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Supporting Information Part A: Experimental Data Structure-Activity Correlation for Relative Chain Initiation to Propagation Rates in Single-Site Olefin Polymerization Catalysis Thomas A. Manza,b*, James M. Caruthersb*, Shalini Sharmac, Khamphee Phomphraic,d, Kendall T. Thomsonb, W. Nicholas Delgassb, and Mahdi M. Abu-Omarc a
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (present address); bSchool of Chemical Engineering, Purdue University, West Lafayette, IN 47907; cDepartment of Chemistry, Purdue University, West Lafayette, IN 47907; d Department of Chemistry, Mahidol University, Bangkok, Thailand (present address). corresponding authors:
[email protected],
[email protected] Experimental details for precatalyst 32 and catalyst 32a are provided below. Experimental details for the other precatalysts and catalysts can be found in the Supporting Information of (a) Manz, T. A.; Phomphrai, K.; Medvedev, G.; Krishnamurthy, B. B.; Sharma, S.; Haq, J.; Novstrup, K. A.; Thomson, K. T.; Delgass, W. N.; Caruthers, J. M.; Abu-Omar, M. M. J. Am. Chem. Soc. 2007, 129, 3776-3777 and (b) Manz, T. A.; Sharma, S.; Phomphrai, K.; Novstrup, K. A.; Fenwick, A. E.; Fanwick, P. E.; Medvedev, G. A.; Abu-Omar, M. M.; Delgass, W. N.; Thomson, K. T.; Caruthers, J. M. Organometallics, 2008, 27, 5504-5520. CONTENTS 1. Synthesis Details and ORTEP Drawings of X-Ray Crystal Structures 2. Kinetic Model Fits and Polymer Molecular Weight Distribution for Catalyst 32a 3. 1H NMR Spectrum of Precatalyst 32 Synthesis and polymerization experiments were carried out with rigorous exclusion of air and moisture using either standard Schlenk line techniques or a circulating nitrogen-filled glove box operating at < 0.2 ppm oxygen. Solvents were distilled from sodium/benzophenone, or purified using an Innovative Technologies solvent purification system, and stored over sodium ribbons under nitrogen until use. B(C6F5)3 (Strem) was used as received without further purification. 1-hexene was purchased from Aldrich, dried over CaH2, vacuum distilled, and stored over activated molecular sieves before use. Precatalysts were discarded and remade if purity was less than ca. 90% by 1H NMR. Solid precatalysts were stored inside a dry box at room temperature and recrystallized before use. Liquid precatalysts were stored at -20 °C in a drybox freezer and discarded 2 – 3 weeks after synthesis. Batch 1-hexene polymerization was followed by 1H NMR. To activate the catalyst, a solution of precatalyst was injected via syringe through the septum of an NMR tube containing the solvent, B(C6F5)3 activator, and Ph2CH2 internal standard. The tube was shaken vigorously and placed into the spectrometer. M consumption was determined by monitoring the integration
