Hydrosilylation in the 2D interlayer space between inorganic layers: Reaction between immobilized C=C groups on the interlayer surface of layered perovskite HLaNb₂O₇·x H₂O 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)₃ O- 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)₃ O- 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·xH ₂O 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.