The synthesis of di(vinyl)chlororhodium dimers was first reported by Cramer, Richard in Inorganic
Chemistry, 1,722-3, where they dissolved RhCl3-(H2O)X in methanol and then passed it through
ethylene gave an orange-red powder product in about 70% yield. Since then Inorganic Syntheses, 28, 86-8 reported in the literature.
Inorganic Syntheses, 28,86-8, they reported their improved method, in which the product was filtered out after the first passage of ethylene, and the acidity was adjusted by the addition of sodium hydroxide before the second passage of ethylene from the mother liquor, and the total amount was reduced to about 70%.
Sodium hydroxide was added to the mother liquor before the second passage of ethylene to adjust the acidity, increasing the total yield to 75% and the reaction time to more than 7 hours. People mostly synthesize di(ethylene)chlororhodium dimer by this method.
