Electrochemisty, Spectroelectrochemistry And/Or Electrosynthesis of Pi-Extended Porphyrins in Nonaqueous Media

Date

2014-05

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Abstract

This dissertation presents the electrochemistry, spectroelectrochemistry and electrosynthesis of pi-extended porphyrins. The electrochemistry and UV-vis spectral properties of neutral and protonated Au(III) quinoxalinoporphyrins containing one to four beta, beta'-fused quinoxalines were characterized in nonaqueous solvents. Mutiple Au(III)/Au(II) centered reductions were observed in acidic media, with the exact number depending on the number of fused quinoxaline groups on the compounds. Electrochemical and thin-layer spectroelectrochemical properties of mono- and bis-beta, beta'-porphyrins containing a beta, beta'-fused tetraazaanthracene (TA) group were also examined in different solvents. Each TA linked bis-porphyrin exhibits a strong interaction between the two equivalent porphyrin macrocycles, the magnitude of which is dependent upon the specific central metal ion. Finally, meso-naphthalene substituted and meso,beta-naphthalene extended porphyrins with five different central ions were characterized as to the their electrochemistry and UV-vis spectroelectrochemistry in CH2Cl2 and PhCN containing 0.1 M TBAP. All of the naphthalene substituted porphyrins could be converted to a naphthalene fused porphyrin after a two-electron oxidation, independent of the metal oxidation state, metal coordination number or solvent. The electron abstraction site of the second oxidation was shown to be dependent on the porphyrin central metal ion and the naphthalene oxidation potentials.

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Keywords

Electrochemistry, Spectroelectrochemistry, Extended porphyrin

Citation

Portions of this document appear in: Ou, Zhongping, Weihua Zhu, Paul J. Sintic, Yuanyuan Fang, Maxwell J. Crossley, and Karl M. Kadish. "Electrochemistry of mono-and bis-porphyrins containing a β, β′-fused tetraazaanthracene group." Journal of Porphyrins and Phthalocyanines 16, no. 05n06 (2012): 674-684. And in: Ou, Zhongping, Weihua Zhu, Yuanyuan Fang, Paul J. Sintic, Tony Khoury, Maxwell J. Crossley, and Karl M. Kadish. "Unusual multi-step sequential AuIII/AuII processes of gold (III) quinoxalinoporphyrins in acidic non-aqueous media." Inorganic chemistry 50, no. 24 (2011): 12802-12809. And in: Ou, Zhongping, Tony Khoury, Yuanyuan Fang, Weihua Zhu, Paul J. Sintic, Maxwell J. Crossley, and Karl M. Kadish. "Gold (III) porphyrins containing two, three, or four β, β′-fused quinoxalines. synthesis, electrochemistry, and effect of structure and acidity on electroreduction mechanism." Inorganic chemistry 52, no. 5 (2013): 2474-2483. And in: Ou, Zhongping, Weihua Zhu, Paul J. Sintic, Yuanyuan Fang, Maxwell J. Crossley, and Karl M. Kadish. "Electrochemistry of mono-and bis-porphyrins containing a β, β′-fused tetraazaanthracene group." Journal of Porphyrins and Phthalocyanines 16, no. 05n06 (2012): 674-684. And in: Chen, Ping, Yuanyuan Fang, Karl M. Kadish, Jan P. Lewtak, Dominik Koszelewski, Anita Janiga, and Daniel T. Gryko. "Electrochemically Driven Intramolecular Oxidative Aromatic Coupling as a Pathway toward π-Extended Porphyrins." Inorganic chemistry 52, no. 16 (2013): 9532-9538.