New titanatranes: Characterization and styrene polymerization behavior

Article abstract of DOI:10.1021/om0109197

New titanatranes containing cyclopentadienyl ligands were prepared by the reactions of various kinds of trialkanolamines with (C₅Me₄R)TiCl₃ (Cp′ = C₅Me₄R) in the presence of triethylamine. The X-ray analyses reveal that they exist in the monomeric form in the solid state and the Ti atom adopts essentially an η⁵ bonding posture with the Cp′ ring and a tetradentate bonding mode with the trialkanolatoamine ligand via a transannular interaction from the bridgehead N atom to Ti. All compounds show very high catalytic activity for the syndiospecific polymerization of styrene in the presence of modified methylaluminoxane (MMAO) cocatalyst.

Full text of DOI:10.1021/om0109197

Organometallics 2002, 21, 1127-1135
1127
New Tita n a tr a n es: Ch a r a cter iza tion a n d Styr en e
P olym er iza tion Beh a vior
Youngjo Kim,† Yonggyu Han, J eong-Wook Hwang, Myong Woon Kim, and
Youngkyu Do*
Department of Chemistry, School of Molecular Science-BK21 and Center for Molecular Design
and Synthesis, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
Received October 22, 2001
New titanatranes containing cyclopentadienyl ligands were prepared by the reactions of
various kinds of trialkanolamines with (C5Me4R)TiCl3 (Cp′ ) C5Me4R) in the presence of
triethylamine. The X-ray analyses reveal that they exist in the monomeric form in the solid
state and the Ti atom adopts essentially an η5 bonding posture with the Cp′ ring and a
tetradentate bonding mode with the trialkanolatoamine ligand via a transannular interaction
from the bridgehead N atom to Ti. All compounds show very high catalytic activity for the
syndiospecific polymerization of styrene in the presence of modified methylaluminoxane
(MMAO) cocatalyst.
Sch em e 1. Syn th etic Rou tes to Com p ou n d s 1-5
In tr od u ction
The chemistry of atranes, a class of compounds
containing the triethanolatoamine ligand, has been
intensively studied, and examples are now known across
the periodic table.1 However, most studies have focused
on the use of main-group elements in the formation of
atrane.2 Only few reports on titanatranes have thus
appeared.3-9 In particular, Verkade et al. synthesized
new several types of titanatranes via the displacement
* To whom correspondence should be addressed. Fax: +82-42-869-
2810. E-mail: ykdo@kaist.ac.kr.
† Current address: Department of Chemistry, 2306 Gilman Hall,
Iowa State University, Ames, IA 50011.
(1) (a) Verkade, J . G. Coord. Chem. Rev. 1994, 137, 233. (b) Verkade,
J . G. Acc. Chem. Res. 1993, 26, 896. (c) Holmes, R. R. Chem. Rev. 1996,
96, 927.
(2) (a) Frye, C. L.; Vogel, G. E.; Hall, J . A. J . Am. Chem. Soc. 1961,
83, 996. (b) de Ruiter, B.; J acobson, R. A.; Verkade, J . G. Inorg. Chem.
1990, 29, 1065. (c) Woning, J .; Verkade, J . G. J . Am. Chem. Soc. 1991,
113, 944. (d) Laramay, M. A. H.; Verkade, J . G. J . Am. Chem. Soc.
1990, 112, 9421. (e) Xi, S. K.; Schmidt, H.; Lensink, C.; Kim, S.;
Wintergrass, D.; Daniels, L. M.; J acobson, R. A.; Verkade, J . G. Inorg.
Chem. 1990, 29, 2214. (f) Schmidt, H.; Lensink, C.; Xi, S.-K.; Verkade,
J . G. Z. Anorg. Allg. Chem. 1989, 578, 75. (g) Chung, T.-M.; Lee, Y.-
A.; Chung, Y. K.; J ung, I. N. Organometallics 1990, 9, 1976. (h) Gade,
L. H.; Mahr, N. J . Chem. Soc., Dalton Trans. 1993, 489. (i) Gade, L.
H.; Becker, C.; Lauher, J . W. Inorg. Chem. 1993, 32, 2308. (j)
Gevorgyan, V.; Borisova, L.; Vyater, A.; Ryabova, V.; Lukevics, E. J .
Organomet. Chem. 1997, 548, 149. (k) Chandrasekaran, A.; Day, R.
O. Holmes, R. R. J . Am. Chem. Soc. 2000, 122, 1066.
of the NR2 group.6 Moreover, Nugent et al. demon-
strated that other type of titanatranes derived from
enantiopure homochiral tri-2-propanolamine or its higher
homologues could be synthesized and is efficient for the
ring opening of meso epoxides under certain conditions
with high selectivity (up to 93% ee).7,8 However, we were
somewhat surprised that, prior to our studies, no
titanatrane has been applied in the field of homogeneous
catalysis for olefin polymerization. In this regard, we
have recently demonstrated that (pentamethylcyclopen-
tadienyl)titanatrane/MMAO is the more active and
syndiospecific catalyst system for the polymerization of
styrene and functionalized styrenes than Cp*TiCl3/
MMAO over a wide range of polymerization conditions.9
We have further extended the series of titanatranes to
include various cyclopentadienyl ancillary ligands (see
Scheme 1). We have also explored the coordination
chemistry of new enantiopure homochiral trialkanol-
amines with titanium metal as summarized in Scheme
(3) Harlow, R. L. Acta Crystallogr. 1983, C39, 1344.
(4) Taube, R.; Knoth, P. Z. Anorg. Allg. Chem. 1990, 581, 89.
(5) Cohen, H. J . J . Organomet. Chem. 1967, 9, 177.
(6) (a) Menge, W. M. B. P.; Verkade, J . G. Inorg. Chem. 1991, 30,
4628. (b) Naiini, A. A.; Menge, W. M. B. P.; Verkade, J . G. Inorg. Chem.
1991, 30, 5009. (c) Naiini, A. A.; Ringrose, S. L.; Su, Y.; J acobson, R.
A.; Verkade, J . G. Inorg. Chem. 1993, 32, 1290.
(7) Nugent, W. A.; Harlow, R. L. J . Am. Chem. Soc. 1994, 116, 6142.
(8) (a) Nugent, W. A.; RajanBabu, T. V.; Burk, M. J . Science 1993,
259, 479. (b) Furia, F. D.; Licini, G.; Modena, G.; Motterle, R.; Nugent,
W. A. J . Org. Chem. 1996, 61, 5175. (c) Bonchio, M.; Licini, G.; Modena,
G.; Moro, S.; Bortolini, O.; Traldi, P.; Nugent, W. A. Chem. Commun.
1997, 869.
(9) (a) Kim, Y.; Hong, E.; Lee, M. H.; Kim, J .; Han, Y.; Do, Y.
Organometallics 1999, 18, 36. (b) Kim, Y.; Do. Y. Macromol. Rapid
Commun. 2000, 21, 1148. (c) Kim, Y.; Han, Y.; Lee, M. H.; Yoon, S.
W.; Choi, K. H.; Song, B. G.; Do, Y. Macromol. Rapid Commun. 2001,
22, 573. (d) Kim, Y.; Han, Y.; Do, Y. J . Organomet. Chem., in press. (e)
Kim, Y.; Lee, M. H.; Han, Y.; Do. Y. Macromol. Chem. Phys., in press.
10.1021/om0109197 CCC: $22.00 © 2002 American Chemical Society
Publication on Web 02/20/2002

1128 Organometallics, Vol. 21, No. 6, 2002
Kim et al.
