The hydroxyl radical reaction rate constant and atmospheric transformation products of 2-butanol and 2-pentanol

✍ Scribed by J. Steven Baxley; J. R. Wells

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 173 KB
• Volume: 30
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1998)30:10<745::aid-kin7>3.0.co;2-v

✦ Synopsis

The relative rate technique has been used to measure the hydroxyl radical (OH) reaction rate constant of ϩ2-butanol (2BU, CH 3 CH 2 CH(OH)CH 3 ) and 2-pentanol (2PE, CH 3 CH 2 CH 2 CH(OH)CH 3 ). 2BU and 2PE react with OH yielding bimolecular rate constants of and respec-Ϫ12 3 Ϫ1 Ϫ1 Ϫ12 3 Ϫ1 Ϫ1 (8.1 Ϯ 2.0) ϫ 10 cm molecule s (11.9 Ϯ 3.0) ϫ 10 cm molecule s , tively, at and 1 atmosphere total pressure. Both 2BU and 2PE OH rate constants 297 Ϯ 3 K reported here are in agreement with previously reported values [1-4]. In order to more clearly define these alcohols' atmospheric reaction mechanisms, an investigation into the OH ϩ reaction products was also conducted. The reaction products and yields alcohol OH ϩ 2BU observed were: methyl ethyl ketone (MEK, CH 3 CH 2 C( "O)CH 3 ) and acetaldehyde (60 Ϯ 2)%, HC(" O)CH 3 ). The reaction products and yields observed were: 2-pen-((29 Ϯ 4)% OH ϩ 2PE tanone (2PO, CH 3 C("O)CH 2 CH 2 CH 3 ), propionaldehyde HC( " (41 Ϯ 4)%, ((14 Ϯ 2)% O)CH 2 CH 3 ), and acetaldehyde HC( "O)CH 3 ). The alcohols' reaction mechanisms ((40 Ϯ 4)%, are discussed in light of current understanding of oxygenated hydrocarbon atmospheric chemistry. Labeled 2BU/OH reactions were conducted to investigate 2BU's atmospheric trans-18

( O) formation mechanism details. The findings reported here can be related to other structurally similar alcohols and may impact regulatory tools such as ground level ozone-forming potential calculations (incremental reactivity) .