Synthesis, optical, and electrochemical properties of novel phthalocyanine derivatives containing [5]helicene moieties

This dissertation describes syntheses, optical and electrochemical properties of a new class of porphyrazine compounds, phthalocyanine and naphthalocyanine derivatives, which contain twisted [5]helicene and tetrahydro[5]helicene moieties. This modification, for the first time, shows a significant role in an improvement of solubility in common organic solvents (e.g., toluene and tetrahydrofuran) even in the absence of traditional solubilizing groups such as aliphatic chains. The thermal stability studies indicated that these compounds are highly thermostable. This modification also shifts ground state electronic absorption (Q-band) of these compounds towards red (bathochromic shift). These molecules also showed excellent fluorescence characteristics. These compounds, when substituted with peripheral alkoxy groups, do not influence much on the Q-band absorption or fluorescence properties. Electrochemical studies of these materials have shown that the oxidation and reduction potentials of these materials are in the same vicinity of the reduction and oxidation potentials of phthalocyanine. The derivatives containing long chain alkoxy groups also exhibit thermotropic liquid crystalline properties.