Synthesis, Characterization, and Syndio‐Specific Styrene Polymerization of Pyrrolyl‐Substituted Cyclopentadienyl Scandium Complexes

Abstract

Acid‐base reaction of Sc(CH2C6H4NMe2‐o)3 with 1 equiv. of pyrrolyl‐substituted cyclopentadienyl ligand C4H2Me2NSiMe2C5Me4H in toluene gave the half‐sandwich scandium bis(aminobenzyl) complex (C4H2Me2NSiMe2C5Me4)Sc(CH2C6H4NMe2‐o)2 (2). Amine elimination between Sc[N(SiHMe2)2]3(THF) and one equivalent of C4H2Me2NSiMe2C5Me4H afforded the scandium bis(silylamide) complex (C4Me2H2NSiMe2C5Me4)Sc[(NSiHMe2)2SiMe2](THF) (3). Both scandium complexes 2 and 3 were characterized by elemental analysis, NMR spectroscopy, and single‐crystal X‐ray diffraction. 2 and 3 could serve as highly active precursors for styrene polymerization to give syndio‐tactic polystyrene (rrrrrr > 99 %).

Synthesis and photophysical properties of rare earth complexes bearing silanediamido ligands Me2Si(NAryl)22− (Aryl = Dipp, Mes)

“…The literature describes the formation of RE complexes bearing bis(amido)silane ligands in some specific reactions, such as a b-hydride shift followed by the elimination of dimethylsilane in dimethylsilanediamido complexes [RE(LBulk)(N(SiHMe 2 ) 2 ) 2 ] (LBulk = bulky chelating ligand, such as scorpionate), 32,33 or elimination of PhSiH 3 from bis(aryl(silyl)amido) complex [Yb(N(Terph)SiH 2 Ph) 2 ] (Terph = bulky terphenyl substituent). 34 More typical approaches include acid-base reactions of the protonated form of a ligand, H 2 L (proligand), with the RE alkyls, 18 or metathesis reactions of alkali metal (A) salt A 2 [R 0 2 Si(NR) 2 ] with RE halides.…”