SUBSTITUENT EFFECTS IN SOLUBLE PHTHALOCYANINATOIRON(II) COMPLEXES

The synthesis and characterization of 1,4- and 2,3-octa- and tetra-sub stituted bis(tert-butylisocyanide)phthalocyaninatoiron(II) complexes w ith linear (n-heptyl, n-octyloxy) and branched (2-ethylhexyloxy) chain s are reported, Analytical, spectroscopic and electrochemical studies have been carried out to obtain an insight into the substituent effect s of these compounds, H-1 NMR spectroscopy shows a smaller upfield shi ft of the axial ligand protons for the 1,4-substituted systems than fo r the 2,3-substituted systems, In the UV-VIS spectra bathochromic shif ts are observed for the systems with their side chains in 1,4-position s in comparison with the 2,3-substituted analogues. Cyclic voltammetri c measurements were carried out in dichloromethane and pyridine to det ermine the redox potentials of these complexes. A decrease of the oxid ation and an increase of the reduction potentials were found by introd ucing substituents in the 1,4-positions of the macrocycle. 1,4-Substit ution perturbs the electronic structure of phthalocyanine ring systems to a larger extent than 2,3-substitution.