As one kind of important functional material, those with advanced optical, electrical and magnetic characteristics have attracted increasing attention due to their essential and irreplaceable role in the daily life of humans. In particular, optical, electrical and magnetic hyperbranched polymers (HBPs) exhibit some unique properties, partially derived from their highly branched topological structures. This review summarizes the recent progress in the field of functional HBPs and their application in optics, electronics and magnetics, including light-emitting polymers, nonlinear optical materials, chemosensors, solar cells, magnetic materials, etc., and also gives some outlooks for further exploration in this field at the end of this paper.

Four 4,4′‐bis(1,2,2‐triphenylvinyl)biphenyl (BTPE) derivatives, 4,4′‐bis(1,2,2‐triphenylvinyl)biphenyl, 2,3′‐bis(1,2,2‐triphenylvinyl)biphenyl, 2,4′‐bis(1,2,2‐triphenylvinyl)biphenyl, 3,3′‐bis(1,2,2‐triphenylvinyl)biphenyl and 3,4′‐bis(1,2,2‐triphenylvinyl)biphenyl (oTPE‐mTPE, oTPE‐pTPE, mTPE‐mTPE, and mTPE‐pTPE, respectively), are successfully synthesized and their thermal, optical, and electronic properties fully investigated. By merging two simple tetraphenylethene (TPE) units together through different linking positions, the π‐conjugation length is effectively controlled to ensure the deep‐blue emission. Because of the minor but intelligent structural modification, all the four fluorophores exhibit deep‐blue emissions from 435 to 459 nm with Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of, respectively, (0.16, 0.14), (0.15, 0.11), (0.16, 0.14), and (0.16, 0.16), when fabricated as emitters in organic light‐emitting diodes (OLEDs). This is completely different from BTPE with sky‐blue emission (0.20, 0.36). Thus, these results may provide a novel and versatile approach for the design of deep‐blue aggregation‐induced emission (AIE) luminogens.

In this paper, by merging the hole-dominated triphenylamine (TPA) and tetraphenylethene (TPE) moieties together with different linkage positions, four derivatives of 1,2-bis[4 0-(diphenylamino)biphenyl-4-yl]-1,2diphenylethene (2TPATPE) were successfully synthesized with confirmed structures, and their thermal, optical and electronic properties were fully investigated. Thanks to the introduction of the meta-linkage mode on the TPE core, their p-conjugation length could be effectively restricted to ensure blue emission. The non-doped OLEDs based on these four emitters exhibit blue emissions from 443-466 nm, largely blue-shifted with respect to the green emission of 2TPATPE (514 nm). Meanwhile, good electroluminescence efficiencies with L max , h C,max , and h P,max of up to 8160 cd m À2 , 3.79 cd A À1 , and 2.94 Im W À1 respectively, have also been obtained, further validating our rational design of blue AIE fluorophores.

7645wileyonlinelibrary.com with external quantum effi ciencies up to 9.9%, nearly doubling the theoretical upper limit (5%) for fl uorescent devices. [ 5 ] This exciting result re-attracted many interests on the pure organic fl uorophors. [ 6,7 ] On the other hand, from 2001, pioneered by Tang et al., the research of organic fl uorophors with the characteristic of aggregation-induced emission (AIE) has become a hot topic. [8][9][10][11] And according to Tang's concept for lightemitting materials, the designed AIEgens demonstrated totally different emissive behavior from conventional fl uorophores with the notorious aggregation-caused quenching (ACQ) effect in the solid state: a series of propeller-like molecules were turned from faint fl uorophores in solution to strong emitters in the aggregation state, derived from the restricted rotation of some aromatic rings. Especially, one typical AIE molecule, 1-methyl-1,2,3,4,5-pentaphenylsilole, demonstrated very high effi ciency of 8% in its OLED device. [ 8,9 ] The emission color was not blue, but green, possibly due to the relatively long conjugation length of this molecule. [ 10 ] Actually, there were few reports concerning the blue AIE fl uorophors, once again showing the diffi culty to achieve good blue organic light-emitting materials.Fortunately, in the past several years, by utilizing different linkage modes and increasing the twisting degree of the molecules in the presence of additional groups, we have successfully developed facile approaches to tune the balance of the molecular rotation and conjugation, and construct blue AIE luminogens. [ 11 ] The OLED devices clearly demonstrated that their intrinsic band gaps have been effi ciently restricted for blue or deep-blue emissions, and the maximum current efficiency is up to 3.74 cd A −1 . Is there any more room to further improve the effi ciency? Considering the different function of the two design strategies, we are wondering how about the combination of these two methods, perhaps, the effect of "one plus one larger than two" could be realized. Thus, we designed and synthesized a series of AIE molecules, TPA-3 m TPE, TPA-3MethylTPE, MethylTPA-3 p TPE, MethylTPA-3 m TPE and MethylTPA-3MethylTPE ( Chart 1 ), by utilizing triphenylamine (TPA) or methyl-substituted TPA as core and tetraphenylethene (TPE) derivatives in peripheries. Indeed, the combination made the conjugation of the fi ve molecules fi nely tuned Great efforts have been devoted to seek novel approaches for constructing blue fl uorescent materials, which is one of the most important prerequisites for the commercialization of OLEDs. In recent years, various outstanding luminogens with aggregation-induced emission characteristic exhibit promising applications as emitters, but blue AIE fl uorophores with excellent EL performance are still very scarce. Here, fi ve hole-dominated blue AIE molecules are demonstrated by adopting construction approaches of changing linkage modes and increasing intramolecular torsion together, with the aim to restrict c...

By simply introducing additional groups with different size and conjugation degree to the 2,2'-positions of BTPE, four BTPE derivatives are prepared which give blue or deep-blue EL emissions when used as emitters in non-doped OLEDs, as the result of the tuned dihedral angles of the biphenyl cores (up to ~89°), providing a new approach to design AIE luminogens with blue and deep-blue emissions.