Double-decker silsesquioxanes have gained a high reputation in many branches of chemistry and process development. In particular, catalytic processes that convert double-decker silsesquioxanes into important functional classes of fine chemicals are a central topic of contemporary organosilicon chemistry. Although the 9,19-di(hydro)octaphenyl double-decker silsesquioxane (DDSQ-2SiH) is known, we report its cis and trans structure and X-ray structure for the first time. The combination of DDSQ-2SiH in a known hydrosilylation reaction protocol with precise reaction time control (FT-IR in situ apparatus) allowed us to selectively assemble a series of previously unreported molecular double-decker silsesquioxanes with ethyl bridged π-conjugated arenes. These compounds were used as a molecular model to obtain their respective macromolecular hybrid analogues. The obtained compounds were characterized spectroscopically and their thermal parameters were also verified.

Synthesis and characterization of new, molecular DDSQ-based compounds functionalized by substituted styrenes (also with heteroatoms) in a stereoselective manner is presented. Additionally, a novel class of vinylene-arylene linear copolymers with double-decker silsesquioxane fragments in the main chain is developed. These molecular and macromolecular compounds were synthesized via efficient and highly stereoselective silylative coupling (and copolycondensation) and cross-metathesis (and ADMET) reactions.