In:
Angewandte Chemie International Edition, Wiley, Vol. 54, No. 16 ( 2015-04-13), p. 4857-4860
Abstract:
The typical activation of a fourth generation Ziegler–Natta catalyst TiCl 4 /MgCl 2 /phthalate with triethyl aluminum generates Ti 3+ centers that are investigated by multi‐frequency continuous wave and pulse EPR methods. Two families of isolated, molecule‐like Ti 3+ species have been identified. A comparison of the experimentally derived g tensors and 35,37 Cl hyperfine and nuclear‐quadrupole tensors with DFT‐computed values suggests that the dominant EPR‐active Ti 3+ species is located on MgCl 2 (110) surfaces (or equivalent MgCl 2 terminations with tetra‐coordinated Mg). O 2 reactivity tests show that a fraction of these Ti sites is chemically accessible, an important result in view of the search for the true catalyst active site in olefin polymerization.
Type of Medium:
Online Resource
ISSN:
1433-7851
,
1521-3773
DOI:
10.1002/anie.201412052
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
2011836-3
detail.hit.zdb_id:
123227-7
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