Scheme 1.

Synthetic pathway for the formation of chlorido[N,N′-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes with fluorine, chlorine and bromine substituents in the position 5 in the salicylidene moieties. Step 1: synthesis of meso-1,2-bis(3-methoxyphenyl)ethylenediamine (II): Reagents and conditions: (i) MeCN anhydrous, reflux 7 h, Diaza-Cope rearrangement of (Ia) [38]; (ii) acid hydrolysis MeCN:HCl 37% 4:1, rt, 17 h, 6 M NaOH. Step 2: Synthesis of the ligands L1–L3 with fluorine, chlorine and bromine substituents in position 5, respectively. (iii) MeCN anhydrous, reflux, 1–5 h. Step 3: Synthesis of iron(III) complexes X1–X3: (iv) FeCl₃ ethanol anhydrous, reflux, 0.5–2 h