Synthesis and properties of donor-free bis(difluoromethyl)cadmium, (CF2H)(2)Cd - NMR spectroscopic detection and structure of tetrakis(difluoromethyl)cuprate(III) and related compounds

The reaction of CdR(2) (R = Me, Et) with CF2HI has been investigated. Insertion of difluorocarbene into Cd-C bonds with formation of 1,1-difluoroethyl, 1,1-difluoropropyl and tetrafluoroethyl derivatives is described. Metathesis of CF2HI with CdEt(2) in non-coordinating solvents gives very reactive, unsolvated (CF2H)(2)Cd in quantitative yield. Spectroscopic and chemical properties are reported. Adducts have been obtained by addition of donors such as diglyme or TMEDA. Partial F vs. Cl exchange with acetyl chloride converts the CF2H group to CFHCl derivatives. Reaction of (CF2H)(2)Cd with CuCl leads to the formation of thermally unstable (difluoromethyl)copper(I) species, 'Cu(CF2H)' and [Cu(CF2H)(2)](theta). Disproportionation of the cuprate(I) or its oxidation by I-2 or O-2 gives the cuprate(III) anion, [Cu-III(CF2H)(4)](theta), which is stable in water and air. The crystal structure of [PNP][Cu(CF2H)(4)] has been determined. Mixed difluoromethyl/trifluoromethyl cuprates have been prepared from (CF3)(2)Cu(S(2)CNEt(2)) and (CF2H)(2)Cd in order to verify the square-planar arrangement of substituents by NMR spectroscopy. Identification of compounds was achieved by multinuclear NMR spectra. NMR parameters are discussed.