Geraniol (2,6-dimethyl-2,6-octadien-8-ol) reactions with ozone and OH radical: Rate constants and gas-phase products

The bimolecular rate constants, k OH+geraniol, (231±58)×10 −12 cm 3 molecule −1 s −1 and k O 3 + geraniol , (9.3±2.3)×10 −16 cm 3 molecule −1 s −1, were measured using the relative rate technique for the reaction of the hydroxyl radical (OH) and ozone (O 3) with 2,6-dimethyl-2,6-octadien-8-ol (geraniol) at (297±3) K and 1 atmosphere total pressure. To more clearly define part of geraniol's indoor environment degradation mechanism, the products of the geraniol+OH and geraniol+O 3 reactions were also investigated. The identified geraniol+OH and geraniol+O 3 reaction products were: acetone, hydroxyacetaldehyde (glycolaldehyde, HC( O)CH 2OH), ethanedial (glyoxal, HC( O)C( O)H), and 2-oxopropanal (methylglyoxal, CH 3C( O)C( O)H). The use of derivatizing agents O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) and N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) were used to propose 4-oxopentanal as the other major geraniol+OH and geraniol+O 3 reaction product. The elucidation of this other reaction product was facilitated by mass spectrometry of the derivatized reaction products coupled with plausible geraniol+OH and geraniol+O 3 reaction mechanisms based on previously published volatile organic compound+OH and volatile organic compound+O 3 gas-phase reaction mechanisms.