Linear‐Reactor‐IR.‐Matrix and Microwave Spectroscopy of the System O₃/NO₂/(Z)‐2‐Butene

Abstract

SummaryInvestigation of the formation of complex reaction products in the gas-phase system 03/NOz/(Z)-2-butene by combination of linear reactors with IR. matrix and microwave Stark spectroscopy is reported. Besides the polyatomic products observed earlier in the gas-phase ozonolysis of (Z)-2-butene, the following products were identified: N205, HNO,, HN04, CH3N02, CH30N0, CH3COON02 and CH3C002N02 (peroxyacetyl nitrate, PAN). Matrix IR. spectra of N205, HNO,, CH3COON0, CH3COON02 required for reference purposes are presented. It is shown that PAN-formation occurs already in the absence of light. A reaction scheme is proposed for explanation of the observed complex NO,-containing products, which assumes methyldioxirane as a central intermediate. Particular reaction steps of the scheme will be discussed, including thermochemical estimates of reaction enthalpies.