The catalytic cycle for the Cativa process, shown above, begins with the reaction of methyl iodide with the square planar active catalyst species ( "'1 "') to form the octahedral iridium ( III ) species ( "'2 "'), the hydrolysed to produce the acetic acid product, in the process generating hydroiodic acid which is in turn used to convert the starting material ( methanol ) to the methyl iodide used in the first step.
