Current location: JICS Archive > Vol. 5 > No. 3 > Articles : 11
Antipyrilquinoneimine Dye Formation by Coupling Aniline Derivatives with 4- Aminoantipyrine in the Presence of Ruthenium Nanoparticles
J. Kasthuri, J. Santhanalakshmi* and N. Rajendiran
aDepartment of Chemistry, S.R.M. University, Faculty of
Engineering and Technology, Chennai-603 203
bDepartment of Physical Chemistry, University of Madras, Guindy
Campus, Chennai-600 025, India
cDepartment of Polymer Science, University of Madras, Guindy Campus,
Chennai-600 025, India
The coupling of 4-aminoantipyrine (4-AAP) with aniline derivatives catalyzed by ruthenium nanoparticles (Rnp) has been studied by UV-Vis spectroscopy in aqueous medium. The rate constant for antipyrilquinoneimine dye formation depends on the nature of the aniline substituent and the pH, ionic strength and temperature of the reaction medium. The maximum rate constant of the dye formation reaction is observed at pH 3.6. Aniline derivatives with electron donating substituents show higher rate constant values than those with electron withdrawing substituents, with increasing rate constant values in the order: N,N-dimethyl aniline > o-toluidine > o-chloroaniline > m-chloroaniline. With pseudo first order kinetics, the total order is 1.0 + 1.0 + 1.0 = 3.0, which includes the orders with respect to amine, 4-AAP and Rnp. Studies on these effects help to complete the kinetic analysis as well as propose the reaction pathway. Furthermore, TEM measurement confirms that the nanoscalar size of the Rnp is 7 nm.
Keywords: Antipyrilquinoneimine dyes, Coupling reaction, Anilines, Reaction kinetics, Ruthenium nanoparticles
