Abstract
For the first time, a Cr(acac)3/PNP mixture (PNP = Ph2PN(i-Pr)PPh2) and a [(PNP)CrC12(,U-CI)12 complex were monitored by in situ EPR in cyclohexane and toluene, respectively, during oligomerization of ethylene. For Cr(acac)3/PNP, Cr 3 + reduction is faster than low-spin Cr+ formation, suggesting that the major active species is EPR-silent, possibly an antiferromagnetic Cr+ dimer and/or Cr 21 Fast decomposition of [(PNP)CrC12(U-CI)12 to [Cr07 6 -CH3C6H5)21-+- is a probable reason for low activity.
Original language | English |
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Pages (from-to) | 3849-3856 |
Number of pages | 8 |
Journal | Organometallics |
Volume | 27 |
Issue number | 15 |
DOIs | |
Publication status | Published - 11 Aug 2008 |
Keywords
- TETRAMERIZATION
- TRIMERIZATION
- COMPLEXES
- ACTIVATION
- PHOSPHINE
- OLEFIN
- LIGAND