Synthesis and Properties of Sulfo and Alkylsulfamoyl Substituted Phthalocyanines and their Copper (II) Complexes Bearing 1-Benzotriazolyl and 4-Cyclohexylphenoxy Groups

Abstract
New sulfo and alkylsulfamoyl substituted 2,9,16,23-tetrakis(1-benzotriazolyl)3,10,17,24-tetrakis(4-cyclohexylphenoxy)phthalocyanines and their Cu(II) complexes were synthesized. Their physicochemical properties such as electronic absorption, solubility in organic solvents, thermostability and mesomorphism were investigated. It was established that introduction of sulfo group into cyclohexylphenoxy fragment of the studied phthalocyanines causes bathochromic shift of long wave band s in both DMF and concentrated sulfuric acid solutions. In contrast, introduction of octadecylsulfamoyl substituentsdoes not influence the position of Q band in DMF, but shifts this band hypsochromically. The performed synthesis revealed that introduction of bulky fragments into ortho-position with respect to the oxygen atom of aryloxy group excludes manifestation of liquid crystalline properties. While substitution by the same substituent in para-position leads to formation of mesophase. This fact can be connected with the sterical hindrance of liquid crystalline molecular packing. Thus, it was established that the presence of donor and acceptor fragments in mix-substituted phthalocyanines is important but not determining factor for their mesophase formation. The forecast data on the absence of mesomorphism of new phthalocyanine derivatives with sulfo and alkylsulfamoyl groups are in a good agreement with the experimental data, which is the evidence of the applicability of the method used to identify mesogen / non-mesogen structures for this class of compounds.

Keywords: phthalocyanines, synthesis, mesomorphism, solubility, thermostability, mesomorphism prognosis