- Structural investigation and photoluminescent properties of gadolinium(III), europium(III) and terbium(III) 3-mercaptopropionate complexes
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This work reports on the synthesis, crystallographic determination and spectroscopic characterization of gadolinium(III), terbium(III) and europium(III) 3-mercaptopropionate complexes, aqua-tris(3-mercaptopropionate) lanthanide(III) - [Ln(mpa)3(H2O)]. The Judd-Ofelt intensity parameters were experimentally determined from emission spectrum of the [Eu(mpa)3(H2O)]complex and they were also calculated from crystallographic data. The complexes are coordination polymers, where the units of each complex are linked together by carboxylate groups leading to an unidimensional and parallel chains that by chemical interactions form a tridimensional framework. The emission spectrum profile of the [Eu(mpa) 3(H2O)] complex is discussed based on point symmetry of the europium(III) ion, that explains the bands splitting observed in its emission spectrum. Photoluminescent analysis of the [Gd(mpa)3(H 2O)] complex show no efficient ligand excitation but an intense charge transfer band. The excitation spectra of the [Eu(mpa)3(H 2O)] and [Tb(mpa)3(H2O)] complexes do not show evidence of energy transfer from the ligand to the excited levels of these trivalent ions. Therefore the emission bands are originated only by direct f-f intraconfigurational excitation of the lantanide(III) ions.
- Souza,Mazali,Sigoli
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- Beta-mercaptopropionic acid synthetic method
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The invention provides a beta-mercaptopropionic acid synthetic method. The method takes acrylamide and hydrogen sulfide or sodium sulfhydrate as raw materials to obtain the addition products through an addition reaction, caustic soda liquid is employed for hydrolyzing the addition products, and acidifying the addition products to obtain the beta-mercaptopropionic acid; the reaction activity of acrylamide is similar with acrylonitrile, when addition is carried out with hydrogen sulfide or sodium sulfhydrate, the yield is high, and the by-product is little. During hydrolysis and acidifying processes, three wastes can be ideally recovered, the three wastes are conversed to the industrial byproduct for sale, economic benefit is provided to the enterprise, and the synthesis route of the beta-mercaptopropionic acid has the advantages of high yield, good purity, less three wastes, easy processing of waste water, and is a better synthesis route.
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Paragraph 0036; 0037; 0041; 0042
(2017/02/02)
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- PROCESS FOR PREPARING ?-MERCAPTOCARBOXYLIC ACID
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There is provided a process for preparing β-mercaptocarboxylic acid represented by the following General Formula (3) comprising step of reacting hydrogen sulfide, alkali hydroxide represented by a formula: XOH (X represents Na or K), and unsaturated carboxylic acid represented by the following General Formula (1) under atmospheric pressure to obtain a reaction solution including a compound represented by the following General Formula (2) and step of neutralizing the reaction solution in an acid. An amount of the alkali hydroxide is equal to or greater than total moles of the unsaturated carboxylic acid and the hydrogen sulfide.
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Paragraph 0073-0076
(2014/09/30)
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