A novel platinum methylene complex

The dichlorobridged diplatinum organyls 4 and 5 undergo the expected chlorine–iodine exchange when treated with lithium iodide in diiodomethylene. Surprisingly, a second type of product, the triple-bridged (one methylene group plus two iodo units between the two Pt atoms) diplatinum complexes 7 and 8, respectively, are also formed in these unusual reactions. The formation of these latter two interesting, novel compounds takes place via a change of configuration of their two ligand sections from anti of their precursors (4 and 5, respectively) to syn present in 7 and 8; the mechanism of this process, however, is not yet clear. The molecular structures of 7 and 8 are based on an X-ray crystal analysis of 7 and on their comparable characteristic NMR data.