Perylenophthalocyanines

The first perylenophthalocyanines have been synthesised using a Diels-Alder reaction between dialkylperylenes and fumaronitrile as the key step towards the dinitrile precursors. As expected the octaalkylperylenophthalocyanines show red-shifted absorption spectra. They are high melting solids that do not display mesophase behaviour at accessible temperatures. A 3:1 phthalocyanine/perylenophthalocyanine hybrid material, prepare by a mixed macrocyclisation reaction, presents an unusual board-like molecular profile. Its absorption maxima lie between those observed for the parent plithalocyanines and the symmetrical perylenophthalocyanines. The spectrum shows a characteristic split Q-band due to the reduced symmetry of the core. This material is non-mesogenic but is sufficiently soluble to permit processing and characterisation. The H-1 NMR spectrum indicates that at least two of the appended alkyl chains are displaced out of the macrocycle plane and lie in its shielding region-an arrangement that disfavours the face-to-face packing required for mesophase formation.