Synthesis, characterisation and aggregation properties of novel metal-free and metallophthalocyanines containing four 21-membered oxatetrathiadiaza macrocycles

The synthesis of novel metal-free phthalocyanine 4 and metallophthalocyanines 5, 6, 7 (MPcs, M = Ni, Zn, Co) containing four 21-membered oxatetrathiadiaza macrocycles at the peripheral positions was achieved by cyclotetramerisation of a novel 6,16-dioxo-5,6,7,9,10,12,13,15,16,17-decahydrotribenzo [h,k,n][1,4,10,13,19,7,16]oxatetrathiadiazacyclohenicosine-24,25-dicarbonitrile. The aggregation behaviours of phthalocyanines 4, 5, 6 and 7 were investigated at different concentrations in dimethylformamide. No aggregation behaviour was observed in dimethylformamide at concentrations between 10 × 10−6 and 1 × 10−6 mol dm−3. The aggregation properties of all phthalocyanines were also investigated in different solvents. All new compounds were characterised by a combination of elemental analysis and 1H NMR, 13C NMR, IR, UV–Vis and MS spectral data.