Table 2. Reaction with Ethylene 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 Cocatalystsa.
| PEc |
oligomer (C4–C22)f |
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| run | V(NR)Cl2(L), R (μmol) | Al cocat. | Al/Vb | wt % | yield/mg | activityd | TOFe/h–1 | activityd | TOFe/h–1 | C4–C22g total | C4g/wt % | C6g/wt % | C8g/wt % | otherh/wt % |
| 1 | Ad (0.5) | MAO | 500 | 16.7 | 9.6 | 115 | 4100 | 574 | 20 500 | 68.1 | 30.5 | 15.8 | 11.8 | 15.1 |
| 2 | Ad (0.5) | MAO | 1000 | 23.7 | 13.8 | 165 | 5890 | 532 | 19 000 | 66.4 | 26.6 | 15.2 | 9.8 | 10.0 |
| 3 | Ad (0.5) | MAO | 2000 | 22.0 | 11.2 | 134 | 4780 | 476 | 17 000 | 64.5 | 26.0 | 14.8 | 9.5 | 13.3 |
| 4 | Ad (0.2) | MAO | 500 | 29.5 | 7.7 | 231 | 8220 | 434 | 15 500 | 55.6 | 20.1 | 15.5 | 9.2 | 14.9 |
| 5 | Ad (0.2) | MAO | 1000 | 28.4 | 8.7 | 261 | 9290 | 534 | 19 000 | 58.3 | 20.5 | 15.9 | 10.6 | 13.2 |
| 6 | Ad (0.2) | Me2AlCl | 1250 | >99 | 311 | 9320 | 332 000 | |||||||
| 7 | Ad (0.2) | Me2AlCl | 2500 | >99 | 327 | 9790 | 349 000 | |||||||
| 8 | C6H5 (0.2) | MAO | 1000 | 49.5 | 7.6 | 228 | 8110 | 232 | 8290 | 30.7 | 12.5 | 7.9 | 6.7 | 19.8 |
| 9 | Ar (0.2) | MAO | 500 | 96.1 | 102 | 3050 | 109 000 | 124 | 4420 | 1.9 | 1.0 | 0.2 | 0.6 | 2.0 |
| 10 | Ar (0.2) | MAO | 1000 | 93.1 | 109 | 3270 | 117 000 | 244 | 8700 | 3.9 | 2.1 | 1.2 | 0.5 | 3.1 |
a
Conditions: ethylene 8 atm, toluene 30 mL, 25 °C, 10 min.
b
Al/V molar ratio.
c
Isolated as MeOH/HCl insoluble portion; details are shown in the Experimental Section.
d
Activity in kg-ethylene reacted/mol-V·h [also kg-PE/mol-V·h].
e
TOF = (molar amount of ethylene reacted)/(mol-V·h).
f
Oligomer (analyzed by GC and CHCl3 extracted portion); details are shown in the Experimental Section.
g
Oligomer (C4–C22 fraction) analyzed by GC vs internal standards.
h
Wax fraction (isolated as CHCl3 soluble fraction after pouring the mixture into MeOH/HCl).