9 H, tBu-H), 1.96 (s, 3 H,
1
3
X-ray crystallography. M.p. 194 °C. H NMR (400 MHz, C6D6, 25
CH3), 2.15 (s, 3 H, CH3), 5.92 (d, JH,H ϭ 2.8 Hz, 1 H, Cp-H),
°C): δ ϭ 1.27 (s, 9 H, tBu-H), 1.60 (s, 3 H, CH3), 1.99 (s, 3 H, CH3), 5.94 (d, 3JH,H ϭ 2.8 Hz, 1 H, Cp-H), 5.98 (s, 1 H, bridge-CH), 6.01
3
3
3
5.77 (d, JH,H ϭ 3.2 Hz, 1 H, Cp-H), 5.91 (s, 1 H, bridge-CH), 5.95
[d, JH,H ϭ 3.2 Hz, 1 H, furyl-C(3)ϪH], 6.04 [dd, JH,H ϭ 3.2,
(d, JH,H ϭ 3.2 Hz, 1 H, Cp-H), 7.00Ϫ7.10 [m, 3 H, Ph-C(meta or 3JH,H ϭ 1.6 Hz, 1 H, furyl-C(4)ϪH], 6.99 [d, JH,H ϭ 1.6 Hz, 1 H,
3
3
para)ϪH], 7.10Ϫ7.22 [m, 2 H, Ph-C(ortho)ϪH] ppm. 13C{1H} NMR furyl-C(5)ϪH] ppm. 13C{1H} NMR (100 MHz, C6D6, 25 °C): δ ϭ
(100 MHz, C6D6, 25 °C): δ ϭ 14.00 (CH3), 16.58 (CH3), 30.70
[C(CH3)3], 57.84 [NC(CH3)3], 59.65 (bridge-CH), 104.27 [Cp-
C(bridgehead)], 116.17 (Cp-CH), 116.40 (Cp-CH), 127.56 (Ph-C),
128.29 (Ph-C), 128.49 (Ph-C), 132.17 [Cp-C(CH3)], 132.25 [Cp-
14.08 (CH3), 16.77 (CH3), 29.11 [C(CH3)3], 53.30 (bridge-CH),
57.53 [NC(CH3)3], 105.13 [Cp-C(bridgehead)], 108.93 [furyl-C(3 or
4)], 110.88 [furyl-C(3 or 4)], 115.55 (Cp-CH), 116.43 (Cp-CH),
131.91 [Cp-C(CH3)], 132.27 [Cp-C(CH3)], 141.17 [furyl-C(5)],
C(CH3)], 142.21 [Ph-C(ipso)] ppm. C18H23Cl2NZr (415.51): calcd. C 153.82 [furyl-C(2)] ppm. C16H21Cl2NOZr (405.47): calcd. C 47.4,
52.0, H 5.59, N 3.37; found C 51.7, H 6.00, N 3.34.
H 5.23, N 3.46; found C 47.1, H 5.68, N 3.54.
[1,3-Me2C5H2؊CH(C4H3O)؊NtBu؊κN]TiCl2 (13): The bis(dime-
thylamido) complex was synthesized according to a procedure simi-
lar to that for 9. The reaction time was 4 days. A deep red oil was
obtained. 1H NMR (400 MHz, C6D6, 25 °C): δ ϭ 1.26 (s, 9 H,
tBu-H), 1.75 (s, 3 H, CH3), 2.07 (s, 3 H, CH3), 3.04 (s, 6 H, NCH3),
[1,3-Me2C5H2؊CH(C6H11)؊NtBu؊κN]ZrCl2 (15): The bis(dime-
thylamido) complex was synthesized according to a procedure simi-
lar to that for 9. The reaction time was 4 days. A white oil was
obtained. H NMR (400 MHz, C6D6, 25 °C): δ ϭ 0.9Ϫ2.5 (m, 11
H, Cy-H), 1.38 (s, 9 H, tBu-H), 2.04 (s, 3 H, CH3), 2.11 (s, 3 H,
1
3
3.22 (s, 6 H, NCH3), 5.50 (d, JH,H ϭ 2.8 Hz, 1 H, Cp-H), 5.91 (s,
CH3), 2.87 (s, 6 H, NCH3), 3.01 (s, 6 H, NCH3), 4.55 (d, JH,H
ϭ
3
8.0 Hz, 1 H, bridge-CH), 5.65 (d, 3JH,H ϭ 2.8 Hz, 1 H, Cp-H), 5.92
1 H, bridge-CH), 5.94 (d, JH,H ϭ 2.8 Hz, 1 H, Cp-H), 6.15Ϫ6.20
3
4
3
(d, JH,H ϭ 2.8 Hz, 1 H, Cp-H) ppm. 13C{1H} NMR (100 MHz,
[m, 2 H, furyl-C(3 and 4)ϪH], 7.17 [dd, JH,H ϭ 1.6, JH,H
