Tungsten binuclear complexes

Some alkynylcarbyne tungsten complexes containing the anion of (34) have been synthesized these constitute good starting compounds for chain extension and for the synthesis of binuclear complexes with an odd number of bridging carbon atoms. The high thermal stability of the... 

With the Ru dimers, [ Ru(bpy)2 2(M-L)], ESR data indicate that these binuclear semiquinone complexes are near the borderline between anion radical complexes and metal-centered mixed-valence species/ The thermal reaction between [W(CO)6] and tetrachloro-l,2-benzoquinone in toluene produces the tris(quinone) tungsten complex/ Features of the molecule indicate that the quinones are coordinated as catecholate ligands and the tungsten ions are in a formal +6 oxidation state. Quinones trapped within a polymeric electrode film can act as electron sinks and/or sources. IJ/I and [FeCCN) ] " " have been utilized as charge-release mediators. 

In 1980 we published a survey (1) of our major results in this area as of late 1979. These results include extensive work on binuclear CF N PF complexes of cobalt (2,3,4,5) and nickel (6). This paper summarizes our more recent results in this area with particular emphasis on binuclear complexes of chromium, molybdenum, and tungsten as well as some new results on iron carbonyl derivatives. 

Figure 11. Scheme showing synthetic routes to mono- and binuclear bis(dithiolene)tungsten(IV) and (V) complexes from [W(CO)2(S2C2R2)2] (R = Me or Ph) (83, 85-87). 

Molecular wires, 208 211 in which two metal centers are connected by an unsupported C3 chain, as in compound 191, have been generated by addition of BF3 to binuclear bridged (l-alkynyl)carbene complex lw (Scheme 80).27 29,212 Similar compounds were derived from tungsten, rhenium, and iron moieties. A binuclear complex 192 containing a C5 bridge has been also obtained 27... 

Tungsten-Re and W-Ir binuclear carbene complexes as well as cluster carbene complexes are prepared via acylation-alkylation of the corresponding carbonyl compounds. 

Chiral binuclear carbene complexes of the Fischer type were synthesized utilizing (/ ,/ )-l-(l-dimethylaminoethyl)-2-lithioferrocene (296). The lithiated precursor reacts with tungsten hexacarbonyl to give a bimetallic acylate, CpFe 7j -2-C5H3 C(Me)HNMe2 C(OLi)W(CO)5 (109t),... 

Tungsten(vi) forms afew oxo complexes,e.g., WOF5, W02F , W02C12 and WO3F2" these are not binuclear, but some bent oxo-bridged complex ions are known, e.g., the peroxo species... 

Reaction of 1 with the metal carbonyls of chromium, molybdenum, and tungsten in dimethylformamide (DMF) gives air-stable, binuclear complexes of t5q>e [(COlsMLMCCOls] (9). These proved to be useful starting species for generating (via oxidative decarbonylation reac-... 

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