Solvent and electrode influence on electrochemical forming of poly-Fe(III)-aminophenylporphyrin films

Abstract

Fe(III)-complexes of amino-substituted tetraphenylporphyrins obtained from solutions in organic solvents: dichloromethane, ethanol, and dimethyl sulfoxide have been electropolymerized. The solvents’ effects on deposition and surface morphology of the obtained polyporphyrin film have been determined. It is only possible to obtain a polyporphyrin film from DMSO solutions through electrochemical activation of electropolymerization by a superoxide anion radical (O[Formula: see text]. The activation effect of the dissolved oxygen becomes evident in porphyrin interaction with the superoxide anion radical (O[Formula: see text] that is synthesized in DMSO thanks to the quasi-reversible redox process. The size of particles forming the film is lowest when the film is deposited from DMSO and highest when it is deposited from dichloromethane. Therefore, the ratio of polyporphyrin phase grain growth rate to the nucleation rate has the highest value when the film is deposited from dichloromethane. Such films have the most developed surfaces, while those deposited from ethanol are the smoothest. If the film is deposited on an ITO-electrode, the particles forming the surface are a little larger than in the case of deposition on Pt, which is explained by a slower nucleation on the ITO surface. FeClT([Formula: see text]-NH2Ph)P-based films obtained from ethanol and dichloromethane have negative photo-EMF values, which indicates that the [Formula: see text]-type films have semiconductor properties.

Self-assembly and photoconductivity of binary porphyrin nanostructures of meso -tetrakis(4-sulfonatophenyl)porphine and Co(III) meso -tetra(4-pyridyl)porphine chloride

“…Porphyrin nanostructures may demonstrate some degree of conductivity [19,20,[22][23][24][25][26][27][49][50][51] due to intermolecular transfer or delocalization of the excitation energy in their nanostructures, which generates photoconductance. Most studies so far have dealt with the Jaggregate nanorods self-assembled from metal-free porphyrins [23][24][25][26][27][28] as it was discussed in the introduction section.…”

Kinetics of Induced Deposition of Films Based on Tetrakis(4-Aminophenyl)Porphyrin

“…The method of electrochemical deposition is characterized by simple implementation and allows obtaining well reproducible films of controlled thickness. Here, film formation is possible in the case of aminophenylporphyrins both as a result of polymerization caused by electrochemical precursor oxidation [19][20][21][22][23][24][25][26][27][28] and as a result of interaction between the porphyrin and the electrochemically synthesized superoxide anion-radical ( ) [29][30][31].…”

Ethynylphenyl-Derivatized Free Base Porphyrins: Anodic Oxidation Processes and Covalent Grafting onto Glassy Carbon Electrodes

“…Anodic polymerization of mesosubstituted porphyrins is generally thought to involve coupling reactions at the meso positions of porphyrins in different redox states which, in the case of a one-electron process, is said to be a "radical-substrate" reaction. 27 Although anilines, pyrroles, and thiophenes are the most commonly employed meso substituents for electrochemical polymerization processes, 19,22,23 oxidation of aryl or polyaryl meso substituents have also been exploited for this purpose. 24−26 We recently reported several approaches to the covalent attachment of molecules to carbon surfaces through an ethynyl linkage, 28−31 in one case including a porphyrin containing ethynylphenyl groups in all four meso positions.…”