Banca de DEFESA: ANALLICY SANTOS DE PAIVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANALLICY SANTOS DE PAIVA
DATA : 02/07/2019
HORA: 14:00
LOCAL: Sala de aula do Química I
TÍTULO:

Iron and manganese complexes with Schiff salen base derivatives and carboxylates ligands

PALAVRAS-CHAVES:

Complexes. Schiff Base. Salicylate. Biphthalate

PÁGINAS: 118
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
ESPECIALIDADE: Campos de Coordenação
RESUMO:

Salen-type complexes are an important class of coordination compounds, with the intention of continuing to investigate this ligand in new complexes, this present work has the objective to synthesize new iron-(III) and manganese-(III) complexes containing as main ligand the salen base Schiff derivaties, 3-MeOsalen or 3-MeOsalophen, and the salicylate and biphthalate carboxylate ligands as auxiliaries. The synthesized ligands, precursors complexes and the novel synthesized carboxylate complexes were characterized by spectroscopic techniques (Vibrational spectroscopy in the infrared region, Raman Spectroscopy,   Electronic spectroscopy in the ultraviolet and visible region and fluorescence), electrochemistry (cyclic voltammetry) and thermal analysis (Thermogravimetry). The complexes presented asymmetric and symmetrical vibrational modes of the carboxylate group, for salicylates,  observed in 1570 cm^-1 (υ_asCO₂^-) and 1370 cm^-1 (υ_sCO₂^- ) while  the spectra of the complexes with biphthalate, the υ_asCO₂^- were observed in around 1700 cm^-1 and υ_sCO₂^- around 1350 cm^-1. By the variation of these stretches, the ligands are coordinated in bidentent form by oxygen from different groups. In relation to the electronic spectra for the carboxylate iron complexes, bathochromic displacement of the LMCT charge transfer band was verified and in the manganese complexes changes in the d-d bands were observed, having as reference the respective precursor complexes. These changes were due to substitution of the chloride ligand by the carboxylate ligand. In the emission spectra of the iron complexes with 3-MeOsalophen ligand, they presented an emission band around 480 nm. In the voltamograms of the complexes was observed a metal redox pair Fe³⁺/Fe²⁺ ou Mn³⁺/Mn²⁺ and processes related to the Schiff base. In replacing the chloride ligand by the carboxylate caused an increase in difference of the cathodic potential and the anodic potential of the metal. In the TG and DTG curves have been observed the decomposition of the carboxylate ligand at around 262°C and the other two losses attributed to Schiff's base.

MEMBROS DA BANCA:
Interno - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Externo ao Programa - 1715109 - DANIEL DE LIMA PONTES
Externa à Instituição - DANYELLE MEDEIROS DE ARAUJO - IFRN
Presidente - 1945343 - FRANCISCO ORDELEI NASCIMENTO DA SILVA
Externa à Instituição - ULISANDRA RIBEIRO DE LIMA - IFRN