Electrochemical doping and semiconductor properties of poly-5,10,15,20-tetrakis(p-aminophenyl)porphyrin films

Poly-5,10,15,20-tetrakis([Formula: see text]-aminophenyl)porphyrin films were obtained by interfacial polymerization and electropolymerization. According to the results of electron spectroscopy and IR spectroscopy it has been determined that oxidative polymerization of 5,10,15,20-tetrakis([Formula: see text]-aminophenyl)porphyrin, regardless of its type (chemical/electrochemical), proceeds through the formation of phenazine and dihydrophenazine fragments. It has been established that the film obtained by the electrochemical method is in the oxidized state, the supporting electrolyte anions are included in the film. The polyporphyrin films obtained by interfacial polymerization are non-conductive. As a result of doping the films obtained by the chemical method, due to the oxidation in the anodic potential region, the polymer acquires [Formula: see text]-type semiconductor properties. It has been shown that electrochemical doping of poly-5,10,15,20-tetrakis([Formula: see text]-aminophenyl)porphyrin films can make them electroconductive. The obtained films can be recommended as elements of photovoltaic devices, the operation of which is based on the excitation of excitons under the action of light radiation, the redistribution of which leads to a change in the potential of the working electrode.

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

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.

Electroconductive films based on amino-substituted tetraphenylporphyrins and their metal copper complexes

Amino-substituted tetraphenylporphyrins (5,10,15,20-tetrakis(4′-aminophenyl)porphyrin, 5-(4′-aminophenyl)–10,15,20-triphenylporphyrin) and their copper complexes in dichloromethane and ethanol were electropolymerized by the cyclic voltammetry method and their electrochemical properties were studied. The polyporphyrin films obtained by electro-oxidation transmit electricity and possess semiconductor properties of different types. The poly-5,10,15,20-tetrakis(4′-aminophenyl)porphyrin films obtained from different solvents are similar to each other in chemical composition but different in morphology. The polyporphyrin film surface morphology was studied by AFM microscopy.