Effects of Side-Chain Topology on Aggregation of Conjugated Polymers

Controlling interchain interactions
in conjugated polymers is critical
to the development of high performance materials. These interchain
interactions are dictated by the aggregation and self-assembly of
conjugated polymers in solution and from processing steps, such as
thermal annealing, in the solid state. Herein, a macrocyclic benzodithiophene
building block for conjugated polymers is developed, and the properties
of the resulting polymers are compared to analogous acyclic derivatives.
The properties of small molecule macrocyclic BDT compounds show the
influence of the side-chain substitution on the thermodynamic forces
of self-assembly. Comparison of the optical properties of conjugated
polymers with macrocyclic and acyclic side-chains in solution and
the solid state reveals the ability of the macrocyclic side-chain
to modify the structure of aggregates. Grazing incidence wide-angle
X-ray scattering shows that the macrocyclic polymers can remain ordered
in the solid state while having higher photoluminescence yields than
the acyclic derivatives.