COMPLEXES OF IRON(III) SALEN AND SALOPH SCHIFF-BASES WITH BRIDGING DICARBOXYLIC AND TRICARBOXYLIC ACIDS

Six new dinuclear or trinuclear Fe-III complexes involving tetradentat e Schiff bases N,N'-bis(salicylidene)ethylenediamine (salenH(2)) or bi s(salicylidene)-o-phenylene-diamine (salophH(2)) with 2,5-pyridinedica rboxylic acid, acetylenedicarboxylic acid or 1,3,5-benzenetricarboxyli c acid have been synthesized and characterized by means of elemental a nalysis, i.r. spectroscopy, thermal analyses, conductivity measurement s and variable-temperature magnetochemical measurements to the tempera ture of liquid nitrogen. The complexes can be characterized as high-sp in distorted octahedral Fe-III bridged by carboxylic acids. The dicarb oxylic or tricarboxylic acids play a role as bridges for weak antiferr omagnetic intramolecular exchange. The antiferromagnetic coupling para meters J vary in the - 1.99 to 5.47 cm(-1) range for the dimers, whils t the values are -2.35 and 1.42 cm(-1) for the salen and saloph trimer s, respectively. One complex, namely [{Fe(saloph)}(2)(2,5-dicarpy)] . H2O, obeys the Curie-Weiss law.