Rhodium-Catalysed Carbonylation of Methanol Using a New Multifunctional Ligand - Isolation and Structural Characterisation of the Macrocycle [Rh₂I₆(CO)₂(C₆H₄N₃CH₂CO₂C₄H₂SCO₂CH₂C₆H₄N₃)]₂

The new multifunctional ligand thiophene-2,5-bis(carboxylatomethylenebenzotriazole) (<b>1</b>) reacts with [RhCl(CO)₂]₂ to give the rhodium complex [RhCl(CO)(<b>1</b>)]₂ (<b>2</b>), which was found to catalyse efficiently the iodide-mediated carbonylation of methanol. The macrocyclic carbonyliodorhodium complex [Rh₂I₆(CO)₂(<b>1</b>)]₂ (<b>3</b>) was isolated from the catalytic mixture and structurally characterised.