Supramolecular conformational effects in the electrocatalytic properties of electrostatic assembled films of meso(3- and 4-pyridyl) isomers of tetraruthenated porphyrins

• Autor(a) principal: Mayer,Ildemar
• Data de Publicação: 2005
• Outros Autores: Eberlin,Marcos N., Tomazela,Daniela M., Toma,Henrique E., Araki,Koiti
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532005000300016
• topic: supramolecular chemistry; metalloporphyrins; electrostatic assembled films; electrocatalysis; electrochemistry; mass spectrometry

Meso(3- and 4-pyridyl)porphyrins coordinated to four [Ru(bipy)2Cl]+ complexes, M(3-TRPyP) or M(4-TRPyP), where M=2H+ and Zn2+, have been obtained and characterized by electrochemistry, spectroscopy and mass spectrometry. Layer-by-layer electrostatic assembled films with tetrasulfonated phthalocyaninatecuprate(II) anion, CuTSPc, displayed distinct electrocatalytic activity towards sulfite and nitrite oxidation. In general, the films derived from the M(4-TRPyP) isomers are more effective for the oxidation of nitrite, whereas those containing the M(3-TRPyP) isomers are more efficient for the oxidation of sulfite. The results demonstrated the influence of molecular geometry on the active sites of porphyrinic nanomaterials, enhancing the electron-transfer process in the M(3-TRPyP) derivative. This effect results from changes in the chemical environment around the active sites, induced by the contrasting molecular packing interactions with CuTSPc.