| Full text | |
| Author(s): |
Goncalves Nunes, Wilhan Donizete
[1]
;
Teixeira, Jose Augusto
[1]
;
Ekawa, Bruno
[1]
;
Carneiro Soares do Nascimento, Andre Luiz
[1]
;
Ionashiro, Massao
[1]
;
Caires, Flavio Junior
[1, 2]
Total Authors: 6
|
| Affiliation: | [1] Univ Estadual Paulista UNESP, Inst Quim, Araraquara, SP - Brazil
[2] Univ Estadual Paulista Unesp, Fac Ciencias, Bauru, SP - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Thermochimica Acta; v. 666, p. 156-165, AUG 10 2018. |
| Web of Science Citations: | 3 |
| Abstract | |
Solid-state M(IN)(2)center dot nH(2)O complexes, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), IN is isonicotinate and n = 0.5 to 4.0 H2O, were synthesized. Characterization and thermal behavior of the compounds were performed employing elemental analysis (EA), complexometric titration with EDTA, powder X-ray diffraction (PXRD), infrared spectroscopy (FTIR), simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC) in dynamic dry air and nitrogen atmospheres, differential scanning calorimetry (DSC) and TG DSC coupled to FT1R. The thermal behavior of isonicotinic acid and its sodium salt was also investigated in both atmospheres. The dehydration of these compounds occurs in a single step in both atmospheres. In air atmosphere, the thermal decomposition of the anhydrous compounds also occurs in a single step, except for the copper compound where two steps are observed. In N, the thermal decomposition of the anhydrous compounds occurs in two consecutive steps, except for iron compound, where three steps are observed. The main gaseous products of thermal decomposition/pyrolysis of the compounds were identified as CO, CO2 and Pyridine. Mn, Co, Cu and Zn compounds show a physical transformation process in DSC curves. The ligand coordinates through the pyridine nitrogen atom to the metal and for the Zn compound, the carboxylate group also participates in the coordination. The IR absorption profile of hydrated and dehydrated compounds suggest that there is a probable change in the coordination mode of the ligand upon dehydration. This change needs to be further investigated, once it is not possible to ensure only with infrared spectroscopy data. (AU) | |
| FAPESP's process: | 17/14936-9 - Preparation, characterization and thermoanalytical studies of heterogeneous catalysts of double selenates of Mg/Co and Mg/Cu in biodiesel production using different oils |
| Grantee: | Massao Ionashiro |
| Support Opportunities: | Regular Research Grants |