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A new diketopyrrolopyrrole-based π-conjugated copolymer(PDPP5T)with high molecular weight has been synthesized by Stille couplingpolymerization of 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-octyldodecyl)pyrrolo-[3,4-c]pyrrole-1,4(2H,5H)-dionewith α,α′-bis(trimethylstannyl)-terthiophene. Itshole mobility without thermal annealing reaches 1.08 cm2V–1s–1, and a higher hole mobilityof 3.46 cm2V–1s–1is obtained annealed at 200 °C directly in an air atmosphere.This indicates that introducing a longer β-unsubstituted quinquethiophene(5T) unit into the main-chain of DPP-oligothiophene copolymer producesmuch pronounced p-type behavior and also reduces the steric hindranceof the bulk side-chain groups, which is favorable to enhance the molecularordering capability at low temperatures and improve the organic thin-filmtransistors (OTFT) performances. This work demonstrates that PDPP5Tis a promising material that can be applied to the cost-effectiveand large-scale production of OTFTs. [ABSTRACT FROM AUTHOR]

A series of new n-type copolymers based on perylene diimide(PDI) or naphthalene diimide (NDI) and phenothiazine (PTZ) with differentside chain length and molecular weight have been designed and synthesizedby Pd-catalyzed Suzuki coupling polymerization with or without phase-transfercatalyst Aliquat 336. The effects of main chain, side chain, and molecularweight on the thermal, optical, electronic, and charge transport propertiesof the polymers have been investigated. Aliquat 336 improves molecularweight as well as reduces polydispersity index of the polymers. Allthe polymers exhibit a broad absorption extending from 300 to 900nm. The main chain and side chain structure and molecular weight haveminor effects on the HOMO (−5.8 to −5.9 eV) and LUMO(−3.7 to −3.8 eV) levels of the polymers. n-Channelfield-effect transistors with bottom-gate top-contact geometry basedon these copolymers exhibit electron mobilities as high as 0.05 cm2V–1s–1and on/off ratiosas high as 105in nitrogen, which are among the best reportedfor rylene diimide-based polymers under the same test conditions. [ABSTRACT FROM AUTHOR]