Mono- and bimetallic gold(I) and silver(I) pentafluoropropionates and related compounds

A series of eight new carboxylate complexes of the general type (L)nMOC(O)R (L=PMe3; n=1; M=Ag, Au; R=C2F5. L=PPh3; n=1–3; M=Ag; R=C2F5, t-Bu) have been prepared in high yields. Crystal and molecular structures have been determined for three representative examples. The crystal structure of (Ph3P)AgOC(O)C2F5 contains dimers in which the silver atoms are bridged by the carboxylate oxygen atoms. This bridging resembles the structural motif found in silver carboxylates without ligand support. Usage of the smaller phosphine PMe3 leads to the formation of a polymeric chain structure in (Me3P)AgOC(O)C2F5 with bridging carboxylate anions and short Ag–Ag contacts holding the monomers together. The reaction of (4-Me2N-C6H4)Ph2 PAuCl with two equivalents of C2F5CO2Ag leads to the formation of a mixed metal product containing both gold and silver. The crystal structure analysis of this compound revealed a tetranuclear complex containing a central dimeric silver pentafluoropropionate unit which is chelated by the (triarylphosphine)gold(I) pentafluoropropionate molecules via Ag–Au metallophilic contacts and Ag–O donor/acceptor interactions.