High-temperature rate constant experiments oil OH with the five large (C-5-C-8) saturated hydrocarbons n-heptane, 2,2,3,3-tetramethylbutane (2,2,33-TMB). n-pentane, n-hexane, and 2,3-dimethylbutane (2,3-DMB) were performed with the reflected-shock-tube technique using multipass absorption spectrometric detection of OH radicals at 308 nm. Single-point determinations at similar to 1200 K oil n-heptane, 2,2,3,3-TMB, n-hexane, and 2,3-DMB were previously reported by Cohen and co-workers; however, the present work Substantially extends the database to both lower and higher temperature. The present experiments span a wide temperature range, 789-1308 K, and represent the first direct measurements of rate constants at T > 800 K for n-pentane. The present work utilized 48 optical passes corresponding to a total path length of similar to 4.2 m. As a result of this increased path length, the high OH concentration detection sensitivity permitted pseudo-first-order analyses for unambiguously measuring rate constants. The experimental results can be expressed in Arrhenius form ill Units of cm(3) molecule(-1) s(-1) as follows: k(OH+n-heptane) = (2.48 +/- 0.17) x 10(-10) exp[(-1927 +/- 69 K)/T] (838-1287 K) k(OH+2,2,3,3-TMB) = (8.26 +/- 0.89) x 10(-11) exp[(-1337 +/- 94 K)/T] (789-1061 K) k(OH+n-pentane) = (1.60 +/- 0.25) x 10(-10) (exp[(-1903 +/- 146 K)/T] (823-1308 K) k(OH+n-hexane) = (2.79 +/- 0.39) x 10(-10) exp[(-2301 +/- 134 K)/T] (798-1299 K) k(OH+2.3-DMB) =(1.27 +/- 0.16) x 10(-10) exp[(-1617 +/- 118 K)/T] (843-1292 K) The available experimental data, along with lower-T determinations, were used to obtain evaluations of the expert mental rate constants over the temperature range from similar to 230 to 1300 K for most of the title reactions. These extended-telllperatUre-range evaluations, given as three-pararneter fits, are as follows: k(OH+n-heptane) = 2.059 x 10(-15)T(1.401) exp(33 K/T) cm(3) molecule(-1) s(-1) (241-1287 K) k(OH+2,2,3,3-TMB) = 6.835 x 10(-17)T(1.886) exp(-365 K/T) cm(3) molecule(-1) s(-1) (290-1180 K) k(OH+n-pentane) = 2.495 x 10(-16)T(1.649) exp(80 K/T) cm(3) molecule(-1) s(-1) (224-1308 K) k(OH+n-hexane) = 3.959 x 10(-18)T(2.218) exp(443 K/T) cm(3) molecule(-1) s(-1) (292-1299 K) k(OH+2,3-DMB) = 2.287 x 10(-17T1.958) exp(365 K/T) cm(3) molecule(-1) s(-1) (220-1292 K) The experimental data and the evaluations obtained for these five larger alkanes in the present work were used along with prior data/evaluations obtained in this laboratory for H abstractions by OH front a series of smaller alkanes (C-3-C-5) to devise rate rules for abstractions from various types of primary, secondary, and tertiary H atoms. Specifically, the current scheme was applied with good Success to H abstractions by OH from a series of n-alkanes (n-octane through n-hexadecane). The total rate constants using this group scheme for reactions of OH with selected large alkanes are given as three-parameter fits in this article. The rate constants for the various abstraction channels in any large n-alkane can also be obtained using the groups listed in this article. The present group scheme serves to reduce the uncertainties in rate constants for OH + alkane reactions.