A spherosilicate oligomer with eight stable silanol groups as a building block of hybrid materials

摘要: Diphenylsilylated double four-membered ring (D4R) spherosilicate possessing eight stable silanol groups ((R1R2(HO)SiO)8Si8O12, R1 and R2 = Ph: PP(OH)-D4R) has been synthesized by silylation of D4R silicate ([Si8O12]8−) with chloroethoxydiphenylsilane (ClSi(OEt)Ph2) followed subsequent hydrolysis. PP(OH)-D4R solid is air for at least 1 week. Ethoxymethylphenylsilylated ethoxydimethylsilylated oligomers (R1R2(EtO)SiO)8Si8O12, Me Ph abbreviated as MP(OEt)-D4R MM(OEt)-D4R) do not provide spherosilicates eventually gel (MP(OEt)-D4R-G MM(OEt)-D4R-G, respectively) hydrolyzed solutions dry. This suggests that bulky phenyl effectively stabilize terminal silanols. Although the silanols are stable, they can be trimethylsilylated or condensed to form Si–O–Si bonds thermal-treatment. on a glass substrate cross-links upon heating. The structural periodicity distance between units in heat-treated sample higher longer than those MP(OEt)-D4R-G MM(OEt)-D4R-G due steric effects groups. Additionally, silica-based derived from also possesses molecularly ordered structure mixture Si(OEt)4 Ph2Si(OEt)2. means building block approach efficient preparing hybrid materials. new will useful preparation various materials such metallosilicates mesostructured