Organometallics
ARTICLE
127.91 (v/ac), 128.66 (y), 128.96 (n), 129.37 (z), 129.56 (x), 129.76 (t),
129.83 (u), 130.01 (w), 130.49 (s), 131.46 (o), 131.88 (m), 131.94 (q),
132.30 (p), 133.09 (r), 135.03 (j/j0), 135.26 (l), 135.42 (k), 138.05 (h),
138.68 (i), 138.81 (d), 140.37 (f/g), 140.41 (f/g), 140.75 (e), 145.25
(c), 169.7 (b), 176.3 (a). Anal. Calcd for C89H58N3PdBF24: C, 61.34; H,
3.35; N, 2.41. Found: C, 61.64; H, 3.32; N, 2.39.
127.74, 128.10, 128.18, 130.14, 130.25, 130.32, 130.43, 130.60, 130.79,
131.50, 131.71, 132.16, 133.40, 133.40, 133.73, 134.19, 134.26, 134.83,
135.21, 136.45, 137.27, 137.75, 141.45, 141.51, 142.36, 146.9, 173.03,
174.36, 179.4; IR (Thin film) 2127.1 cmꢀ1 [ν(CO)].
[(CF3-Cyc)PdMe(CO)]þ (15e). 1H NMR (500 MHz, CD2Cl2) δ
1.02 (s, 3H), 2.90ꢀ3.22 (m, 8H), 6.31 (d, 2H, J = 7.8 Hz), 6.44 (d, 2H,
J = 7.8 Hz), 6.56 (d, 2H, J = 7.7 Hz), 6.74 (d, 1H, J = 7.3 Hz), 6.79 (d, 2H,
J = 8.0 Hz), 6.99 (d, 2H, J = 7.8 Hz), 7.01ꢀ7.08 (m, 5H), 7.19 (d, 2H, J =
7.9 Hz), 7.68ꢀ7.78 (m, 6H, partially obscured by BAFꢀ), 8.26 (d, 1H,
J = 8.3 Hz), 8.30 (d, 1H, J = 8.3 Hz); 13C NMR (125 MHz, CD2Cl2) δ
10.9, 34.46, 34.66, 123.88 (q, 1JCF = 273.3 Hz), 123.94 (q, 1JCF = 273.3
Hz), 125.4, 126.24, 126.89, 127.51, 127.78, 128.15, 128.79 (q, 2JCF = 24.0
Hz), 130.29, 130.39, 130.46, 130.60, 130.73, 130.91, 132.23, 133.21,
133.53, 134.51, 135.53, 135.91, 136.79, 141.71, 141.78, 141.96, 146.39,
147.11, 172.6, 174.1, 179.0; IR (thin film) 2127.1 cmꢀ1 [ν(CO)].
General Procedure for Ni(II)-Catalyzed Polymerizations. A
600 mL autoclave was heated under vacuum to 120 °C for 2 h, then twice
purged with ethylene, and adjusted to the desired polymerization
temperature by external oil bath. A flask was charged with a desired
amount of Ni(II) catalyst under a nitrogen atmosphere, and to this was
added 10 mL of 1,2-dichlorobenzene. In a separate flask was added
80 mL of dry toluene or 1,2-dichlorobenzene, the latter solvent if the
polymerization was conducted at temperatures higher than 80 °C, and a
suitable amount of aluminum coactivator solution in toluene ([Al]/[Ni]
= 1500). An additional 10 mL of solvent was set aside. The solution of Al
activator was then transferred into the reactor by vacuum under a
nitrogen stream. Ethylene was introduced to a pressure of 200 psi, and
the mixture was rapidly stirred for 10 min and then vented. The catalyst
solution was transferred into the reactor by vacuum under a nitrogen
stream and flushed with the final 10 mL of solvent. The reactor was filled
with ethylene to 200 psi, and the polymerization was allowed to proceed
for the desired time with rapid stirring. The reactor was vented, a mixture
of 70 mL of acetone, 30 mL of methanol, and 1 mL of concentrated
hydrochloric acid was transferred into the reactor by vacuum, the
autoclave was opened, and the polymer was collected, decanted, and
dried in vacuo at 80 °C overnight. The reactor was twice cleaned with
boiling toluene before subsequent polymerizations.
[(Me-Cyc)PdMe(Me2S)]BAF (19). Complex 19 was prepared
in situ by the addition of 1 equiv of dimethyl sulfide to a CD2Cl2
solution of 18. Representative 2D NMR spectra and NOE measure-
ments used during assignment are given in the Supporting Information.
