(A) Schematic structure of the TMG3tren ligand. (B) Thermal ellipsoid drawing of [FeII(TMG3tren)(OTf)]+ (2), showing 50% probability ellipsoids. Hydrogen atoms have been omitted for clarity. Selected bond distances (Å): Fe-O, 2.156(2); Fe-Naxial, 2.118(3); Fe-Nguanidine(ave), 2.094. (C) Ball-and-stick and (D) space-filling models of the DFT geometry optimized structure of 3. Selected bond distances (Å): Fe=O, 1.648; Fe-Naxial, 2.121; Fe-Nguanidine(ave), 2.034. Atom color scheme: C, gray; N, blue, O, red; S, yellow; F, light blue; Fe, magenta.