ϭ
0.8 Hz, 1 H, furyl-C(5)ϪH] ppm. 13C{1H} NMR (100 MHz, C6D6,
25 °C): δ ϭ 13.50 (CH3), 14.49 (CH3), 31.27 [C(CH3)3], 48.35
[N(CH3)2], 52.40 [N(CH3)2], 54.94 (bridge-CH), 59.62 [NC(CH3)3],
102.26 [Cp-C(bridgehead)], 106.94 [furyl-C(3 or 4)], 109.31 (Cp-
CH), 110.75 [furyl-C(3 or 4)], 115.68 (Cp-CH), 123.23 [Cp-
C(CH3)], 126.06 [Cp-C(CH3)], 139.91 [furyl-C(5)], 158.57 [furyl-
C(2)] ppm. Chlorination was accomplished using the method and
conditions developed for 10. A crude red oil, which is quite pure
(analyzed by NMR spectroscopy), was obtained by evaporation of
all the volatiles, in a 86% yield. An analytically pure compound
was obtained by recrystallization in pentane at Ϫ30 °C. M.p. 117
C6D6, 25 °C): δ ϭ 13.31 (CH3), 16.64 (CH3), 27.23, 27.48, 27.83,
31.35 [C(CH3)3], 35.45, 44.00 [N(CH3)2], 44.31, 45.48, 46.94, 55.39,
62.80 (bridge-CH), 108.08 (Cp-CH), 109.03 [Cp-C(bridgehead)],
111.57 (Cp-CH), 123.54 [Cp-C(CH3)], 124.03 [Cp-C(CH3)] ppm.
Chlorination was accomplished by stirring the crude bis(dimethyl-
amido) complex with 3.0 equivalent dichlorodimethylsilane in pen-
tane overnight. The precipitated white solid was filtered and dried
1
under vacuum. The yield was 83%. H NMR (400 MHz, C6D6, 25
°C): δ ϭ 0.7Ϫ2.2 (m, 11 H, Cy-H), 1.39 (s, 9 H, tBu-H), 1.87 (s, 3
3
H, CH3), 1.94 (s, 3 H, CH3), 4.89 (d, JH,H ϭ 8.4 Hz, 1 H, bridge-
CH), 5.96 (s, 2 H, Cp-H) ppm. 13C{1H} NMR (100 MHz, C6D6,
25 °C): δ ϭ 13.82 (CH3), 16.93 (CH3), 26.32, 26.82, 27.04, 29.02
[C(CH3)3], 30.00, 35.68, 41.97, 56.69 [NC(CH3)3], 63.20 (bridge-
CH), 107.54 [Cp-C(bridgehead)], 114.97 (Cp-CH), 116.39 (Cp-
CH), 130.26 [Cp-C(CH3)], 130.84 [Cp-C(CH3)] ppm.
C18H29Cl2NZr (421.56): calcd. C 51.3, H 6.95, N 3.32; found C
51.6, H 7.32, N 3.25.
1
°C. H NMR (400 MHz, C6D6, 25 °C): δ ϭ 1.33 (s, 9 H, tBu-H),
3
1.82 (s, 3 H, CH3), 2.01 (s, 3 H, CH3), 5.97 [d, JH,H ϭ 3.6 Hz, 1
3
3
H, furyl-C(3)ϪH], 6.00 [dd, JH,H ϭ 3.6, JH,H ϭ 1.6 Hz, 1 H,
3
furyl-C(4)ϪH], 6.14 (s, 1 H, bridge-CH), 6.16 (d, JH,H ϭ 3.6 Hz,
1 H, Cp-H), 6.17 (d, 3JH,H ϭ 3.6 Hz, 1 H, Cp-H), 6.92 [dd, 3JH,H ϭ
1.6, JH,H ϭ 0.8 Hz, 1 H, furyl-C(5)ϪH] ppm. 13C{1H} NMR
4
(100 MHz, C6D6, 25 °C): δ ϭ 15.08 (CH3), 18.12 (CH3), 29.29
[C(CH3)3], 55.88 (bridge-CH), 63.09 [NC(CH3)3], 102.95 [Cp-
C(bridgehead)], 109.36 [furyl-C(3 or 4), 110.95 [furyl-C(3 or 4)],
121.52 (Cp-CH), 122.68 (Cp-CH), 137.46 [Cp-C(CH3)], 138.83 [Cp-
C(CH3)], 141.31 [furyl-C(5)], 152.64 [furyl-C(2)] ppm.
