Highly conductive electrostatically assembled porphyrazine films

Toyama, Marcos Makoto; Demets, Grégoire Jean-François; Araki, Koji; Toma, Henrique E.

doi:10.1016/s1388-2481(00)00114-4

Cited by 28 publications

(24 citation statements)

References 14 publications

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“…33 On the other hand, the Nyquist plot obtained at 0.97 V, i.e., at Ru(III/II) redox potential exhibited a quite different profile as compared with the free-base derivative, in which case an inductive component has been reported. 33 In the case of the copper(II) derivative no semi-circle associated with activated electron transfer processes nor diffusion controlled Warburg region could be observed, but only a saturation line indicated by a curve nearly perpendicular to the Z Re axis. This indicates that at this potential, the electrode/film/solution interface behaves as a low resistance metallic electronic conductor.…”

Section: Preparation and Electrochemical Properties Of The Supramolecmentioning

confidence: 99%

“…33,36,[41][42][43] Such molecular films are relatively soluble in conventional solvents, but can be employed in aqueous solution in the presence of a large excess of counter ions, such as PF 6 − , triflate or perchlorate anions, in order to reduce their solubility. A better approach, however, is by carrying out a layer-by-layer self-assembly, based on a combination with sulphonated porphyrins or phtalocyanines.…”

Section: Preparation and Electrochemical Properties Of The Supramolecmentioning

confidence: 99%

“…In this case, in contrast to the tetrapyridylporphyrins, the bridging pyridyl rings are fused to the macrocycle, becoming part of the π-extended system. [33][34][35] In a previous work, 34 we have demonstrated that the free-base tetra(3,4-pyridyl)porphyrazine molecule can bind four [Ru(bpy) 2 Cl] + complexes, yielding a stable cationic system. Now, we are focusing on a new tetraruthenated copper(II) tetra(3,4-pyridyl)porphyrazine complex, including an investigation on its interaction with the anionic tetrasulfonated copper(II) phtalocyanine species ( Figure 1).…”

Section: Introductionmentioning

confidence: 99%

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Electronic conduction and electrocatalysis by supramolecular tetraruthenated copper porphyrazine films

Matsumoto

Toyama

Mayer

et al. 2009

J. Braz. Chem. Soc.

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Uma nova espécie cobre(II)-tetra(3,4-piridil)porfirazina tetrarrutenada, [CuTRPyPz] 4+ foi sintetizada e sua caracterização conduzida por meio de métodos analíticos, espectroscópicos e eletroquímicos. Sua extensa conjugação-π a distingue dos derivados análogos da mesotetrapiridilporfirina, levando à ocorrência de interações eletrônicas mais fortes entre os complexos periféricos e o anel porfirazínico central. Com base nas interações eletrostáticas e de empilhamento-π, foram realizadas montagens, camada-por-camada, de filmes funcionais, combinando-se a [CuTRPyPz] 4+ com a ftalocianina de cobre(II) tetrassulfonada, [CuTSPc] 4−. As propriedades condutoras e eletrocatalíticas desses filmes foram investigadas através de técnicas de impedância e de voltametria de disco rotatório, observando-se um comportamento metálico nas proximidades do potencial do par redox Ru(III)/(II), bem como uma pronunciada atividade catalítica na oxidação de íons nitrito e sulfito, em meio aquoso.A new tetraruthenated copper(II)-tetra(3,4-pyridyl)porphyrazine species, [CuTRPyPz] 4+ , has been synthesized and fully characterized by means of analytical, spectroscopic and electrochemical techniques. This π-conjugated system contrasts with the related meso-tetrapyridylporphyrins by exhibiting strong electronic interaction between the coordinated peripheral complexes and the central ring. Based on favorable π-stacking and electrostatic interactions, layer-by-layer assembled films were successfully generated from the appropriate combination of [CuTRPyPz] 4+ with copper(II)-tetrasulfonated phtalocyanine, [CuTSPc] 4− . Their conducting and electrocatalytic properties were investigated by means of impedance spectroscopy and rotating disc voltammetry, exhibiting metallic behavior near the Ru(III/II) redox potential, as well as enhanced catalytic activity for the oxidation of nitrite and sulphite ions.Keywords: molecular conductors, porphyrazines, ruthenium polypyridines, thin films, electrocatalysis IntroductionPhthalocyanines and porphyrins are important macrocyclic compounds exhibiting a wide variety of applications in science and technology. [1][2][3][4][5][6][7][8][9][10][11][12][13] Their main characteristics are associated with the π-conjugated ring which imparts interesting physical and chemical properties, including the facility of stacking and yielding molecular films. The possibility of rationally manipulating their properties at the nanoscale is a relevant issue to be pursued, aiming the generation of functional molecular materials for nanotechnology devices. [14][15][16][17] As a matter of fact, tetrapyridyl porphyrins have already been modified with transition metal complexes in order to generate convenient building-blocks and connectors for assembling supramolecular systems and nanostructured materials. 18,19 In such systems, the transition metal complexes can play many roles, because of their wide variety of structural, electronic, redox and catalytic properties. [20][21][22][23][24][25][26] In particular, the coordinati...

