Síntese, estudos espectroscópicos e estruturais de sistemas supramoleculares, obtidos a partir da reação de ácidos orgânicos, ligantes nitrogenados e metais da primeira série de transição

Abstract

This thesis presents the synthesis, spectroscopic and structural characterization of twenty-four supramolecular compounds, obtained from the reaction involving organic acids, nitrogenous ligands and several transition metal ions. The obtained compounds were named [Mn(bpa)(H2O)4]B2.4H2O (1),[Fe(bpa)(H2O)4]B2.4H2O (2), [Co(bpa)(H2O)4]B2.4H2O (3), [Zn(bpa)(H2O)4]B2.4H2O (4), [Co2(mal)2(bpa)(H2O)2] (5), (bipi)(Hbipi+)AS-.H2O (6), [Co(bipi)2(H2O)4]ASCl.3H2O (7), (H2bpe)B2.2H2O (8), [Fe(bpe)(H2O)4]B2.4H2O (9), [Co(bpe)(H2O)4]AS2.4H2O (10), [Ni(bpe)(H2O)4]AS2.4H2O (11), [Zn(bpe)(H2O)4]AS2.4H2O (12), HASbpa (13), [Co(bpa)(H2O)4]AS2.4H2O (14), [Mn2(bpp)4(H2O)4]AS4.H2O (15), [Co2(bpp)4(H2O)4]AS4.H2O (16), [Zn(bpp)(AS)2] (17), [Mn(Hbpa)2(H2O)2(4-sb)2].2H2O (18), [Co(Hbpa)2(H2O)4](4-sb)2 (19), [Ni(Hbpa)2(H2O)4](4-sb)2 (20), [Zn(Hbpa)2(H2O)4](4-sb)2 (21), [Mn(bipi)2(H2O)4](H2Vi)2 (22), Mn(bpa)2(H2O)4](H2Vi)2 (23) and [Mn(bpp)2(HVi)]H2O (24). For most of the obtained compounds, the X-ray single crystal diffraction technique has been used to describe the coordination mode, distances, bond angles as well as the presence of supramolecular interactions, such as π-stacking, hydrogen bonding, C–H…π, N–H…π and electrostatic interactions. Such interactions were considered very important for the stability of the structures and for the generation of the so-called non-covalent arrangements, which are classified according to the literature nomenclature, being mentioned in this work for some of the compounds, such as pseudo honeycomb, chain or rectangle, among others. The vibrational study of all the synthesized compounds, involving infrared and Raman spectroscopic techniques, has also provided important information about the coordination geometry and the presence of the building blocks used in each synthesis. The use of specific vibrational bands, used as markers to monitoring the ligands present in the obtained products, has shown the importance of the wavenumber position of each one of the bands, when compared to the free ligands, in order to identify the presence of each one of the building blocks used. At last, all the structural and spectroscopic information have been discussed in order to understand the non covalent forces responsible for the existence of the solid state structures, considered very important in the context of supramolecular chemistry.