Journal of the American Chemical Society, Vol.118, No.42, 10085-10093, 1996
Separation of 2(3),9(10),16(17),23(24)-Tetrasubstituted Phthalocyanines with Newly Developed HPLC Phases
The synthesis of 2(3),9(10),16(17),23(24)-tetrasubstituted phthalocyanines from 1,2-dicyano-4-alkoxybenzenes or the corresponding isoindolines is reported, In each case, four isomers with D-2h, C-4h, C-2v and C-s symmetry are obtained in the statistical expected yield. The separation of the C-4h and the D-2h isomers was achieved successfully for the first time from the other two isomers with newly developed HPLC phases based on pi-pi interactions. In one case, phthalocyanine 12 could be separated into the isomers 12a-d and characterized by UV/vis and H-1-NMR spectroscopy. Due to line broadening at room temperature, T-1 and T-2 relaxation time measurements of two phthalocyanines (3 and 12) at different temperatures are carried out. Whether the broad peaks are due to aggregation or due to a short relaxation time is explained.