Hydrosilylation in the 2D interlayer space between inorganic layers: reaction between immobilized CC groups on the interlayer surface of layered perovskite HLaNb2O7·xH2O and chlorohydrosilanes

The CC bonds immobilized in the interlayer space of layered perovskite, HLaNb2O7·xH2O, have undergone hydrosilylation reactions with chlorohydrosilanes. The CC bonds are immobilized by the reaction between an n-propoxyl derivative of HLaNb2O7·xH2O and 4-penten-1-ol to form a CH2CH(CH2)3O derivative of HLaNb2O7·xH2O, and a corresponding increase in the interlayer distance from 1.54 to 1.85 nm is observed. The CH2CH(CH2)3O derivative is further treated with dichloromethylsilane or trichlorosilane, and the interlayer distance increases to 2.41 (dichloromethylsilane) or 2.07 (trichlorosilane) nm. Solid-state 13C-CP/MAS-NMR spectroscopy and infra-red (IR) spectroscopy reveal that the CC groups disappear after the treatment with dichloromethylsilane or trichlorosilane, and 13C-NMR signals assignable to the hydrosilylated products are clearly observed. Besides hydrosilylation reactions, siloxane formation involving hydrolysis of the SiCl groups also proceeds. The structure of the perovskite-like slabs in HLaNb2O7·xH2O is preserved throughout the process, indicating the successful modification of immobilized CC groups via hydrosilylation with no structural change in the inorganic host layers.