Under hydrothermal conditions, 2-（pyridin-4-yl）-lH-imidazole-4,5-dicarboxylaic acid （H3PIDC） reacted with Gd（NO3）3 to give a 3D complex {[Gd（HPIDC）＇a-C204）0.5＂H20]＂ 2H20}n （1）. Single-crystal X-ray deter...Under hydrothermal conditions, 2-（pyridin-4-yl）-lH-imidazole-4,5-dicarboxylaic acid （H3PIDC） reacted with Gd（NO3）3 to give a 3D complex {[Gd（HPIDC）＇a-C204）0.5＂H20]＂ 2H20}n （1）. Single-crystal X-ray determination shows that complex 1 crystallizes in the monoclinic system, space group P21/c with a = 8.287（8）, b = 14.796（14）, c = 11.559（11） ]k, fl = 90.969（15）, Z = 4, V = 1417（2） A3, C11H11GdN3Og, Dc = 2.280 g/cm3, Mr = 486.48, 2（MoKa） = 0.71073 A, p = 4.738 mm-1, F（000） = 936, R = 0.0248 and wR = 0.0522. Dielectric constant of complex 1 was measured at different frequencies with temperature variation.展开更多
Trivalent chromium(Cr(Ⅲ))can form stable soluble complexes with organic components,altering its adsorption properties in the water-soil environment.This increases the risk of Cr(Ⅲ)migrating to deeper soils and trans...Trivalent chromium(Cr(Ⅲ))can form stable soluble complexes with organic components,altering its adsorption properties in the water-soil environment.This increases the risk of Cr(Ⅲ)migrating to deeper soils and transforming into toxic Cr(VI)due to the presence of manganese oxides in sediments.In this study,Citric Acid(CA)was selected as a representative organic ligand to prepare and characterize Cr(III)-CA complexes.The characteristics,mechanisms and environmental factors influencing the adsorption of Cr(Ⅲ)-CA on porous media(silts and fine sands)were investigated in the study.The results show that Cr(Ⅲ)coordinates with CA at a 1:1 molar ratio,forming stable and soluble Cr(Ⅲ)-CA complexes.Compared to Cr(III)ions,the equilibrium adsorption capacity of Cr(Ⅲ)-CA is an order of magnitude lower in silts and fine sands.The adsorption of Cr(Ⅲ)-CA in silts and fine sands is dominated by chemical adsorption of monolayers,following the pseudo-second-order kinetic equation and the Langmuir isotherm adsorption model.Varying contents of clay minerals and iron-aluminum oxides prove to be the main causes of differences in adsorption capacity of Cr(Ⅲ)-CA in silts and fine sands.Changes in solution pH affect the adsorption rate and capacity of Cr(Ⅲ)-CA by altering its ionic form.The adsorption process is irreversible and only minimally influenced by ionic strength,suggesting that inner-sphere complexation serves as the dominant Cr(Ⅲ)-CA adsorption mechanism.展开更多
Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the...Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the structure and bonding in lanthanide and actinide metal complexes using 166Er, t55Gd, and 237Np Mtissbauer spectroscopies in connection with single-crystal and/or powder X-ray diffraction, making clear the differences on their structures as well as the differences in the participation of 4f and 5f orbitals in the chemical bonds. In this article, the crystal structures of two novel Gd（Ⅲ） acetylacetonato complexes, Gd（pta）3 · 2H2O （pta = 1,1,1 -trifluoro-5,5-dimethy 1-2,4-hexanedione） and Gd（bfa）3 · 2H2O （bfa = 1, 1, 1 -trifluoro-4-phenyl-2-4-butanedione） were reported. Though both of them were dihydrate and had distorted square antiprismatical structure, Gd（pta）3 · 2H2O crystallizes in the P 2 1/n （#14） monoclinic space group and its lattice parameters are a = 1.4141（6） nm, b = 1.0708（3） nm, c =2.2344（4） nm, β =952.4（2）°, and Gd（bfa）3· 2H2O crystallizes in P 212121 orthorhombic space group and its lattice parameters were a = 1.322 （1） nm, b = 2.295 （1） nm, c = 1. 0786（8） nm. In the meantime, the authors had finished a systematic investigation on the ^155Gd Mossbauer isomer shift （δ） of various Gd（Ⅲ） metal complexes having a different coordination number （C.N.） and different ratios coordinating oxygen to nitrogen. A tendency for the 6 value to decrease with an increase in the C.N, and the number of the nitrogen atom coordinating to Gd was confirmed. This indicated that the Gd-O and/or Gd-N bond in the investigated Gd（Ⅲ） metal complexes had a small covalent contribution, which was possible to be deduced from the O and/or N atoms of the lisands donating electrons to 6s, 5d, and 4f orbitals of Gd.展开更多
