Synthesis, characterization and bioinspired reactivity of metal complexes by fluorinated hydrotrispyrazolylborate and dihydrobispyrazolylborate ligands

Using fluorinated hydrotrispyrazolylborate (Tp) ligand, we have synthesized a series of copper(I) complexes, including a copper(I) dimer (with TpCF3,CH3) and the first structurally characterized mononuclear copper(I)-acetone complex (with TpCF3,CF3). Bioinspired reactivity of CH₂Cl₂ solution of both complexes towards dioxygen and ethylene has been studied. The first room-temperature reversible oxygen binding was achieved by the copper-TpCF3,CH3 system, which behaved as a functional model for hemocyanin (Hc). The dicopper(II) side-on (or μ-η2:η2) peroxo complexes with TpCF3,CH3 and TpCF3,CF3 were isolated as unusual room-temperature stable solid, and fully characterized. Resonance Raman data showed increased fluorination of Tp ligand resulted in stronger O-O bond in these dicopper(II) peroxo complexes. Two stable copper(I)-ethylene complexes were synthesized as the models for the ethylene-binding sites in plants. Fluorination on Tp ligand increases the σ-donation from ethylene to copper(I), but decreases the π-backdonation from copper(I) to ethylene. Since σ-donation is dominant in copper(I)-ethylene complexes, copper(I) fluorinated-Tp ethylene complexes are more stable than the nonfluorinated analog.; Manganese and cobalt complexes with fluorinated Tp ligands were synthesized and compared with their nonfluorinated analog. Some copper complexes with fluorinated dihydrobispyrazolylborate (Bp) ligands were synthesized and characterized, including a copper(I)-cyclohexene complex with BpCF3,CF3 ligand.