C16H21Cl2NOTi (362.12): calcd. C 53.1, H 5.85, N 3.86; found C
52.8 (52.6), H 6.32 (6.30), N 3.80 (3.75).
Ethylene Polymerization: In a dry box, toluene (30 mL) was added
to a dried 70 mL glass reactor. The activated complex, prepared by
mixing the complex (10 µmol) and MAO (Al/Zr or Ti ϭ 500), was
added to the reactor. The reactor was assembled and removed from
the dry box. The reactor was immersed in an oil bath whose tem-
perature had been set to 60 °C, and stirred for 15 minutes, at which
time the solution temperature reached that of the bath. Ethylene
was fed under the pressure of 100 psig. After the polymerization
reaction was performed for the given time, it was quenched by vent-
ing ethylene gas and pouring the mixture into acetone. The white
precipitates were collected by filtration and dried under vacuum.
Table 2 summarizes the polymerization results.
[1,3-Me2C5H2؊CH(C4H3O)؊NtBu؊κN]ZrCl2 (14): The bis(dime-
thylamido) complex was synthesized according to a procedure simi-
lar to that for 9. The reaction time was 4 days. A white oil was
obtained. 1H NMR (400 MHz, C6D6, 25 °C): δ ϭ 1.21 (s, 9 H,
tBu-H), 1.92 (s, 3 H, CH3), 2.13 (s, 3 H, CH3), 2.91 (s, 6 H, NCH3),
3.04 (s, 6 H, NCH3), 5.56 (d, 3JH,H ϭ 2.8 Hz, 1 H, Cp-H), 5.87 (d,
3JH,H ϭ 2.8 Hz, 1 H, Cp-H), 5.93 (s, 1 H, bridge-CH), 6.18Ϫ6.22
X-ray Crystallographic Study: Crystals of 9, 10, and 12 were coated
with grease (Apiezon N) and mounted inside a thin glass tube with
3
4
[m, 2 H, furyl-C(3 and 4)ϪH], 7.18 [dd, JH,H ϭ 2.8, JH,H
ϭ
0.8 Hz, 1 H, furyl-C(5)ϪH] ppm. 13C{1H} NMR (100 MHz, C6D6, epoxy glue and placed on an EnrafϪNonius CCD single-crystal X-
25 °C): δ ϭ 13.22 (CH3), 14.01 (CH3), 31.21 [C(CH3)3], 43.52
[N(CH3)2], 47.14 [N(CH3)2], 53.45 (bridge-CH), 55.86 [NC(CH3)3], ation (λ ϭ 0.71073 A). The crystal of 11 was mounted onto a thin
ray diffractometer using graphite-monochromated Mo-Kα radi-
˚
105.55 [Cp-C(bridgehead)], 107.12 (Cp-CH), 107.71 [furyl-C(3 or
glass fiber with paratone and immediately placed in a cold nitrogen
4)], 110.72 [furyl-C(3 or 4)], 112.55 (Cp-CH), 123.91 [Cp-C(CH3)], stream at 150 K on a MXC3 diffractometer (Mac Science) The
125.29 [Cp-C(CH3)], 140.00 [furyl-C(5)], 158.71 [furyl-C(2)] ppm.
