The modification of some metal complexes on Pt/Al2O3 clusters leads to remarkable increases in both the activity and the selectivity for meso-2,3-butanediol in the stereoselectivity hydrogenation of 2,3-butanedione.
The complex of Eu(IH) with 1-(6-hydroxy- 1-naphthyl)- 1,3-butanedione (HNBD) was prepared for the first time and characterized by elemental analysis, IR, UV, fluorescence spectrum, and DTA-TG-DTG techniques. The...The complex of Eu(IH) with 1-(6-hydroxy- 1-naphthyl)- 1,3-butanedione (HNBD) was prepared for the first time and characterized by elemental analysis, IR, UV, fluorescence spectrum, and DTA-TG-DTG techniques. The IR and UV-visible spectra showed that Eu(Ⅲ) ion was coordinated to the HNBD ligand. The fluorescence spectrum showed the presence of Eu^3+ characteristic emission. The TG-DTA-DTG curves showed that the thermal decomposition of the anhydrous complex was a two-stage process and the final residue was Eu2O3. The thermal decomposition kinetic parameters of the complex were evaluated from TG-DTG data by using three kinds of integral methods (Coat-Redfem equation, Horowitz and Metzger equation, Madhusudanan-Krishnan-Ninan equation). The kinetic parameters of the first stage are E^* = 164.02 kJ.moll, A = 1.31 × 10^15 s^-l, AS^*= 42.27 J·K^-l·mol^-l, △H^* = 159.51 kJ·mol^-l, △G^*= 136.54 kJ·mol^-l, and n = 3.1, those of the second stage are E^*= 128.52 kJ·mol^-l, A = 1.44× 106 s^-1, △S^*= - 136.89 J·K^-l·mol^-l, △H^* = 120.41 kJ·mol^-l, △G^*= 283.85 kJ·mol^-l, and n = 1.1.展开更多
The coordination behavior of 2,3-butanedionemonoxime Girard’s T hydrazone (L<sup>1</sup>) towards Hg<sup>2+</sup> ion has been investigated. The structure of Hg<sup>2+</sup> comple...The coordination behavior of 2,3-butanedionemonoxime Girard’s T hydrazone (L<sup>1</sup>) towards Hg<sup>2+</sup> ion has been investigated. The structure of Hg<sup>2+</sup> complex, [Hg(L<sup>1</sup>)Cl]Cl·5H<sub>2</sub>O, is elucidated using elemental analyses, spectral (IR, UV-visible, 1H-NMR and mass) and TGA measurements. IR spectrum suggests that L<sup>1</sup> behaves in a bidentate manner through the azomethine groups. The molecular modeling of L<sup>1</sup> and its Hg<sup>2+</sup> complex has been investigated. The bond lengths, bond angles, HOMO and LUMO have been calculated. The thermal behavior and kinetic parameters are determined using Coats-Redfern method. The use of L<sup>1</sup> for preconcentration and separation via flotation of Hg<sup>2+</sup> complex and determination using cold vapor atomic spectrometry (CVAAS) is described. The effects on the percentage of recovered Hg<sup>2+</sup> by pH of sample solutions, oleic acid (HOL) concentration, Hg<sup>2+</sup> and L<sup>1</sup> concentrations are studied in details. The method is applied for the determination of the total Hg<sup>2+</sup> (mg·mL<sup>-1</sup>) in natural water samples.展开更多
文摘The modification of some metal complexes on Pt/Al2O3 clusters leads to remarkable increases in both the activity and the selectivity for meso-2,3-butanediol in the stereoselectivity hydrogenation of 2,3-butanedione.
基金financially supported by the Important Foundation of the Educational Commission of Hubei Province (No. Z200622001)the Natural Science Foundation of the Educational Commission of Hubei Province, China (No. J200522002)
文摘The complex of Eu(IH) with 1-(6-hydroxy- 1-naphthyl)- 1,3-butanedione (HNBD) was prepared for the first time and characterized by elemental analysis, IR, UV, fluorescence spectrum, and DTA-TG-DTG techniques. The IR and UV-visible spectra showed that Eu(Ⅲ) ion was coordinated to the HNBD ligand. The fluorescence spectrum showed the presence of Eu^3+ characteristic emission. The TG-DTA-DTG curves showed that the thermal decomposition of the anhydrous complex was a two-stage process and the final residue was Eu2O3. The thermal decomposition kinetic parameters of the complex were evaluated from TG-DTG data by using three kinds of integral methods (Coat-Redfem equation, Horowitz and Metzger equation, Madhusudanan-Krishnan-Ninan equation). The kinetic parameters of the first stage are E^* = 164.02 kJ.moll, A = 1.31 × 10^15 s^-l, AS^*= 42.27 J·K^-l·mol^-l, △H^* = 159.51 kJ·mol^-l, △G^*= 136.54 kJ·mol^-l, and n = 3.1, those of the second stage are E^*= 128.52 kJ·mol^-l, A = 1.44× 106 s^-1, △S^*= - 136.89 J·K^-l·mol^-l, △H^* = 120.41 kJ·mol^-l, △G^*= 283.85 kJ·mol^-l, and n = 1.1.
文摘The coordination behavior of 2,3-butanedionemonoxime Girard’s T hydrazone (L<sup>1</sup>) towards Hg<sup>2+</sup> ion has been investigated. The structure of Hg<sup>2+</sup> complex, [Hg(L<sup>1</sup>)Cl]Cl·5H<sub>2</sub>O, is elucidated using elemental analyses, spectral (IR, UV-visible, 1H-NMR and mass) and TGA measurements. IR spectrum suggests that L<sup>1</sup> behaves in a bidentate manner through the azomethine groups. The molecular modeling of L<sup>1</sup> and its Hg<sup>2+</sup> complex has been investigated. The bond lengths, bond angles, HOMO and LUMO have been calculated. The thermal behavior and kinetic parameters are determined using Coats-Redfern method. The use of L<sup>1</sup> for preconcentration and separation via flotation of Hg<sup>2+</sup> complex and determination using cold vapor atomic spectrometry (CVAAS) is described. The effects on the percentage of recovered Hg<sup>2+</sup> by pH of sample solutions, oleic acid (HOL) concentration, Hg<sup>2+</sup> and L<sup>1</sup> concentrations are studied in details. The method is applied for the determination of the total Hg<sup>2+</sup> (mg·mL<sup>-1</sup>) in natural water samples.