KINETIC-STUDIES OF THE REACTIONS OF ATOMIC CHLORINE WITH N-METHYLMETHYLENIMINE AND 1,3,5-TRIMETHYLHEXAHYDRO-1,3,5-TRIAZINE

The reaction of Cl + CH3N=CH2-HCl --> CH2=NCH2. has been studied with the very low pressure (VLPR) technique in the temperature range 303-363 K. The rate constant for the forward reaction is given by the expression k1 = (7.54 +/- 1.60) X 10(-11) exp(-826 +/- 240/RT) cm3 molecule-1 s-1 where R is expressed in cal mol-1 K-1. The rate constant for the reaction of atomic chlorine with 1,3,5-trimethylhexahydro-1,3,5-triazine was also measured in the temperature range 303-363 K and found to be k4 = (5 +/- 2) x 10(-10) cm3 molecule-1 s-1 at all temperatures. The conventional transition state theory suggests that the TS for reaction 1 is bent with the Cl atom forming a Cl...H...C angle ca. 160-degrees, and placed away from the nitrogen lone pair. The heat of formation of CH2=NCH2. radical is ca. 63 +/- 3 kcal/mol, and reaction 1 is exothermic by ca. 5 +/- 3 kcal/mol.