Conjugated systems optical properties

Experiments on transport, injection, electroluminescence, and fluorescence probe the spatial correlation within the film, therefore we expect that their response will be sensitive to the self-affinity of the film. This approach, which we proved useful in the analysis of AFM data of conjugated molecular thin films grown in high vacuum, has never been applied to optical and electrical techniques on these systems and might be an interesting route to explore. We have started to assess the influence of different spatial correlations in thin films on the optical and the electro-optical properties, as it will be described in the next section. 

Poly(para-phenylenevinylene)s (PPVs) represent one of the most intensively investigated classes of rr-conjugated materials. Many synthetic procedures to generate unsubstituted and substituted PPVs have been developed. They include 1,6-polymerizations of 1,4-xylylene intermediates as well as several polycondensation methods. Parallel to the polymer syntheses, several series of PPV oligomers (OPVs) have been synthesized and characterized. Such model oligomers of different molecular size allow for a study of the dependence of electronic and optical properties on the length of the conjugated Ti-system. 

Conjugated polyenes exhibit large linear and nonlinear optical properties due to the mobility of electrons in extended TT-orbital systems. Hence, this is another reason for the growing interest shown in these molecules in recent years2,79-89. 

Phthalocyanines 244 and hemiporphyrins 245 and 246 are aromatic systems. Extended conjugation confers special properties to these molecules that make them building blocks for new molecular organic materials with useful electric and nonlinear optical applications (Scheme 85).288... 

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