First experimental evidence for a bis-ethene chromium(I) complex forming from an activated ethene oligomerization catalyst
Abstract
A bis-ethene chromium(I) species, which is the postulated key intermediate in the widely accepted metallacyclic mechanism for ethene oligomerization, is experimentally observed. This catalytic transformation is an important commercial route to linear α-olefins (primarily, 1-hexene and 1-octene), which act as comonomers for the production of polyethene. Here, electron paramagnetic resonance studies of a catalytic system based on [Cr(CO)4(PNP)][Al(OC(CF3)3)4] [PNP = Ph2PN(iPr)PPh2] activated with Et6Al2 provide the first unequivocal evidence for a chromium(I) bis-ethene complex. The concentration of this species is enhanced under ethene and isotope labeling studies that confirm its composition as containing [Cr(C2H4)2(CO)2(PNP)]+. These observations open a new route to mechanistic studies of selective ethene oligomerization.
Citation
Chabbra , S , Smith , D M , Bell , N L , Watson , A J B , Buehl , M , Cole-Hamilton , D J & Bode , B E 2020 , ' First experimental evidence for a bis-ethene chromium(I) complex forming from an activated ethene oligomerization catalyst ' , Science Advances , vol. 6 , no. 51 , eabd7057 . https://doi.org/10.1126/sciadv.abd7057
Publication
Science Advances
Status
Peer reviewed
ISSN
2375-2548Type
Journal article
Description
Funding: This work was supported by Sasol Ltd. SC is grateful for a St Leonard’s postgraduate fellowship by the University of St Andrews.Collections
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