Pentaaza macrocycles synthesis

In a manner similar to that used to prepare 112, the reaction of the diformyl-tripyrrane 114 with o-phenylenediamine was found by Sessler and coworkers to result in the synthesis of a pentaazamacrocycle 115 (Scheme 13) [59], An X-ray structure of a derivative of 115 is shown in Fig. 19. Unfortunately, no structurally characterized metal complexes of 115 have been reported to date. However, oxidation of 115 in the presence of cadmium(II) was found to give the aromatic pentaaza-macrocycle metal complex 116, which has been characterized by X-ray diffraction [60]. The properties and chemistry of these tripyrroledimethine-derived texaphyrins is reported in the next section. 

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