Some solid effects in iron(II) complexes with ligands of potential biological interest
&&za& - New complexes of iron(I1) with bidentate ligands derived from 5-bromo-salicylaldehyde and monosubstituted anilines have been synthesized and characterized by chemical analyses and conventional spectroscopies. Several properties were characterized in these complexes in the solid phase: (a) absence of oxygen bridges, (b) anomalously high magnetic moment values at room temperature, (c) an antiferromagnetic behavior at low temperatures, (d) a doublet Mossbauer spectrum with a normal isomer shift value for low spin iron(I1) complexes at room temperature, (e) presence of hyperfine pattern Mossbauer spectra at 4K with at least a sextuplet and a doublet having an internal magnetic field of ca 460 KOe. These results together with the simulation curves of magnetic susceptibilities versus temperature, suggest the existence of at least two sites for the iron atom and could tentatively be interpreted assuming the existence of a formal planar geometry around the iron atoms, probably in a triplet state, and ferrimagneticantiferromagnetic interactions.