Towards the mechanism of heteroborane isomerisation: 1,2 → 1,2 and 1,2 → 1,7 low-temperature isomerisations from metallations of [5-I-7,8-Ph2-7,8-nido-C2B9H8]2−

Five isomerised nickelacarboranes and platinacarboranes carrying (iodide) labelled boron vertices have been prepared and characterised. The structures found are discussed in terms of a triangle face rotation mechanism.