Regioisomerism of an alkyl-substituted bithiophene comonomer in (3E,8E)-3,8-bis(2-oxoindolin-3-ylidene)naphtho-[1,2-b:5,6-b′]difuran-2,7(3H,8H)-dione (INDF)-based D–A polymers for organic thin film transistors

Abstract

Two INDF-based polymers with regioisomerically substituted bithiophene units show distinctly different charge transport performances.

The Effects of Side Chains on the Charge Mobilities and Functionalities of Semiconducting Conjugated Polymers beyond Solubilities

“…For certain conjugated polymers, the substitution positions of alkyl chains also influence the backbone coplanarity, electronic structure, interchain packing and thin film morphology, and accordingly the charge transporting performances are varied . Li and co‐workers investigated two conjugated polymers, i. e., P10 and P11 , in which the two alkyl chains attached to the bithiophene moiety are positioned differently ( Scheme ) . The two n ‐dodecyl chains are placed in tail‐to‐tail (TT) and head‐to‐head (HH) manners for P10 and P11 , respectively.…”

Side-Chain Sequence Enabled Regioisomeric Acceptors for Conjugated Polymers

“…The side-chain sequence has little impact on electrochemical properties of PTBI polymers. It is worth noting that for polymers having alkyl chain substitution positions directly on aromatic rings (i.e., P3AT-like side-chain regioisomers), their regioisomers typically present a noticeable HOMO/LUMO energy level difference. ,, …”

“…It has been repeatedly shown in the case of polyalkylthiophenes that the side-chain sequence affects both physical and electronic properties . (Scheme b) However, little has been known about side-chain regioisomerism in D–A polymers. , Herein, we demonstrate for the first time side-chain sequence enabled regioisomeric acceptors for D–A copolymers based on the bis-thieno-benzo-isoindigo (bis-TBI) acceptor–acceptor type building block (Scheme c). Owing to its convergent synthetic approach, two pairs of side chains can be efficiently mounted onto the bis-TBI compound .…”

Recent structural evolution of lactam- and imide-functionalized polymers applied in organic field-effect transistors and organic solar cells

“…Later, the different sidechains were substituted in both donor and acceptor units of another INDF-based polymer, P110. 113 The increased solubility of the whole polymer backbone gave a much apparent red-shied absorption compared to that of P109, indicating a stronger tendency of mainchain aggregation in solution and denser lm packing in the solid state. Finally, good FET performance of P110 lm was obtained, with the max m e /m h of 0.15 and 0.33 cm 2 V À1 s À1 , respectively, which were comparable to those of most polymers with INDF.…”