Temperature-dependent morphology-electron mobility correlations of naphthalene diimide-indacenodithiophene copolymers prepared via direct arylation polymerization

Abstract

A series of defect-free n-type copolymers poly(naphthalene diimide-alt-indacenodithiophene) P(NDI-IDT) comprising alternating naphthalene diimide (NDI) and indacenodithiophene (IDT) units is prepared using atom-economic direct arylation polycondensation (DAP). Copolymers with varying molecular...

Direct (hetero)arylation (DHAP) polymerization of conjugated polymers – new A–B–A monomer design for P(NDI2OD-T2) & the challenges of adopting DHAP for continuous flow processes

“…45 The melting characteristics of a polymer are influenced by its molecular weight, the molar mass dispersity etc. 26,46,47 Therefore, differential scanning calorimetry was used to evaluate the melting temperature ( T m ) and melting enthalpy (Δ H m ), which conveys important information regarding the extent of crystallinity of the polymer sample. Fig.…”

“…The melting characteristics of a polymer are influenced by its molecular weight, the molar mass dispersity etc. 26,46,47,49,50 The high temperature proton NMR studies did not provide any proof for the existence of beta defects in the polymer; however the low values for the melting transition and enthalpy of melting could be an indication of branching due to beta defects also being present in the polymer. The polymer B developed by the continuous flow approach using the regular monomers, yielded a polymer with narrow molar mass dispersity (Ð M : 1.7) and much better crystallinity with higher T m (292 1C) and melting enthalpies DH m (1.75 J g À1 ) despite having comparatively lower molecular weight than polymer A.…”

Solution processed organic thermoelectric generators as energy harvesters for the Internet of Things

“…Despite that, different strategies have been used to improve the electrical conductivity, dopant-miscibility, film structure, and stability of PNDI-T2 and other NDI-based polymers, such as side chain engineering, 80,100,101 end group control, 90 and modification or substitution of the copolymer backbone. 65,86,91,[102][103][104][105] A PNDI-T2 derivative with triethylene glycol side chains, PNDI2TEG-2Tz, synthesized by Liu et al, remains one of the best performing NDI-based organic semiconductors, reaching a r max ¼ 1.8 S cm À1 and PF max ¼ 4.5 lW m À1 K À2 when doped with N-DMBI. 101 Despite considerable improvements to the electrical conductivity of doped NDI-based polymers, the stability of the doped state in air is still a challenge.…”

“…15 In addition to interchain proximity, the conformation of a single conjugated backbone, including defects like twisted and kinked chains, will affect the species' intrachain charge carrier mobility. 15,17 It would follow that thermoelectric films with less defects and higher degrees of crystallinity will have superior properties, and this is true in some cases, 103,127 but the relationship is not so simple across all systems.…”

n-Type conjugated polymers comprising bithiophene imide and multifluorinated thiophene moieties synthesized by direct arylation polycondensation

“…In view of this challenge, it is not surprising that only a limited number of high-performance CPs have been synthesized by DArP. 21,32,[44][45][46][47][48][49][50][51][52][53][54][55][56] Recently, we developed two weak D units, 3,3 0 ,4,4 0 -tetrafluoro-2,2 0 -bithiophene (4FBT) and (E)-1,2bis(3,4-difluorothien-2-yl)ethene (4FTVT), by installing F atoms at the b-positions of the thiophene rings. Both 4FBT and 4FTVT show high reactivity and selectivity in DArP.…”