Incorporating selenophene into organic semiconductors has recently shown promising results in both organic solar cells (OSCs) and organic field-effect transistors (OFETs). In most studies, replacing thiophene with selenophene has improved the performance in OSCs and OFETs. However, some other reports do not show the same trend. Therefore, the structure−property relationship of selenophene-containing semiconducting materials is still to be investigated and understood. On the other hand, reports have shown that thiophene flanked benzothiadiazole-and thieno-[3,2-b]pyrrole-based donor−acceptor−donor molecular architecture gave a banana-shaped small organic conjugated molecule with moderate OFETs performance. To understand the structure− property relationship and influence on OFETs performance, by replacing thiophene with selenophene in chalcogenopheno[3,2-b]pyrrole, we report a nonconventional fused ring system, estermonocapped selenopheno[3,2-b]pyrrole, which was coupled with chalcogenophene spacer flanked benzothiadiazole to yield two curved small organic conjugated molecules, diethyl 2,2′-(5,5′-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(thiophene-5,2-diyl))bis(4dodecyl-4H-selenopheno[3,2-b]pyrrole-5-carboxylate (BT-2T-2SeP) and diethyl 2,2′-(benzo[c][1,2,5]thiadiazole-4,7-diylbis-(selenophene-5,2-diyl))bis(4-dodecyl-4H-selenopheno[3,2-b]pyrrole-5-carboxylate (BT-2Se- 2SeP). This is the first report of selenopheno [3,2-b]pyrrole incorporated in donor−acceptor small conjugated organic molecules for OFETs applications. BT-2T-2SeP and BT-2Se-2SeP exhibited comparable maximum hole mobilities of 8.82 × 10 −3 cm 2 V −1 s −1 and 1.44 × 10 −2 cm 2 V −1 s −1 , respectively. Furthermore, these molecules exhibited lower threshold voltages between 0-(−5) V and high on−off current ratios of 10 4 and ∼10 5 , respectively, for BT-2T-2SeP and BT-2Se-2SeP.

The self-assembly of functionalized polycaprolactone amphiphilic diblock copolymers is explored for carrier-mediated doxorubicin delivery for cancer treatment. In this report, functionalized polycaprolactone-based amphiphilic block copolymers with controlled branching architecture are investigated. Star-like copolymers, namely 4-arm and 6-arm poly(γ-benzyloxy-εwere synthesized by living ring-opening block copolymerization (ROP) of γ-(2-benzyloxy)-ε-caprolactone and γ-2-[2-(2-methoxyethoxy)ethoxy]ethoxy-εcaprolactone using multifunctional initiators. A systematic investigation of the effect of branching points on polymer properties and micellar carrier properties was carried out. The star-like PBCL-b-PMEEECL micelles displayed better thermodynamic stability, size reduction, and enhanced doxorubicin encapsulation than the linear PBCL-b-PMEEECL. Furthermore, the π-π stacking between the benzyl group of the hydrophobic PBCL core and the doxorubicin, the anti-cancer drug, also increases the stability and loading capacity of the micelles. The star-polymers dis-

Side chain engineering has been used for tuning the opto‐electronic properties of organic semiconductors. In this work, a series of pyrimidine‐based donor‐acceptor (D‐A) conjugated polymers functionalized with electron‐withdrawing or electron‐donating side chains were synthesized. The opto‐electronic properties of the pyrimidine D‐A conjugated polymers were investigated focusing on the dependence on the electron withdrawing strength of the acceptor moiety, while maintaining the same donor moiety. Fine‐tuning of the energy levels was achieved by introducing electron donating (alkoxy [OR] and alkylthio [SR]) or electron withdrawing (alkylsulfinyl [SOR] and alkylsulfonyl [SO2R]) side chains onto the acceptor moiety. The effects of side chain modification have been investigated through DFT calculations, UV–vis analysis, and electrochemical measurements. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2547–2553

The structural alteration of semiconducting polymer backbones can improve the optoelectronic properties of organic semiconductors and enhance field-effect mobilities. In our efforts towards improving the performance of organic field-effect transistors (OFETs), we are reporting a donor–acceptor polymer containing thieno[3,2-b]pyrrole (TP) donor and a furan-flanked diketopyrrolopyrrole (DPP) electron acceptor, which yielded an asymmetric poly(methylthienopyrrolo)furanyl)diketopyrrolopyrrol) P(FDPP-TP) organic semiconducting polymer. The introduction of a furan spacer improved thermally induced crystallinity and molecular packing, as confirmed by grazing incidence X-ray diffraction (XRD) and tapping-mode atomic force microscopy (TMAFM). The tested OFET devices gave maximum hole mobility of 0.42 cm2 V−1 s−1 with threshold voltages around 0 V for bottom-gate bottom-contact device configuration.

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