Potential precursors for terminal ytterbium(ii) imide complexes bearing the hydrotris(3-tert-butyl-5-methylpyrazolyl)borato ligand

Abstract

Monomeric, divalent ytterbium primary amides TptBu,MeYb(NHR)(thf)x (R = C6H3iPr2-2,6 = AriPr = Dipp, C6H3(CF3)2-3,5 = ArCF3, SiPh3) supported by the bulky tris(3-tBu-5-Me-pyrazolyl)borato scorpionate ligand are synthesized acccording to salt metathesis...

Terminal dysprosium and holmium organoimides

“…18 Less surprising, terminal imides of the extremely large divalent rareearth-metal centres have remained elusive. 19 Common features of all terminal rare-earth-metal imides, reported so far, are that the imido ligand is derived from a substituted aniline, H 2 NAr R (R = iPr, Me, CF 3 ), and an indispensable kinetic stabilization by use of sterically demanding ancillary co-ligands. Aliphatic amines, benzylic amines, and silylamines engage in imido ligand formation as well but have been detected only as metal-bridging and Lewis acid stabilized versions.…”

“… 18 Less surprising, terminal imides of the extremely large divalent rare-earth-metal centres have remained elusive. 19 …”

Lanthanide Amide Complexes Supported by the Bis‐tris(pyrazolyl)borate Ligand Environment

“…[14] The smaller unsubstituted hydrotris(1-pyrazolyl)borate (Tp) ligand can be utilised to overcome this steric limitation, and the Ln(III) complexes [Ln(Tp) 2 (N'')] (Ln = Y, Yb) were reported recently. [15] The primary lanthanide Ln(II) amide complexes with one Tp R ancillary ligand, [Ln(Tp tBu,Me )(NHR)(do) x ] (Ln = Sm, Eu, Yb; R = Dipp or C 6 H 3 i Pr 2 -2,6, Ar Me or C 6 H 3 Me 2 -2,6, Ar CF3 or C 6 H 3 (CF 3 ) 2 -3,5, SiPh 3 ; do = THF; x = 0, 1, or 2), [16] the Ln(III) complexes [Lu-(Tp tBu,Me )(NHR)(CH 3 )] (R = t Bu, adamantyl) [17] and [Y-(Tp*)(NHR)(CH 2 Ph)(THF)] (R = Ph, Dipp) [18] have been reported. In the case of the putative Tm(II) [Tm(Tp tBu,Me )(NHC 6 H 3 (2,5-t Bu 2 ))], dinitrogen activation was observed.…”