[(1,2,5,6-η)-Cyclo-octa-1,5-diene](1-ethyl-3-isopropyl-1,3-imidazol-2-yl-idene)(tri-phenyl-phosphane)rhodium(I) tetra-fluorido-borate.

A new N -heterocyclic cationic rhodium(I) complex with a tetra-fluorido-borate counter-anion, [Rh(C 8 H 14 N 2 )(C 8 H 12 )(C 18 H 15 P)]BF 4 , has been prepared and structurally characterized. The cationic complex exhibits a distorted square-planar environment around the rhodium(I) ion. Two connections are made from rhodium(I) to the carbon atom of an N -heterocylic carbene ligand and to the phospho-rus atom of a tri-phenyl-phosphane ligand. The remaining two coordination sites are made via a bidentate inter-action from the two olefinic bonds of cyclo-octa-diene to the rhodium(I) ion. The compound includes an out-sphere tetra-fluorido-borate counter-anion. Within the crystal of the compound exist several weak inter-molecular C-H⋯F inter-actions.