Using long-chain fatty acid as extractant, the process of removing the impurity element aluminum in the solution of praseodymium-neodymium chloride and the influence of extracting conditions were studied. The results ...Using long-chain fatty acid as extractant, the process of removing the impurity element aluminum in the solution of praseodymium-neodymium chloride and the influence of extracting conditions were studied. The results show that the amount of aluminum can be decreased from 728 to 14 mg·L -1 that is the 98% of total in the solution of praseodymium-neodymium chloride by one-stage extraction under the condition as follows: the concentration of rare earth is 100～200 g·L -1, the organic phase is 20% fatty acid -10% isooctanol -70% kerosene (V/V), saponification number is 20% with dense ammonia, and the extracting equilibrium time is 5～15 min. Under the same conditions, the extraction ratio of aluminum in the system of fatty acid is 3～5 times of that in naphthene acid. The fatty acid extractant is distinctly better than naphthene acid.展开更多
The complexes with the general formula REP3A· H2O [P = 2- (COO ) C6H4CONHC6H4X, X=2-CI, 4-Br; A=Gly, Ala, Leu; RE=Pr3+, Nd3+] were synthesized and characlerized by elemental analysis, IR and reflectance electro...The complexes with the general formula REP3A· H2O [P = 2- (COO ) C6H4CONHC6H4X, X=2-CI, 4-Br; A=Gly, Ala, Leu; RE=Pr3+, Nd3+] were synthesized and characlerized by elemental analysis, IR and reflectance electronic spectra and TG methods. The results show that rare earth ion in each complex is coordinated by three oxygen atoms. One is from the amido and the other two from the hydroxyl in the carboxylate and the amino acid respectively, and each complex contains one coordinate water molecule. Condon parameters Fk, Lande parameters(4f), Nephelanxetic ratio(β), percentage convalency parameter(δ) and bonding parameter(b ) of the chelates were calculated from the reflectance electronic spectra, indicating certain covalent character in the metalligand bond. The apparent decompose activation energies were evaluated and the decompose mechanism were discussed.展开更多
Reaction of Na2CO3, Pr6O11 and H3PO4 gave the sodium praseodymium polyphosphate NaPr（PO3）4.The title compound crystallized in the monoclinic P21/n space group with a=0.9965（4） nm, b=1.31437（4） nm, c=0.72271（3）...Reaction of Na2CO3, Pr6O11 and H3PO4 gave the sodium praseodymium polyphosphate NaPr（PO3）4.The title compound crystallized in the monoclinic P21/n space group with a=0.9965（4） nm, b=1.31437（4） nm, c=0.72271（3） nm, β=90.429（3）°, V=0.9465（4） nm3, Z=4, R=0.0493 and wR=0.1266 for 1855 independent reflections.The structure of NaPr（PO3）4 consisted of PrO8 polyhedra sharing oxygen atoms with phosphoric group PO4 to form a three-dimensional framework, delimiting intersecting tunnels in which the sodium ion was located.Each Na＋ ion was bonded to seven oxygen atoms.展开更多
During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln 3+ ∶IMDA=1∶2) for the anion-excha...During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln 3+ ∶IMDA=1∶2) for the anion-exchanger Dowex 1 in the acetate and IMDA forms is non-typical: Dy 3+ > Ho 3+ > Gd 3+ >Eu 3+ >Er 3+ >Y 3+ >Sm 3+ >Tm 3+ >Nd 3+ >Pr 3+ >>La 3+ . In the affinity series La 3+ is characterised as the lowest affinity in comparison with other rare earth elements, which indicates possibility of purification of La 3+ from all remaining lanthanides as well as Pr 3+ in the macro-micro systems by the frontal analysis technique. In the investigations strongly basic gel anion-exchangers Dowex 1×8 (type 1) and Dowex 2×8 (type 2) and strongly basic and weakly basic macroporous anion-exchangers Dowex MSA-1 and Dowex MWA 1 were used. Macroporous ion-exchangers have a sponge-like matrix which contains pores larger than molecules in size and the exchange of large ions is faster. The studies indicate that both the gel and macroporous anion-exchangers are useful for purification of La 3+ from Pr 3+ complexes with iminodiacetic acid.展开更多
We introduced a new catalyst,rare earth element praseodymium,for the catalytic graphitization of furan resin carbon.The extent of graphitization of the furan resin carbon was examined by X-ray diffraction and Raman sp...We introduced a new catalyst,rare earth element praseodymium,for the catalytic graphitization of furan resin carbon.The extent of graphitization of the furan resin carbon was examined by X-ray diffraction and Raman spectroscopy.The morphology of furan resin carbon was characterized by scanning electron microscopy.The effects of the praseodymium content and the heat-treatment temperature on the catalytic graphitization of furan resin carbon were also investigated.The results indicated that the praseodymium c...展开更多
Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5...Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5032 observed reflections. The coordination polyhedron of Pr( Ⅲ) ion comprises six oxygen atoms from the L-Pro molecules and two from the water molecules, Each L-Pro molecule coordinates to two Pr(Ⅲ) ions through the carboxyl oxygens in a bidentate bridging mode, thus creating one-dimensional chain structure.展开更多
The Pr(TTA)_3phen(C_2H_5OH)quarternary complex with 2-thenoyltrifluoro-acetone(TTA), 1,10-phenanthroline(phen)and ethanol were synthesized and characterized by single-crystal X-ray diffraction. The central Pr^(3+) ion...The Pr(TTA)_3phen(C_2H_5OH)quarternary complex with 2-thenoyltrifluoro-acetone(TTA), 1,10-phenanthroline(phen)and ethanol were synthesized and characterized by single-crystal X-ray diffraction. The central Pr^(3+) ion is nine-coordinated. The infrared(IR)spectrum, diffuse reflectance(DR)spectrum and fluorescence measurements of the complex were investigated.展开更多
Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature - programmed desportion/reduction (TPD/TPR) experiments. Pr2O3 possesses the similar oxygen storag...Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature - programmed desportion/reduction (TPD/TPR) experiments. Pr2O3 possesses the similar oxygen storage properties to CeO2, and its dynamic oxygen storage capacity is 14.9 mumol.g(-1). The studies on TPD Of O-2, H2O and CO and TPR show that Pr2O3 provides more active surface oxygen species and at a lower temperature than CeO2. It is suggested that Pr2O3 can be a well candidate as an oxygen storage component in automobile three-way catalyst.展开更多
The new lanthanum (Ⅲ) and praseodymium (Ⅲ) complexes of the general formula [Ln(L)3] (Ln=La(Ⅲ) or Pr(Ⅲ); LK=potassium salt of dithiocarbazinates) were prepared by both, conventional thermal and by the use of micro...The new lanthanum (Ⅲ) and praseodymium (Ⅲ) complexes of the general formula [Ln(L)3] (Ln=La(Ⅲ) or Pr(Ⅲ); LK=potassium salt of dithiocarbazinates) were prepared by both, conventional thermal and by the use of microwave technology. Elemental analyses, electrical conductance, magnetic moment and electronic, infrared, far-infrared, 1H and 13C NMR spectral studies were used to characterize the complexes. The molecular weights of few complexes were determined by FAB-mass spectra. Nephelauxetic ratio, covalency parameter and bonding parameter for these complexes were also calculated. The probable structures of the complexes were proposed. The antifungal and antibacterial activities of the complexes were evaluated. The activities were correlated with the structures of the compounds.展开更多
Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5...Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5032 observed reflections. The coordination polyhedron of Pr( Ⅲ) ion comprises six oxygen atoms from the L-Pro molecules and two from the water molecules, Each L-Pro molecule coordinates to two Pr(Ⅲ) ions through the carboxyl oxygens in a bidentate bridging mode, thus creating one-dimensional chain structure.展开更多
文摘Using long-chain fatty acid as extractant, the process of removing the impurity element aluminum in the solution of praseodymium-neodymium chloride and the influence of extracting conditions were studied. The results show that the amount of aluminum can be decreased from 728 to 14 mg·L -1 that is the 98% of total in the solution of praseodymium-neodymium chloride by one-stage extraction under the condition as follows: the concentration of rare earth is 100～200 g·L -1, the organic phase is 20% fatty acid -10% isooctanol -70% kerosene (V/V), saponification number is 20% with dense ammonia, and the extracting equilibrium time is 5～15 min. Under the same conditions, the extraction ratio of aluminum in the system of fatty acid is 3～5 times of that in naphthene acid. The fatty acid extractant is distinctly better than naphthene acid.
基金The Fund for Tobacco Science Studies and Gechnical Development, Tobaceo Bureau of hina !19980655
文摘The complexes with the general formula REP3A· H2O [P = 2- (COO ) C6H4CONHC6H4X, X=2-CI, 4-Br; A=Gly, Ala, Leu; RE=Pr3+, Nd3+] were synthesized and characlerized by elemental analysis, IR and reflectance electronic spectra and TG methods. The results show that rare earth ion in each complex is coordinated by three oxygen atoms. One is from the amido and the other two from the hydroxyl in the carboxylate and the amino acid respectively, and each complex contains one coordinate water molecule. Condon parameters Fk, Lande parameters(4f), Nephelanxetic ratio(β), percentage convalency parameter(δ) and bonding parameter(b ) of the chelates were calculated from the reflectance electronic spectra, indicating certain covalent character in the metalligand bond. The apparent decompose activation energies were evaluated and the decompose mechanism were discussed.
