Gas-Phase Ozone Oxidation of Monoterpenes: Gaseous and ...

246 JIANZHEN YU ET AL.
Figure 10. Measured log(K om,i ) versus estimated log pL o
β-pinene/O 3 and α-pinene/O 3 systems.
for the major products in the
Table XIV. Sub-cooled liquid vapor pressure estimates
Compound T b (K) a Vapor pressure estimates at 306 K b
mm Hg
ppmv
Hydroxy pinonic acid 606 1.9 × 10 −5 0.048
Pinic acid 601 5.1 × 10 −5 0.067
Hydroxy pinonaldehydes 577 2.4 × 10 −4 0.32
Pinonic acid 572 3.4 × 10 −4 0.45
Norpinonic acid and isomers 558 8.4 × 10 −4 1.1
Hydroxy pina ketone 542 2.2 × 10 −3 2.9
Pinonaldehyde 530 4.4 × 10 −2 58
3-Oxo-pina ketone 521 6.9 × 10 −2 91
Nopinone 482 4.7 × 10 −1 620
a T b , boiling point at 1 atm if decomposition would not occur, estimated using
Meissner’s method (Rechsteiner, 1990). T b is needed to estimate vapor pressure.
Meissner’s method underestimates the T b for each of C 5 –C 10 n-alkanoic acids
by ∼6.5%, therefore a correction formula is obtained by a linear regression (r 2 =
0.994) for C 5 –C 10 n-alkanoic acids, and applied to the compounds of unknown T b .
This correction is also justified for carbonyl-containing compounds. For example,
Meissner’s method estimates that the T b for nopinone is 453 K before correction,
and 485 K after correction, which agrees well with the experimental value 482 K.
b Sub-cooled liquid vapor pressures are estimated using a modification of the
Clausius-Claperyron equation (Schwarzenbach et al., 1993).