Yttrium Complexes with Group 13 Heterobenzene‐Type Ligands

Abstract

AbstractThe yttrium gallabenzene complex [(1‐Me‐3,5‐tBu2−C5H3Ga)(μ‐Me)Y(2,4‐dtbp)] is accessible from Y(GaMe4)3 and K(2,4‐dtbp) via a tandem salt metathesis/methane elimination (2,4‐dtbp=2,4‐di‐tert‐butyl‐pentadienyl). The pentadienyl ligand in [(1‐Me‐3,5‐tBu2−C5H3E)(μ‐Me)Y(2,4‐dtbp)] (E=Al, Ga) is easily displaced by salt metathesis with KC5Me5 and KTpMe,Me (TpMe,Me=tris(pyrazolyl‐Me2‐3,5)borato) affording [(1‐Me‐3,5‐tBu2−C5H3E)(μ‐Me)Y(TpMe,Me)] and [(1‐Me‐3,5‐tBu2−C5H3E)(μ‐Me)Y(C5Me5)]. The yttrium center in [(1‐Me‐3,5‐tBu2−C5H3E)(μ‐Me)Y(2,4‐dtbp)] readily forms adducts with neutral Lewis bases like 4‐DMAP (4‐dimethylaminopyridine), PMe3, DMPE (1,2‐bis(dimethylphosphino)ethane), and DME (1,2‐dimethoxyethane). In stark contrast, addition of TMEDA (N,N,N’,N’‐tetramethylethylenediamine) results in methyl/pentadienyl exchange between aluminum and yttrium resulting in [(1‐(2,4‐dtbp)‐1‐Me‐3,5‐tBu2−C5H3Al)Y(Me)(tmeda)]. The bonding features of the newly synthesized complexes are analyzed by single‐crystal X‐ray diffraction (SCXRD) and heteronuclear (89Y, 31P) NMR spectroscopy.