基金supported by the Ministry of Higher Education,Scientific Research and Technology of Tunisia
文摘Reaction of Na2CO3, Pr6O11 and H3PO4 gave the sodium praseodymium polyphosphate NaPr（PO3）4.The title compound crystallized in the monoclinic P21/n space group with a=0.9965（4） nm, b=1.31437（4） nm, c=0.72271（3） nm, β=90.429（3）°, V=0.9465（4） nm3, Z=4, R=0.0493 and wR=0.1266 for 1855 independent reflections.The structure of NaPr（PO3）4 consisted of PrO8 polyhedra sharing oxygen atoms with phosphoric group PO4 to form a three-dimensional framework, delimiting intersecting tunnels in which the sodium ion was located.Each Na＋ ion was bonded to seven oxygen atoms.
文摘During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln 3+ ∶IMDA=1∶2) for the anion-exchanger Dowex 1 in the acetate and IMDA forms is non-typical: Dy 3+ > Ho 3+ > Gd 3+ >Eu 3+ >Er 3+ >Y 3+ >Sm 3+ >Tm 3+ >Nd 3+ >Pr 3+ >>La 3+ . In the affinity series La 3+ is characterised as the lowest affinity in comparison with other rare earth elements, which indicates possibility of purification of La 3+ from all remaining lanthanides as well as Pr 3+ in the macro-micro systems by the frontal analysis technique. In the investigations strongly basic gel anion-exchangers Dowex 1×8 (type 1) and Dowex 2×8 (type 2) and strongly basic and weakly basic macroporous anion-exchangers Dowex MSA-1 and Dowex MWA 1 were used. Macroporous ion-exchangers have a sponge-like matrix which contains pores larger than molecules in size and the exchange of large ions is faster. The studies indicate that both the gel and macroporous anion-exchangers are useful for purification of La 3+ from Pr 3+ complexes with iminodiacetic acid.
基金supported by the National Basic Research Program of China (2006CB600903)
文摘We introduced a new catalyst,rare earth element praseodymium,for the catalytic graphitization of furan resin carbon.The extent of graphitization of the furan resin carbon was examined by X-ray diffraction and Raman spectroscopy.The morphology of furan resin carbon was characterized by scanning electron microscopy.The effects of the praseodymium content and the heat-treatment temperature on the catalytic graphitization of furan resin carbon were also investigated.The results indicated that the praseodymium c...
文摘Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5032 observed reflections. The coordination polyhedron of Pr( Ⅲ) ion comprises six oxygen atoms from the L-Pro molecules and two from the water molecules, Each L-Pro molecule coordinates to two Pr(Ⅲ) ions through the carboxyl oxygens in a bidentate bridging mode, thus creating one-dimensional chain structure.
文摘The Pr(TTA)_3phen(C_2H_5OH)quarternary complex with 2-thenoyltrifluoro-acetone(TTA), 1,10-phenanthroline(phen)and ethanol were synthesized and characterized by single-crystal X-ray diffraction. The central Pr^(3+) ion is nine-coordinated. The infrared(IR)spectrum, diffuse reflectance(DR)spectrum and fluorescence measurements of the complex were investigated.
文摘Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature - programmed desportion/reduction (TPD/TPR) experiments. Pr2O3 possesses the similar oxygen storage properties to CeO2, and its dynamic oxygen storage capacity is 14.9 mumol.g(-1). The studies on TPD Of O-2, H2O and CO and TPR show that Pr2O3 provides more active surface oxygen species and at a lower temperature than CeO2. It is suggested that Pr2O3 can be a well candidate as an oxygen storage component in automobile three-way catalyst.
文摘The new lanthanum (Ⅲ) and praseodymium (Ⅲ) complexes of the general formula [Ln(L)3] (Ln=La(Ⅲ) or Pr(Ⅲ); LK=potassium salt of dithiocarbazinates) were prepared by both, conventional thermal and by the use of microwave technology. Elemental analyses, electrical conductance, magnetic moment and electronic, infrared, far-infrared, 1H and 13C NMR spectral studies were used to characterize the complexes. The molecular weights of few complexes were determined by FAB-mass spectra. Nephelauxetic ratio, covalency parameter and bonding parameter for these complexes were also calculated. The probable structures of the complexes were proposed. The antifungal and antibacterial activities of the complexes were evaluated. The activities were correlated with the structures of the compounds.
文摘Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5032 observed reflections. The coordination polyhedron of Pr( Ⅲ) ion comprises six oxygen atoms from the L-Pro molecules and two from the water molecules, Each L-Pro molecule coordinates to two Pr(Ⅲ) ions through the carboxyl oxygens in a bidentate bridging mode, thus creating one-dimensional chain structure.
