Complexes of Iron(III) and Chromium(III) Salen and Salophen Schiff Bases with Bridging 1,3,5-Triazine Derived Multidirectional Ligands

A new synthetic route for preparing multidirectional ligands was developed by using 2,4,6-trichloro-1,3,5- triazine (cyanuric chloride) as core. The reaction included the selective substitutions of 4-aminobenzoic acid onto three chlorides of the triazine ring via a stepwise manner at 1:1, 1:2, or 1:3 equiv. and 0, 25, 130 degrees C, respectively. An efficient synthesis of a novel class of multidirectional ligands'' has been developed based on high-yielding chloride substitutions of 2,4,6-trichloro-1,3,5-triazine by amines. Sixteen new mono-, di-, tri-, and tetra-nuclear Fe(III) and Cr(III) complexes involving tetradenta Schiff bases N,N'-bis(salicylidene)ethylenediamine-(salenH(2)) or bis(salicylidene)-o-phenylenediamine-(salophenH(2)) with two new 1,3,5-triazine derived multidirectional ligands were synthesized and characterized by means of elemental analysis, H-1 NMR, FT-IR spectroscopy, LC-MS analysis, AAS, thermal analysis, and magnetic susceptibility measurements. The complexes were also characterized as low-spin distorted octahedral Fe(III) and Cr(III) bridged by carboxylic acids. It was understood that the [{Fe(salen)/(salophen)}(2)O] and [{Cr(salen)/(salophen)}(2)O] containing compounds could be represented by the electronic structure of t(2g)(6)e(g)(0) and t(2g)(3)e(g)(0).