Two new Gd Ⅲ complexes with nitrilotriacetic acid(nta) and trans-1,2-cyclohexanediaminetetraacetic acid(Cydta) ligands were synthesized. Their crystal structures were determined by single-crystal X-ray structure anal...Two new Gd Ⅲ complexes with nitrilotriacetic acid(nta) and trans-1,2-cyclohexanediaminetetraacetic acid(Cydta) ligands were synthesized. Their crystal structures were determined by single-crystal X-ray structure analyses. The crystal data are as follows: K 3[Gd Ⅲ(nta) 2·(H 2O)]·6H 2O, monoclinic system, C2/c space group, a=1.534 81(15) nm, b=1.292 05(12) nm, c=2.610 8(3) nm, β=96.244(2)°, V=5.146 7(9) nm 3, Z=8, M=776.87, D c=2.005 g/cm 3, μ= 3.149 mm -1 and \{F(000)=\}3 080, R=0.024 5, wR=0.064 3 for 4 455 unique reflections and R= 0.028 9, wR=0.067 2 for all 10 305 reflections. The Gd ⅢN 2O 7 part in the [Gd Ⅲ(nta) 2(H 2O)] 3- anion is a pseudo-monocapped square antiprismatic nine-coordination structure.(NH 4)[Gd Ⅲ(Cydta)(H 2O) 2]·5H 2O, triclinic system, P1 space group, a=0.866 2(3) nm, b=1.006 7(3) nm, c= 1.444 8(5) nm, α= 88.282(5)°, β=75\^190(5)°, γ=88.317(4)°, V=1.217 2(7) nm 3, Z=2, M=643.69, D c=1.756 g/cm 3, μ=2.798 mm -1 and F(000)=650, R=0.030 3, wR=0.080 9 for 4 273 unique reflections and R=0.033 2, wR=0.082 5 for all 5 062 reflections. The Gd ⅢN 2O 6 part in the [Gd Ⅲ(Cydta)(H 2O) 2] - anion has a pseudo-square antiprismatic eight-coordination structure.展开更多
Diethylenetriaminepentaacetic dianhydride was co-polymerized with dodecyl ester and benzyl ester of lysine,and octodecyl ester and benzyl ester of lysine respectively to give two terpolymers. These two terpolymer liga...Diethylenetriaminepentaacetic dianhydride was co-polymerized with dodecyl ester and benzyl ester of lysine,and octodecyl ester and benzyl ester of lysine respectively to give two terpolymers. These two terpolymer ligands were reacted with GdCl 3 to afford amphiphilic oligomers of Gd(Ⅲ) complexes. These new ligands and Gd(Ⅲ) complexes were characterized by IR, 1H NMR and elemental analysis. The oligomeric complexes show a higher relaxivity as compared to that of Gd(DTPA) which is widely used in clinic diagnoses. The Gd(Ⅲ) complex derived from octodecyl ester demonstrated liver-selective enhancement for MR imaging of Wistar rat. The ratios of signal to noise ( S/N ) in the proton intensity imaging were enhanced,respectively,by 15%,27%,and 36% at the time of 5,30 and 45 min after injection of this complex.展开更多
The title complex K [Gd~Ⅲ(edta)(H_2O)_3]·5H_2O was synthesized, where edta denotes ethylenediamine- tetraacetic acid. The crystal and molecular structure of the complex were determined by single-crystal X-ray st...The title complex K [Gd~Ⅲ(edta)(H_2O)_3]·5H_2O was synthesized, where edta denotes ethylenediamine- tetraacetic acid. The crystal and molecular structure of the complex were determined by single-crystal X-ray structure analysis. The crystal belongs to an orthorhombic crystal system and an Fdd2 space group. The complex anion [Gd~Ⅲ(edta)(H_2O)_3] has a pseudo-monocapped square antiprismatic nine-coordinate structure in which six coordinate atoms (two N and four O) are from an edta ligand and three water molecules coordinate to Gd~Ⅲ ion directly. It can be predicted that Gd~Ⅲ ion can also form a nine-coordinate complex with ttha (triethylenetetraminehexaacetic acid) li- gand, so the GdⅢ complex anion [Gd~?é¨(r)(Httha)]~￡¨2-￡(c) can supply a free non-coordinate carboxyl group (-C-CH_2COOH) used for molecular embellishment in some biological molecules to form a contrast agent of Magnetic Resonance Imagine (MRI) with targeting function.展开更多
