Easy and environmentally friendly synthesis method for T8H (HSiO3/2)8.

Environmentally friendly methods for the synthesis of T₈^H were developed. A combination of triethoxysilane (TES), concentrated HCl aqueous solution, and FeCl₃ produced T₈^H with almost the same yield as the previously known methods. We also found that HNO₃ could be used instead of HCl, resulting in a similar yield. No toxic gases were generated during the reaction with HNO₃. Additionally, the synthesis of T₈^H based on TES did not generate dangerous substances such as hydrogen chloride and methanol, unlike when trichlorosilane or trimethoxysilane are used. Therefore, our new method for the synthesis of T₈^H is considered to be safer, although the yield is the same as the conventional methods. [ABSTRACT FROM AUTHOR]