Monomeric imidozirconocene complexes, Cp₂Zr=NCMe₃ (Cp = cyclopentadienyl), undergo 1,2-RH (R = aryl) additions across the Zr=N bond to give products of a formal C-H bond activation (R-Zr-NH).  This activation of arenes does not extend to the C-H bonds of saturated hydrocarbons.  In contrast, the more electron-donating ethylenebis(tetrahydro)indenyl (ebthi) ligand promotes the rac-(ebthi)Zr=NCMe₃ complex to cleanly and quantitatively activate a wide range of n-alkane, alkene, and arene C-H bonds.  To investigate the factors responsible for this observed increase in reactivity, a series of complexes bearing substituted Cp ligands, such as Cp* (C₅Me₅), has been prepared and reactivity toward C-H bonds has been investigated.  Ligands that present an electron-donating environment, such as in Cp*CpZr=NCMe₃, also promote C-H bond activation of n-alkanes, whereas complexes bearing less electron-donating Cp-based ligands react only with arenes.  The observed differences in reactivity can be attributed predominantly to the electronic contribution of the substituents on the Cp rings.