Model of 4-acac derived from DFT geometry optimizations. The computed structure exhibits almost perfect C2h symmetry. Computed bond distances (Å) and angles (deg): Fe–O1(2) 1.994, Fe–Neq (ave) 2.173, Fe–Nax 2.364, Fe–Oac (ave) 2.037, O1–O2 1.389, Fe…Fe 4.882, Fe–O1–O1 122.8.