Unique chlorine-containing compounds from the reaction of atomic chlorine with 1,3-butadiene in air at room temperature

Chlorine atoms may be generated by reactions of sea salt particles transported inland with air masses. A potential approach to investigate chlorine atom production in the troposphere is to identify and measure unique chlorine-containing products of the reactions of Cl with organics in air. 1,3-Butadiene is an airborne toxic organic and is emitted from motor vehicles. If any unique chlorine-containing products can be determined from the reaction of Cl with 1,3-butadiene, they could serve as "markers" for chlorine atom chemistry in coastal areas. We present studies of mechanisms and products of this reaction in 1 atm air and room temperature. Products were characterized using FTIR and GC-MS. Chlorocrotonaldehyde (CCA) has been identified as a unique chlorine-containing product from the reaction of 1,3-butadiene with chlorine atoms in the presence and absence of NO in air. The preliminary estimate of the yield of CCA is about 35% independent of the presence of NO. The yield of chloromethyl vinyl ketone (CMVK), another chlorine-containing compound from this reaction, is 17 ± 6% (1s) in the absence of NO. In the presence of NO, the upper limit of the yield of CMVK is < 9%. The atmospheric implications will be discussed.