2 research outputs found
Pentacoordinated Rhodium(I) Complexes Supported by Coumarin-Functionalized <i>N</i>‑Heterocyclic Carbene Ligands
New coumarin-tethered
benzimidazolium (BzICou<sup>R</sup>HCl) and
imidazolium (ICou<sup>R</sup>HCl) salts have been prepared as precursors
for coumarin–NHC rhodium(I) complexes RhCl(NHC)(cod). Trigonal
bypiramidal pentacoordinated bis-coumarin–NHC rhodium(I) species,
RhCl(NHC)<sub>2</sub>, can be obtained by heating rhodium-cod derivatives
in the presence of coumarin–azolium salts and a base. These
unusual species are stabilized by coordination of the unsaturated
bond of both coumarin moieties by the same enantioface. The allyl
substituent on doubly functionalized NHC competes for coordination
with coumarin wingtips. DFT calculations upon coordination of the
olefin moieties support the experimental results
Pentacoordinated Rhodium(I) Complexes Supported by Coumarin-Functionalized <i>N</i>‑Heterocyclic Carbene Ligands
New coumarin-tethered
benzimidazolium (BzICou<sup>R</sup>HCl) and
imidazolium (ICou<sup>R</sup>HCl) salts have been prepared as precursors
for coumarin–NHC rhodium(I) complexes RhCl(NHC)(cod). Trigonal
bypiramidal pentacoordinated bis-coumarin–NHC rhodium(I) species,
RhCl(NHC)<sub>2</sub>, can be obtained by heating rhodium-cod derivatives
in the presence of coumarin–azolium salts and a base. These
unusual species are stabilized by coordination of the unsaturated
bond of both coumarin moieties by the same enantioface. The allyl
substituent on doubly functionalized NHC competes for coordination
with coumarin wingtips. DFT calculations upon coordination of the
olefin moieties support the experimental results