Strategies toward Controlling the Topology of Nonlinear Poly(thiophenes)

Abstract

In this contribution, we report the synthesis of all-conjugated branched poly(thiophenes) with a control over the degree of nonlinearity via two different routes. In the first approach a branched monomer is polymerized using three different catalysts which differentiate in the degree of association to the π-system of the polymer backbone. In the second approach a copolymerization is performed with the branched and a linear monomer. In a next step the influence of the different degrees of nonlinearity on the optoelectronic properties are investigated by UV-vis and fluorescence spectroscopy. Finally, the thermal behavior, the morphology and the electrical properties at the nanoscale of the material in solid state is studied using DSC and AFM techniques, respectively.

Synthesis of Hyperbranched Polypyridine via a Cross Coupling Approach as an n‐Type π‐Conjugated Polymer

“…Linear thiophene‐based polymers, such as poly(3‐hexylthiopthene), have been thoroughly investigated because of their useful charge transport properties and good processability . Higher dimensional conjugated polymers, such as star‐shaped and cruciform oligoarylenes, also have been studied in an attempt to optimize polymer properties …”

“…[4][5][6][7] Higher dimensional conjugated polymers, such as star-shaped and cruciform oligoarylenes, also have been studied in an attempt to optimize polymer properties. [8][9][10] Conjugated hyperbranched polymers, which can be categorized as higher dimensional polymers, also have attracted interest, although only a few examples have been reported. [11,12] Hyperbranched polymers have a large free volume, numerous terminal groups, and high solubility in solvents.…”

Influence of Branching of Polythiophenes on the Microporosity

“…In contrast to, for example, Ni catalysts, the Pd(Ruphos) can get loose from one growing chain and oxidatively insert in an active CBr bond of another chain in the polymerization mixture. This behavior enables to achieve a higher degree of branching with the Pd(Ruphos) catalyst as it was reported by Steverlynck et al…”

“…The CI bond, however, enabled a selective metalation of the precursor monomer prior to the in situ formation of the corresponding 5‐organozinc monomer (step (vi) in Scheme ) . The latter can therefore be polymerized via chain growth using a Pd(Ruphos) catalyst to give a well‐defined hyperbranched PT …”

“…Among the investigated branched CPs, polythiophene (PT), the benchmark CP and the most investigated in electro‐optical applications, has scarcely been reported . The reason for this can be ascribed to a lesser developed controlled polymerization of branched PTs in contrast to their linear counterparts . This explains why almost all investigated branched PTs in gas separation and/or gas storage were synthesized via a noncontrolled route, mostly by chemical oxidative polymerization .…”