1H NMR (500 MHz, CD2Cl2) δ 0.69 (s, 3H, Pd-Me), 2.20 (s, 6H,
SMe2), 2.45 (s, 3H, Ar-Me), 2.46 (s, 3H, Ar-Me), 2.93 ꢀ 3.09 (m, 8H,
N), 6.38 (d, 2H, J = 7.8 Hz, L), 6.40 (d, 2H, J = 7.8 Hz, J), 6.50 (d, 2H, J =
8.0 Hz, I), 6.52 (d, 2H, J = 7.9 Hz, M), 6.82 (d, 1H, J = 7.4 Hz, G), 6.90
(d, 1H, J = 7.2 Hz, K), 6.92 (d, 2H, J = 8.0 Hz, D), 6.97 (d, 2H, J = 7.9 Hz,
H), 7.05 (d, 2H, J = 7.6 Hz, A), 7.15 (d, 2H, J = 7.9 Hz, E), 7.19 (s, 2H, F/
F0), 7.21 (s, 2H, F/F0), 7.63 (t, 1H, J = 8.1 Hz, C), 7.65 (t, 1H, J = 8.1 Hz,
C), 8.16 (d, 1H, J = 8.3 Hz, B/B0), 8.19 (d, 1H, J = 8.3 Hz, B/B0).
Cyclophane Pd(II) Carbonyl Complexes. All complexes were
synthesized by the reported method.20 As the spectral data for the BAFꢀ
counterion were previously reported, only the characterization of the
cations is given below.
[(NMe2-Cyc)PdMe(CO)]þ (15a). 1H NMR (500 MHz, CD2Cl2)
δ 1.02 (s, 3H), 2.90ꢀ3.18 (m, 8H), 3.00 (s, 6H), 6.28 (d, 2H, J = 7.9
Hz), 6.39 (d, 2H, J = 7.8 Hz), 6.52 (d, 2H, J = 7.9 Hz), 6.63 (s, 2H), 6.64
(s, 2H), 6.71 (d, 2H, J = 7.9 Hz), 6.87 (d, 1H, J = 7.2 Hz), 6.96 (d, 2H, J =
7.6 Hz), 7.03 (d, 2H, J = 7.7 Hz), 7.07 (d, 2H, J = 7.6 Hz), 7.10ꢀ7.15 (m,
3H), 7.69 (t, 2H, obscured by BAFꢀ), 8.17 (d, 1H, J = 8.3 Hz), 8.21 (d,
1H, J = 8.3 Hz); 13C NMR (125 MHz, CD2Cl2) δ 10.5, 34.38, 34.58,
40.66, 40.73, 113.86, 113.88, 126.27, 126.46, 127.110, 127.66, 127.71,
127.95, 128.30, 128.51, 128.88, 129.64, 129.80, 129.86, 129.98, 130.19,
130.42, 131.9, 133.04, 134.06, 135.28, 135.86, 136.11, 136.16, 140.43,
140.45, 146.2, 149.94, 150.12, 173.8, 175.2, 180.1; IR (thin film)
2119.4 cmꢀ1 [ν(CO)].
[(OMe-Cyc)PdMe(CO)]þ (15b). 1H NMR (500 MHz, CD2Cl2) δ
1.02 (s, 3H), 2.90ꢀ3.17 (m, 8H), 3.86 (s, 3H), 6.28 (d, 2H, J = 7.7 Hz),
6.39 (d, 2H, J = 7.9 Hz), 6.53 (d, 2H, J = 8.0 Hz), 6.73 (d, 2H, J = 7.9 Hz),
6.79 (d, 1H, J = 7.3 Hz), 6.92 (s, 2H), 6.94 (s, 2H), 6.96 (d, 2H, J = 7.9
Hz), 7.02 (d, 2H, J = 7.9 Hz), 7.07 (d, 2H, J = 7.9 Hz), 7.10 (d, 1H, J = 7.3
Hz), 7.14 (d, 2H, J = 7.9 Hz), 7.68 (t, 2H, obscured by BAFꢀ), 8.21 (d,
1H, J = 8.3 Hz), 8.24 (d, 1H, J = 8.3 Hz); 13C NMR (125 MHz, CD2Cl2)
δ 10.5, 34.45, 34.64, 56.3, 116.59, 116.78, 125.94, 126.66, 126.80,
127.56, 127.82, 127.87, 128.18, 128.35, 129.88, 130.00, 130.08,
130.16, 130.36, 130.59, 132.45, 133.56, 134.58, 134.78, 135.09,
136.00, 136.85, 137.33, 140.89, 140.93, 146.6, 159.19, 159.45, 173.6,
174.8, 179.8; IR (thin film) 2123.3 cmꢀ1 [ν(CO)].
