SYNTHESIS OF 3-NITROPHTHALONITRILE AND TETRA-ALPHA-SUBSTITUTED PHTHALOCYANINES

An efficient synthesis of phthalocyanines prepared from ortho-substitu ted phthalonitriles is described. The precursor to these phthalocyanin es, 3-nitrophthalonitrile, is a key reagent for syntheses of phthaloni triles substituted at the 3-position by means of nucleophilic aromatic substitutions. An example of this type of phthalocyanine, prepared fr om 3-(4-cumylphenoxy)phthalonitrile, is compared with the phthalocyani ne derived from 4-(4-cumylphenoxy)phthalonitrile. Substitution of the phthalocyanine at this more sterically crowded site causes a 20 nm bat hochromic shift of the Q-band (pi-pi transition).