Photolysis of 3-methyl-3-chlorodiazirine

Abstract

The photolysis of 3-methyl-3-chlorodiazirine has been investigated in the gas phase at pressures (with added bath gases) up to 6000 Torr (800 kPa). The principal products were vinyl chloride, nitrogen, acetylene, hydrogen chloride and 1,1-dichloroethane. The experimental results indicate that the vinyl chloride is formed with a very wide energy spread; at low pressures most of it decomposes to yield acetylene and HCl. Evidence is presented that the dichloroethane results from the reaction of methylchlorodiazomethane, formed by photoisomerization from the diazirine, with the HCl produced in the system. There is no evidence that trapping by HCl of methylchlorocarbene, formed as the primary decomposition product of the electronically excited methylchlorodiazirine, can be more than a minor reaction pathway.