Aluminum Coactivator Screen. The general procedure for
Ni(II)-catalyzed polymerizations was followed using 1.0 μmol of catalyst
and 1500 equiv of the coactivator of choice. Polymerizations were run
for 10 min at 35 or 80 °C.
Variable-Temperature Screen. The general procedure for Ni-
(II)-catalyzed polymerizations was followed using 1.0 μmol of catalyst
and triisobutylaluminum as the coactivator (1.5 mL of a 10% w/w
solution in toluene, 1.0 M). Polymerizations were run for 10 min at the
desired temperature.
[(Me-Cyc)PdMe(CO)]þ (15c). H NMR (500 MHz, CD2Cl2) δ
1
Thermal Stability Study at 80 °C. The general procedure for
Ni(II)-catalyzed polymerizations was followed using 0.5 μmol of
catalysts and triisobutylaluminum as the coactivator (1.5 mL of a 10%
w/w solution in toluene, 1.0 M). Temperature was maintained at 80 °C.
General Procedure for Pd(II)-Catalyzed Ethylene Homo-
polymerizations. An oven-dried two-neck flask was charged with 20
μmol of Pd(II) catalyst and 30 μmol of NaBAF under a nitrogen
atmosphere, and to this was added 50 mL of dry toluene. In the case for
polymerizations run at elevated temperature, a reflux condenser was
attached. Temperature was controlled by placement in an external bath
as needed. For the duration of the polymerization, ethylene was slowly
bubbled through the solution with stirring to maintain ambient pressure.
At 3, 6, and 20 h, 10 mL aliquots of the polymerization mixture were
removed and the solvent was dried in vacuo to afford the polymer. To
compensate for solvent evaporation and/or polymer formation, the
volume of remaining reaction mixture was measured immediately after
the removal of each aliquot by syringe. After 48 h, the flow of ethylene
1.01 (s, 3H), 2.46 (s, 3H), 2.47 (s, 3H), 2.87 ꢀ 3.20 (m, 8H), 6.27 (d,
2H, J = 7.7 Hz), 6.38 (d, 2H, J = 7.8 Hz), 6.52 (d, 2H, J = 7.8 Hz),
6.68ꢀ6.75 (m, 3H), 6.95 (d, 2H, J = 7.8 Hz), 7.00 (d, 2H, J = 7.8 Hz),
7.05 (d, 2H, J = 7.7 Hz), 7.14 (d, 2H, J = 7.9 Hz), 7.20ꢀ7.24 (m, 5H),
7.68 (t, 2H, obscured by BAFꢀ), 8.19 (d, 1H, J = 8.3 Hz), 8.23 (d, 1H, J =
8.3 Hz); 13C NMR (125 MHz, CD2Cl2) δ 10.3, 21.28, 21.35, 34.51,
34.71, 125.92, 126.22, 126.69, 126.78, 127.65, 127.89, 128.25, 128.39,
128.45, 129.86, 129.98, 130.07, 130.12, 130.31, 130.57, 132.03, 132.26,
133.54, 134.43, 134.55, 134.87, 136.77, 139.01, 139.61, 140.74, 140.77,
141.56, 146.6, 172.9, 174.8, 179.2; IR (thin film) 2123.3 cmꢀ1 [ν(CO)].
[(Cl-Cyc)PdMe(CO)]þ (15d). H NMR (500 MHz, CD2Cl2) δ
1
1.03 (s, 3H), 2.87ꢀ3.21 (m, 8H), 6.27 (d, 2H, J = 7.9 Hz), 6.41 (d, 2H,
J = 7.8 Hz), 6.52 (d, 2H, J = 7.9 Hz), 6.75 (d, 2H, J = 7.8 Hz), 6.83 (d, 1H,
J = 7.3 Hz), 6.97 (d, 2H, J = 7.7 Hz), 6.99ꢀ7.05 (m, 4H), 7.13ꢀ7.18 (m,
3H), 7.43 (s, 3H), 7.46 (s, 3H), 7.68ꢀ7.78 (m, 2H, partially obscured by
BAFꢀ), 8.25 (d, 1H, J = 8.3 Hz), 8.28 (d, 1H, J = 8.2 Hz); 13C NMR (125
MHz, CD2Cl2) δ 10.7, 34.46, 34.66, 125.55, 126.42, 126.88, 127.48,
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dx.doi.org/10.1021/om200193r |Organometallics 2011, 30, 2432–2452