A (mu-eta(2):eta(2)-peroxo)dicopper(II) complex, [Cu-2(H-L)(O-2)](2+) (1-O-2), supported by the dinucleating ligand 1, 3-bis[bis(6-methyl-2-pyridylmethyl)aminomethyl]benzene (H-L) is capable of initiating C-H bond activation of a variety of external aliphatic substrates (SHn): 10-methyl-9,10-dihydroacridine (AcrH(2)), 1,4-cyclohexadiene (1,4-CHD), 9,10-dihydroanthracene (9,10-DHA), fluorene, tetralin, toluene, and tetrahydrofuran (THF), which have C-H bond dissociation energies (BDEs) ranging from similar to 75 kcal mol(-1) for 1,4-CHD to similar to 92 kcal mol(-1) for THF. Oxidation of SHn afforded a variety of oxidation products, such as dehydrogenation products (SH(n-2)), hydroxylated and further-oxidized products (SH(n-1)OH and SH(n-2)=O), dimers formed by coupling between substrates (H(n-1)S-SH(n-1)) and between substrate and H-L (H-L-SH(n-1)). Kinetic studies of the oxidation of the substrates initiated by 1-O-2 in acetone at-70 degrees C revealed that there is a linear correlation between the logarithms of the rate constants for oxidation of the C-H bonds of the substrates and their BDEs, except for THF. The combination of this correlation and the relatively large deuterium kinetic isotope effects (KIES), k(2)(H)/k(2)(D) (13 for 9,10-DHA, >= 29 for toluene, and similar to 34 for THF at-70 degrees C and similar to 9 for AcrH(2) at -94 degrees C) indicates that H-atom transfer (HAT) from SHn (SDn) is the rate-determining step. Kinetic studies of the oxidation of SHn by cumylperoxyl radical showed a correlation similar to that observed for 1-O-2, indicating that the reactivity of 1-O-2 is similar to that of cumylperoxyl radical. Thus, 1-O-2 is capable of initiating a wide range of oxidation reactions, including oxidation of aliphatic C-H bonds having BDEs from similar to 75 to similar to 92 kcal mol(-1), hydroxylation of the m-xylyl linker of H-L, and epoxidation of styrene (Matsumoto, T.; et al. J. Am. Chem. Soc. 2006, 128, 3874).