Yttrium tris(trimethylsilylmethyl) complexes grafted onto MCM-48 mesoporous silica nanoparticles.

A series of tris(trimethylsilylmethyl) yttrium donor adduct complexes was synthesized and fully characterized by X-ray diffraction, 1 H/ 13 C/ 29 Si/ 31 P/ 89 Y heteronuclear NMR and FTIR spectroscopies as well as elemental analyses. Treatment of Y(CH 2 SiMe 3 ) 3 (thf) x with various donors Do led to complete (Do = TMEDA, DMAP) and partial displacement of THF (Do = NHC i Pr , DMPE). Exceptionally large 89 Y NMR shifts to low field were observed for the new complexes. Complexes Y(CH 2 SiMe 3 ) 3 (tmeda) and Y(CH 2 SiMe 3 ) 3 (dmpe)(thf) were chosen to perform surface organometallic chemistry, due to a comparatively higher thermal stability and the availability of the 31 P nucleus as a spectroscopic probe, respectively. Mesoporous nanoparticles of the MCM-48-type were synthesized and used as a 3 rd generation silica support. The parent and hybrid materials were characterized using X-ray powder diffraction, solid-state-NMR spectroscopy, DRIFTS, elemental analyses, N 2 -physisorption, and scanning electron microscopy (SEM). The presence of surface-bound yttrium alkyl moieties was further proven by the reaction with carbon dioxide. Quantification of the surface silanol population by means of HN(SiHMe 2 ) 2 -promoted surface silylation is shown to be superior to titration with lithium alkyl LiCH 2 SiMe 3 .