LIGAND-STABILIZED COPPER(I) HEXAFLUOROACETYLACETONATE COMPLEXES - NMR-SPECTROSCOPY AND THE NATURE OF THE COPPER ALKENE BOND

Ligand-stabilized copper(I) hexafluoroacetylacetonate complexes display varying degrees of stability to oxidation and thermal decomposition. In an effort to understand the nature of the copper-alkene bond in these complexes better, H-1 and C-13 nuclear magnetic resonance spectra were obtained and compared to the spectra of the free alkene. In accord with Dewar-Chatt-Duncanson theory, the extent of pi and sigma-bonding contributions can be qualitatively determined by the observed chemical shift changes upon complexation of the alkene to the copper(I) center.