Bridged cyclopentadienyl indenyl (fluorenyl) zirconocene complexes
Two diastereomers existed. 1H NMR (500 MHz, 298 K, CDCl3): δ
7.79 (d, 0.8H, 3J = 8.1 Hz, Ph), 7.78 (d, 1.2H, 3J = 8.6 Hz, Ph), 7.76
M+−Cl),535[53,M+−(CH3-C6H4)],491{14,M+−[C(CH3)3-C6H4]},
491 (13, M+− ZrCl2). Anal. calcd for C36H32ZrCl2·C7H8: C, 71.84; H,
5.61. Found: C, 71.60; H, 5.92%.
3
4
(dd, 1H, J = 8.1 Hz, J = 2.1 Hz, Ph), 7.65 (d, 1H, 3J = 8.7 Hz,
3
4
Ind), 7.58 (dd, 1H, J = 8.1 Hz, J = 2.1 Hz, Ph), 7.40 (dd, 0.4H,
3J = 8.0, 4J = 2.1 Hz, Ph), 7.37 (d, 1.2H, 3J = 8.6 Hz, Ph), 7.34–7.30
(m, 1.4H, 1H-Ind, 0.4H-Ph), 7.23 (d, 3J = 8.0 Hz, 0.6H, Ph), 7.20
(d, 3J = 8.1 Hz, 0.8H, Ph), 7.14 (d, 3J = 8.0 Hz, 0.6H, Ph), 6.89 (m,
1H, Ind), 6.72–6.68 (m, 1H, Ind), 6.58–6.54 (m, 2H, Cp), 6.38 (dd,
Homopolymerization
A 100 ml autoclave, equipped with a magnetic stirrer, was
evacuated under vacuum, and then filled with ethylene. Toluene
was injected into the reactor. After equilibrating, the appropriate
volume of catalyst solution and cocatalyst were injected to start
the reaction. The ethylene pressure was kept constant during the
reaction. The polymerization was carried out for 30 min and then
quenched with 30 ml 3% HCl in ethanol. The collected polymer
was washed to neutral with ethanol and then dried overnight in a
vacuum oven at 60 ◦C to constant weight.
3
4
3
0.6H, J = 8.9 Hz, J = 0.7 Hz, Ind), 6.31 (dd, 0.4H, J = 8.9 Hz,
4J = 0.7 Hz, Ind), 6.29 (d, 0.6H, 3J = 3.5 Hz, Ind), 6.25 (d, 0.4H,
3J = 3.5 Hz, Ind), 5.89 (dd, 0.4H, 3J = 5.3 Hz, 4J = 2.8 Hz, Cp), 5.86
(dd, 0.6H, 3J = 5.3 Hz, 4J = 2.8 Hz, Cp), 5.74 (dd, 0.6H, 3J = 5.3 Hz,
4J = 2.8 Hz, Cp), 5.72 (dd, 0.4H, 3J = 5.3 Hz, 4J = 2.8 Hz, Cp), 2.35
(s, 1.8H, CH3), 2.34 (s, 1.2H, CH3), 1.2 (s, 9H, C(CH3)3); IR (KBr, cm−1):
3049m, 3028m, 2959s, 2867m, 1608 w, 1510s, 1461m, 1409m,
1362m, 1266m, 1130m, 1111m, 1078m, 1041s, 952 w, 866 w, 825s,
803s, 742s, 723m, 589s, 508s, 468s; MS (m/z): 574 (100, M+), 538
(11, M+− Cl), 483 [14, M+− (CH3-C6H4)], 442 {13, M+− [C(CH3)3-
C6H4]}. Anal. calcd for C32H30ZrCl2: C, 66.64; H, 5.24. Found: C,
66.97; H, 5.81%.
Copolymerization
All copolymerizations were carried out in a 100 ml autoclave
reactor. According to the conventional copolymerization, the
macromonomer was first added to the dry reactor, then toluene
and MAO were introduced. After equilibrating, the appropriate
catalystsolutionof2awasinjectedtoinitiatethecopolymerization.
For the tandem copolymerization, a conventional ethylene
polymerization was done using the toluene solution of complex
1a after the reactor was set with the toluene, MAO, temperature,
and ethylene pressure and stirred for 30 min. Then a solution of
complex 2a in toluene was added to start the copolymerization.
The simultaneous copolymerization was carried out by injecting
a mixture of 1a and 2a after the reactor was set. The polymer
product was then quenched with 30 ml of 3% HCl in ethanol.
The precipitated polymer was filtered, and extracted with hot
toluene for 24 h in a Soxhlet apparatus to separate the residue
macromonomer from high molecular weight component. Then
the macromonomer and polyethylene were dried overnight in a
vacuum oven at 60 ◦C.
