Síntese, caracterização e reatividade de complexos de ferro contendo bases de Schiff funcionalizadas

Abstract

Two iron complexes with N-Heterocyclic functionalized ligands were synthesized, and designated as [Fe(bapzdip)](PF6)2 and [Fe(apimpi)3(PF6)2, where the Schiff base bapzdip (N,N'-bis(7metil-2piridilmetilneo)-1,3 diiminopropano) acts as a tetradentate ligand and derived apimpi ((1-(piridin-4-il)-N-[(1E)-1-(piridin-2-il)etilideno]metanimina)) as bidentate. The characterization of these complexes were used spectroscopic and electrochemical methods, from which showed the interaction between the metal ion and the imine ligands. You can also say that there is a large relocation of load on the system Fe dπ-π* imine as a consequence of receptor character of the Schiff bases. The reaction between iron complexes with and Na3[Fe(CN)5NH3] resulted in two complexes with formulas proposed {Fe(bapzdip)[Fe(CN)5]2)4- and {[Fe(apimpi)3][Fe(CN)5]3}7- whose values of redox potentials and absorption maxima allowed to assess the strong character of the π-receptor ligands imine. Interactions with Au0 led to the formation of nanoparticle clusters and the results obtained by the SERS effect, withdrew the information that the complex of iron(II) is adsorbed on the surface of gold nanoparticles through the pyrazine nitrogen. As a result of this interaction, there was a significant enhancement of Raman scattering, which opens a field for possible studies using the system Au0/Fe (bapzdip) in chemical sensing of biomolecules. For the interaction of iron complex with bovine serum albumin was observed that the fluorescence quenching was induced by the static process, while 60.50% of the fluorescence is accessible to the suppressor (complex [Fe(bapzdip)]2+). With the values obtained for the thermodynamic parameters (ΔG, ΔH and ΔS) inferred that the process of formation of BSA-complex [Fe (bapzdip)] is spontaneous and that the strength of van der Waals and hydrogen bonding played important roles in stabilizing the complex.