Synthesis and structural characterization of stable coinage metal (Cu, Ag, Au) cyclopentadienyl complexes

Abstract

The electron withdrawing and oxidatively stable perfluorinated Cp* ligand [C₅(CF₃)₅]⁻ allowed for the isolation of rare and unusually stable coinage metal complexes [M(C₅(CF₃)₅)(P^tBu₃)] (M = Cu, Ag, Au), representing the first complete and structurally comparable series of group 11 Cp coordination compounds. Full characterization and structure analysis revealed distinct and partly unknown coordination motifs with hapticities ranging from η¹, η³/η¹ and η³/η² for gold, silver and copper, respectively. Quantum-chemical studies using DFT methods confirm these findings and connect them to the unique electronic structure of the given ligand system.