Glycerol is converted to a mixture of butyric and isobutyric acid by rhodium- or iridium-catalysed carbonylation using HI as the co-catalyst. The initial reaction of glycerol with HI results in several intermediates that lead to isopropyl iodide, which upon carbonylation forms butyric and isobutyric acid. At low HI concentration, the intermediate allyl iodide undergoes carbonylation to give vinyl acetic acid and crotonic acid. Higher polyols C_nH_n+2(OH)_n are carbonylated to the corresponding C_n+1 mono-carboxylic acids.

A series of cationic cis-dicarbonylrhodium(I) complexes [Rh(L)(CO)₂]SbF₆ has been prepared containing 2,2′-bipyridine ligands with proximate H-bonding substituents R in the 6- and 6′-position (R = OH, NH₂, COOEt and PO(OEt)₂). The solid-state structures have been determined by X-ray crystallography for the complexes where R = OH, NH₂ and COOEt. The molecular structures have revealed metal–metal and π–π interactions between the square-planar complexes resulting in the formation of molecular chains in the solid state. IR studies on the reaction of [Rh(bipy)(CO)₂]SbF₆ with MeI have shown the formation of a neutral complex [RhI(CO)(bipy)], which undergoes oxidative addition of MeI much faster than the cationic complex [Rh(bipy)(CO)₂]⁺. Although all complexes show good activities for the carbonylation of methyl acetate, this is believed to be due to their instability and the formation of [RhI₂(CO)₂]^– under the reaction conditions.

A series of iron(II) bis(triflate) complexes [Fe(L)(OTf)₂] containing linear tetradentate bis(pyridylmethyl)diamine ligands with a range of ligand backbones has been prepared. The backbone of the ligand series has been varied from a two-carbon linkage [ethylene (1), 4,5-dichlorophenylene (2) and cyclohexyl (3)] to a three-carbon [propyl (4)) and a four-carbon linkage (butyl (5)]. The coordination geometries of these complexes have been investigated in the solid state by X-ray crystallography and in solution by ¹H and ¹⁹F NMR spectroscopy. Due to the labile nature of high-spin iron(II) complexes in solution, dynamic equilibria of complexes with different coordination geometries (cis-α, cis-β and trans) are observed with ligands 2–5. In these cases, the geometry observed in the solid state does not necessarily represent the only or even the major geometry present in solution. The ligand field strength in the various complexes has been investigated by variable temperature magnetic moment measurements and UV-vis spectroscopy. The strongest ligand field is observed with the most rigid ligands 1 and 2, which generate complexes [Fe(L)(OTf)₂] with a cis-α coordination geometry and the corresponding complexes [Fe(L)(CH₃CN)₂]²⁺ display spin crossover behaviour. The catalytic properties of the complexes for the oxidation of cyclohexane, using hydrogen peroxide as the oxidant, have been investigated. An increased flexibility in the ligand results in a weaker ligand field, which increases the lability of the complexes. The activity and selectivity of the catalysts appear to be related to the strength of the ligand field and the stability of the catalyst in the oxidising environment.