Investigation of the Reactivity of Hydroxyborate Salts with Group IV Metal Complexes: Synthesis and Structural Characterization of the Zirconium and Hafnium Ionic Complexes [PPN]⁺[Cp₂MMe(OB(C₆F₅)₃)]⁻

The syntheses of some novel fluorinated and nonfluorinated hydroxyborate salts, [Q]+[HOB(C6F5)3]− and [Q]+[HOBPh3]− ([Q]+ = aprotic cation), are reported. The reactivities of both salts with group IV metal complexes were compared. The reaction of [PPN]+[HOB(C6F5)3]− ([PPN]+ = bis(triphenylphosphoranylidene)ammonium) with Cp2ZrMe2 and Cp2HfMe2 resulted in the formation of the ionic complexes [PPN]+[Cp2ZrMe(OB(C6F5)3)]− and [PPN]+[Cp2HfMe(OB(C6F5)3)]− in high yields. These complexes were fully characterized, and the covalent characteristics of the M–O and B–O bonds were established by X-ray crystallographic structural determination.