Synthesis and characterization of metal-free and metallo-phthalocyanines with four pendant coumarinthio/oxy-substituents

The synthesis of novel metal-free and metallo-phthalocyanines with four, peripheral 7-thio- and 7-oxo-4-methyl-2H-1-benzopyran-2-one (coumarin) groups were prepared by cyclotetramerization of 7-(3,4-dicyanophenylthio)-4-methylcoumarin and 7-(3,4-dicyanophenoxy)-4-methylcoumarin. The novel chromogenic compounds were characterized by elemental analysis, 1H NMR, 13C NMR, Mass, IR and UV–vis spectral data. The electronic spectra exhibit a band of coumarin identity with characteristic Q and B bands of the phthalocyanine core. The IR spectra showed two characteristic intense bands at 1718 cm−1 for lactone carbonyl and at 1595 cm−1 for the α, β unsaturated doubled bond.