A novel platinum methylene complex

The dichlorobridged diplatinum organyls 4 and 5 undergo the expected chlori ne-iodine exchange when treated with lithium iodide in diiodomethylene. Sur prisingly, a second type of product, the triple-bridged (one methylene grou p 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 o f 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 pr ocess, however, is not yet clear. The molecular structures of 7 and 8 are b ased on an X-ray crystal analysis of 7 and on their comparable characterist ic NMR data. (C) 1999 Elsevier Science S.A. All rights reserved.