Fig. 4.

ORTEP structural diagram showing 50% probability ellipsoids and partial atom numbering schemes for Cu(II)-bound FlamS. (a) orientation showing the full tetranuclear arrangement of [Cu₂Cl(FlamS)₂]₂²⁺ (two outer-sphere Cl⁻ anions not shown). (b) truncated orientation rotated forward 90° from (a) with two FlamS units deleted for clarity to highlight the coordination spheres around the Cu centers. The two units are related by a 2–fold rotation axis where the atoms labeled XX_2 are symmetry generated. Selected bond distances (Å) and angles (˚): Cu1–O4, 2.041(4); Cu1–N2, 1.930(5); Cu1–O5, 1.943(4); Cu1–Cl1, 2.533(2); Cu1–O5_2, 1.913(4); N1–N2, 1.361(7); N2–C21, 1.291(8);