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A Cyclometalated NHC Iridium Complex Bearing a Cationic (η 5 ‐Cyclopentadienyl)(η 6 ‐phenyl)iron Backbone **
Author(s) -
Malchau Christian,
Milbert Tom,
Eger Tobias R.,
Fries Daniela V.,
Pape Pascal J.,
Oelkers Benjamin,
Sun Yu,
Becker Sabine,
Prosenc Marc H.,
NiednerSchatteburg Gereon,
Thiel Werner R.
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202102520
Subject(s) - cyclopentadienyl complex , hexafluorophosphate , chemistry , iridium , cationic polymerization , medicinal chemistry , imidazole , substituent , iodide , polymer chemistry , inorganic chemistry , stereochemistry , catalysis , organic chemistry , ionic liquid
Nucleophilic substitution of [(η 5 ‐cyclopentadienyl)(η 6 ‐chlorobenzene)iron(II)] hexafluorophosphate with sodium imidazolate resulted in the formation of [(η 5 ‐cyclopentadienyl)(η 6 ‐phenyl)iron(II)]imidazole hexafluorophosphate. The corresponding dicationic imidazolium salt, which was obtained by treating this imidazole precursor with methyl iodide, underwent cyclometallation with bis[dichlorido(η 5 ‐1,2,3,4,5‐pentamethylcyclopentadienyl]iridium(III) in the presence of triethyl amine. The resulting bimetallic iridium(III) complex is the first example of an NHC complex bearing a cationic and cyclometallated [(η 5 ‐cyclopentadienyl)(η 6 ‐phenyl)iron(II)] + substituent. As its iron(II) precursors, the bimetallic iridium(III) complex was fully characterized by means of spectroscopy, elemental analysis and single crystal X‐ray diffraction. In addition, it was investigated in a catalytic study, wherein it showed high activity in transfer hydrogenation compared to its neutral analogue having a simple phenyl instead of a cationic [(η 5 ‐cyclopentadienyl)(η 6 ‐phenyl)iron(II)] + unit at the NHC ligand.