Effect of polycyclosilane microstructure on thermal properties

Abstract

Thermal characterization of polysilanes has focused on the influence of organic side chains, whereas little is understood about the influence of silane backbone microstructure on thermal stability, phase properties, and pyrolysis.

Highly selective addition of cyclosilanes to alkynes enabling new conjugated materials

“…Our group is interested in the synthesis and properties of (macro)molecular mimics of crystalline silicon and we have described new approaches to the selective synthesis of materials based on cyclohexasilanes. We reported the ve-step synthesis and chemoselective polymerization of the cyclohexasilane building blocks 1,4Si 6 and 1,3Si 6 , [16][17][18][19][20][21] as well as the seven-step stereocontrolled synthesis of cis-and trans-Si 10 H 4 (Fig. 1).…”

Poly(cyclosilane) Connectivity Tunes Optical Absorbance

“…Monohydrosilanes are inert to dehydrocoupling polymerization, indicating that macrocyclization of a 1,3Si 6 block would terminate polymerization by removing reactive SiH 2 groups from the polymerization medium. Finally, the thermal properties of the copolymers were similar to linear homopolymers, as determined by differential scanning calorimetry (DSC, Figure S4).…”

“…Prior work has shown that lin -poly­( 1,4Si 6 ) and cyc -poly­( 1,3Si 6 ) were bathochromically shifted relative to their respective monomers (Table ), but experimental and computational comparison of the homopolymers was not reported. The optical properties of lin -poly­( 1,3Si 6 ) have not previously been described in any form …”

“…The metal-catalyzed dehydrogenative coupling of hydrosilanes promised greater functional group tolerance than Wurtz polymerization, , leading to the design and synthesis of the bifunctional cyclosilane monomers 1,4Si 6 and 1,3Si 6 (Scheme ). In earlier reports, we described the structural characterization of the linear and cyclic poly­(cyclosilane)­s arising from 1,4Si 6 and 1,3Si 6 dehydropolymerization, − as well as the effect of poly­(cyclosilane) microstructure on thermal properties …”

Isolation of a Cyclopentasilane from Magnesium Reduction of a Linear Hexasilane

“…[15] Towards the goal of uncovering new nanostructured materials that combine these compelling properties with the processability and tunability of organic conjugated polymers, we reported the synthesis of organosilicon polymer mimics of the crystalline silicon lattice such as polycyclosilane poly(1,4Si 6 ) (Scheme 1a). [16] Key to this work is the synthesis of multifunctional cyclosilanes [17,18] amenable to dehydrocoupling [19][20][21][22][23] or reductive polymerization. [24] The rational design and synthesis of new building blocks could further expand the structural and functional diversity of polycyclosilanes and other nanostructured silanes.…”