Sch em e 2. Syn th etic Rou tes to Liga n d s 6a -11a a n d Com p ou n d s 6-12
vated molecular sieves (3A).11 CDCl3 was dried over activated
molecular sieves (4A) and used after vacuum transfer to a
Schlenk tube equipped with a J . Young valve.
2. We expect that the synthesis, structures, and styrene
polymerization behavior, reported herein, will facilitate
the development of additional useful catalysts for olefin
polymerization on the basis of these readily available
ligands.
Mea su r em en ts. 1H and 13C{1H} NMR spectra were re-
corded on a Bruker AM 300 or a Bruker Spectrospin 400
spectrometer at room temperature. The chemical shifts are
referenced to the residual peaks of CDCl3 (7.24 ppm for 1H
NMR and 77.0 ppm for 13C{1H} NMR). EI and HR mass
spectra were obtained on a VG Auto spectrometer. Elemental
analyses were performed by the Korea Basic Science Center,
Seoul, Korea. The thermal properties of syndiotactic polysty-
rene (sPS) were investigated on a Thermal Analyst 200 DSC
system under a nitrogen atmosphere at a heating rate of 20
°C/min. Molecular weights of sPS were determined at 140 °C
in 1,2,4-trichlorobenzene on a PL 220+220R GPC calibrated
with standard polystyrenes.
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All reactions were carried out
under an argon atmosphere using standard Schlenk and
glovebox techniques.10 Argon was deoxygenated with activated
Cu catalyst (regenerated by heating to 300 °C under H2 gas)
and dried with Drierite. All solvents were dried by distilling
from sodium-potassium alloy/benzophenone ketyl (toluene,
tetrahydrofuran (THF), diethyl ether) or CaH2 (methylene
chloride) under a nitrogen atmosphere and stored over acti-
(10) Schriver, D. F. The Manipulation of Air-Sensitive Compounds;
McGraw-Hill: New York, 1969.
(11) Perrin, D. D.; Armarego, W. L. F.; Perrin, D. R. The Purification
of Laboratory Chemicals; Pergamon: New York, 1980.

New Titanatrenes
Organometallics, Vol. 21, No. 6, 2002 1129
1
Syn th eses. Modified methylaluminoxane (MMAO; 3A type)
was supplied by Akzo Co. Cp′TiCl312 and Cp*Ti(TEA) (1)9 were
synthesized by the literature procedures. All other chemicals
were purchased from Aldrich.
6a : yield 96%; H NMR (300.13 MHz, CDCl3, ppm) δ 5.10
(br s, 3H, -OH), 3.86 (m, 3H, OCH), 2.34 (dd, 3H, J ) 10, 13
Hz, NCH2 anti to OCH proton), 2.19 (dd, 3H, J ) 1.6, 13 Hz,
NCH2 gauche to OCH proton), 1.08 (d, 9H, J ) 6.3 Hz,
CHCH3); 13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 63.66
(OCH), 63.24(NCH2), 20.18(CHCH3).
Syn th eses of (η5-C5Me4R)Ti(TEA) (R ) H, 2; R ) Et, 3;
R ) P h , 4; R ) Tol, 5). These compounds were prepared in a
similar manner, as outlined in Scheme 1, and thus only one
representative preparation is described. A reddish solution of
(η5-C5Me4H)TiCl3 (1.4 g, 5.0 mmol) in 40 mL of CH2Cl2 was
added dropwise to a stirred solution of triethanolamine (0.75
g, 5.0 mmol) and triethylamine (2.1 mL, 15 mmol) in 40 mL
of CH2Cl2 at -78 °C. After the completion of the addition, the
reaction mixture was warmed to room temperature and stirred
for 12 h. The residue, obtained by removing the solvent under
vacuum, was redissolved in toluene, and the resulting mixture
was filtered through a Celite bed. The removal of solvent from
the yellow filtrate gave the desired product 2 in 80% yield (1.3
g). 2: 1H NMR (400.13 MHz, CDCl3, ppm) δ 5.51 (s, 1H,
C5HMe4), 4.27 (t, 6H, 3J HH ) 5.6 Hz, NCH2CH2O), 2.91 (t, 6H,
3J HH ) 5.6 Hz, NCH2CH2O), 1.98 (s, 6H, CH3), 1.82 (s, 6H,
CH3); 13C{1H} NMR (100.62 MHz, CDCl3, ppm) δ 124.80,
123.73, 114.19, 70.73, 58.05, 13.13, 10.86; EI-MS (intensity)
1
7a : yield 94%; H NMR (300.13 MHz, CDCl3, ppm) δ 4.10
(br s, 3H, -OH), 3.86 (m, 2H, OCH), 3.70 (m, 1H), 3.49 (m,
1H), 2.68 (m, 1H), 2.29 (m, 5H), 1.09 (d, 6H, J ) 6.3 Hz,
CHCH3); 13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 64.10
(OCH), 63.00 (OCH2), 59.41 (OCHCH2), 57.39 (OCH2CH2),
20.15 (CHCH3).
1
8a : yield 96%; H NMR (300.13 MHz, CDCl3, ppm) δ 5.01
(br s, 3H, -OH), 3.84 (m, 1H, OCH), 3.64 (m, 2H), 3.45 (m,
2H), 2.70 (m, 2H), 2.33 (m, 4H), 1.07 (d, 3H, J ) 6.2 Hz,
CHCH3); 13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 64.33
(OCH), 63.36 (OCH2), 59.44 (OCHCH2), 57.43 (OCH2CH2),
19.98 (CHCH3).
1
9a : yield 94%; H NMR (300.13 MHz, CDCl3, ppm) δ 5.18
(br s, 3H, -OH), 3.85 (m, 3H, OCH), 2.32 (dd, 3H, J ) 10, 13
Hz, NCH2 anti to OCH proton), 2.16 (dd, 3H, J ) 1.6, 13 Hz,
NCH2 gauche to OCH proton), 1.06(d, 9H, J ) 6.3 Hz, CHCH3);
13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 63.76 (OCH), 63.37
(NCH2), 20.21 (CHCH3).
10a : yield 96%; 1H NMR (300.13 MHz, CDCl3, ppm) δ 4.91
(br s, 3H, -OH), 3.93 (m, 2H, OCH), 3.70 (m, 1H), 3.50 (m,
1H), 2.70 (m, 1H), 2.32 (m, 5H), 1.08 (d, 6H, J ) 6.3 Hz,
CHCH3); 13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 64.00
(OCH), 63.30 (OCH2), 59.37 (OCHCH2), 57.41 (OCH2CH2),
20.11 (CHCH3).
m/z 315 (100%, M+), 285 (94%, M+ - CH2O), 255 (98%, M+
-
2CH2O), 227 (83%, M+ - 2CH2CH2O), 212 (77%, M+ - N(CH2-
CH2O)2), 194 (96%, M+ - Cp′), 168 (85%, Cp′Ti+), 134 (88%,
M+ - N(CH2CH2O)3), 121 (69%, M+ - TiN(CH2CH2O)3). Anal.
Calcd for C15H25NO3Ti: C, 57.15; H, 7.99; N, 4.44. Found: C,
57.22; H, 7.92; N, 4.38.
