Electrochemical synthesis and properties of poly(3-methylthiophene): Novel synthesis of poly(3-methylthiophene) with pentachlorostannate and hexachloroantimonate

Abstract

Poly(3-methylthiophene) (P3-MeT) doped with different anions were prepared electrochemically in the presence of tetraalkylammonium salts. The new poly(3-methylthiophene) SnCl 5 Ϫ and SbCl 6 Ϫ (P3-MeT SnCl 5 and P3-MeT SbCl 6 ) were prepared electrochemically using tetra-n-butylammonium pentachlorostannate and tetra-n-butylammonium hexachloroantimonate as the supporting electrolytes. The effect of current density, salt concentration, reaction temperature, and the nature of solvents on the polymer yield and polymer conductivities have been investigated. Cyclic voltammetry of poly(3-methylthiophene) has been examined at platinum electrode in 1,2-dichloroethane medium containing n-Bu 4 NSnCl 5 , Bu 4 NSbCl 6 , and Bu 4 NClO 4 as the supporting electrolytes in the range of Ϫ1.0 to 1.7 V versus SCE in the presence and absence of 3-methylthiophene. Electrical conductivity, magnetic susceptibility measurements, and structural determination by elemental analysis and infrared studies were also made. Scanning electron microscopy revealed a globular, branched, fibrous and a spongy, fibrous morphology of poly(3-methylthiophene) SnCl 5 Ϫ , ClO 4 Ϫ , and SbCl 6 Ϫ , respectively. The thermal analysis of the polymers was also investigated. Possible causes for the observed lower conductivity of these polymers have also been discussed.

Pyrolysis mass spectrometry analyses of poly(3-methylthiophene)

“…Thermogravimetric analysis of SnCl 5 doped PMTh indicated three stages of weight loss, at 150, 300-500, and 500-700 8C. Weight loss around 150 8C was assigned to the loss of water and weight loss around 300-500 8C was assigned to the loss of low molecular weight species and dopant SnCl 5 À and that around 500-700 8C to the decomposition of PMTh [10]. However, the applied technique was not suitable for characterization of degradation products.…”

“…Although several studies on thermal degradation of polythiophene appeared in the literature [5][6][7][8][9], there are only few studies on thermal stability of PMTh [2,10]. The thermal stability of PMTh films electrochemically doped with SnCl 5 À and SbCl 6 À anions was studied by thermogravimetric analysis, TGA.…”

“…The thermal stability of PMTh films electrochemically doped with SnCl 5 À and SbCl 6 À anions was studied by thermogravimetric analysis, TGA. It has been determined that the decomposition of the SbCl 6 À doped PMTh occurs at a temperature lower than that of SnCl 5 À doped PMTh [10]. The weight loss at 250 8C was assigned to loss of the dopant, SbCl 6 À and the weight loss in the temperature range of 300-500 8C was assigned to the degradation of the polymer.…”

Synthesis and Characterization of Thiophen-3-yl Acetic Acid 4-Pyrrol-1-yl Phenyl Ester and its Conducting Polymers

“…The electropolymerization reaction is sensitive to nucleophilicity of the environment in the region near the electrode surface since the reaction proceeds via radical cation intermediates, which limits the choice of solvent and electrolyte. The electrolysis potential should be also carefully controlled since high potentials may lead to the breakdown of electrolytes [43].…”