Polymers perylene-containing

H. Quante, P. Schlichting, U. Rohl, Y. Geerts, and K. Mullen, Novel perylene-containing polymers, Macromol. Chem. Phys., 197 4029-4044, 1996. 

Generation layers have recently been prepared from aqueous dispersions. Hoshino et al. (1991) described the cathodic deposition of various phthalo-cyanines and perylenes from aqueous dispersions containing poly(oxyethylene dodecyl ether) and LiBr. The pigment-polymer aggregate was plated onto an Al cathode. The layer was then coated with a transport layer using conventional solvent coating techniques. Hiruta et al. (1991) described a related technique as thermoinduced deposition. Aqueous phthalocyanine dispersions, as described above, were found to adsorb on an Al substrate at 90 C. 

It should be noted that a number of SPC polymers which contain other heterocycles have been prepared, motivated by their promising optical or electrical properties. Examples include pyridine (65) [123], pyrrole (66) [124], oxadiazole (67) [125], selenophene (68) [126], benzo[2,l,3]thiadiazole (69) [127], benzo[2,l,3]selenadiazole (70) [126], perylene bisimide (71) [128], 1,4-diketo- pyrrolo[3,4-c]pyrrole-l,4-dione (72 and 73) [127,129], and triphenyleamine (74) [127] as part of the polymer backbone by SPC (Figure 19c). Specifically for metal complexation, porphyrin [130], difluoroboraindacene [131], bipyridine [132], phenanthroHne [113], terpyridine [133, 134], and the like [123] were embedded in the backbone. In this context, an interesting report was submitted by Rehahn et al., in which l,l -ferrocenyl units were incorporated into a PPP (Figure 22.20). Due to a low-energy barrier for rotation around the Cp-Fe-Cp axes (Cp = cyclopentadienyl), the obtained polymer 75 was assumed to take randomly coiled conformations [135]. 

A natural development was the introduction of hole and/ or electron transporting groups in EL polymers aiming the improvement of injection/transporting properties as in the case of the incorporation of triphenyl amine and cyano groups in MEH-PPV [135,136]. Recent advances in PPV-related structures include soluble PPV derivatives containing pyrene [137] or perylene [138] dyes in the main and C60 grafted units [139]. 

Figure 16 shows a SNOM image for PiBMA thin films, containing the labeled PiBMA-Pe polymers with a fraction F = 0.14%, taken with perylene fluorescence intensity under the excitation at 442 nm by a He-Cd laser [26,60]. Several small spots are observed in the picture, although the smface was very flat over the whole area of the topographic images taken at the same time. 

Nanostructured semiconducting block copolymers containing triphenylamine as hole transport moiety and perylene bisimide as dye and electron transport, have been investigated in view of applications in photovoltaic devices. The polymers show nanowire like structure which formation is driven by the crystallization of perylene bisimides via n- n stacking and since this self-assembly gives rise to domains size comparable to the exciton diffusion length, these materials offer perspectives for the implementation of organic solar cells [357]. 

Excimer formation has been found to be most prominent for small organic aromatic molecules such as benzene [13],p-xylene [14], naphthalene [15], anthracene [16], pyrene [17], perylene [18], stilbene [19], and others [20]. Some polymers that contain aromatic groups, such as polystyrene [21] and poly (ethylene terephthalate) (PET) [22], and polynucleotides such as cytosine and thymine [23] have also been shown to exhibit excimer emission. Excimer emission is, in fact, widely observed in aromatic hydrocarbons [20]. 

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