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of olefinic peak (CH2=CH-Bun) with respect to the internal standard. At the end of reaction the NMR tube’s contents were quenched with methanol, which precipitated polyhexene from solution. Methanol was decanted and the polymer was dried in vacuum overnight. The polymer sample was purified by extraction into tetrahydrofuran and passed through a short plug of alumina to remove the catalyst. Molecular weight distributions were then measured using gel permeation chromatography. 1. Synthesis Details and ORTEP Drawings of X-Ray Crystal Structures Cp*Zr(OC6H-2,3,5,6-Ph4)(CH2Ph)2 (32) A diethyl ether solution of [Cp*Zr(OC6H2,3,5,6-Ph4)Cl2] (0.4 g, 0.58 mmol) was cooled to 0°C in an ice bath. To this solution was added (CH2Ph)MgCl (1.21 mL, 1.22 mmol) via syringe under a flush of nitrogen. The solution was stirred at 0 °C in ice bath for 2 h and the solution remained clear for this duration. Upon bringing the solution to room temperature, MgCl2 began to precipitate and the solution was stirred for an additional 1 h. The solvent was removed under vacuum and replaced with benzene. The suspension was filtered through a plug of Celite over fritted glass to remove magnesium chloride. The filtrate was then evacuated to give sticky yellow oil, which solidified into solid overnight (0.36 g, 78%). The solid (50 mg) was dissolved in minimum amount of hot benzene and layered with hexane and allowed to sit overnight to give brilliant light yellow needle-shaped crystals of the title compound as a benzene solvate (42 mg, 84%). Anal. Calc. for C54H50OZr. C6H6: C, 80.45; H, 6.25. Found: C, 80.62; H, 6.37. 1H NMR (C6D6, 25 °C): δ 6.80-7.50 (aromatics); 1.43 (s, 15H, C5Me5); Hidden under Cp* peak (4H, Zr-CH2Ph). Selected 13 C NMR (C6D6, 25 °C): δ 158.0 (Zr-O-C); 121.6 (C5Me5); 70.9 (Zr-CH2Ph); 11.4 (C5Me5). [Cp*Zr(OC6H-2,3,5,6-Ph4)(CH2Ph)] [(CH2Ph)-B(C6F5)3] (32a) An NMR tube was charged with 20 mg (0.025 mmol) of Cp*Zr(OC6H-2,3,5,6-Ph4)(CH2Ph)2 , 13 mg (0.025 mmol ) of B(C6F5)3 and 0.5 mL of C6D5Br. The color changed from light yellow to dark yellow immediately. 1H NMR (C6D5Br, 25°C): δ 6.36 (d, 2H, ortho Zr-η3-CH2Ph), 6.62-7.21 (other aromatics), 1.38 (s, 15H, C5Me5), 3.23 (br, 2H, B-CH2Ph), 1.91 (s, 2H, Zr-CH2Ph).
Figure A: ORTEP drawing for Cp*Zr(OC6H-2,3,5,6-Ph4)Cl2. Hydrogen atoms are omitted for clarity. Thermal ellipsoids are drawn at 50% probability. Selected Bond Distances (Å) and Angles (deg) Zr-O 1.934(3), Zr-Cl1 2.389(1), Zr-Cl2 2.385(2), Zr-Cp* 2.165(6); O-Zr-Cl1 108.5(1), Cl1-Zr-Cp* 112.8(2), O-Zr-Cl2 107.9(1), Cl2-Zr-Cp* 110.2(1), O-Zr-Cp* 115.9(2), Zr-O-C11 169.4(3), C11-Zr-Cl2 100.23(6).
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Figure B: ORTEP drawing for Precatalyst 32: Cp*Zr(OC6H-2,3,5,6-Ph4)Bn2. Hydrogen atoms are omitted for clarity. Thermal ellipsoids are drawn at 50% probability. Selected Bond Distances (Å) and Angles (deg) Zr-O2 = 1.978(2), Zr-C40 = 2.277(2), Zr-C30 = 2.256(2), Zr-Cp* = 2.205(1), O2-Zr-C30 = 105.35(5), C40-Zr-Cp* = 110.36(5), O2-Zr-C40 = 102.33(6), C30-Zr-C40 = 107.19(6), O2-Zr-Cp* = 117.56 (4), Zr-O2-C21 = 159.67(9), and C30-Zr-Cp* = 113.08(5), C41-C40-Zr 100.85(6), C31-C30-Zr 135.03 (6).
