Multiple studies have explored using cage silsesquioxanes (SQs) as backbone elements in hybrid polymers motivated by their well-defined structures and physical and mechanical properties. As part of this general exploration, we report unexpected photophysical properties of copolymers derived from divinyl double decker (DD) SQs, [vinyl(Me)Si-(O 0.5 ) 2 ][PhSiO 1.5 ] 8 [(O 0.5 ) 2 Si(Me)vinyl] (vinylDDvinyl). These copolymers exhibit strong emission red-shifts relative to model compounds, implying unconventional conjugation, despite vinyl(Me)Si(O-) 2 siloxane bridges. In an effort to identify minimum SQ structures that do/do not offer extended conjugation, we explored Heck catalyzed co-polymerization of vinyl-ladder(LL)-vinyl compounds, vinyl(Me/Ph)Si(O 0.5 ) 2 -[PhSiO 1.5 ] 4 (O 0.5 ) 2 Si(Me/Ph)vinyl, with Br-Ar-Br. Most surprising, the resulting oligomers show 30-60 nm emission redshifts beyond those seen with vinylDDvinyl analogs despite lacking a true cage. Further evidence for unconventional conjugation includes apparent integer charge transfer (ICT) between LL-co-thiophene, bithiophene, and thienothiophene with 10 mol % F 4 TCNQ, suggesting potential as p-type doped organic/inorganic semiconductors.

PurposeSilsesquioxanes with well-de ned structures have been of great interest recently because of their superior properties. Among them, laddersiloxanes (ladder-type silsesquioxanes with de ned structure) were less explored because step-by-step synthesis is usually necessary. In order to investigate the properties of laddersiloxane, and apply these compounds to the monomers of high function materials, we prepared laddersiloxanes with reactive vinyl groups. MethodsThe target compounds were obtained in a two-step reaction from commercially available alkoxysilanes, and total yields were good. Three stereoisomers included in the products were fully investigated by spectroscopic methods and structures were determined. ResultsAs an extension of our previous research of constructing new laddersiloxanes, here we will describe the synthesis, characterization, and functionalization of novel divinyl-substituted laddersiloxanes. Further transformation of all products proceeded smoothly, and extended laddersiloxanes were obtained by hydrosilylation. One of the isomers was isolated and the structure was determined unequivocally by X-ray analysis. ConclusionThe laddersiloxanes described here have two reactive vinyl groups at each end of the molecule. Various reactions including hydrosilylation, polymerization, or ole n metathesis are possible, thus these compounds can be potential monomers for highly functionalized materials.

Multiple studies have explored using cage silsesquioxanes (SQs) as backbone elements in hybrid polymers motivated by their well-defined structures and physical and mechanical properties. As part of this general exploration, we report unexpected photophysical properties of copolymers derived from divinyl double decker (DD) SQs, [vinyl(Me)Si-(O 0.5 ) 2 ][PhSiO 1.5 ] 8 [(O 0.5 ) 2 Si(Me)vinyl] (vinylDDvinyl). These copolymers exhibit strong emission red-shifts relative to model compounds, implying unconventional conjugation, despite vinyl(Me)Si(O-) 2 siloxane bridges. In an effort to identify minimum SQ structures that do/do not offer extended conjugation, we explored Heck catalyzed co-polymerization of vinyl-ladder(LL)-vinyl compounds, vinyl(Me/Ph)Si(O 0.5 ) 2 -[PhSiO 1.5 ] 4 (O 0.5 ) 2 Si(Me/Ph)vinyl, with Br-Ar-Br. Most surprising, the resulting oligomers show 30-60 nm emission redshifts beyond those seen with vinylDDvinyl analogs despite lacking a true cage. Further evidence for unconventional conjugation includes apparent integer charge transfer (ICT) between LL-co-thiophene, bithiophene, and thienothiophene with 10 mol % F 4 TCNQ, suggesting potential as p-type doped organic/inorganic semiconductors.