The Synthesis and Characterization of Dipodal 2-Chloro-4,6-Diamino-1,3,5-Triazine-Schiff Bases and Investigation of Their Monomer and Dimer Fe(III) Metal Complexes

In this study, A new synthetic route for the preparation of multidirectional ligands was developed using 2‑chloro-4,6-diamino-1,3,5-triazine (DACT) as starting material. Novel triazine-centered dipodal Schiff bases were synthesized via condensation reactions. (DACT) has been reacted with 2,5-dihydroxybenzaldehyde (gentisaldehyde) (GA) molecule in the presence of acetic acid and acetone to get 2‑chloro-4,6-N,N'-bis(2,5-dihydroxybenzilidene)-1,3,5-triazine (DACTGA). After pure ethylenediamino-bis[4,6-N,N'-bis(2,5-dihydroxybenzylidine)-1,3,5-triazine] (DACTGAMA)2 had been obtained by the dimerization with ethylenediamine was isolated by filtration directly from the reaction mixture. N,N'-Diisopropylethylamine (DIPEA, ‘Hunig's base’) was used to trap the HCl formed during the substitution reaction. On the other hand, pentadentate (ONNNO) Schiff bases, mononuclear [Fe(DACTGA)Cl] and binuclear complex [Fe(DACTGAMA)Cl]2 of (DACTGA) and (DACTGAMA)2 have been gained via the reaction with nonaqueous FeCl3. The complexes were characterized as high spin d5 (S = 5/2) distorted trigonal bipyramidal. The binuclear complex [Fe(DACTGAMA)Cl]2 plays a role as a bridge for weak anti-ferromagnetic intramolecular exchange. Dipodal structure provides bridge formation; The 2‑chloro substitute, on the other hand, modulates metal-ligand interactions by altering the electron attraction and nucleophilic location of the ligand. These compounds are model systems for controlling Fe(III) bridging behaviour by modifying ligand electronic parameters. As a result, two different ligands have been characterized by FT-IR, 1HNMR and TGA. Structures of isolated monomer and dimer complexes have been clarified with the analysis of FT-IR LC-MS analysis, AAS, and elemental analysis and data of magnetic susceptibility taken by TGA.