Bithiophenesilane-Based Dendronized Polymers: Facile Synthesis and Properties of Novel Highly Branched Organosilicon Macromolecular Structures

The synthesis of two novel bithiophenesilane-based dendronized polymers by a chain growth Kumada polymerization, their molecular properties in dilute solutions and thermal properties in the bulk are described and compared with those of bithiophenesilane dendrimers. GPC equipped with a dual light scattering detector has shown that the polymers exhibit narrow polydispersity indices (PDI = 1.22-1.23) and have a weight-average polymerization degree of 44 for P1 and 30 for P2, which correspond to 88 and 120 bithiophenesilane fragments, respectively. Spectral-luminescent investigations showed that both polymers among with the bithiophenesilanes contain from 1 to 4 terthiophenesilane fragments in every macromolecule, which leads to the so-called dendritic molecular antenna effect. The intramolecular energy transfer efficiency was measured to be SO and 70% for polymers P1 and P2 respectively, which, alongside with the results of viscometric studies, points out to the compact conformation of these macromolecules in solution, which is close to those of bithiophenesilane dendrimers.