Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral tec...Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral techniques, and Rose-Dragomethod. Electronic effects in metalloporphrins and effects of ligands, temperature andsolvents were investigated. It was found that equilibrium constants for reactions of ZnT(p-X)PP with ligands follow Hammett equation. The changes of standard molar enthalpy△rHm and the changes of standard molar entropy △rSm of the reactions were obtainedfrom the plots of lnK vs. 1/T.展开更多
The mechanism of phthalic acid,a dicarboxylic acid collector,in flotation separation of fluorite and rare earth(RE)was studied in this paper.The experimental data of flotation show that phthalic acid,as the collector,...The mechanism of phthalic acid,a dicarboxylic acid collector,in flotation separation of fluorite and rare earth(RE)was studied in this paper.The experimental data of flotation show that phthalic acid,as the collector,can realize highly efficient separation of fluorite and rare earth under weakly acidic conditions.The adsorption mechanism of phthalic acid on the surface of fluorite and bastnaesite was analyzed in this paper by means of the zeta potential measurement,the Fourier transform infrared(FT-IR),the X-ray photoelectron spectroscopy(XPS)and the stability constant measurement of active metal ion and phthalic acid coo rdination complex.According to the zeta potential testing results,the surfaces of fluorite adsorb the collector phthalate ion with negative charge under weakly acidic conditions which,in turn,increases its electronegativity and results in the motion of its potential.After the reaction between phthalic acid and fluorite ores under weakly acidic conditions,the peak of the fluorite ores is found to have significant changes in the FT-IR results,indicating strong chemical adsorption on the surfaces of phthalic acid and fluorite ores.According to the XPS analysis,the peak of benzene ring of phthalic acid is as high as 2%on the surface of fluorite,while no obvious characteristic peak of benzene ring is found on the surface of bastnaesite.According to the pH potentiometric titration results,the stability constant Ktotal of calcium phthalate complex within the acid range is higher than the stability constant K’total of cerium phthalate complex,indicating that the complex generated between phthalic acid and Ca^(2+)is more stable than the complex generated between phthalic acid and Ce^(3+).The possible reason is that Ca^(2+),with the highest reticular density,plays a prevailing role in the octahedron structure of fluorite amidst the acidic media.As the active point of flotation,Ca^(2+)works with the carboxyl groups of the collector phthalic acid(-C=O-)to form polycyclic calcium phthalate complex.展开更多
To discover the mechanism of side-effect brought on fluorouracilum for human, FeTPP was prepared for simulating the character of haemachrome. Equilibrium constants β, Δ rH 0- m and Δ rS 0- m in the axial coordinati...To discover the mechanism of side-effect brought on fluorouracilum for human, FeTPP was prepared for simulating the character of haemachrome. Equilibrium constants β, Δ rH 0- m and Δ rS 0- m in the axial coordination reaction between FeTPP and fluorouracilum were evaluated by means of spectral absorption. The structure of the complex was optimized by MM + molecular mechanics method. We found that fluorouracilum can react with FeTPP and form octahedron complex with two axial ligands. The viewpoint that fluorouracilum can damage biological function of metal porphyrin and bring about the medication sickness for human was proposed.展开更多
文摘Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral techniques, and Rose-Dragomethod. Electronic effects in metalloporphrins and effects of ligands, temperature andsolvents were investigated. It was found that equilibrium constants for reactions of ZnT(p-X)PP with ligands follow Hammett equation. The changes of standard molar enthalpy△rHm and the changes of standard molar entropy △rSm of the reactions were obtainedfrom the plots of lnK vs. 1/T.
基金Project supported by the National Natural Science Foundation of China(51634005,51564042)Inner Mongolia Autonomous Region Natural Science Foundation(2014ZD04.2016ZD05)。
文摘The mechanism of phthalic acid,a dicarboxylic acid collector,in flotation separation of fluorite and rare earth(RE)was studied in this paper.The experimental data of flotation show that phthalic acid,as the collector,can realize highly efficient separation of fluorite and rare earth under weakly acidic conditions.The adsorption mechanism of phthalic acid on the surface of fluorite and bastnaesite was analyzed in this paper by means of the zeta potential measurement,the Fourier transform infrared(FT-IR),the X-ray photoelectron spectroscopy(XPS)and the stability constant measurement of active metal ion and phthalic acid coo rdination complex.According to the zeta potential testing results,the surfaces of fluorite adsorb the collector phthalate ion with negative charge under weakly acidic conditions which,in turn,increases its electronegativity and results in the motion of its potential.After the reaction between phthalic acid and fluorite ores under weakly acidic conditions,the peak of the fluorite ores is found to have significant changes in the FT-IR results,indicating strong chemical adsorption on the surfaces of phthalic acid and fluorite ores.According to the XPS analysis,the peak of benzene ring of phthalic acid is as high as 2%on the surface of fluorite,while no obvious characteristic peak of benzene ring is found on the surface of bastnaesite.According to the pH potentiometric titration results,the stability constant Ktotal of calcium phthalate complex within the acid range is higher than the stability constant K’total of cerium phthalate complex,indicating that the complex generated between phthalic acid and Ca^(2+)is more stable than the complex generated between phthalic acid and Ce^(3+).The possible reason is that Ca^(2+),with the highest reticular density,plays a prevailing role in the octahedron structure of fluorite amidst the acidic media.As the active point of flotation,Ca^(2+)works with the carboxyl groups of the collector phthalic acid(-C=O-)to form polycyclic calcium phthalate complex.
文摘To discover the mechanism of side-effect brought on fluorouracilum for human, FeTPP was prepared for simulating the character of haemachrome. Equilibrium constants β, Δ rH 0- m and Δ rS 0- m in the axial coordination reaction between FeTPP and fluorouracilum were evaluated by means of spectral absorption. The structure of the complex was optimized by MM + molecular mechanics method. We found that fluorouracilum can react with FeTPP and form octahedron complex with two axial ligands. The viewpoint that fluorouracilum can damage biological function of metal porphyrin and bring about the medication sickness for human was proposed.
