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Switching the Electron‐Donating Ability of Phosphines through Proton‐Responsive Imidazolin‐2‐ylidenamino Substituents
Author(s) -
Mehlmann Paul,
Dielmann Fabian
Publication year - 2019
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.201805540
Subject(s) - phosphine , protonation , substituent , chemistry , proton , ligand (biochemistry) , selectivity , transition metal , metal , catalysis , combinatorial chemistry , medicinal chemistry , organic chemistry , ion , biochemistry , physics , receptor , quantum mechanics
Stimuli‐responsive ancillary ligands are valuable tools to control the activity and selectivity of transition‐metal catalysts. The synthesis and characterization of a series of metal complexes containing phosphines with proton‐responsive imidazolin‐2‐ylidenamino substituents are reported. Determination of the ligand‐donor properties revealed that protonation of each substituent increases the Tolman electronic parameter (TEP) of the phosphine by 22 cm −1 , hence allowing for switching of the electron‐donor power of phosphine 2 within an unprecedented range (ΔTEP=43.4 cm −1 ).