Publication
Article Metrics
Citations
Online attention
Activation and Deactivation of a Robust Immobilized Cp*Ir-Transfer Hydrogenation Catalyst: A Multielement
DOI:
10.1021/ja512868a
Authors:
Grant J.
Sherborne
(University of Leeds)
,
Michael
Chapman
(University of Leeds)
,
A. John
Blacker
(University of Leeds)
,
Richard
Bourne
(University of Leeds)
,
Thomas
Chamberlain
(University of Nottingham)
,
Benjamin D.
Crossley
(Yorkshire Process Technology Ltd.)
,
Stephanie J.
Lucas
(University of Leeds)
,
Patrick C.
Mcgowan
(University of Leeds)
,
Mark
Newton
(European Synchrotron Radiation Facility)
,
Thomas E. O
Screen
(Yorkshire Process Technology Ltd)
,
Paul
Thompson
(University of Liverpool)
,
Charlotte E.
Willans
(University of Leeds)
,
Bao
Nguyen
(University of Leeds)
Co-authored by industrial partner:
Yes
Type:
Journal Paper
Journal:
Journal Of The American Chemical Society
, VOL 137 (12)
State:
Published (Approved)
Published:
March 2015
Diamond Proposal Number(s):
8071
Open Access
Abstract: A highly robust immobilized [Cp*IrCl2]2 precatalyst on Wang resin for transfer hydrogenation, which can be recycled up to 30 times, was studied using a novel combination of X-ray absorption spectroscopy (XAS) at Ir L3-edge, Cl K-edge, and K K-edge. These culminate in in situ XAS experiments that link structural changes of the Ir complex with its catalytic activity and its deactivation. Mercury poisoning and hot filtration experiments ruled out leached Ir as the active catalyst. Spectroscopic evidence indicates the exchange of one chloride ligand with an alkoxide to generate the active precatalyst. The exchange of the second chloride ligand, however, leads to a potassium alkoxideiridate species as the deactivated form of this immobilized catalyst. These findings could be widely applicable to the many homogeneous transfer hydrogenation catalysts with Cp*IrCl substructure.
Subject Areas:
Chemistry,
Technique Development
Instruments:
B18-Core EXAFS
Other Facilities: BM28, ESRF