Hidratação reversível de complexos fenilseleninatos para- substituído de cobalto(II)

Abstract

In this study eight novel compounds were synthesized and characterized from pre-ligands pheylseleninic acid 1, 4-t-butiphenyilseleninic acid 2, 4-methylphenyilseninic acid 3 and 4-clorophenylseleninic acid 4. The ability of each compound in the process of reversibility of hydration was studied with emphasis on their properties and structural characterization by infrared spectroscopy, single-crystal x-ray diffraction, powder x-ray diffraction, elemental analysis and thermogravimetric analysis. The reactions were carried out ammonium salts of seleninics acids and metal salt Co(II). Hydrated complexes obtained single crystals suitable for x-ray diffraction, were obtained by hydrothermal synthesis reactions the complexes 3b and 4b show molecular compounds with the formula [Co (OH2)4(O2SeC6H4X)2], x = CH3 3B, and x= Cl 4B, dimensional form complex networks through hydrogen bonds and are isostructural. 1A and 2B of complex structures were determined by powder x-ray diffraction. Dehydration process of complexes 1A, 2B, 3B and 4B, at a temperature of 140 °C about 2 hours in argon atmosphere, the obtained coordination polymers: phyllo poli [Co(O2SeC4H5)2] 1C, phyllo poli [Co(O2SeC6H4t-But)2]2C, phyllo poli [Co(O2SeC6H4Me)2] 3C e phyllo poli [Co(O2SeC6H4Cl)2] 4C. The dehydrated complex (1C, 2C, 3C and 4C), were stored in a humid environment (84% RH). After five days it was possible the realization of rehydration of each complex 1A', 2B' and 3B' to their original products. The reversibility 4A' occurs to a lesser extent when compared with your original product Analyses thermogravimetric, infrared spectroscopy, scanning electron microscopy, elemental analysis and melting point for all complex hydrated, dehydrated and rehydrated. Proving beyond purity, the changes that occur in each phase obtained in complex hydrated, dehydrated and rehydrated.