3: yield 83%; 1H NMR (400.13 MHz, CDCl3, ppm) δ 4.23 (t,
3
3
6H, J HH ) 5.6 Hz, NCH2CH2O), 2.86 (t, 6H, J HH ) 5.6 Hz,
NCH2CH2O), 2.30 (q, 2H, CH2Me), 1.88 (s, 6H, C5Me4Et), 1.85
(s, 6H, C5Me4Et), 1.00 (t, 6H, CH2Me); 13C{1H} NMR (100.62
MHz, CDCl3, ppm) δ 127.2, 122.3, 122.1, 70.65, 56.11, 19.40,
14.37, 11.00, 10.95; EI-MS (intensity) m/z 343 (98%, M+), 313
11a : yield 94%; 1H NMR (300.13 MHz, CDCl3, ppm) δ 5.01
(br s, 3H, -OH), 3.84 (m, 1H, OCH), 3.64 (m, 2H), 3.45 (m,
2H), 2.70 (m, 2H), 2.33 (m, 4H), 1.07 (d, 3H, J ) 6.2 Hz,
CHCH3); 13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 64.35
(OCH), 63.32 (OCH2), 59.43 (OCHCH2), 57.38 (OCH2CH2),
19.96 (CHCH3).
(89%, M+ - CH2O), 283 (95%, M+ - 2CH2O), 255 (66%, M+
-
2CH2CH2O), 240 (67%, M+ - N(CH2CH2O)2), 194 (100%, M+
Syn th eses of Com p lexes (η5-C5Me5R)Ti(TAA) (6-12).
These compounds, listed in Scheme 2, were prepared in a
manner analogous to the procedure for 2 using the scale of
- Cp′), 149 (48%, M+ - TiN(CH2CH2O)3). Anal. Calcd for
C
17H29NO3Ti: C, 59.48; H, 8.51; N, 4.08. Found: C, 59.44; H,
8.47; N, 4.12.
2.0 mmol of (η5-C5Me5)TiCl3 (6): yield 84%; H NMR (300.13
1
4: yield 81%; 1H NMR (400.13 MHz, CDCl3, ppm) δ 7.28
3
MHz, CDCl3, ppm) δ 4.53 (m, 3H, OCH), 2.70 (dd, 3H, J )
(m, 5H, Ph), 4.26 (t, 6H, J HH ) 5.6 Hz, NCH2CH2O), 2.92 (t,
3
3
3.8, 12 Hz, NCH2), 2.54 (t, 3H, J HH ) 11 Hz, NCH2), 1.84 (s,
6H, J HH ) 5.6 Hz, NCH2CH2O), 1.96 (s, 6H, C5Me4Ph), 1.93
15H, C5(CH3)5), 0.99 (d, 9H, J ) 6.0 Hz, CHCH3); 13C{1H} NMR
(75.1 MHz, CDCl3, ppm) δ 121.7 (C5(CH3)5), 75.32 (OCH), 63.01
(NCH2), 22.59 (CHCH3), 11.08 (C5(CH3)5); EI-MS (intensity)
m/z 371 (93%, M+), 327 (92%, M+ - OCHMe), 283 (100%, M+
(s, 6H, C5Me4Ph); 13C{1H} NMR (100.62 MHz, CDCl3, ppm) δ
137.17, 130.73, 127.27, 125.38, 124.84, 124.17, 122.15, 70.94,
56.16, 12.21, 11.11; EI-MS (intensity): m/z 391 (100%, M+),
361 (89%, M+ - CH2O), 331 (80%, M+ - 2CH2O), 303 (77%,
M+ - 2CH2CH2O), 288 (78%, M+ - N(CH2CH2O)2), 244 (78%,
M+ - N(CH2CH2O)3), 194 (96%, M+ - Cp′). Anal. Calcd for
- 2OCHMe), 236 (73%, M+ - Cp*), 228 (95%, M+
-
(OCHCH2)3N), 199 (49%, M+ - (OCHMeCH2)2NCH2CH2O),
182 (71%, Cp*Ti+); exact mass calcd for C19H33O3NTi 371.1940.
found: 371.1941. Anal. Calcd: C, 61.45; H, 8.96; N, 3.77.
Found: C, 61.60; H, 9.10; N, 3.72.
C
21H29NO3Ti: C, 64.45; H, 7.47; N, 3.58. Found: C, 64.80; H,
7.36; N, 3.64.
5: yield 82%; 1H NMR (300.13 MHz, CDCl3, ppm) δ 7.20
3
7: yield 81%; 1H NMR (300.13 MHz, CDCl3, ppm) δ 4.54
(m, 2H, OCH), 4.36 (td, 1H, J ) 3.9, 12 Hz, OCH2), 4.06 (dd,
1H, J ) 6.2, 12 Hz, OCH2), 3.05 (m, 1H), 2.77-2.50 (m, 5H),
1.84 (s, 15H, C5(CH3)5), 0.97 (dd, 6H, J ) 1.3, 6.0 Hz, CHCH3);
13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 121.7 (C5(CH3)5),
75.51 (OCH), 75.42 (OCH), 70.39 (OCH2), 63.31 (OCHCH2),
62.28 (OCHCH2), 56.59 (OCH2CH2), 22.50 (CHCH3), 11.05 (C5-
(CH3)5); EI-MS (intensity) m/z 357 (78%, M+), 313 (78%, M+
- OCHMe), 269 (100%, M+ - 2OCHMe), 222 (19%, M+ - Cp*),
214 (68%, M+ - (OCHCH2)3N); exact mass calcd for C18H31O3-
NTi 357.1783, found 357.1786. Anal. Calcd: C, 60.50; H, 8.74;
N, 3.92. Found: C, 60.62; H, 9.01; N, 3.80.
(d, 2H, Ph), 7.15 (d, 2H, Ph), 4.29 (t, 6H, J HH ) 5.6 Hz,
3
NCH2CH2O), 2.94 (t, 6H, J HH ) 5.6 Hz, NCH2CH2O), 2.37 (s,
3H, PhCH3), 1.98 (s, 6H, C5Me4Tol), 1.96 (s, 6H, C5Me4Tol);
13C{1H} NMR (75.1 MHz, CDCl3, ppm) δ 134.7, 134.1, 130.5,
128.1, 124.9, 124.1, 122.0, 70.90, 56.11, 21.21, 12.20, 11.10;
EI-MS (intensity) m/z 405 (100%, M+), 375 (84%, M+ - CH2O),
345 (85%, M+ - 2CH2O), 317 (73%, M+ - 2CH2CH2O), 302
(77%, M+ - N(CH2CH2O)2), 258 (77%, M+ - N(CH2CH2O)3),
211 (35%, M+ - TiN(CH2CH2O)3), 194 (96%, M+ - Cp′). Anal.
Calcd for C22H31NO3Ti: C, 65.19; H, 7.71; N, 3.46. Found: C,
65.44; H, 7.36; N, 3.40.
Syn t h eses of H om och ir a l Tr ia lk a n ola m in e Liga n d s
(TAA) 6a -11a . Ligand 6a was prepared according to the
reported synthetic route,7 and similar synthetic routes were
employed in preparing 7a -11a (see Scheme 2).
