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Perylene bisimide (PBI) derivatives are n-type semiconductor materials widely used in a variety of optoelectronic devices. Great efforts have been devoted to the synthesis of soluble PBIs to allow processing by inexpensive solution-state methods. Recently, water-soluble compounds are receiving special attention for their potential in the fields of biology and “green” organic electronics. There is also a growing interest in the development of liquid crystalline PBIs, in order to improve the supramolecular organization and hence the transport performance. This work reports the first investigation of the mobility measured by the time-of-flight technique and the photoconductive response of the perylene derivative N,N′-bis[1-(2,5,8,11-tetraoxadodec-1-yl)-3,6,9,12-tetraoxatridec-1-yl]-perylene-3,4:9,10-bis(dicarboximide) (PBI-W), which is simultaneously water-soluble and liquid-crystalline. For comparison purposes, a parallel investigation with the commercial derivative N,N′-bis(1-hexylheptyl)-perylene-3,4:9,10-bis(dicarboximide) (PBI-C6), which is neither liquid-crystal nor water-soluble, has also been carried out. The conductive spectral response and the mobility dependence on the strength of the applied electric field were studied in order to optimize mobility measurements conditions. The mobility was determined as a function of temperature from room temperature (22 °C) up to 100 and 120 °C, for PBI-W and PBI-C6, respectively. Results are discussed in correlation with the crystalline or liquid-crystalline character phase of the material.

Here we present the synthesis and optical and structural characterization of a new series of alternating donor–acceptor copolymers based on 3,4-ethylenedioxythiophene (EDOT). The donor consists of phenylene, alkylated fluorene, or diethynyl-1,4-phenylene as the aryl units copolymerized with the EDOT group with and without a 9,10-anthraquinone (AQ) side chain as the acceptor group, namely, as PEX-AQand PEX, respectively. The changes in the electronic absorption/emission spectra and redox properties are analyzed in detail as a function of (i) the composition of the copolymers and (ii) the inclusion of the pendant 9,10-anthraquinone. Density functional theory calculations are used to interpret the experimental results. Special emphasis is placed on the flexibility of the phenylene-based copolymer spine which favors the tendency toward aggregation and confers interesting solvathocromic, thermochromic, and sonochromic properties when applying external stimuli. This is explained by means of an order–disorder conformational transformation (driven by π–π stacking) in solution upon ultrasonication, temperature changes, and the nature of the solvents. A comparison of the transient triplet–triplet absorption spectra of the phenylene-based PEBcopolymer in the unaggregated and aggregated forms reveals the formation of accessible triplet excited states whose nature is discussed in connection with the molecular flexibility of the copolymer backbone. These studies highlight the relevance of the precise control of the polymer architecture (donor–acceptor strategy in PEXversus double-cable concept in PEX-AQ) for suitable tunability of the optical and electronic properties of processable conjugated polymers for organic electronics.