Organosilicon Amine Gels Based on 3-Aminopropyltriethoxysilane, Cobalt(II) or Chromium(III) Clorides, and Triethoxysilane

Abstract

Organosilicon gels [Co(NH2R2)2Cl2] and [Cr(NH2R2)3Cl3], containing a diaminodichloride complex of cobalt(II) and triaminotrichloride complex of chromium(III) (R2 = CH2CH2CH2SiO(OEt)), were synthesized by the hydrolysis of complexes [Co(NH2R1)2Cl2] (I) and [Cr(NH2R1)3Cl3] (II) incorporating peripheral triethoxysilyl groups (R1 = CH2CH2CH2Si(OEt)3). The coprecipitated [Co(NH2R2)2Cl2] · 4NH2R3, [Cr(NH2R2)3Cl3] · 6NH2R3, [Co(NH2R2)2Cl2] · 2SiO2, and [Cr(NH2R2)3Cl3] ·xSiO2 · (3 – x )SiHO1.5 (R3 = CH2CH2CH2SiO1.5) gels were obtained by cohydrolysis of complexes I and II with 3-aminopropyltriethoxysilane or triethoxysilane. Interaction with SiH(OEt)3 is accompanied by the decomposition of silicon hydride groups and the formation of tetraethoxysilane derivatives. The heating of dry gels in a flow of argon or oxygen to 600°С results in the formation of amorphous silica having a specific surface area 2–467 m2/g and containing crystalline metals, their chlorides, oxides, silicates, or carbides.