Synthesis of pentafluorophenyl silver by means of lewis acid catalysis: Structure of silver solvent complexes

Article abstract of DOI:10.1021/om901063a

The synthesis and structure of lithium, and silver tetrakis(pentafluorophenyl)borate salts have been studied in different solvents ranging from polar (CH₂Cl₂, diethyl ether) to nonpolar (toluene, pentane). While Li[B(C₆F₅)₄]is stable in all studied, solvents and crystallizes with four ether molecules from ether and with two toluene molecules from toluene, the silver salt, is only stable when the Ag⁺ ion is strongly coordinated such as in [Ag(toluene) ₃][B(C₆F₅)₄] or [Ag(Et ₂O)₃][B(C₆F₅)₄]. Li weakly coordinating solvents such as CH₂Cl₂ Ag[B(C ₆F₅)₄] decomposes, yielding AgC ₆F₅ and B(C₆F₅)₃. The overall process of the AgC₆F₅ synthesis starting from B(C₆F₅)3 and LiC₆F₅ can formally be regarded as a B(C₆F₅)₃-catalyzed reaction. The salt [Ag(toluene)₃][B(C₆F₅)₄] presents an easily accessible, ether-free, stable silver salt of the [B(C ₆F₅)₄]^-anion. All compounds have been fully characterized.