78818-71-0Relevant articles and documents
Kinetics and Mechanism of Oxidative Cyclization of Formazans to Tetrazolium Salts by Thallium(III) Acetate
Balakrishnan, R.,Srinivasan, V. S.,Venkatasubramanian, N.
, p. 404 - 406 (2007/10/02)
The kinetics of thallium(III) acetate oxidation of 1,3,5-triarylformazans have been investigated in acetic acid-water mixture.The reaction, which leads to tetrazolium salt as the product, follows the rate-law .The effect of substituent in the aldehyde (3-phenyl), the phenylhydrazine (l-phenyl) and the aryldiazonium (5-phenyl) moieties on the reaction rate has been studied and the corresponding Hammett rhos are -0.78, -0.85 and -0.8 respectively.A mechanism for the oxidative cyclization is proposed involving the formation of a N-thallated complex between the formazan and T1 (III) acetate which decomposes in a slow step accompanied by a ring closure between N-1 and N-5.
