Charge transfer intoteraction of picoline with iodine and <img src='/image/spc_char/pi.gif' border=0> acceptors- A spectroscopic study

Abstract

The interaction of 2-amino-6-methyl ridine, 2-picoline and 4-picoline as donors with iodine, 7,7',8, 8'-tetracyanoquinodimethane,2,3-dichlo -5,6-dicyano-1 ,4-benzoquinone, <i>p</i>-chloranil, <i>o</i>-chloranil, 2,4, 7- . trinitro-9-fluorenone and 2,4,5,7-tetranitro-9-fluorenone as acceptors has been studied by measuring visible and ultraviolet spectra. Infrared , electron paramagnetic and nuclear magnetic resonance spectra have also been obtained. Kinetic parameters have been derived. The results indicate that the charge transfer interaction occurs through the formation of free radicals which is followed by a slow reaction to give a diamagnetic product. However, with iodine, the charge transfer complex formation occurs without the formation of free radicals. The donor site is inferred to be the lone pair of electrones on the amino nitrogen of 2-amin -6-methylpyridine whereas for 2- and 4-picolines, the preferred site is lone pair of electrons on the pyridine nitrogen.