DIELECTRIC-PROPERTIES OF SOME SEMICONDUCTING PHTHALOCYANINE PIGMENTS

A different series of metal phthalocyanine and biphthalocyanine pigmen ts have been prepared via the urea fusion technique in the dry method by the condensation of phthalic anhydride, urea, and metal salt (at 22 0 degrees C for 4 h in the presence of ammonium molybdate as a reactio n promoter) in the synthesis of a phthalocyanine derivative, or phthal ic anhydride, pyromellitic dianhydride, urea, and metal salt in the sy nthesis of the biphthalocyanine derivatives. The dielectric properties of the prepared pigments were studied at various ranges of temperatur es and frequencies. The dielectric constant epsilon' and the dielectri c loss epsilon '' for the various complexes were calculated and discus sed. The effect of various types of metal ion and also bromination on the dielectric properties of these compounds were studied. A polarizat ion and dielectric relaxation process for such compounds were proposed .