8: yield 82%; 1H NMR (300.13 MHz, CDCl3, ppm) δ 4.55
(m, 1H, OCH), 4.35 (m, 2H), 4.10 (dd, 2H, J ) 6.1, 12 Hz),
3
3.04 (m, 2H), 2.74 (m, 2H), 2.52 (t, 2H, J HH ) 11 Hz), 1.85 (s,
15H, C5(CH3)5), 1.00 (d, 3H, J ) 5.9 Hz, CHCH3); 13C{1H} NMR
(75.1 MHz, CDCl3, ppm) δ 122.1 (C5(CH3)5), 75.67 (OCH), 70.62
(OCH2), 70.50 (OCH2), 62.63 (OCHCH2), 56.92 (OCH2CH2),
55.97 (OCH2CH2), 22.47 (CHCH3), 11.03 (C5(CH3)5); EI-MS
(intensity) m/z 343 (94%, M+), 299 (99%, M+ - OCHMe), 269
(12) (a) Bjo¨rgvinsson, M.; Halldorsson, S.; Arnason, I.; Magull, J .;
Fenske, D. J . Organomet. Chem. 1997, 544, 207. (b) Llinas, G. H.;
Mena, M.; Palacios, F.; Royo, P.; Serrano, R. J . Organomet. Chem.
1988, 340, 37.

1130 Organometallics, Vol. 21, No. 6, 2002
Ta ble 1. Cr ysta llogr a p h ic Da ta for th e Str u ctu r a l An a lysis
Kim et al.
2
4
5
6
8
empirical formula
fw
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
C
15H25NO3Ti
C21H29NO3Ti
391.35
C22H31NO3Ti
405.35
C19H33O3NTi
371.36
C17H29O3NTi
315.25
343.31
orthorhombic
P212121 (No. 19)
8.674(2)
12.066(3)
17.448(8)
90
triclinic
P1h (No. 2)
8.000(3)
8.694(2)
12.818(3)
74.67(2)
74.49(2)
70.73(3)
795.5(4)
2
triclinic
P1h (No. 2)
8.528(3)
11.427(5)
11.511(4)
68.69(4)
70.42(3)
87.00(4)
981.4(6)
2
triclinic
P1h (No. 2)
12.649(6)
12.628(7)
15.435(7)
66.86(4)
66.81(4)
80.59(5)
2083.9(19)
2
monoclinic
P21 (No. 4)
8.6020(10)
14.2711(20)
16.7553(3)
90.00
91.855(16)
90.00
2055.82(53)
4
90
90
1826.1(10)
4
1.25
0.710 73
736
4.80
Z
Dcalcd (g cm-3
λ(Mo KR)
F(000)
)
1.316
0.710 73
336
1.324
0.710 73
416
1.292
0.710 73
864
1.20
0.710 73
800
µ (cm-1
)
5.44
4.56
4.32
4.31
cryst size (mm)
θ range (deg)
scan type
0.25 × 0.28 × 0.28
2< θ <25
ω/2θ
(9; -10 to +9; (15 (10; (13; -12 to +13 -14 to +15; (14;
-16 to +18
2058
0.29 × 0.29 × 0.29
2< θ <25
ω/θ
0.28 × 0.28 × 0.28 0.19 × 0.20 × 0.25 0.20 × 0.18 × 0.25
2< θ <25
ω/θ
1< θ <25
ω/2θ
2< θ <25
ω/2θ
h; k; l
(10; (16; (19
(10; (14; (20
total no. of rflns
2583
5329
3546
2719
no. of data with I > 2σ(I) 1154
1450
239
0.0933
0.1499
1.247
3027
497
0.0833
0.1535
1.137
1988
433
2152
208
no. of params refined
185
R1(I > 2σ(I))a
0.0832
0.1606
1.237
0.0746
0.1646
1.201
0.53, -0.56
-0.03(8)
0.0848
0.0840
0.0973
0.2051
1.213
1.94, -1.77
-0.06(12)
0.1446
0.0000
wR2(I > 2σ(I))b
GOF(I > 2σ(I))
peak and hole (e Å-3
Flack param
)
0.45, -0.33
0.34, -0.45
0.45, -0.54
x
y
0.0730
0.5987
0.0549
0.0000
0.0713
2.5614
a
2
The structure was refined in Fo using all data; the value of R1 is given for comparison with older refinements based on Fo with a
typical threshold of Fo > 4σ(Fo). R1 ) ∑||Fo| - |Fc||/∑|Fo|. wR2 ) [∑[w(Fo - Fc2)2/∑[w(Fo2)2]]1/2, where w ) 1/[σ2(Fo2) + (xP)2 + yP], P )
b
2
2
(Fo + 2Fc2)/3.
(100%, M+ - (OCHMeCH2)N), 241 (49%, M+ - (OCH2CH2)2N),
226 (48%, M+ - (OCH2CH2)N(CH2CHMeO)), 214(96%, M+
(OCH2CH2)N(CH2CHMeO)(CH2)); exact mass calcd for C17H29O3-
NTi 343.1627, found 343.1626. Anal. Calcd: C, 59.48; H, 8.51;
N, 4.08. Found: C, 59.40; H, 8.56; N, 4.00.
(intensity) m/z 343 (83%, M+), 299 (100%, M+ - OCHMe), 269
(89%, M+ - (OCHMeCH2)N), 241 (29%, M+ - (OCH2CH2)2N),
-
226 (22%, M+ - (OCH2CH2)N (CH2CHMeO)), 214 (62%, M+
-
(OCH2CH2)N(CH2CHMeO)(CH2)); exact mass calcd for C17H29O3-
NTi 343.1627, found 343.1630. Anal. Calcd: C, 59.48; H, 8.51;
N, 4.08. Found: C, 59.52; H, 8.56; N, 4.30.
12: yield 75%; 1H NMR (300.13 MHz, CDCl3, ppm) δ 4.60-
4.35 (m, 3H), 3.16 (dd, 1H, J ) 6.8, 13 Hz), 2.96 (dd, 1H, J )
3.9, 12 Hz), 2.74-2.66 (m, 3H), 2.60-2.48 (m, 3H), 1.86 (d,
15H), 1.16 (d, 3H, J ) 6.7 Hz), 1.13-0.96 (m, 9H); 13C{1H}
NMR (75.1 MHz, CDCl3, ppm) δ 121.76, 121.70, 76.57, 75.93,
75.32, 75.20, 69.13, 65.16, 64.14, 63.00, 25.11, 22.59, 22.19,
11.07.
9: yield 84%; 1H NMR (400.13 MHz, CDCl3, ppm) δ 4.53
(m, 3H, OCH), 2.70 (dd, 3H, J ) 3.8, 12 Hz, NCH2), 2.54 (t,
3H, 3J HH ) 11 Hz, NCH2), 1.84 (s, 15H, C5(CH3)5), 0.99 (d, 9H,
J ) 6.0 Hz, CHCH3); 13C{1H} NMR (100.62 MHz, CDCl3, ppm)
δ 121.7 (C5(CH3)5), 75.32 (OCH), 62.97 (NCH2), 22.59 (CHCH3),
11.08 (C5(CH3)5); EI-MS (intensity) m/z 343 (88%, M+), 299
(90%, M+ - OCHMe), 269 (100%, M+ - (OCHMeCH2)N), 241
(55%, M+ - (OCH2CH2)2N), 226 (70%, M+ - (OCH2CH2)N(CH2-
CHMeO)), 214 (79%, M+ - (OCH2CH2)N(CH2CHMeO)(CH2));
exact mass calcd for C19H33O3NTi 371.1940; found 371.1940.
Anal. Calcd: C, 61.45; H, 8.96; N, 3.77. Found: C, 61.55; H,
9.18; N, 3.76.
X-r a y Str u ctu r a l Deter m in a tion . Crystals suitable for
X-ray crystallography were obtained by slow cooling of toluene/
pentane solutions of 2, 4-6, and 8 in a refrigerator (-15 °C).
