Regioselective functionalization of core per-substituted perylene diimides has been achieved efficiently based on a new versatile building block, named tetrabromotetrachloro-perylene-3,4:9,10-tetracarboxylic acid dianhydride (Br₄Cl₄-PTCDA), which affords a series of novel chromophores with impressive optoelectronic properties. Direct palladium-catalyzed fourfold intramolecular ring fusion affords successfully unique propeller-shaped biscarbazole[2,3-b]carbazole diimides with six annulated rings.

The dibromomaleimide derivative, N-(4-bromobutyl)-dibromomaleimide (dBMIB), is found to be a highly efficient coupling agent to dimerize thiol-terminated hydrophilic polymers by substituent reaction. When mono-thiol poly(ethylene oxide) (PEO₄₅-SH) is mixed with dBMIB in an equivalent molar feed in water, a dimer of PEO₄₅ with a maleimide unit located at the chain center, (PEO₄₅)₂MIB, is obtained quantitatively. The dBMIB is also used to dimerize thiol- terminated poly(N-(2-acryloyloxyethyl) pyrrolidone) and poly(N,N-dimethyl acrylamide). Moreover, the butylene bromide of (PEO₄₅)₂MIB is transferred into a butylene azide, which is allowed to react with alkynyl-terminated polystyrene to give a A₂B miktoarm star polymer via a copper-catalyzed azide–alkyne cycloaddition coupling reaction.

The copper-mediated Ullmann coupling of 1,7-dibromoperylene bisimides afforded structurally perfect singly-linked perylene bisimide (PBI) arrays, whilst the homo-coupling of 1,12-dibromoperylene bisimides gave doubly-linked and triply-linked diperylene bisimides. The interactions of three bay-linked diperylene bisimides that differed in their linkage (singly, doubly, and triply) were investigated in their neutral and reduced forms (mono-anion to tetra-anion). UV/Vis absorption and fluorescence spectroscopy revealed different degrees of interaction, which was explained by exciton coupling and conjugation effects. The electrochemical properties and spectroelectrochemistry also showed quite-different degrees of PBI interactions in the reduced mixed-valence species, which was apparent by the observation of CT bands. The interpretation of the experimental findings was supported by spin-restricted and -unrestricted DFT and time-dependent TD-DFT calculations with the long-range-corrected CAM-B3LYP functional. Accordingly, the degree of interaction in both the neutral and reduced forms of the bay-linked PBIs was qualitatively in the order doubly linked<singly linked≪triply linked, owing to the different degrees of twisting and flexibility between the two PBIs moieties. Only triply linked diPBI showed completely delocalized wavefunctions over the entire π-system.

Asymmetric tetrachlorinated perylene-3,4,9,10-tetracarboxylic acid bisimides (4Cl-PBI) were prepared in one-pot by a reaction of tetrachlorinated perylene-3,4,9,10-tetracarboxylic acid dianhydride with a mixture of 2-aminoethanol and dodecanamine or 2-decyltetradecan-1-amine. Then, two 4Cl-PBI methacrylates bearing one (M1) and two (M2) long alkyl tails were prepared, and a series of functional homopolymers were obtained by subjecting conventional radical polymerization and atom transfer radical polymerization. Furthermore, amphiphilic block copolymers pendent with 4Cl-PBI units, PEO-PM1 and PEO-PM2, were prepared using monomethoxyl PEO bromoisobutyrate as a macroinitiator. Size exclusion chromatography, UV–vis spectroscopy, fluorescence spectroscopy, and cyclic voltammetry have been applied to characterize the polymers obtained. Moreover, the Ullmann reactions between the grafted 4Cl-PBI units were conducted to form large π units, and the PEO-PM2 block copolymers gave di- or tri-PBI units in about 30%. Also, self-assembly of the amphiphilic block copolymers PEO-PM1 and PEO-PM2 in water was applied to generate spherical nanoparticles of 4Cl-PBI. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

A novel semiconductor based on annelated β-trithiophenes is presented, possessing an extraordinary compressed packing mode combining edge-to-face π–π interactions and S…S interactions in single crystals, which is favorable for more effective charge transporting. Accordingly, the device incorporating this semiconductor shows remarkably high charge carrier mobility, as high as 0.89 cm² V⁻¹ s⁻¹, and an on/off ratio of 4.6 × 10⁷ for vacuum-deposited thin films.