Synthesis of single component element‐block materials based on siloxane‐based cage frameworks

This mini‐review focuses on recent efforts to prepare single component element‐block materials based on siloxane‐based cage frameworks, a promising approach to control the sequence of organic and inorganic segments in organic–inorganic hybrids at the molecular level. Polyhedral octasilsesquioxanes, denoted (RSiO1.5)8 or labeled T8 cages, and octadimethylsiloxy‐Q8 cages, denoted (RSiMe2OSiO1.5)8, are used here as siloxane‐based cage frameworks. Thermoplastic optically transparent silsesquioxane materials derived from a single cage compound can be obtained with dumbbell‐ and star‐shaped cage structures, allowing precise design of their structures for tuning properties. The siloxane‐based cage core dendrimers are ideal candidates for single component element‐block materials which possess three‐dimensional, well‐defined molecular level structures. Their rigid and cubic inorganic frameworks provide unique features for siloxane‐based cage core dendrimers. These topics attract attention in both academia and industry.