Position isomer separation of non-peripheral substituted zinc dibenzo-di(3,4-pyrido)porphyrazines

The cyclotetramerisation products from the 1,8-diazabicyclo[5,4,0]undec-7-ene catalysed reaction of a 1:1 mol mixture of 3,6-didecylphthalonitrile and 3,4-dicynopyridine in the presence of zinc chloride have been isolated by chromatography. The fractions comprise zinc octadecylphthalocyanine and compounds in which one, two, three and four pyridinoid rings replace the didecylbenzenoid moiety. The zinc bis(1,4-didecylbenzo)bis(3,4-pyrido)porphyrazine fraction was separated further into four sub-fractions and the components have been characterised by 400 MHz proton nuclear magnetic resonance spectroscopy, visible region spectroscopy, fluorescence spectroscopy and by cyclic voltammetry.