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Compound
Cp*Zr(OC6H-
Cp*Zr(OC6H-
Cp*Zr(OC6H-
2,3,5,6-Ph4)Cl2
2,3,5,6-Ph4)Me2
2,3,5,6-Ph4)Bn2
Empirical Formula
C43H39Cl2OZr
C45H45OZr
C60H56OZr
Formula Weight
733.92
693.08
884.33
Crystal system
monoclinic
triclinic
triclinic
Space Group
P21
P-1
P-1
a (Å)
10.9415(7)
11.3794(2)
9.7276(2)
b (Å)
27.534(2)
12.5637(6)
11.2587(2)
c (Å)
12.2533(5)
14.6962(7)
21.9640(5)
α (°)
90.00
70.816(2)
78.6497(7)
β (°)
101.981(4)
67.903(3)
87.4688(7)
γ (°)
90.00
74.723(3)
84.6684(8)
Z
4
2
2
Volume (Å3)
3611.1(4)
1815.0(1)
2347.43(8)
Densitycalc (g/cm3)
1.350
1.268
1.251
Theta range (°)
1-27
1.96 – 27.49
2-30
Radiation (Wavelength) Reflections collected
Mo-Kα (0.71073 Å) 28142
19600
13685
Independent reflections R
13837
8268
11006
0.056
0.038
0.037
Rw
0.142
0.107
0.090
Goodness of Fit
1.004
1.039
1.086
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2. Kinetic Model Fits and Polymer Molecular Weight Distribution for Catalyst 32a 1-Hexene polymerization over 32a was followed by measuring monomer consumption versus time using 1H NMR. In the glove box, 62.5 μL 1-hexene, 50 μL of 0.10 M stock solution of B(C6F5)3 in C6D5Br, 10 μL of Ph2CH2 as internal standard, and 0.33 mL C6D5Br were added to a WILMAD screw-cap 5mm NMR tube with an open-top cap PTFE/Silicone septum. 1H NMR of the mixture was taken and the integrals of the monomer olefinic peaks were noted. To start the polymerization reaction, 50 μL of 0.10 M solution of precatalyst 32 was injected via syringe into the NMR tube and the contents of the mixture turned bright yellow. The tube was shaken vigorously and placed back into the spectrometer. Monomer consumption was determined by monitoring the integration of olefinic peak (CH2=CH-Bun) with respect to the internal standard Ph2CH2. At the end of reaction the contents of the NMR tube were quenched with methanol, which precipitated polyhexene from the solution. Methanol was decanted and the polymer was dried in vacuum overnight. The polymer sample was purified by extraction into THF and passed through a short plug of alumina to remove the catalyst. The molecular weight distribution was measured using a Waters Alliance GPCV 2000. The kinetic model fits and polymer molecular weight distributions were obtained by procedures in the Supporting Information of Manz, T. A.; Sharma, S.; Phomphrai, K.; Novstrup, K. A.; Fenwick, A. E.; Fanwick, P. E.; Medvedev, G. A.; Abu-Omar, M. M.; Delgass, W. N.; Thomson, K. T.; Caruthers, J. M. Organometallics, 2008, 27, 5504-5520.
Figure C: Polymerization of 1-hexene in bromobenzene by Cp*Zr(OC6H-2,3,5,6-Ph4)Bn2 (32) /B(C6F5)3 at 25 °C, 100:1 monomer-to-catalyst ratio, [M]0 = 1 M.
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(a) first-order catalyst deactivation fit: kp = 0.06 M-1 s-1, ki/kp = 0.001, kd = 4.2 x 10-4 M-1 s-1, theoretical Mn using this kinetic model =11 kDa.
(b) zero-order catalyst deactivation fit: kp = 0.045 M-1 s-1, ki/kp = 0.001, kd = 1.3 x 10-4 s-1, theoretical Mn using this kinetic model =13 kDa. Figure D: Polymerization of 1-hexene in bromobenzene at 25 °C, 100:1 monomer:catalyst ratio, [M]0 = 1 M. (This catalyst fits zero-order in monomer deactivation better than first-order in monomer deactivation.)
Organometallics 3. 1H NMR Spectrum of Precatalyst 32 (Cp*Zr(OC6H-2,3,5,6-Ph4)Bn2) recorded in C6D6 solvent and referenced to the protio impurity of the solvent (7.16 ppm)
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