A set of independent reflections was measured on an Enraf-
Nonius CAD4TSB diffractometer at 293 K with λ(Mo KR
radiation) ) 0.710 73 Å. All data were corrected for Lp effects,
and ψ-scan absorption corrections were applied. The structures
were solved by a semiinvariant direct method (SIR 92 in
MoleN) and refined by full-matrix least-squares calculations
(SHELXL 93) with anisotropic thermal parameters for all non-
hydrogen atoms.13 Hydrogens were placed at their geometri-
cally calculated positions (dC-H ) 0.96 for methyl hydrogens,
dC-H ) 0.97 for methylene hydrogens, dC-H ) 0.93 for phenyl
hydrogens) and refined riding on the corresponding carbon
atoms with isotropic thermal parameters (1.5U for methyl
hydrogens, 1.2U for methylene hydrogens, 1.5U for phenyl
hydrogens). All calculations were performed on a Silicon
Graphics Indigo2XZ workstation. The detailed data are listed
in Table 1.
1
10: yield 71%; H NMR (400.13 MHz, CDCl3, ppm) δ 4.54
(m, 2H, OCH), 4.36 (td, 1H, J ) 3.9, 12 Hz, OCH2), 4.06 (dd,
1H, J ) 6.2, 12 Hz, OCH2), 3.05 (m, 1H), 2.77-2.50 (m, 5H),
1.85 (s, 15H, C5(CH3)5), 1.00 (dd, 6H, J ) 1.5, 6.0 Hz, CHCH3);
13C{1H} NMR (100.62 MHz, CDCl3, ppm) δ 122.0 (C5(CH3)5),
75.54 (OCH), 75.45 (OCH), 70.44 (OCH2), 63.38 (OCHCH2),
62.36 (OCHCH2), 56.64 (OCH2CH2), 22.50 (CHCH3), 11.04 (C5-
(CH3)5); EI-MS (intensity) m/z 357 (95%, M+), 313 (98%, M+
- OCHMe), 269 (100%, M+ - 2OCHMe), 222 (79%, M+ - Cp*),
214 (99%, M+ - (OCHCH2)3N); exact mass calcd for C18H31O3-
NTi 357.1783, found 357.1785. Anal. Calcd: C, 60.50; H, 8.74;
N, 3.92. Found: C, 60.52; H, 8.59; N, 3.88.
1
11: yield 84%; H NMR (300.13 MHz, CDCl3, ppm) δ 4.55
(m, 1H, OCH), 4.35 (m, 2H), 4.09 (dd, 2H, J ) 6.1, 12 Hz),
3
3.04 (m, 2H), 2.74 (m, 2H), 2.52(t, 2H, J HH ) 11 Hz), 1.85 (s,
15H, C5(CH3)5), 1.01 (d, 3H, J ) 5.9 Hz, CHCH3); 13C{1H} NMR
(75.1 MHz, CDCl3, ppm) δ 122.2 (C5(CH3)5), 75.68 (OCH), 70.63
(OCH2), 70.51 (OCH2), 62.65 (OCHCH2), 56.94 (OCH2CH2),
55.99 (OCH2CH2), 22.47 (CHCH3), 11.03 (C5(CH3)5); EI-MS
(13) User’s Manual of: Sheldrick, G. M. SHELXL-93: A Computer
Program for Crystal Structure Refinement; University of Go¨ttingen,
Go¨ttingen, Germany, 1993.

New Titanatrenes
Organometallics, Vol. 21, No. 6, 2002 1131
P olym er ization P r ocedu r e. Styrene polymerizations were
carried out in a 250 mL Schlenk flask with magnetic stirring.
Toluene, the polymerization solvent, was distilled from sodium-
potassium alloy under an argon atmosphere just before use.
Styrene monomer was distilled from calcium hydride and
stored in a refrigerator. Polymerizations were carried out as
following: toluene, styrene, MMAO, and the titanium com-
pound were injected into a 250 mL Schlenk flask with
magnetic stirring in that order at the desired temperature of
70 °C. After the desired reaction time was reached, the reaction
was terminated by the addition of 50 mL of methanol and the
addition of 50 mL of 10% HCl in methanol was followed. The
resulting precipitated polymer was collected, washed three
times each with 500 mL of methanol, and dried in vacuo at 70
°C for 12 h. The polymer was extracted with refluxing
2-butanone for 12 h, and the resulting insoluble portion was
determined as the sPS portion (SI) of the polymer obtained.
Syndiotacticity of the insoluble portion was confirmed by
measuring 13C NMR spectra at 100 °C in 1,1,2,2-tetrachloro-
ethane-d2. For each given polymerization run, two or three
serial experiments were carried out to confirm the reproduc-
ibility of the formation of the polymer, and the average values
of these serial experimental results are given.
EI mass spectra of the compounds exhibit molecular
peaks for the corresponding complexes.
NMR Stu d ies. In the case of 2-5, methylene signals
1
of the triethanolatoamine ligand in the H and 13C{1H}
NMR spectra are shifted downfield compared to the
signals for free triethanolamine, presumably due to the
high Lewis acidity of the titanium metal. The extent of
1
downfield shift in H NMR spectra is greater for OCH2
resonances (0.8 ppm) than for CH2N resonances (0.4
ppm). Two virtual triplets are seen, indicating the
presence of average C3v symmetry in solution at ambient
temperature and thus rapid conformational change
within the structural unit. This pattern is a general
feature of monomeric atrane and azatrane complexes.6,15
It is interesting to note that the coupling constants (5.6
Hz) of these triplets for 1-5 are independent of the
kinds of Cp rings.
For 6a and 9a , the NCH2 and OCH proton signals
typically appear as two doublets of doublets and mul-
tiplets, respectively, while only three 13C{1H} NMR
peaks are observed, clearly showing the enantiopurity
of them. However, commercially available tri-2-pro-
panolamine (12a ) turns out to be a mixture of about 40%
(R,R,R)/(S,S,S) enantiomeric pair and about 60% (R,R,S)/
(S,S,R) enantiomeric pair, as judged by nine 13C{1H}
NMR resonances at 65.7, 66.5, 65.9, 65.5, 63.7, 63.1,
20.5, 20.4, and 20.2 ppm. The ligands 7a , 8a , 10a , and
11a display particularly informative 13C{1H} NMR
spectra consistent with the homochiral ligand: one kind
of methine CH peak, one kind of methyl CH3 peak, and
three kinds of methylene CH2 peaks are observed. Their
1H NMR spectra are much less informative, due to the
presence of large numbers of different CH2 and CH
protons with a complicated coupling pattern. However,
the stoichiometry of the reaction was ascertained from
Resu lts a n d Discu ssion
P r ep a r a tion of Liga n d s. The preparation of 6a from
2 M ammonia solution in methanol and (S)-propylene
oxide was previously reported by Nugent.7 Nugent’s
synthetic route was also analogously applied to the
syntheses of 7a -11a . Slightly more than the appropri-
ate equivalent of enantiopure propylene oxide and 1
equiv of amine in methanol solution were mixed in a
10 mL screw-cap vial and allowed to stand overnight
at room temperature. The mixture was then heated for
several days at 50 °C to ensure a complete reaction.
NMR studies in benzene-d6 indicate that the reaction
is essentially complete after 3 days. The corresponding
enantiopure homochiral ligands could be isolated in
pure form by removal of the solvent at reduced pressure.
6a and 9a were obtained in the solid form, but the
ligands 7a , 8a , 10a , and 11a were obtained only as
sticky oils.
