| dc.identifier | SILVA, Ricardo Soares Mota. Complexos mono, bi e trinucleares de metais de transição com bases de Schiff tridentadas tipo ONN e tetradentadas do tipo ONNO : síntese, caracterização e estudos como catalisadores na oxidação de catecois. 2015. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2015. Disponível em: https://repositorio.ufscar.br/handle/ufscar/7311. | |
| dc.description.abstract | Salen-type complexes are an important class of
coordination compounds, which have been used to catalyze a wide variety of
reactions in various homogeneous and heterogeneous systems. Complexes of
transition metals are very versatile and participate in many chemical processes,
which make the study of these very interesting. Research shows that the complexes
of salen [salen = N, N'-ethylenebis (salicilidenoamina)] are efficient catalysts, and
some compounds of this type have been investigated as catalysts in the oxidation of
catechol. In this work were synthesized six types of compounds, ligands, symmetric
mononuclear complexes, tridentate complexes, asymmetric mononuclear complexes,
binuclear and trinuclear complexes. The series have satisfactory yields. The
synthesized compounds in this work were characterized by melting point, elemental
analysis, vibrational spectroscopy in the IR region, absorption spectra in the UV-vis,
conductivity measurements and solubility. The ligands and three palladium(II)
complexes were also characterized by nuclear magnetic resonance. From these
characterizations, comparisons were made between ligands, mononuclear,
tridentate, binuclear and trinuclear complexes, and also with respect to the effects of
the substituents on the aromatic ring at positions 4 and 5. The kinetics was
performed using a spectrophotometer, following the formation of the product derived
from oxidation of 3,5-di-tert-butylcatechol at 400 nm. In kinetic study were tested the
binuclear and the trinuclear complexes which showed catalytic activities compatible
with those of similar complexes described in the literature, among them we can
mention the binuclear complexes [Cu(Cu(t-4DEA-salcn))Cl2] e [Cu(Cu(t-5NO2-
salcn))Cl2] , kcat = 0,132 s-1 e kcat = 0,108 s-1, respectively; and the palladium(II)
copper(II) binuclear complexes [Cu(Pd(t-salcn))Cl2] e [Cu(Pd(t-4-DEA-salcn))Cl2], kcat
= 0,113 s-1 e kcat = 0,240 s-1, respectively. | |
