Electrochemical and Spectroelectrochemical Studies on Bis-porphyrins, Porphyrins with Charged Substituents and Water-soluble Porphyrazines

In this thesis, the electrochemical and spectral properties of a series of bis-porphyrins, porphyrins with charged subsituents and water-soluble porphyrazines are investigated in aqueous or non-aqueous media. Bis-porphyrins containing a β,β'-fused pyrazino (Pz) linking group were examined by electrochemistry and thin-layer UV-visible spectroelectrochemistry in PhCN containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) as supporting electrolyte. The investigated compounds are represented as M(TPP)-Pz-(TPP)M, where TPP is the dianion of tetraphenylporphyrin and M = ZnII, CuII or AgII. The effect of the linking Pz group on the redox potentials and UV-visible spectra of the neutral, electroreduced and electrooxidized bis-porphyrins is discussed. Electrochemical and spectral properties of a new class of water-soluble porphyrazine complexes are characterized in pyridine, DMSO, DMF and water media. The investigated compounds are represented as [{Pd(OAc)2}4LM] (L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato dianion; M = MgII(H2O), ZnII, CuII, CoII, PdII, PtII) and bear four Pd(OAc)2 units, each externally coordinated at the vicinal pyridine N atoms of a single dipyridinopyrazine fragment of the porphyrazine macrocycle (“py-py” coordination). The electrochemistry and spectroelectrochemistry of a series of tetra-N-alkylpyridyl and tetrasulfonato manganese porphyrins are studied in DMSO and DMF. The mixture of tetra-N-alkylpyridyl and tetrasulfonato manganese porphyrins with 1:1 molar ratio in DMF solution is also studied by electrochemistry and spectroelectrochemistry and is described in this thesis.