1,3-Dimethyl-4-(diphenylphosphino)imidazolium Triflate: A Functionalized Ionic Liquid with Ambivalent Coordination Capability

Simply
using 1-methylimidazole as the starting material, the functionalized
ionic liquid 1,3-dimethyl-4-(diphenylphosphino)­imidazolium triflate
([3]­OTf) has been prepared, from which the corresponding
4-phosphino-substituted N-heterocyclic carbene 4 was
generated. The coordination capability of 3 and 4 toward a variety of transition-metal centers has been studied,
as well as their electron-donor character through an evaluation of
the TEP parameter. 3 behaves as a cationic phosphine
ligand, whereas 4 shows a strong preference to coordinate
to transition metals through the carbene carbon atom, leading to the
obtention of mononuclear complexes with a free phosphine arm which
act as metalloligands, allowing for the modular formation of homo-
and heterodinuclear transition-metal complexes.