Ying Jiang's research while affiliated with Stanford University and other places

... A representative case is provided by pentacenecontaining copolymers, which are typically regiorandom 62,63 , due to difficulties in separating regio-isomeric dibrominated precursors. The copolymerization of pure 2,9-and 2,10dibromopentacene derivatives with distannyled bithiophene comonomer gives the well-defined RR copolymers PnBT-2,9 and PnBT-2,10 ( Fig. 3a) 64 . In contrast, mixed dibromopentace starting materials and the same bithiophene reactant yield the regiorandom counterpart PnBT-RRa. ...

... Pentacene-based copolymers constructed via attachments at the 2,9-or 2,10-positons are also worth considering within the context of structural precision 78 . A synthetic route to obtain pure 2,9-and 2,10-dibromopentacene precursors was reported, see Fig. 3a, which enabled the synthesis of regioregular pentacene-containing copolymers 80 . Despite the relatively low n-type mobility (10 À 4 -10 À 5 cm 2 V À 1 s À 1 ) of the resulting RR copolymers, these values are considerably higher than what is obtained when using the regiorandom counterpart (8 Â 10 À 7 cm 2 V À 1 s À 1 ). ...

... In the study of contact propensities in the crystal structures of halogenated organic molecules [44], the packing of the C 22 H 12 Br 2 molecule (OKANOE [32,52]) was identified as having a particularly high Br···Br contact enrichment. The molecule 2,3-dibromopentacene is a very long rigid elongated molecule bearing two Br atoms on its extremities where the shape of the molecule plays an essential role in the crystal packing formation. ...

... Second, the use of homogeneous palladium catalysts in polymerization reactions could cause a high level of palladium impurity which is firmly embedded in the polymer chains formed because of palladium leaching [27,28]. The post-treatment of polymers frequently required the use of a palladium scavenger to achieve a high purity [28][29][30], and the process for purifying polymers is quite tedious, thereby limiting application of such catalytic systems in large-scale preparation of highly purified polymers. Therefore, from the viewpoint of green and sustainable chemistry, development of a recyclable heterogeneous palladium-catalyzed carbonylative polycondensation for the preparation of PAIs is highly desirable. ...

... [35] In addition to pentacene, anthradithiophene, with two thiophenes on each end of anthracene, is more stable than pentacene and can form a more coplanar structure with other conjugated units. [36] Two alternating high molecular weight polyfluorene-based polymers containing pentacene (P3) or anthradithiophene (P4) units were successfully synthesized by Suzuki coupling (Scheme 2). [37] The synthetic routes to (triisopropylsilyl)-ethynylsubstituted pentacene and anthradithiophene have been previously reported. ...

... However, in relation to pentacene-based polymers, 15-17 even fewer conjugated polymers containing the more stable ADT derivatives have been prepared. [18][19][20][21][22] Here we report the synthesis of a new series of conjugated copolymers (1-5, Fig. 1) that are accessible through a metal catalyzed cross-coupling reaction at the 5 and 11 positions of dihexylanthradithiophene (DHADT). This strategy is different than the traditional method to create 5,11-functionalized ADT polymers, which rely on nucleophilic substitutions on anthradithiophene quinones. ...