Syn th esis of Meta l Com p lexes 1-12. (η5-C5Me4R)-
TiCl3 (R ) Me, H, Et, Pri, Ph, Tol) were obtained in more
than 95% yield as reddish solids from the reactions of
TiCl4 with C5Me4R(TMS) in toluene.12 They were puri-
fied by recrystallization from toluene/pentane. Like
other titanium complexes containing a single η5 ligand,
all (η5-C5Me4R)TiCl3 compounds are slightly moisture-
sensitive. They are all readily soluble in toluene and
dichloromethane. The reaction of a solution of (η5-
C5Me4R)TiCl3 in CH2Cl2 with trialkanolamine ligand in
the presence of triethylamine afforded the yellow crys-
talline solids 1-12 in yields of 71-84% (see Schemes 1
and 2). The attempted use of trilithiated species instead
of neutral trialkanolamine in toluene was not successful,
and a mixture of several unidentified compounds was
obtained, suggesting that mild reaction conditions of
HCl elimination are essential for the synthesis of 1-12.
The yellow crystalline solids 1-12 are freely soluble
in toluene, methylene chloride, and ethereal solvent
and slightly soluble in hydrocarbon solvents such as
hexane. Further characteristics worthy of mention for
the compounds 1-12 are their air and thermal stability
and the ease of their handling and purification.14 In
addition, all compounds have a volatile nature and the
1
the integral ratio of the H NMR spectra.
The NMR spectra of an enantiomeric pair of 6 and 9
are similar in the aspect of peak position and intensity
and are consistent with the trigonal-bipyramidal struc-
ture of C3 symmetry in solution. The three arms of the
trialkanolamine ligand are magnetically equivalent in
1
1H and 13C{1H} NMR spectra. In the H NMR spectra,
the NCH2 methylene protons are diastereotopic, giving
an AB spin system (2.70 and 2.54 ppm). Unlike 6 and
9, the NMR spectra of the compounds 7, 8, 10, and 11
show a trigonal-bipyramidal structural nature with no
symmetric elements such as mirror plane and rotational
axis. The three arms of the trialkanolamine ligand are
magnetically nonequivalent in 1H and 13C{1H} NMR
spectra. The NMR spectra of enantiomeric pairs 7 and
10 and 8 and 11 are also similar with respect to peak
position and intensity. In comparison to the free trial-
kanolamine precursors, all signals are shifted downfield,
which is a consequence of the complexation with Lewis
acidic titanium metal. The greater extent of downfield
(14) In general, the syntheses and purification of the compounds
Cp*Ti(OR)3 are difficult due to their air instability and high boiling
points: Kucht, A.; Kucht, H.; Barry, S.; Chien, J . C. W.; Rausch, M.
D. Organometallics 1993, 12, 3075.
(15) (a) Duan, Z.; Naiini, A. A.; Lee, J .-H.; Verkade, J . G. Inorg.
Chem. 1995, 34, 5477. (b) Pinkas, J .; Wang, T.; J acobson, R. A.;
Verkade, J . G. Inorg. Chem. 1994, 33, 4202. (c) Schubart, M.; O’Dwyer,
L.; Gade, L. H.; Li, W.-S.; McPartlin, M. Inorg. Chem. 1994, 33, 3893.
(d) Cummins, C. C.; Schrock, R. R.; Davis, W. M. Organometallics 1992,
11, 1452. (e) Cummins, C. C.; Lee, J .; Schrock, R. R.; Davis, W. D.
Angew. Chem., Int. Ed. Engl. 1992, 31, 1501.

1132 Organometallics, Vol. 21, No. 6, 2002
Kim et al.
F igu r e 3. ORTEP drawing of the compound 5, showing
50% probability thermal ellipsoids and atom labeling.
F igu r e 1. ORTEP drawing of the compound 2, showing
50% probability thermal ellipsoids and atom labeling.
F igu r e 2. ORTEP drawing of the compound 4, showing
50% probability thermal ellipsoids and atom labeling.
shifts of OCH or OCH2 NMR resonances as compared
to those of NCH2 resonances suggests a strong bond
between the O atom and Ti atom and a weak interaction
between the N atom and the Ti atom upon complexation.
The solution structures, therefore, are consistent with
the solid-state structures described below.
Cr ysta l Str u ctu r es of 2, 4-6, a n d 8. ORTEP16
representations of 2, 4-6, and 8 are shown in Figures
1-5, and selected bond distances and angles are sum-
marized in Table 2. For the systems 5 and 6, only one
of two molecules that show similar structural features
in the asymmetric unit is presented. In contrast to the
often observed oxygen-bridged dimeric structural fea-
ture of titanatranes,6 the crystal structures of these five
compounds show monomeric character, which is con-
sistent with their NMR spectra, presumably because of
the bulky nature of the Cp′ ancillary ligand. The Ti atom
adopts essentially an η5 bonding posture with the Cp′
ring and a tetradentate bonding mode with the TEA or
TAA ligand via a transannular interaction from the
bridgehead N atom to Ti. The overall coordination
geometry of the complexes is slightly distorted trigonal
bipyramidal. The amino nitrogen and Cp′ ligand occupy
the axial positions of a trigonal-bipyramidal coordina-
F igu r e 4. (a) ORTEP drawing of the compound 6, showing
50% probability thermal ellipsoids and atom labeling. (b)
Top view of compound 6 through its 3-fold axis (the Cp*
ligand is omitted for clarity).
tion array. The Ti atom is displaced from the plane
formed by the three equatorial oxygen atoms in the
direction of the Cp′ ring by approximately 0.47 Å. The
centroid of the Cp′ ring, Ti atom, and N atom lie on the
pseudo 3-fold axis and approach linearity with devia-
tions of 0.34-1.46°. The three five-membered rings
adopt an envelope conformation, similar to all the
previously investigated monomeric atranes and aza-
tranes.6,15 All Cp′ rings exhibit highly regular η5 coor-
dination. The distances between the Cp′ centroid and
(16) J ohnson, C. K. ORTEP; Report ORNL-5138; Oak Ridge Na-
tional Laboratory, Oak Ridge, TN, 1976.

New Titanatrenes
Organometallics, Vol. 21, No. 6, 2002 1133
8. Thus, the stereochemistry of the ligands is retained
after the complexation with titanium metal.
Syn d iosp ecific P olym er iza tion of Styr en e. A
wide variety of sPS catalytic systems based on titanium
or zirconium organometallic complexes have been re-
ported in the literature.20 The examples include Cp′TiX3
(Cp′ ) C5H5, C5Me5 and X ) halide, alkyl, alkoxy),21
(indenyl)TiCl3,22 and substituted indenyl derivatives,23
which are among the most active catalysts. Recently,
we reported that the 1/MMAO catalyst system is highly
active and syndiospecific for the polymerization of
styrene as compared to Cp*TiCl3/MMAO.9 To investi-
gate the effect of the substituents in the cyclopentadi-
enyl ligand and the chiral substituents in the tetraden-
tate ligand of the precatalyst 1 on the polymerization
behavior, the compounds 2-12 are examined as cata-
lysts for syndiospecific polymerization of styrene in the
presence of MMAO. The polymerization results are
summarized in Table 3 along with those for the 1/MMAO
catalyst system in terms of the activity of the catalyst,
conversion, syndiotacticity, and Tm value. The sPS
samples were analyzed by GPC and DSC. Furthermore,
to assess the significance of the quoted activity values,
we also carried out control polymerization experiments
using the trichloride analogue of 1-5/MMAO systems
under the same polymerization conditions. Table 3
shows that precatalysts containing the TEA ligand are
much better catalyst systems for sPS than correspond-
ing Cl-based precatalysts in terms of activity, Tm, SI,
and molecular weight.
