Tuning of phthalocyanine absorption ranges by additional substituents

A new phthalonitrile derivative with two different substituents on 4- and 5-positions has been synthesized and its cyclotetramerization in the presence of anhydrous metal salts without any solvent resulted with phthalocyanines (4–6) containing a hexylthio group and malonylester on each benzo unit. When phthalocyanine formation was carried out in high-boiling alcohols in the presence of a base transesterification of malonyl esters gave products with enhanced solubility in apolar solvents. These new compounds have been characterized by 1H NMR, FT-IR, UV–vis and mass spectroscopies.