Rate constant and products for the reaction of Cl atom withn-butyraldehyde

The photooxidations of n-butyraldehyde initiated by Cl atom were carried out at room temperature (298 +/- 2K) and 1 atm pressure. The rate coefficient for the reactions of Cl atom with n-butyraidehyde was determined as k = (2.04 +/- 0.36) x 10(-10) cm(3) molecule(-1) s(-1) by using relative rate techniques. The photooxidation products of n-butyraldehyde reaction with Cl atom were also studied by using both gas chromatography-mass spectrometry (GC-MS) and gas chromatography techniques. C2H5CHO, CH3CHO, CO and CO2 were the major products observed. in the absence of NO, the observed yields of C2H5CHO, CH3CHO, and CO were 60%, 3%, and 9%, respectively. However, when NO was introduced into the reaction chamber and the initial ratios of [NO](0)/[n-butyraldehyde](0) were between I and 8, the yield of C2H5CHO decreased to 33%, whereas that of CH3CHO and CO rose up to 21% and 25%, respectively. On the basis of mechanism data deduced in this study and the fraction molar yields, the approximate branching ratios for Cl atom attack at -C(O)H, alpha-, beta-, and gamma-positions in n-butyraldehyde could be derived as >= 42%, < 25%, 21%, and