Methylaluminium‐stabilisierte Seltenerdmetalldihydride

Rare‐Earth‐Metal Methyl, Amide, and Imide Complexes Supported by a Superbulky Scorpionate Ligand

“…The 89 Y NMR resonances of 5 a and 6 a are shifted to lower field than that of [{Y(NMes*)(AlMe 4 )} 2 ]13b and experience a high‐field shift relative to the hydride complex [(Tp t Bu,Me )Y(NC 6 H 3 Me 2 ‐2,6)(HAlMe 2 )] (Table 1). 10f Due to the paramagnetic behavior of Ho III , the 1 H NMR spectra of 1 b , 2 b , 5 b , and 6 b were not conclusive.…”

“…In both complexes, the coordination geometry around the lanthanide metal center is best described as distorted trigonal bipyramidal. Typically for related five‐coordinate complexes, the Tp t Bu,Me ligand adopts the commonly observed κ 3 ‐coordination mode;10f the axial LuN distances are longer than those of the equatorial ones. Overall, the LnN(pz) (pz=pyrazolyl) bond lengths in 3 (2.347(2)–2.506(2) Å) and 4 (2.343(2)–2.531(2) Å) are slightly longer than in the respective precursor 2 c (2.339(2)–2.483(2) Å); this is attributable to the increased steric bulk of the amido ligands and nicely shows that the ancillary ligand easily adapts to the given steric requirements.…”

“…Superbulky and chelating ligands such as anionic tris(3‐R,5‐R′‐pyrazolyl)borate (referred to as Tp R,R′ , Trofimenko’s scorpionate) not only stabilize reactive rare‐earth‐metal hydrides10 and hydrocarbyls,10c, 11 but also dianionic bridging ligand fragments in [LnX], such as methylidenes (X=CH 2 ),11a imides (X=NR),10f and phosphinidenes (X=PR) 12. Previous studies from our group on the reactivity of methylaluminum‐supported rare‐earth‐metal dihydrides allowed the isolation of discrete imide complexes.…”

“…Previous studies from our group on the reactivity of methylaluminum‐supported rare‐earth‐metal dihydrides allowed the isolation of discrete imide complexes. More precisely, the reaction of [(Tp t Bu,Me )Ln(HAlMe 3 ) 2 ] with 2,6‐dimethylaniline afforded complete deprotonation, resulting in the formation of complexes [(Tp t Bu,Me )Ln(NC 6 H 3 Me 2 ‐2,6)(HAlMe 2 )] (Ln=Y, Lu), which contained bridging hydrido and imido moieties 10f. Organoaluminum‐assisted deprotonation of primary amines has already been proven as a viable strategy for the synthesis of rare‐earth‐metal imide complexes (cf., C , Figure 1).…”

“…Organoaluminum‐assisted deprotonation of primary amines has already been proven as a viable strategy for the synthesis of rare‐earth‐metal imide complexes (cf., C , Figure 1). 7b, 10f, 13 Herein, distinct reaction patterns of rare‐earth‐metal tetramethylaluminate and (aluminum‐free) dimethyl complexes are presented.…”