Chlorination was accomplished by stirring the crude bis(dimethyl-
structures were solved by direct methods (SHELXS-97)[15] and re-
fined against all F2 data (SHELXS-97). All non-hydrogen atoms
amido) complex with 3.0 equivalents of dichlorodimethylsilane in were refined with anisotropic thermal parameters. The hydrogen
pentane overnight. The precipitated white solid was filtered and atoms were treated as idealized contributions. The crystal data and
1528
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2004, 1522Ϫ1529

Titanium and Zirconium Complexes and Their Reactivities towards Ethylene Polymerization
FULL PAPER
Table 3. Crystallographic parameters of 9, 10, 11, and 12
9
10
11
12
Empirical formula
Formula mass
C22H35N3Zr
432.75
C18H23Cl2NTi
372.17
C18H23Cl2NZr
415.49
C21H27Cl2NO0.50Zr
463.56
Temperature [K]
293
293
150
293
˚
a (A)
11.5090(10)
13.3210(10)
15.3180(10)
90
101.808(2)
90
2298.7(3)
Monoclinic, P21/n
1.250
19.7430(10)
14.5910(10)
16.3030(10)
90
126.436(2)
90
3778.4(4)
Monoclinic, C2/c
1.309
8.982(5)
9.246(4)
11.639(7)
83.84(4)
70.32(4)
84.76(4)
903.2(8)
Triclinic, P1
1.528
2
10.6331(6)
12.3576(7)
16.3256(10)
90
103.888(3)
90
2082.5(2)
Monoclinic, P21/c
1.479
˚
b (A)
˚
c (A)
α [°]
β [°]
γ [°]
3
˚
Volume [A ]
¯
Crystal system, space group
d (calcd.) [g/cm3]
Z
Absorption coefficient [mmϪ1
F(000)
4
8
4
]
0.488
912
0.732
1552
0.901
424
0.791
952
Crystal size [mm]
θ range [°]
Limiting indices
0.2 ϫ 0.15 ϫ 0.15
3.12 to 27.45
Ϫ14 Յ h Յ 14
Ϫ15 Յ k Յ 16
Ϫ18 Յ l Յ 18
0.3 ϫ 0.2 ϫ 0.15
2.79 to 25.72
Ϫ23 Յ h Յ 24
Ϫ15 Յ k Յ 17
Ϫ19 Յ l Յ 19
0.3 ϫ 0.2 ϫ 0.2
1.86 to 25.00
Ϫ10 Յ h Յ 10
0 Յ k Յ 10
Ϫ13 Յ l Յ 13
0.3 ϫ 0.2 ϫ 0.2
2.84 to 27.07
Ϫ13 Յ h Յ 13
Ϫ14 Յ k Յ 15
Ϫ20 Յ l Յ 20
Reflections collected/unique
Data/restraints/parameters
Final R indices [I Ͼ 2σ(I)]
R indices (all data)
7542/4567 [R(int) ϭ 0.0921] 6099/3501 [R(int) ϭ 0.0655] 3237/3032 [R(int) ϭ 0.0308] 8034/4536 [R(int) ϭ 0.0726]
4567/0/244 3501/0/205 3032/0/204 4536/0/241
R1 ϭ 0.0443, ωR2 ϭ 0.0674 R1 ϭ 0.0523, ωR2 ϭ 0.1320 R1 ϭ 0.0342, ωR2 ϭ 0.0858 R1 ϭ 0.0493, ωR2 ϭ 0.0984
R1 ϭ 0.1830, ωR2 ϭ 0.0811 R1 ϭ 0.1408, ωR2 ϭ 0.1506 R1 ϭ 0.0411, ωR2 ϭ 0.0887 R1 ϭ 0.1413, ωR2 ϭ 0.1152
3
˚
Largest diff. peak and hole [e·A ] 0.326 and Ϫ0.283
0.428 and Ϫ0.479
0.435 and Ϫ0.592
0.468 and Ϫ0.371
Goodness-of-fit on F2
0.759
0.815
1.066
0.882
[5]
[5a] K. Kunz, G. Erker, S. Doring, R. Fröhlich, G. Kehr, J. Am.
refinement results are summarized in Table 3. Selected bond
lengths and angles are listed in Table 1.
[5b]
Chem. Soc. 2001, 123, 6181Ϫ6182.
K. Kunz, G. Erker, S.
Doring, S. Bredeau, G. Kehr, R. Fröhlich, Organometallics
2002, 21, 1031Ϫ1041.
CCDC-221028 (for 9), -221029 (for 10), -221030 (for 11), and
-221031 (for 12) contain the supplementary crystallographic data
for this paper. These data can be obtained free of charge at
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge
CB2 1EZ, UK; Fax: (internat.) ϩ 44-1223-336-033; E-mail:
deposit@ccdc.cam.ac.uk].
[6] [6a]
K. J. Stone, R. D. Little, J. Org. Chem. 1984, 49,
[6b]
1849Ϫ1853.
I. Erden, F.-P. Xu, A. Sadoun, W. Smith, G.
Sheff, M. Ossun, J. Org. Chem. 1995, 60, 813Ϫ820.
