SYNTHESIS AND CHARACTERIZATION OF TRIMETALLIC COMPLEXES [ETA(5)-RC5H4(CO)3E]2HG (E=CR, MO, W R=ME, ET, N-BU) - CRYSTAL-STRUCTURE OF [ETA(5)-ETC5H4(CO)3CR]2HG

The synthesis of six linear trimetallic compounds of the type [eta5-RC 5H4 (CO)3E]2Hg (E = Cr, Mo, W; R = Me, Et, n-Bu), from phenylmercuric chloride and corresponding transition metal lithium salts [eta5-RC5H4( CO)3E]Li is described. The new compounds were characterized by element al analysis, MS, IR and H-1 NMR spectroscopy and the structure of [eta 5-EtC5H4(CO)3Cr]2Hg as determined by X-ray diffraction. The Cr-Hg-Cr s keleton of the molecule is diagonal with some departure from linearity and the coordination geometry around each chromium atom approximates to a square-based pyramid with one substituted cyclopentadienyl ring o ccupying the apical position.