[FeIII(bztpen)(OCH3)](PF6)2: Stable Methoxide–Iron(III) Complex Exhibiting Spin Crossover Behavior in the Solid State

Complex [FeIII(bztpen)(OCH3)](PF6)2 (1) crystallizes as the major yellow‐brown product from spontaneous oxidation of its corresponding iron(II) counterpart in methanol solution. Magnetic measurements and EPR spectra demonstrate that 1 undergoes a poorly cooperative 6A1↔2T2 spin conversion in the temperature range 300–50 K, with characteristic thermodynamic parameters ΔH = 6.15 kJ mol–1, ΔS = 39.88 J K–1 mol–1, and T1/2 = 154 K. The crystal structure of 1 has been investigated at 100 and 293 K.