Macrocycles as Molecular Units to Build up Electroresponsive Materials: A Comparative Theoretical Investigation of the Electronic and Optical Properties of Phthalocyanine and Related Systems

Besides their classical and well-known applications as, e.g., dyes, pigments, catalysts, etc. [1], phthalocyanines (Pc’s) have been of particular interest in many fields of basic and applied research concerning solar cells [2], photosensitizers [3], low dimensional metals [4], gas sensors [5], electrochromism [6], Langmuir-Blodgett (LB) films [7], and nonlinear optics [8]. As an example, gas sensors [9], electronic devices [10], laser recording materials [11], and photovoltaic cells [12] can now be built from LB films of phthalocyanines. This great variety of interesting applications results from a number of unique properties that phthalocyanines exhibit On the one hand, they show an except…