Synthesis of Complex [(p-CH3-Ph)2C(C5H4)(C13H8)]ZrCl2 (2a)
To a solution of (p-CH3-Ph)2C(C5H5)(C13H9) (1.0g, 2.4 mmol)
in 30 ml of Et2O, 1.75 mol/l n-butyllithium in hexane (2.8 ml,
4.9 mmol) was added dropwise at −78 ◦C. After being stirred
overnight, ZrCl4 (0.55 g, 2.4 mmol) was added directly to the
solution as a solid. The resulting suspension was stirred for 8 h
at room temperature, and then filtered. The solid residue was
recrystallized in toluene to give complex 2a as a red crystal
(350 mg, yield 25.4%). 1H NMR (500 MHz, 298 K, CDCl3): δ 8.19
3
3
4
(d, 2H, J = 8.3 Hz, Flu), 7.80 (dd, 2H, J = 8.3 Hz, J = 1.9 Hz,
Ph), 7.77 (dd, 2H, 3J = 8.3 Hz, 4J = 1.9 Hz, Ph), 7.56 (quasi t, 2H,
Flu), 7.27–7.21 (m, 4H, 2H-toluene-Ph, 2H-Ph), 7.18–7.15 (m, 3H,
toluene-Ph), 7.13 (d, 2H, 3J = 8.3 Hz, Ph), 7.01 (quasi t, 2H, Flu), 6.45
(d, 2H, 3J = 8.3 Hz, Flu), 6.37 (quasi t, 2H, Cp), 5.79 (quasi t, 2H, Cp),
2.35 (s, 3H, toluene-CH3), 2.34 (s, 6H, CH3); IR (KBr, cm−1): 3112m,
3083m, 3024s, 2968 w, 2918s, 1590m, 1512m, 1504m, 1494m,
1462s, 1427s, 1326s, 1212m, 1126m, 1082m, 1042s, 1018m, 952 w,
896 w, 823s, 786m, 753s, 730s, 695m, 473s; MS (m/z): 582(63, M+),
546 (14, M+− Cl), 491 [100, M+− (CH3-C6H4)], 422 (14, M+− ZrCl2).
Anal. calcd for C33H26ZrCl2·C7H8: C, 70.98; H, 5.06. Found: C, 71.30;
H, 5.42%.
Results and Discussion
Synthesis of Zirconocene Complexes
The new ansa-cyclopentadienyl indenyl (or fluorenyl) zirconocene
complexes 1a–b and 2a–b were synthesized as illustrated
in Scheme 1. For comparison purposes, complexes 1c–d were
synthesized according to our previous paper.[19]
Synthesis of Complex {(p-CH3-Ph)[p-C(CH3)3-Ph]C(C5H4)(C13
H8)}ZrCl2 (2b)
The bridged cyclopentadienyl indenyl (or fluorenyl) preligand
compounds were synthesized analogously to the literature.[22,23]
Thesubstituteddiphenylfulveneswerepreparedbythereactionof
substitutedbenzophenonswithcyclopentadienylsodiuminether.
Then the indenyl (or fluorenyl) lithium salt was allowed to react
with the fulvenes. After hydrolysis, the preligand compounds were
precipitatedfromdiethyletheraswhitesolids.Thepreligandswere
treated with two equivalents of n-butyl lithium in diethyl ether
and reacted respectively with one equivalent of zirconium tetra-
chloride to afford zirconocene complexes 1a–b and 2a–b after
recrystallization from toluene. All the complexes were character-
ized by 1H NMR spectroscopy and elemental analysis methods.
Following the procedure described for 2a, (p-CH3-Ph)[p-C(CH3)3-
Ph]C(C5H5) (C13H9) (1.1 g, 2.36 mmol), 2.50 mol/l n-butyllithium
in hexane (1.9 ml, 4.75 mmol) and ZrCl4 (0.55 g, 2.36 mmol) were
used to give 2b as an orange crystal (226 mg, yield 15.3%). 1H NMR
(500 MHz, 298 K, CDCl3): δ 8.19(d, 2H, 3J = 8.4 Hz, 4J = 0.9 Hz, Flu),
7.80 (d, 2H, 3J = 8.3 Hz, Ph), 7.77 (dt, 2H, 3J = 8.3 Hz, 4J = 2.3 Hz,
Ph), 7.58–7.55 (m, 2H, Flu), 7.41 (dd, 1H, 3J = 8.3 Hz, 4J = 2.1 Hz,
Ph), 7.36 (dd, 1H, 3J = 8.3 Hz, 4J = 2.1 Hz, Ph), 7.27–7.22 (m, 2H,
toluene-Ph), 7.18–7.14 (m, 5H, 3H-toluene-Ph, 2H-Ph), 7.03–6.99
(m, 2H, Flu), 6.45 (d, 1H, 3J = 8.3 Hz, Flu), 6.37 (d, 1H, 3J = 8.3 Hz,
Flu), 6.35 (m, 2H, Cp), 5.82-5.78 (m, 2H, Cp), 2.36 (s, 3H, CH3), 2.35
(s, 3H, toluene-CH3), 1.32 (s, 9H, C(CH3)3); IR (KBr, cm−1): 3115m,
3031m,2959s,2865m,1595 w,1510s,1493m,1460s,1428s,1409m,
1328m, 1214m, 1128m, 1081m, 1043m, 1017m, 823s, 808m,
753s, 730s, 695m, 587s, 475s; MS (m/z): 626 (100, M+), 588 (14,
Synthesis of Polyethylene Macromonomer
Vinyl-terminated PE macromonomers were usually obtained with
low Al : Zr molar ratios.[18] In this work, an Al : Zr molar ratio of
c
Appl. Organometal. Chem. 2010, 24, 727–733
Copyright ꢀ 2010 John Wiley & Sons, Ltd.
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