The catalytic efficiency in terms of activity decreases
in the order of 1/MMAO > 2/MMAO . 4/MMAO >
3/MMAO > 5/MMAO, indicating that the electronic and
steric effects of the substituent in the new titanatranes
(C5Me4R)Ti(TEA) are best optimized when R is methyl
group. In addition, the catalytic activity decreases in
the order of 1/MMAO > 9/MMAO > 7/MMAO ≈ 10/
MMAO ≈ 6/MMAO > 8/MMAO ≈ 11/MMAO > 12/
MMAO, indicating that the steric effect of the substit-
uent in the new titanatranes (C5Me5)Ti(N(CH2CR1HO)-
(CH2CR2HO)(CH2CR3HO)) is the dominant factor in
determining the activity for sPS.
F igu r e 5. (a) ORTEP drawing of the compound 8, showing
50% probability thermal ellipsoids and atom labeling. (b)
Top view of the compound 8 through its 3-fold axis (the
Cp* ligand is omitted for clarity).
Ti for 2, 4-6, and 8 are in the range 2.119-2.139 Å,
which are longer than that (2.119(10) Å) found in the
compound 1. The Ti to Cp′ carbon distances, listed in
Table 2, fall in the range observed for other known Ti-
Cp complexes.18 The average Ti-O distances of 1.870,
1.868, 1.880, 1.867, and 1.880 Å for 2, 4-6, and 8,
respectively, are similar to those observed for other
structurally characterized titanatranes6 and titanium
alkoxides.17 The transannular Ti-N bond distances for
2 (2.307(7) Å), 4 (2.331(8) Å), 5 (2.322 Å), 6 (2.328 Å),
and 8 (2.314(5) Å) fall at the long end of the range
(2.264(3)-2.342(9) Å) found in the eight other3,6,7,9
structurally characterized titanium trialkanolamine
derivatives. This observation confirms the existence of
the transannular interaction. Figures 4 and 5 illustrate
that all the methyl substituents at OC carbons for the
compounds 6 and 8 adopt the Cahn-Ingold-Prelog S
configuration. The absolute configuration is confirmed
by the Flack parameters19 of -0.03 for 6 and -0.06 for
The molecular weights of all the resulting polymers
obtained by 1-12/MMAO are in the range Mw
)
31 400-292 000 with Mw/Mn ) 1.77-4.07. In particular,
the molecular weights of all the resulting polymers by
6-11/MMAO are in the range Mw ) 31 400-34 100
with Mw/Mn ) 1.8-1.98. Polydispersity index (PDI)
values of ca. 2 were seen for all the catalytic systems,
except for 1/MMAO, which gave a PDI of 4.07. This is
presumably due to the formation of polymer precipitate
prior to the termination of the polymerization, which
was observed only for the 1/MMAO system at 70 °C. It
(20) (a) Ishihara, N.; Seimiya, T.; Kuramoto, M.; Uoi, M. Macro-
molecules 1986, 19, 2464. (b) Ishihara, N.; Kuramoto, M.; Uoi, M.
Macromolecules 1988, 21, 3356. (c) Soga, K.; Nakatani, H.; Monoi, T.
Macromolecules 1990, 23, 953. (d) Kucht, A.; Kucht, H.; Barry, S.;
Chien, J . C. W.; Rausch, M. D. Organometallics 1993, 12, 3075. (e)
Flores, F. C.; Chien, J . C. W.; Rausch, M. D. Macromolecules 1996,
29, 8030.
(17) (a) Wright, D. A.; Williams, D. A. Acta Crystallogr. 1968. B24,
1107. (b) Hampden-Smith, M. J .; Williams, D. S.; Rheingold, A. L.
Inorg. Chem. 1990, 29, 4076. (c) Doeuff, S.; Dronzee, Y.; Taulelle, F.;
Sanchez, C. Inorg. Chem. 1989, 28, 4439. (d) Ibers J . A. Nature 1963,
197, 686. (e) Witters, R. D.; Caughlan, C. N. Nature 1965, 205, 1312.
(18) Engelhardt, L. M.; Papasergio, R. I.; Raston, C. L.; White, A.
H. Organometallics 1984, 3, 18.
(21) Ishihara, N.; Kuramoto, M. Syntheses and Properties of Syn-
diotactic Polystyrene. In Catalyst Design for Tailor-Made Polyolefins;
Soga, K., Terano, M. Eds.; Kodansha: Tokyo, 1994; p 339.
(22) Ready, T. E.; Day, R. O.; Chien, J . C. W.; Rausch, M. D.
Macromolecules 1993, 26, 5822.
(23) (a) Foster, P.; Chien, J . C. W.; Rausch, M. D. Organometallics
1996, 15, 2404. (b) Kim, Y.; Koo, B. H.; Do, Y. J . Organomet. Chem.
1997, 527, 155.
(19) Flack, H. D. Acta Crystallogr. 1983, A39, 876.

1134 Organometallics, Vol. 21, No. 6, 2002
Kim et al.
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles (d eg) for Com p ou n d s 2, 4-6, a n d 8
(η5-C5Me4H)Ti(TEA) (2)
Ti-O(1)
Ti-N
1.880(6)
2.307(7)
2.461(8)
2.134(9)
Ti-O(2)
Ti-C(1)
Ti-C(4)
1.856(7)
2.411(9)
2.445(10)
Ti-O(3)
Ti-C(2)
Ti-C(5)
1.874(7)
2.460(9)
2.453(11)
Ti-C(3)
Ti-CENT
CENT-Ti-O(3)
O(2)-Ti-N
104.89(3)
75.2(3)
CENT-Ti-O(1)
CENT-Ti-N
O(3)-Ti-N
105.09(3)
178.67(3)
75.8(3)
CENT-Ti-O(2)
O(1)-Ti-N
103.53(3)
75.5(3)
(η5-C5Me4Ph)Ti(TEA) (4)
Ti-O(1)
Ti-N
Ti-C(3)
Ti-CENT
1.869(6)
2.331(8)
2.420(9)
2.139(9)
Ti-O(2)
Ti-C(1)
Ti-C(4)
1.869(7)
2.483(9)
2.456(9)
Ti-O(3)
Ti-C(2)
Ti-C(5)
1.867(8)
2.468(9)
2.440(9)
CENT-Ti-O(3)
O(2)-Ti-N
105.07(3)
75.7(3)
CENT-Ti-O(1)
CENT-Ti-N
O(3)-Ti-N
104.46(3)
179.74(3)
75.1(3)
CENT-Ti-O(2)
O(1)-Ti-N
104.35(3)
75.3(3)
(η5-C5Me4Tol)Ti(TEA) (5)
Ti-O(1)
Ti-N
Ti-C(3)
Ti-CENT
1.876(7)
2.312(8)
2.404(10)
2.124(9)
Ti-O(2)
Ti-C(1)
Ti-C(4)
1.879(6)
2.432(9)
2.464(9)
Ti-O(3)
Ti-C(2)
Ti-C(5)
1.882(7)
2.434(10)
2.466(8)
CENT-Ti-O(3)
O(2)-Ti-N
105.25(3)
76.2(3)
CENT-Ti-O(1)
CENT-Ti-N
O(3)-Ti-N
