Polarography of thiocyanato-derivatives of thiophene
The polarographic reduction of 17 thiocyanatothiophenes with various functional substituants was studied. The mechanism of the reduction of the thiocyanato-group in this series does not differ from that known for other thiocyanato-derivatives. The mercapto-group formed in the reduction exists in the form of the thienylmercaptide anion in neutral unbuffered medium.
Satisfactory correlation is observed between the half-wave potential and the Hammett constants for 5-substituted 2-thiocyanatothiophenes with a value of the slope 0.48±0.03. On the basis of the correlation equation obtained, an approximate value of −(0.14±0.06) was calculated for the Hammett constant of the substituent S−.
KeywordsThiophene Correlation Equation Polarography Satisfactory Correlation Hammett Constant
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