Direct measurement of singlet methylene removal rates by organic species containing the – O – and > C = O moieties
Abstract
The technique of laser flash photolysis/laser absorption has been used to obtain absolute removal rate constants for singlet methylene 1CH2(ã1A1) with dimethyl ether (CH3OCH3), acetaldehyde (CH3CHO), acetone (CH3COCH3), acetic acid (CH3CO2H), methyl formate (HCO2CH3), acetic anhydride (CH3CO2COCH3), and dimethyl carbonate (CH3OCO2CH3). The removal rate constants were found to be (1.80 ± 0.22), (2.81 ± 0.35), (4.48 ± 0.35), (5.71 ± 0.40), (2.82 ± 0.32), (5.27 ± 0.71) and (2.68 ± 0.28)× 10–10 cm3 molecule–1 s–1, respectively. Removal rate constants for the molecules containing the > CO moiety are considerably greater than those for the corresponding alkanes, but the removal rate constant for dimethyl ether is significantly less than that for the alkane analogue, propane. Removal rate constants were also remeasured for ethane (C2H6), ethene (C2H4) and methanol (CH3OH) and found to be (1.95 ± 0.48), (2.46 ± 0.23) and (3.69 ± 0.37)× 10–10 cm3 molecule–1 s–1, respectively.