Preparation of N-bridged diiron phthalocyanines bearing bulky or small electron-withdrawing substituents

The synthesis of novel mu-nitrido diiron phthalocyanine with electron-withdrawing substituents is reported: mu-nitrido tetra-methylsulfonylphthalocyanine (13), mu-nitrido tetra-ethylsulfonyl-phthalocyanine (14), mu-nitrido tetra-adamantylsulfonylphthalocyanine (15), mu-nitrido tetra-cyclohexyl-sulfonylphthalocyanine (16). These complexes were characterized by ESI-MS, UV-vis, FT-IR and EPR techniques. The state of these complexes depends on the size of the substituents. Complexes 13 and 14 bearing small methylsulfonyl and ethylsulfonyl substituents are cationic ((PcFeNFePc)-N-IV-Pc-IV)(+)N(3)(-)complexes while complexes 15 and 16 with bulkier adamantylsulfonyl and cyclohexylsulfonyl substituents are formally neutral (PcFeNFePc)-N-III-Pc-IV complexes which can be represented as PcFe(+3.5)NFe(+3.5)Pc.