| The electrochemistry, spectroelectrochemistry, and axial ligand binding reactions of porphyrins and diruthenium complexes are presented. The compounds investigated were: (i) seventeen water-soluble porphyrins of the type [(TMpyP)M II]4+(X−)4 or [(TMpyP)M IIICl]4+(Cl−)4 where TMpyP is the dianion of meso-tetrakis(N-methylpyridiniumyl)porphyrin and X− = Cl− or BPh 4−; (ii) M(PQ) (PQ = 5,10,15,20-tetrakis(3,5-di- tert-butylphenyl)quinoxalino [2,3-b':7,8- b"]porphyrin) and M(QPQ)+ (QPQ = 5,10,15,20-tetrakis(3,5-di- tert-butylphenyl)bisquinoxalino[2,3-b': 12,13- b"]porphyrin); and (iii) Ru2(CH3CO2) x(Fap)4-xCl where x = 1-3 and Fap is 2-fluoroanilinopyridinate. The primary focus of this work was to elucidate the overall redox mechanisms of the investigated compounds as well as to examine their electron transfer reactions by using electrochemical techniques along with ESR, mass spectroscopy, and UV-visible spectroscopy. More specifically, we investigated (a) how differences in the central metal ions and counterions of positively charged porphyrins affect the electrochemistry and spectroelectrochemistry, (b) how the presence of metal ions in solution but not coordinated in the central cavity of the porphyrin affect the electrochemistry and spectroelectrochemistry of quinoxalinoporphyrins, and (c) how the reactivity of mixed-ligand diruthenium compounds with small molecules that bind axially affect the electrochemistry. |
