Optimized synthesis of fluorinated dithienyl-diketopyrrolopyrroles and new copolymers obtained via direct heteroarylation polymerization

Abstract

<p>Optimized synthesis of fDT-DPP and related 3-fluorothiophene comonomers and application in highly fluorinated polymers obtained <italic>via</italic> direct heteroarylation polymerization.</p>

Identifying the Trade-off between Intramolecular Singlet Fission Requirements in Donor–Acceptor Copolymers

“…metalation and halogenation) necessary for functionalization, as indicated by the 'X' in Figure 1. For instance, the backbone fluorination of thiophene moieties, either alone [33][34][35][36] or as a component of more complex units [37][38][39][40] is a widely-reported approach to tuning the electronic properties of the heterocycle and the resulting extended material. 30 The chlorination of monomers [41][42][43][44][45] has also been used experimentally to modify the electronic and steric properties of conjugated polymers, as has esterification, cyanation and alkoxylation.…”

“…Functionalization plays a key role in the chemistry of conjugated polymers and small molecule organic electronics, as it provides opportunities to fine-tune the electronic structure and conformational preferences of the building blocks through electron-donating and -withdrawing groups, and with moieties which form noncovalent inter- and intramolecular interactions, respectively. − To include only reasonable functionalization patterns in our database, we considered the substitution sites which have been reported in the experimental literature as amenable to the reactions ( e.g ., metalation and halogenation) necessary for functionalization, as indicated by the “X” in Figure . For instance, the backbone fluorination of thiophene moieties, either alone − or as a component of more complex units, − is a widely reported approach to tuning the electronic properties of the heterocycle and the resulting extended material . The chlorination of monomers − has also been used experimentally to modify the electronic and steric properties of conjugated polymers, as has esterification, cyanation, and alkoxylation. − N-substituted side-chains on the amide and imide moieties found on isoindigo (iI), diketopyrrolopyrrole (DPP), naphthalene diimide (NDI), and thienopyrroledione (TPD) acceptors are readily accessible through the condensation of anhydrides with amines and substitution reactions. , These sites and similar ones on other cores are tagged for side-chain substitution, as shown by the “R” in Figure .…”

Direct (Hetero)arylation: A Tool for Low-Cost and Eco-Friendly Organic Photovoltaics

“…Therefore, brominated thiophene units with an unprotected β-position is likely to cause polymer defects. For similar reasons, our group developed several thiophene-based monomers, β-protected by fluorine or nitrile, both to disable the β-position and to reduce the barrier energy for polymerization at the desired α-positions. − Also, it was recently shown that ester functionalization can act as a directing group to enhance the reactivity and selectivity of C–H bonds on thiophene derivatives. , The lower energy barrier is explained by the stabilization of the concerted metalation deprotonation (CMD, Figure b) transition state by the ester group, which acts as a coordinating ligand upon the palladium. This methodology could be of high importance, as ester functionalization may increase the material performance and solubility, thereby enabling green solvent processing. , Nowadays, the C–H selectivity can easily be estimated through DFT calculations by measuring the CMD transition energy.…”

Identifying the Trade-off between Intramolecular Singlet Fission Requirements in Donor-Acceptor Copolymers

“…metalation and halogenation) necessary for functionalization, as indicated by the 'X' in Figure 1. For instance, the backbone fluorination of thiophene moieties, either alone [33][34][35][36] or as a component of more complex units [37][38][39][40] is a widely-reported approach to tuning the electronic properties of the heterocycle and the resulting extended material. 30 The chlorination of monomers [41][42][43][44][45] has also been used experimentally to modify the electronic and steric properties of conjugated polymers, as has esterification, cyanation and alkoxylation.…”