Table 3. Ethylene Polymerization Using V(NR)Cl2(L) [R = Ad (1), C6H5 (2), and Ar (3, Ar = 2,6-Me2C6H3); L = 2-(2′-Benzimidazolyl)-6-methylpyridine] in the Presence of Al Alkyl Cocatalystsa,f.
| run | V(NR)Cl2(L), R (μmol) | Al cocat. | Al/Vb | ETA/Vc | time/min | yield/mg | activityd | TOFe/h–1 (s–1) |
|---|---|---|---|---|---|---|---|---|
| 6 | Ad (0.2) | Me2AlCl | 1250 | 0 | 10 | 311 | 9320 | 332 000 (92) |
| 7 | Ad (0.2) | Me2AlCl | 2500 | 0 | 10 | 327 | 9790 | 349 000 (97) |
| 11 | Ad (0.1) | Me2AlCl | 2500 | 0 | 10 | 221 | 13 300 | 472 000 (131) |
| 12 | Ad (0.1) | Me2AlCl | 2500 | 0 | 6 | 143 | 14 300 | 508 000 (141) |
| 13 | Ad (0.1) | Me2AlCl | 5000 | 0 | 6 | 265 | 26 500 | 946 000 (263) |
| 14 | Ad (0.05) | Me2AlCl | 5000 | 0 | 6 | 108 | 21 700 | 773 000 (215) |
| 15 | Ad (0.05) | Me2AlCl | 10 000 | 0 | 6 | 278e | 55 700 | 1 990 000 (553) |
| 16 | Ad (0.05) | Me2AlCl | 10 000 | 10 | 6 | 155 | 31 000 | 1 110 000 (308) |
| 17 | Ad (0.05) | Me2AlCl | 10 000 | 50 | 6 | 234 | 46 700 | 1 670 000 (464) |
| 18 | Ad (0.05) | Me2AlCl | 10 000 | 100 | 6 | 410 | 82 000 | 2 930 000 (814) |
| 19 | Ad (0.05) | Me2AlCl | 10 000 | 1000 | 6 | 269 | 53 700 | 1 920 000 (533) |
| 20 | C6H5 (0.05) | Me2AlCl | 5000 | 0 | 6 | 400 | 80 100 | 2 850 000 (792) |
| 21 | C6H5 (0.05) | Me2AlCl | 10 000 | 0 | 6 | 332 | 66 400 | 2 370 000 (658) |
| 22 | C6H5 (0.05) | Et2AlCl | 10 000 | 0 | 6 | 7.3 | 1460 | 52 000 (14.5) |
| 23 | C6H5 (0.5) | Et2AlCl | 100 | 0 | 6 | 127 | 2540 | 90 700 (25.2) |
| 24 | C6H5 (0.5) | Et2AlCl | 1000 | 0 | 6 | 73.7 | 1470 | 52 400 (14.6) |
| 25 | C6H5 (0.05) | AliBu3 | 5000 | 0 | 6 | trace | ||
| 26 | C6H5 (0.5) | AliBu3 | 100 | 0 | 6 | trace | ||
| 27 | C6H5 (0.05) | AlEt3 | 5000 | 0 | 6 | trace | ||
| 28 | C6H5 (0.5) | AlEt3 | 100 | 0 | 6 | trace | ||
| 29 | Ar (0.1) | Me2AlCl | 2500 | 0 | 6 | 299 | 29 900 | 1 070 000 (297) |
| 30 | Ar (0.1) | Me2AlCl | 5000 | 0 | 6 | 186 | 18 600 | 662 000 (184) |
| 31 | Ar (0.05) | Me2AlCl | 5000 | 0 | 6 | 106 | 21 100 | 753 000 (209) |
| 32 | Ar (0.05) | Me2AlCl | 2000 | 0 | 6 | 178 | 35 700 | 151 000 (42) |
| 33 | Ar (0.05) | Me2AlCl | 1000 | 0 | 6 | 117 | 23 400 | 834 000 (232) |
a
Conditions: ethylene 8 atm, toluene 30 mL, 25 °C, 10 min.
b
Al/V molar ratio.
c
ETA = Cl3CCO2Et (molar ratio).
d
Activity in kg-PE/mol-V·h.
e
TOF = (molar amount of ethylene reacted)/(mol-V·h).
f
Melting temperature at 136 °C by DSC thermogram (shown in the Supporting Information).