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Section: Preparation and Electrochemical Properties Of The Supramolecmentioning

confidence: 99%

Section: Preparation and Electrochemical Properties Of The Supramolecmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Electronic conduction and electrocatalysis by supramolecular tetraruthenated copper porphyrazine films

Matsumoto

Toyama

Mayer

et al. 2009

J. Braz. Chem. Soc.

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“…11,12 Solvent polymeric membrane sensors based on porphyrin and phthtalocyanine systems have been investigated for a broad range of mono-and di-valent cations. 13 Porphyrazines substituted in the periphery have myriad potential applications as photosensitizers for photodynamic therapy of cancer, 14 gas and metal ion sensors, 15 molecular conductors 16 and non-linear optical materials. 17 Phthalocyanines, while interacting with a Lewis acid (e.g.…”

Section: Introductionmentioning

confidence: 99%

Potential Aluminium(III)- and Gallium(III)-selective Optical Sensors Based on Porphyrazines

et al. 2011

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Porphyrazines possessing non-coordinating alkyl (propyl) and aralkyl (4-tert-butylphenyl) groups in the periphery were studied as optical sensors for a set of mono-, di-and trivalent cations. Investigated porphyrazines in the UV-Vis monitored titrations revealed significant responses towards aluminium and gallium cations, unlike other metal ions studied. Additionally, porphyrazine possessing 4-tert-butylphenyl peripheral substituents showed sensor property towards ruthenium cation and was chosen for further investigation. The presence of isosbestic points in absorption spectra for its titration with aluminium, gallium and ruthenium cations, accompanied by a linear Benesi-Hildebrand plot, proved complex formation. The continuous variation method was used to determine binding stoichiometry in 1:1 porphyrazine-metal ratio. X-Ray studies and density functional theory calculations were employed to investigate octa(4-tert-butylphenyl)-porphyrazine structure. The results helped to explain the observed selectivity towards certain ions. Interaction between ion and porphyrazine meso nitrogen in a Lewis acid-Lewis base manner is proposed.

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“…Particularmente, o mecanismo (b) é favorecido pelas estruturas de pilhas de porfirinas e já foi atribuído em filmes gerados por ELSA de porfirinas [224] e porfirazinas [225] . Esse mecanismo deve ser preponderante em filmes gerados por evaporação de solvente (drop cast) (filmes 2 e 3), desde que estes formem estruturas colunares (cap.…”

Section: Propriedades Eletroquímicas De Filmes De Porfirinas Polinuclunclassified

Interfaces e dispositivos baseados em porfirinas supramoleculares

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Highly conductive electrostatically assembled porphyrazine films

Cited by 28 publications

References 14 publications

Electronic conduction and electrocatalysis by supramolecular tetraruthenated copper porphyrazine films

Electronic conduction and electrocatalysis by supramolecular tetraruthenated copper porphyrazine films

Potential Aluminium(III)- and Gallium(III)-selective Optical Sensors Based on Porphyrazines

Interfaces e dispositivos baseados em porfirinas supramoleculares

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