Supramolecular Polymer and Sheet and a Double Cubane Structure in Platinum(IV) Iodide Chemistry: Solution of a Longstanding Puzzle

The complexes [PtMe2(L)], L = 2-C5H4NCH2NH-x-C6H4OH (x = 2, 3, or 4), react with iodine to form [PtI2Me2(L)], by trans oxidative addition, when x = 3 or 4, and they are shown to have polymeric or sheet structures formed through NH···I hydrogen bonding. However, ligand dissociation occurs when x = 2 to give [(PtI2Me2)n] and, with methyl group transfer, the complex [(PtIMe3·PtI2Me2)2]. This tetraplatinum cluster complex is shown to have a double cubane structure, thus solving a longstanding puzzle.