LINEAR OLIGONUCLEAR METAL-METAL MULTIPLE BONDS. Shie-Ming Peng*, Shen-Jye Shieh, Cheng-Chen Lin, Jinn-Tsair Sheu, Chin-Cheng Chou, Gene-Hsiang Lee Department of Chemistry National Taiwan University Taipei Taiwan, R.O.C

The nature of metal-metal bonding in dinuclear metal complexes is well understood. The extension of dinuclear metal complexes to oligonuclear metal-chain complexes is rare.

The bis(2-pyridyl)amido ligand (dpa) in the syn-syn conformation allows each nitrogen atom to coordinate with a separate metal ions forming metal-metal multiple bonds. e.g. the triruthenium(II) complex, [Ru₃(dpa)₄Cl₂], exhibits a three-centred triple bond among the three ruthnium ions (Ru-Ru, 2.2537(5) Å). The structure and magnetic interaction of quadruply bridged trinuclear metal complexes [M^II₃(u₃-dpa)₄X₂]deg. (M = Ru^II, Rh^II, co^II, Ni^II; X = Cl^-, NCS^- etc) are discussed. The work of further extension to tpda and tpda ligands wil1 be presented.