Postfunctionalization of periodic mesoporous silica SBA-1 with magnesium(II) and iron(II) silylamides

Magnesium silylamide complexes Mg[N(SiHMe2)(2)](2)(THF)(2) and Mg[N(SiPhMe2)(2)](2) were synthesized according to transsilylamination and alkane elimination protocols, respectively, utilizing Mg[N(SiMe3)(2)](2)(THF)(2) and [Mg(n-Bu)](2) as precursors. Cage-like periodic mesoporous silica SBA-1 was treated with donor solvent-free dimeric [Mg{N(SiHMe2)(2)}(2)](2), [Mg{N(SiMe3)(2)}(2)](2) and monomeric Mg[N(SiPhMe2)(2)](2), producing hybrid materials [Mg(NR2)(2)]@SBA-1 with magnesium located mainly at the external surface. Consecutive grafting of [Mg{N(SiHMe2)(2)}(2)](2) and [Fe-II{N(SiHMe2)(2)}(2)](2) onto SBA-1 led to heterobimetallic hybrid materials which exhibit complete consumption of the isolated surface silanol groups, evidencing intra-cage surface functionalization. All materials were characterized by DRIFT spectroscopy, nitrogen physisorption and elemental analysis.