Optical electroluminescent polymers

Thin Films of Electroluminescent Polymers 335 Electronic Eneigy Structure 336 Optical Properties 336 Electrical Transport Properties 338... 

Optically active polymers are potentially very useful in areas such as asymmetric catalysis, nonlinear optics, polarized photo and electroluminescence, and enantioselective separation and sensing.26 Transition metal coupling polymerization has also been applied to the synthesis of these polymers.27 For example, from the Ni(II)-catalyzed polymerization, a regioregular head-to-tail polymer 32 was obtained (Scheme 9.17).28 This polymer is optically active because of the optically active chiral side chains. 

Nonlinear Optical and Electroluminescence Polymers Volume Editor Lee, K.-S. 

Although effective as electroluminescent polymers, fluorene-containing polymers have limited hole transporting properties because of the tendency of fluor-ene units to aggregate. To impede aggregration Mckieman et al. (3) prepared diindenofluorene monomers, ( ), which were readily processable and had excellent electrical and optical properties. 

Aromatic compounds have not only been of academic interest ever since organic chemistry became a scientific discipline in the first half of the nineteenth century but they are also important products in numerous hydrocarbon technologies, e.g. the catalytic hydrocracking of petroleum to produce gasoline, pyrolytic processes used in the formation of lower olefins and soot or the carbonization of coal in coke production [1]. The structures of benzene and polycyclic aromatic hydrocarbons (PAHs) can be found in many industrial products such as polymers [2], specialized dyes and luminescence materials [3], liquid crystals and other mesogenic materials [4]. Furthermore, the intrinsic (electronic) properties of aromatic compounds promoted their use in the design of organic conductors [5], solar cells [6],photo- and electroluminescent devices [3,7], optically active polymers [8], non-linear optical (NLO) materials [9], and in many other fields of research. 

Moreover, organic functionalization of a polymer chain can lead to improvement in the physical properties, such as thermal stability and mechanical strength of the resulting siloxanes (Figure 3.1). Appropriate substitution on the polysiloxane backbone can lead to diverse materials such as liquid crystals," crosslinking agents, conductive and electroluminescent polymers, nonlinear optical materials,and bactericides. ... 

C.R. Mendonea, D.S. Correa, F. Marlow, T. Voss, P. Tayalia, E. Mazur, Three-dimensional fabrication of optically active microstiuctures containing an electroluminescent polymer. Appl. Phy. Lett. 95, 113309-113313 (2009)... 

Since multiple electrical and optical functionality must be combined in the fabrication of an OLED, many workers have turned to the techniques of molecular self-assembly in order to optimize the microstructure of the materials used. In turn, such approaches necessitate the incorporation of additional chemical functionality into the molecules. For example, the successive dipping of a substrate into solutions of polyanion and polycation leads to the deposition of poly-ionic bilayers [59, 60]. Since the precursor form of PPV is cationic, this is a very appealing way to tailor its properties. Anionic polymers that have been studied include sulfonatcd polystyrene [59] and sulfonatcd polyanilinc 159, 60]. Thermal conversion of the precursor PPV then results in an electroluminescent blended polymer film. 

Figure 11-4. Electroluminescence and optical absorption spectrum of the soluble polymer MEH-PPV.

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