104.13(3)
179.56(3)
75.2(3)
CENT-Ti-O(2)
O(1)-Ti-N
103.48(3)
75.7(3)
Ti′-O(1′)
Ti′-N′
Ti′-C(3′)
Ti′-CENT
1.873(6)
2.331(8)
2.422(10)
2.125(9)
Ti′-O(2′)
Ti′-C(1′)
Ti′-C(4′)
1.880(7)
2.428(9)
2.460(9)
Ti′-O(3′)
Ti′-C(2′)
Ti′-C(5′)
1.888(7)
2.439(10)
2.473(9)
CENT-Ti′-O(3′)
O(2′)-Ti′-N′
105.18(3)
75.3(3)
CENT-Ti′-O(1′)
CENT-Ti′-N′
O(3′)-Ti′-N′
104.03(3)
179.66(3)
75.1(3)
CENT-Ti′-O(2′)
O(1′)-Ti′-N′
104.14(3)
76.0(3)
(Pentamethylcyclopentadienyl)titanium (S,S,S)-Tri-2-propanolaminate (6)
Ti1-O(11)
Ti1-N1
Ti1-C(13)
Ti1-CENT
1.878(9)
2.336(6)
2.449(11)
2.129(13)
Ti1-O(12)
Ti1-C(11)
Ti1-C(14)
1.869(7)
2.447(9)
2.462(14)
Ti1-O(13)
Ti1-C(12)
Ti1-C(15)
1.873(9)
2.407(14)
2.448(14)
CENT-Ti1-O(13)
O(12)-Ti1-N1
104.99
76.2(2)
CENT-Ti1-O(11)
CENT-Ti1-N1
O(13)-Ti1-N1
103.95
179.12
75.5(4)
CENT-Ti1-O(12)
O(11)-Ti1-N1
104.59
74.9(4)
Ti2-O(21)
Ti2-N2
Ti2-C(23)
Ti2-CENT
1.865(10)
2.319(7)
2.42(2)
Ti2-O(22)
Ti2-C(21)
Ti2-C(24)
1.860(6)
2.445(15)
2.396(14)
Ti2-O(23)
Ti2-C(22)
Ti2-C(25)
1.857(11)
2.423(9)
2.464(12)
2.120(14)
CENT-Ti2-O(23)
O(22)-Ti2-N2
105.72
75.6(3)
CENT-Ti2-O(21)
CENT-Ti2-N2
O(23)-Ti2-N2
104.00
179.43
73.8(5)
CENT-Ti2-O(22)
O(21)-Ti2-N2
105.72
76.0(4)
(Pentamethylcyclopentadienyl)titanium (S)-2-Propanoldiethanolaminate (8)
Ti-O(1)
Ti-N
Ti-C(3)
Ti-CENT
1.878(5)
2.314(5)
2.436(5)
2.119(7)
Ti-O(2)
Ti-C(1)
Ti-C(4)
1.873(5)
2.461(8)
2.427(6)
Ti-O(3)
Ti-C(2)
Ti-C(5)
1.888(5)
2.416(6)
2.445(8)
CENT-Ti-O(3)
O(2)-Ti-N
104.10
75.8(2)
CENT-Ti-O(1)
CENT-Ti-N
O(3)-Ti-N
106.04
178.54
75.3(2)
CENT-Ti-O(2)
O(1)-Ti-N
103.32
75.4(2)
is interesting to note that the 12/MMAO system can
produce sPS with high molecular weight compared with
6/MMAO and 9/MMAO systems. The syndiotacticity of
all the resulting polymers exceeds 96.8%, as determined
by 13C NMR spectra of the 2-butanone-insoluble portion
at 110 °C in 1,1,2,2-tetrachloroethane-d2. The signals
for methylene, methine, and ipso phenyl carbons of sPS
appear at 40.51, 43.68, and 145.36 ppm, respectively.
The chemical shifts of the methine and ipso phenyl
carbons are sensitive to the microstructure of sPS and
are used to interpret the stereospecificity of sPS, and
thus, the appearance of only one methine and one ipso
phenyl carbon signal at those particular positions is a
clear indication of the syndiotacticity.24 In addition, all
catalytic systems, except 2/MMAO, afford polystyrenes
(24) (a) Mani, R.; Burns, C. M. Macromolecules 1991, 24, 5476. (b)
Dias, M. L.; Giarrusso, A.; Porri, L. Macromolecules 1993, 26, 6664.

New Titanatrenes
Organometallics, Vol. 21, No. 6, 2002 1135
Ta ble 3. Styr en e P olym er iza tion Ca ta lyzed by 1-12/MMAOa
d
f
f
f
catalyst
amt of PS (g)
10-7Ab
conversn (%)c
Tm
SIe (%)
Mw
Mn
Mw/Mn
(η5-C5Me5)TiCl3
3.00
4.01
1.50
3.25
0.72
1.46
1.32
1.98
0.59
1.17
2.23
2.31
1.92
2.61
2.29
1.83
0.92
2.12
2.83
1.06
2.29
0.51
1.03
0.93
1.40
0.42
0.83
1.57
1.63
1.35
1.84
1.61
1.29
0.65
66
88
33
71
16
32
29
44
13
26
50
51
42
57
50
40
20
272.7
273.4
260.4
261.9
265.9
274.1
269.4
273.7
260.1
271.8
273.9
273.6
273.3
274.8
275.4
273.6
273.5
95.4
98.2
86.7
96.8
40.3
98.3
69.7
98.7
32.2
97.5
98.7
98.4
98.5
98.8
99.0
98.8
97.4
182 300
292 000
15 300
43 200
25 300
65 700
22 000
123 500
30 300
133 600
31 400
33 700
34 000
31 600
33 400
34 100
135 800
87 000
71 700
8 300
22 500
9 600
34 600
12 400
68 800
11 400
74 600
17 100
18 500
18 900
17 200
17 900
17 200
48 400
2.09
4.07
1.85
1.92
2.62
1.90
1.77
1.80
2.65
1.79
1.84
1.82
1.80
1.84
1.86
1.98
2.81
1
(η5-C5Me4H)TiCl3
2
(η5-C5Me4Et)TiCl3
3
(η5-C5Me4Ph)TiCl3
4
(η5-C5Me4Tol)TiCl3
5
6
7
8
9
10
11
12
a
b
Polymerization conditions: [styrene] ) 0.436 M (5 mL); [Ti] ) 0.195 mM; Al/Ti ) 1000; time 10 min; Tp ) 70 °C. A ) activity ) (g
of sPS)/((mol of Ti)(mol of styrene) h). c Conversion ) ((g of polymer)/(g of monomer)) × 100. Determined by DSC. e SI ) 2-butanone-
d
insoluble portion whose tacticity was established by 13C NMR in 1,1,2,2-tetrachloroethane-d2. f Determined by GPC.
with Tm values of greater than 271 °C, even at a high
polymerization temperature of 70 °C. Overall, the 1-12/
MMAO catalytic systems produce highly syndiotactic
polystyrenes with good activity.
Ack n ow led gm en t. We gratefully acknowledge fi-
nancial support from the Korea Science and Engineer-
ing Foundation and the Brain Korea 21 Project.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
In conclusion, we have synthesized various kinds of
new titanatranes containing Cp ancillary ligands and
trialkanolamine auxiliary ligands. They are good and
efficient catalysts for the syndiospecific polymerization
of styrene in terms of activity, Tm value, and syndio-
tacticity.
data, atomic coordinates, thermal parameters, and bond
1
distances and angles for 2, 4-6, and 8 and figures giving H
and 13C{1H} NMR spectra for 2-8 and 12. This material is
available free of charge via the Internet at http://pubs.acs.org.
OM0109197