Asymmetric bis-PNP pincer complexes of zirconium and hafnium – a measure of hemilability

Abstract

Asymmetrically-bound pyrrolide-based bis-PNP pincer complexes of zirconium and hafnium have been formed. The [κ²-PNP^Ph][κ³-PNP^Ph]MCl₂ species are in direct contrast to previous zirconium PNP pincer complexes. The pincer ligands are fluxional in their binding and the energy barrier for exchange has been approximated using VT-NMR spectroscopy and the result validated by DFT calculations.