A polycyclosilane precursor was synthesized to develop soluble silicon materials and silicon thin films with optical properties at 193 nm, high silicon content, and etch selectivity for O₂ and CF_x plasmas. A new class of polycyclosilane–polysiloxane hybrid materials and their thin films exhibited good etch selectivity and good optical properties at 193 nm without organic absorbents.

The sol–gel polymerization of alkoxysilanes is a convenient and widely used method for the synthesis of silicon polymers and silicon–organic composites. The development of new sol–gel precursors is very important for obtaining new types of sol–gel products. New condensation polymer precursors containing consecutive silicon atoms—decaisopropoxycyclopentasilane (CPS) and dodecaethoxyneopentasilane (NPS)—were synthesized for the preparation of polysilane–polysiloxane material. The CPS and NPS xerogels were prepared by the sol–gel polymerization of CPS and NPS under three reaction conditions (acidic, basic and neutral). The CPS and NPS xerogels were characterized using N₂ physisorption measurements (Brunauer–Emmett–Teller; BET and Brunauer-Joyner-Halenda; BJH), solid-state CP/MAS (cross-polarization/magic angle spinning) NMRs (nuclear magnetic resonances), TEM, and SEM. Their porosity and morphology were strongly affected by the structure of the precursors, and partial oxidative cleavage of Si-Si bonds occurred during the sol–gel process. The new condensation polymer precursors are expected to expand the choice of approaches for new polysilane–polysiloxane.

Binding constants between polycyclic aromatic hydrocarbons (PAHs) and tetranuclear rutheno macrocycles are successfully manipulated via covalent post-assembly modification (PAM).