Synthesis, Characterization, and Olefin/CO Exchange Reactions of Copper(I) Derivatives Containing Bidentate Oxygen Ligands

New hexafluoroacetylacetonate (hfacac) and trifluoroacetato olefin complexes of copper(I) of the general formulas Cu(hfacac)(olefin) and Cu(CF 3 COO)(olefin) have been prepared from Cu 2 O/hfacacH/olefin or Cu(CF 3 COO)(toluene) 0.5 /olefin systems. The structures of [Cu(hfacac)(coe)], [Cu(hfacac)(van)], [Cu(μ - CF 3 COO)(tbve)] n, and [Cu(μ - CF 3 COO)(van)] 2 ·C 7 H 8 have been determined by X-ray diffraction methods, where coe = cyclooctene, van = 4-vinylanisole, and tbve = tert -butyl vinyl ether. In the solid state, the 4-vinylanisole/trifluoroacetate complex [Cu(CF 3 COO)(van)] 2 is dimeric with two carboxylato groups symmetrically bridging two copper atoms, while the tert -butyl vinyl ether derivative [Cu(μ - CF 3 COO)(tbve)] n is polymeric with single [CF 3 COO] - bridges between adjacent copper atoms. Olefin hfacac complexes are monomeric, and considering the two oxygen atoms and the midpoint of the double bond of the coordinated olefin, the copper atom lies in a nearly trigonal-planar environment. The carbonylation reactions of Cu(CF 3 COO)(olefin), (olefin = tbve, van; 2Cu(CF 3 COO)(olefin) + 2CO ⇆ [Cu(CF 3 COO)(CO)] 2 + 2(olefin)) and of Cu(hfacac)(olefin) (olefin = coe, 1,5-cyclooctadiene (cod), norbornene (nbe), van; Cu(hfacac)(olefin) + CO ⇆ Cu(hfacac)(CO) + olefin) have been studied gas volumetrically, and the equilibrium constants for the displacement of the coordinated olefin by carbon monoxide have been determined at different temperatures. Some hypotheses on the copper−olefin bond have been formulated on the basis of structural, thermodynamic and spectroscopic ( 13 C NMR) data.