Structural Diversity of Silver Fluorinated β-Diketonates: Effect of the Terminal Substituent and Solvent.

In order to demonstrate the role of the fluorination and some solvents in the structural organization of the Ag(I) coordination polymers with β-diketonate ligands (RC(O)CHC(O)R) we synthesized a series of the compounds containing tfac- (R = CH, R = CF) and pfpac- (R = CH, R = CF) anions. Solvent-free [Ag(L)] (L = tfac , pfpac ) compounds and the corresponding acetonitrile and toluene adducts have been characterized by elemental analysis and/or NMR, IR and single-crystal XRD. This series includes five new coordination polymers. Compound is a 3D coordination framework based on Ag-O, Ag-C bonds, and argentophilic interactions. An increase in the fluorinated group leads to a chain coordination polymer of an unusual structural organization. These chains can be represented as a "DNA-type", where two intertwined helices based on Ag-O and Ag-C bonds are connected through Ag-O ones. Two structural types of chain coordination polymers, [Ag(tfac)(CHCN)] and [Ag(L)(solvent)], have been revealed for the adducts. The latter structural type differs significantly from the previously studied toluene and acetonitrile adducts of fluorinated Ag(I) β-diketonates of the same stoichiometry. Thermal analysis in helium showed that both and decompose to metallic silver with the compound of pfpac-ligand being slightly more stable.