Synthesis and characterization of dendrimeric melamine cored [salen/salophFe(III)] and [salen/salophCr(III)] capped complexes and their magnetic behaviors

摘要

2,4,6-Tris(4-hydroxybenzimino)-1,3,5-triazine [1] 2 has been synthesized from the reaction of 1 equiv. melamine (2,4,6-triamino-1,3,5-triazine) and 3 equiv. 4-hydroxybenzaldehyde. Then, 2,4,6-tris(4-(4,6-dichloro-1,3,5-triazine-2-yloxy)benzimino)-1,3,5-triazine 3 has been synthesized from the reaction of 1 equiv. 2 and 3 equiv. cyanuric chloride. And then, two new triazine centered dendrimeric ligands 2,4,6-tris(4-(4,6-bis(4-carboxyphenyloxy)-1,3,5-triazine-2-yloxy)benzimino)-1,3,5-triazine 4 and 2,4,6-tris(4-(4,6-bis(3,5-dicarboxyphenyloxy)-1,3,5-triazine-2-yloxy)benzimino)-1,3,5-triazine 5 have been synthesized from the reaction of 1 equiv. 3 and 6 equiv 4-hydroxybenzoic acid or 5-hydroxyisophtalic acid. Finally, eight new multinuclear Fe(III) and Cr(III) complexes involving tetradenta Schiff bases N,N'-bis(salicylidene)ethylenediamine-(salenH_2) or bis(salicylidene)-o-phenylene diamine-(salophH_2) with 4 or 5 have been synthesized and characterized by means of elemental analysis, ~1H NMR, FT-IR spectroscopy, thermal analyses and magnetic susceptibility measurements. The complexes can also be characterized as low-spin distorted octahedral Fe(III) and Cr(III) bridged by carboxylic acids.