Microwave spectroscopic and ab initio studies of pyrolysis products of 2-nitrosopropene (syn form) and its pyrolysis mechanism

The pyrolysis products of CH2=(CH3)-NO (syn form) have been determined by m icrowave spectroscopy. The pyrolysis products of CH2=(CH3)-NO (syn form) an d its N-15 isotopic species were found to be CH2=O CH3CN, and (CH3CN)-N-15. The produce of formaldehyde and methyl cyanide suggests that the C=C and N =O double bonds of CH2=(CH3)-N=O (syn form) were broken. To explain the gen eration of the two molecules, a four-membered ring molecule (9) as an inter mediate, is proposed. The four-membered ring molecule as an intermediate is also supported by ab initio MO calculation. Applying the pyrolysis mechani sm obtained for 2-nitrosopropene (syn form) to that of 1,1,2-trichloronitro soethane, one of its complicated pyrolysis mechanisms was explained. The ro tational constants and geometrical parameters of two intermediates, 9 and C H2=CCl-NO (13), were obtained by ab initio MO calculation (MP2/6-31G**) to predict their microwave spectra. (C) 2001 Elsevier Science B.V. All rights reserved.