Premium
Between T and Y: Asymmetry in the Interaction of LAu(I) with Bipy and β‐Diiminate‐like Ligands
Author(s) -
Cataffo Andrea,
Haas Titus,
Ehm Christian,
Budzelaar Peter H. M.
Publication year - 2021
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.202000929
Subject(s) - chemistry , denticity , phosphine , stereochemistry , ligand (biochemistry) , imine , chelation , bipyridine , phenanthroline , asymmetry , crystallography , medicinal chemistry , crystal structure , inorganic chemistry , organic chemistry , catalysis , biochemistry , physics , receptor , quantum mechanics
Abstract The combination of an LAu(I) fragment with a potentially chelating ligandL'^L'can result in different coordination modes ofL'^L': strictly monodentate, symmetrically bidentate, or intermediate with asymmetric bidentate binding ofL'^L'. Density Functional calculations indicate that for π‐acceptor ancillary ligands L (C 2 H 4 , CO) and bis(nitrogen) donorsL'^L'(bipyridine, phenanthroline, β‐diiminate) symmetric chelate structures are obtained. With primarily σ‐donating ancillary ligands L (Me − , Cl − , MeCN) the asymmetric coordination mode is the norm. Phosphine ancillary ligands L are on the edge and display the highest sensitivity to ligand variation. Asymmetry increases when (a) going from anionic (β‐diiminate) to neutral (bipyridine, phenanthroline) bidentatesL'^L'; (b) makingL'^L'less electron‐rich e. g. through having aryl instead of alkyl groups at N or through introduction of CF 3 substituents. Inversion of the asymmetry through “gold hopping” is remarkably facile (barrier mostly <6 kcal/mol, often ∼1 kcal/mol). The high‐temperature fluxionality reported for two (PPh 3 )Au(β‐diiminate) complexes is tentatively assigned to imine inversion (rather than gold hopping) as the rate‐limiting step.