Trinuclear cobalt(II) and binuclear iron(III) complexes with unsymmetricaltetradentate Schiff-base ligands derived from 3-formylsalicyclic acid: Synthesis, magnetic, spectroscopic and Mossbauer investigations
F. Tuna et al., Trinuclear cobalt(II) and binuclear iron(III) complexes with unsymmetricaltetradentate Schiff-base ligands derived from 3-formylsalicyclic acid: Synthesis, magnetic, spectroscopic and Mossbauer investigations, REV RO CHIM, 45(7-8), 2000, pp. 795-800
Two Schiff bases, 3-((N-2-carboxyphenyl)formimidoyl)salicylic acid, H(3)fsa
amb, and 3-((N-2-carboxyethyl)formimidoyl)salicylic acid, H(3)fsaala which
are obtained by condensation of 3-formylsalicylic acid with 2-aminobenzoic
acid and beta -alanine respectively, are used as ligands for the design of
homotrinuclear metal(II) and homodinuclear metal(III) complexes. The metal
centers are bridged by carboxylic and/or phenolic oxygen atoms. Three new c
ompounds, [Co-3(fsaamb)(2)(H2O)(6)], [Co-3(fsaala)(2)(H2O)(6)], and [Fe-2(f
saamb)(2)(H2O)(2)], have been synthesized by reacting the above Ligands wit
h the appropriate metal perchlorates in slightly basic solutions. The IR sp
ectra show that the ligands act in a tetradentate manner, coordinating thro
ugh the imino, phenolato,and the two carboxylato groups. The stereochemistr
y of the metal ions in the three compounds is assigned according to the mag
netic and UV/VIS spectroscopic data. The Fe(III) derivative has been also c
haracterized by Mossbauer spectroscopy (delta = 0.67 mm s(-1) and DeltaE(q)
= 0.94 mm s(-1) at 300 K; delta = 0.77 mm s(-1) and DeltaE(q) = 0.93 mm s(
-1) at 80 K).