Imidazoporphyrins with appended polycyclic aromatic hydrocarbons: To conjugate or not to conjugate?

Ammonium Imidazoporphyrin – a Newborn in a Family of Porphyrins for Hybrid Materials

“…Thus, the introduction of the butoxy-substituents to the para-positions of meso-aryl groups drastically enhances the solubility of the obtained porphyrins in organic media even in the presence of large appended polyaromatic fragments. [24] The interaction of the starting free-base porphyrin 1 with Ni(acac) 2 provided the corresponding complex 2, which was further introduced to the nitration at b-position (Scheme 1). The application of the metal nitrate in the combination with acid anhydride is a general approach allowing selective b-nitration of various porphyrin metal complexes under mild conditions.…”

“…UV-Vis data could be used for the determination of the electronic interaction between the porphyrin macrocycle and peripheral fragments. [24] The introduction of the peripheral electron-acceptor cationic unit could initiate the bathochromic shift of absorption bands in the case of interaction with the porphyrin p-system. The comparison of the UV-Vis spectra of the imidazoporphyrins, bearing terminal hydroxy-, tosyloxy-and ammoniumsubstituents revealed negligible difference in the positions of the absorption bands (Table 1).…”