Poly[bis(ethylglycoxypropyl)silylene]s and poly[n-alkyl-(ethylglycoxy)silylene]s and their higher homologues, 1. Monomer synthesis and polymerization

Abstract

SUMMARY Dichlorosilanes with ethyloligoglycoxypropyl substituents were synthesized from dichlorosilane and the respective allyl compounds. Wurtz-type coupling reaction led to a series of ether substituted polysilylenes with a distinct amphiphilic character. Formation of high molecular weight polymers becomes increasingly difficult as the length of the ether substituents is increased.

Novel design, facile synthesis and low infrared emissivity properties of single-handed helical polysilanes

“…In order to eliminate the interference aroused by PDHS homopolymer fraction, PDHS mixed with HPS-1 and HPS-3 at the weight ratio of 1 : 1 were measured additionally. In line with literature, the DSC curves showed the combined thermal property of both proportions and immiscibility induced by crystallization, 17 disclosing the absence of PDHS homopolymer.…”

“…Thus, functional groups like methoxycarbonyl and ether can be employed in preparing functional polysilanes as well. [16][17][18][19][20] The addition of unsaturated group C]O makes the synthesis of HPS meaningful. Moreover, due to the chiral structure of functional group, lactic acid-based polymers exhibit excellent optical and physical properties.…”

Multihydroxy-Functional Polysilanes via an Acetal Protecting Group Strategy

“…The hydrosilylation product was purified by fractional distillation, which was difficult due to the formation of side products at elevated temperatures (≥140 °C), indicated by a color change to dark yellow or brown, diminishing yield and purity of the obtained monomer. This phenomenon is well-known in silane chemistry and has already been reported for dichlorosilane monomers containing ether linkages. , This detrimental behavior has been proposed to be caused by inter- and intramolecular reactions of the polar Si−Cl bonds with the oxygen atoms in the substituents, leading to thermodynamically favored Si−O bonds as well as C−Cl compounds. Only freshly distilled DCIMS was used for all further reactions and characterization due to the limited shelf life of the monomer.…”

“…This phenomenon is wellknown in silane chemistry and has already been reported for dichlorosilane monomers containing ether linkages. 17,21 This detrimental behavior has been proposed to be caused by inter-and intramolecular reactions of the polar Si-Cl bonds with the oxygen atoms in the substituents, leading to thermodynamically favored Si-O bonds as well as C-Cl compounds. Only freshly distilled DCIMS was used for all further reactions and characterization due to the limited shelf life of the monomer.…”

“…Ether moieties are known to be stable under the harsh polymerization conditions of the Wurtz coupling reaction. − Thus, ether-substituted polysilanes can be obtained from the corresponding dichlorosilane monomers directly. However, it is crucial that the position of the ether moiety is chosen at least three methylene units away from the silicon backbone to avoid possible β-elimination of the electron-withdrawing group during polymerization .…”