Open AccessSubstituent-Induced Control of fac/mer Isomerism in Azine-NHC Fe(II) Complexes
Author(s) -
Ulises Carrillo,
Antonio FrancésMonerris,
Anil Reddy Marri,
Cristina Cebrián,
P. Gros
Publication year - 2022
Publication title -
acs organic and inorganic au
Language(s) - English
Resource type - Journals
ISSN - 2694-247X
DOI - 10.1021/acsorginorgau.2c00038
Subject(s) - azine , steric effects , zonal and meridional , chemistry , carbene , stereochemistry , selectivity , ligand (biochemistry) , denticity , crystallography , substituent , medicinal chemistry , crystal structure , catalysis , organic chemistry , biochemistry , receptor , atmospheric sciences , geology
The stereoselective synthesis of geometrical iron(II) complexes bearing azine-NHC ligands is described. Facial and meridional selectivity is achieved as a function of the steric demand of the azine unit, with no remarkable influence of the carbene nature. More specifically, meridional complexes are obtained upon selecting bulky 5-mesityl-substituted pyridyl coordinating units. Unexpectedly, increase of the steric hindrance in the α position with respect to the N coordinating atom results in an exclusive facial configuration, which is in stark contrast to the meridional selectivity induced by other reported α-substituted bidentate ligands. Investigation of the structure and the optical and electrochemical properties of the here-described complexes has revealed the non-negligible effect of the fac / mer ligand configuration around the metal center.