Y. C. Won, H. Y. Kwon, B. Y. Lee, Y.-W. Park, J. Organemet.
Chem. 2003, 677, 133Ϫ139.
[7]
[8]
B. Y. Lee, Y. H. Kim, Y. C. Won, J. W. Han, W. H. Suh, I. S.
Lee, Y. K. Chung, K. H. Song, Organometallics 2002, 21,
1500Ϫ1503.
[1] [1a]
S. A. Miller, J. E. Bercaw, Organometallics 2002, 21,
[9] [9a]
[1b]
U. Wieser, F. Schaper, H.-H. Brintzinger, N. I. Makela, H.
934Ϫ945.
W. Kaminsky, R. Engehausen, J. Kopf, Angew.
R. Knuuttila, M. Leskela, Organometallics 2002, 21, 541Ϫ545.
Chem. 1995, 107, 2469Ϫ2470; Angew. Chem. Int. Ed. Engl.
[9b]
1995, 34, 2273Ϫ2275. [1c] H. Alt, R. Zenk, J. Organomet. Chem.
U. Wieser, D. Babushkin, H.-H. Brintzinger, Organometall-
[1d]
ics 2002, 21, 920Ϫ923.
P. Jutzi, Chem. Rev. 1986, 86, 983Ϫ996.
1996, 518, 7Ϫ15.
H. G. Alt, M. Jung, J. Organomet. Chem.
[10]
[1e]
1998, 568, 87Ϫ112.
C. A. Willoughby, W. M. Davis, S. L.
[11] [11a] G. M. Diamond, R. F. Jordan, J. L. Petersen, J. Am. Chem.
Buchwald, J. Organomet. Chem. 1995, 497, 11Ϫ15.
[11b]
[2] [2a]
Soc. 1996, 118, 8024Ϫ8033.
J. N. Christopher, R. F. Jor-
T. Koch, S. Blaurock, F. B. Somoza, A. Voigt, R. Kirmse,
E. Hey-Hawkins, Organometallics 2000, 19, 2556Ϫ2563. [2b] D.
dan, J. L. Petersen, V. G. Jr. Young, Organometallics 1997, 16,
[11c]
3044Ϫ3050.
J. N. Christopher, G. M. Diamond, R. F. Jor-
T. Mallin, M. D. Rausch, Y. G. Lin, J. Am. Chem. Soc. 1990,
[2c]
dan, J. L. Petersen, Organometallics 1996, 15, 4038Ϫ4044.
B. Y. Lee, J. W. Han, I. S. Lee, Y. K. Chung, J. Organomet.
Chem. 2001, 627, 233Ϫ238.
D. W. Carpenetti, L. Kloppenburg, J. T. Kupec, J. L. Petersen,
Organometallics 1996, 15, 1572Ϫ1581.
I. Kim, R. F. Jordan, Macromolecules 1996, 29, 489Ϫ491.
G. M. Sheldrick, SHELXL-97, University of Göttingen, Ger-
many, 1997.
112, 2030Ϫ2031.
R. Fierro, M. D. Rausch, G. S. Herrman,
[12]
[13]
H. G. Alt, J. Organomet. Chem. 1995, 485, 11Ϫ17.
[3] [3a]
J. J. Eisch, X. Shi, F. A. Owuor, Organometallics 1998, 17,
[3b]
5219Ϫ5221.
P.-J. Sinnema, P. J. Shapiro, B. Hohn, T. E.
Bitterwolf, B. Twamley, Organometallics 2001, 20, 2883Ϫ2888.
[3c] S. Fox, J. P. Dunne, M. Tacke, D. Schmitz, R. Dronskowski,
Eur. J. Inorg. Chem. 2002, 3039Ϫ3046.
[14]
[15]
[4] [4a]
S.-D. Bai, X.-H. Wei, J.-P. Guo, D.-S. Liu, Z.-Y. Zhou, An-
gew. Chem. 1999, 111, 2051Ϫ2053; Angew. Chem. Int. Ed. 1999,
38, 1926Ϫ1928. [4b] S. Venne-Dunker, G. Kehr, R. Fröhlich, G.
Erker, Organometallics 2003, 22, 948Ϫ958.
Received October 7, 2003
Early View Article
Published Online February 26, 2004
Eur. J. Inorg. Chem. 2004, 1522Ϫ1529
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1529