Bridged Transition Metal Cluster Derivatives and Their Precursor

MERCURY-BRIDGED TRANSITION METAL CLUSTER DERIVATIVES AND THEIR PRECURSOR 

Submitted by EDWARD ROSENBERG AND BRUCE NOVAK Checked by W. EDWARD L1NDSELU 

Transition metal complexes with mercury directly bound to one or two transition metal centers are well known.1 They have found use as relatively air-stable sources of carbonyl metallate anions in polar solvents and as intermediates in the syntheses of bimetallic transition metal complexes. They are probably the key intermediates in the many transition metal promoted 

There are three important routes to the formation of the mercury-transition metal bond (a) displacement of halogen or pseudohalogen from mercury(II) salts with carbonyl metallate anions (b) reaction of a halo-phenylmercury compound with a transition metal hydride and (c) oxidative addition of a mercury halide to neutral zero valent metals.1 We report here the syntheses of three compounds containing three-centre, two-electron, mercury-ruthenium bonds utilizing trinuclear cluster anions and mercury(II) halides.2-4 

The procedures for the syntheses presented here are representative and are general for a variety of transition metal cluster and mononuclear anions. 

The reactivities of these compounds have yet to be compared in detail with those of the mononuclear analogs, but some preliminary results from our laboratories are summarized here. Substitution of up to three carbonyl ligands by triphenylphosphine can be accomplished by simple thermolysis with [Ru3( 3-K / -C2-t-Bu) (CO)9]2 Substitution of phosphine for 

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