Hydroxyl Radical OH

The hydroxyl radical has a strong tendency to abstract a hydrogen atom whenever possible, forming the thermodynamically stable water molecule. In the case of alkanes, the reaction is therefore

Table 6.2 summarizes rate constants for some OH-al-kane reactions; for recent recommendations for other alkanes, see Atkinson (1994, 1997a) and Atkinson et al. (1997a).

The temperature dependence is given in the form k = BT"e~c/ J, where n is usually taken as 2, except for CH4. This fit procedure provides curvature in the Arrhenius plot similar to that which is observed. Donahue et al. (1998a) propose an alternate form of the

TABLE 6.2 Rate Constants and Temperature Dependence"'®' for Reaction of OH Radicals with Some Alkanes

Jt(10"l2cm3 D

Alkane at 298 K molecule"1 s"r) (K) n em's"1) (K)

Methane

0 0

Post a comment