Monometallic and mixed-valence bimetallic Rh(I/III) complexes: Synthesis, structure, electrochemistry and application in 1-octene hydroformylation

Two mononuclear rhodium complexes, Rh(I)-1,5-cyclooctadiene and Rh(III)-pentamethylcyclopentadienyl, and a bimetallic Rh(I)-Rh(III) mixed-valence complex were synthesised. The complexes were fully characterised using an array of analytical techniques which included NMR and infrared spectroscopy, single-crystal X-ray diffractometry, elemental analysis, and mass spectrometry. These complexes were evaluated as catalyst precursors in the hydroformylation of olefins. All catalyst precursors were active in the hydroformylation of 1-octene under optimised conditions. The rhodium complexes generally showed chemoselectivity towards the formation of linear aldehydes. The electrochemical behaviour of the rhodium complexes was examined using cyclic voltammetry.