The thermal behavior of [Tb_2( m -MBA)_6(phen)_2](H_2O)_2( m -MBA=C_8H_7O_2, methoxybenzoate; phen=C_ 12 H_8N_2, 1,10-phenanthroline) in static air atmosphere was investigated by means of TG-DTG and DTA methods. The...The thermal behavior of [Tb_2( m -MBA)_6(phen)_2](H_2O)_2( m -MBA=C_8H_7O_2, methoxybenzoate; phen=C_ 12 H_8N_2, 1,10-phenanthroline) in static air atmosphere was investigated by means of TG-DTG and DTA methods. The thermal decomposition of the title compound takes place mainly in two steps. The intermediate and the residue for each decomposition were identified by the TG curve. By the kinetic method of processing thermal analysis data put forward by Malek et al ., it is defined that the kinetics model for the first-step thermal decomposition is SB( m,n ).展开更多
A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these c...A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these complexes were also studied.展开更多
基金Supported by the National Natural Science Foundation of China(No.21201087)the Foundation of Jiangsu Educational Committee(11KJB150004)Qing Lan Project of Jiangsu province
文摘Under hydrothermal conditions, 2-（pyridin-4-yl）-lH-imidazole-4,5-dicarboxylaic acid （H3PIDC） reacted with Gd（NO3）3 to give a 3D complex {[Gd（HPIDC）＇a-C204）0.5＂H20]＂ 2H20}n （1）. Single-crystal X-ray determination shows that complex 1 crystallizes in the monoclinic system, space group P21/c with a = 8.287（8）, b = 14.796（14）, c = 11.559（11） ]k, fl = 90.969（15）, Z = 4, V = 1417（2） A3, C11H11GdN3Og, Dc = 2.280 g/cm3, Mr = 486.48, 2（MoKa） = 0.71073 A, p = 4.738 mm-1, F（000） = 936, R = 0.0248 and wR = 0.0522. Dielectric constant of complex 1 was measured at different frequencies with temperature variation.
基金financially supported jointly by Natural Science Foundation of Fujian Province of China(NO.2023J01227)Natural Science Foundation of Hebei Province(NO.D2020504003)Key Laboratory of Groundwater Remediation of Hebei Province and China Geological Survey(NO.SK202303).
文摘Trivalent chromium(Cr(Ⅲ))can form stable soluble complexes with organic components,altering its adsorption properties in the water-soil environment.This increases the risk of Cr(Ⅲ)migrating to deeper soils and transforming into toxic Cr(VI)due to the presence of manganese oxides in sediments.In this study,Citric Acid(CA)was selected as a representative organic ligand to prepare and characterize Cr(III)-CA complexes.The characteristics,mechanisms and environmental factors influencing the adsorption of Cr(Ⅲ)-CA on porous media(silts and fine sands)were investigated in the study.The results show that Cr(Ⅲ)coordinates with CA at a 1:1 molar ratio,forming stable and soluble Cr(Ⅲ)-CA complexes.Compared to Cr(III)ions,the equilibrium adsorption capacity of Cr(Ⅲ)-CA is an order of magnitude lower in silts and fine sands.The adsorption of Cr(Ⅲ)-CA in silts and fine sands is dominated by chemical adsorption of monolayers,following the pseudo-second-order kinetic equation and the Langmuir isotherm adsorption model.Varying contents of clay minerals and iron-aluminum oxides prove to be the main causes of differences in adsorption capacity of Cr(Ⅲ)-CA in silts and fine sands.Changes in solution pH affect the adsorption rate and capacity of Cr(Ⅲ)-CA by altering its ionic form.The adsorption process is irreversible and only minimally influenced by ionic strength,suggesting that inner-sphere complexation serves as the dominant Cr(Ⅲ)-CA adsorption mechanism.
基金Project supported by the Grants-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, Japan andin Part by the Inter-University Joint Research Program for the Common Use of JAERI (Japan Atomic Energy Research Institute)Facilities
文摘Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the structure and bonding in lanthanide and actinide metal complexes using 166Er, t55Gd, and 237Np Mtissbauer spectroscopies in connection with single-crystal and/or powder X-ray diffraction, making clear the differences on their structures as well as the differences in the participation of 4f and 5f orbitals in the chemical bonds. In this article, the crystal structures of two novel Gd（Ⅲ） acetylacetonato complexes, Gd（pta）3 · 2H2O （pta = 1,1,1 -trifluoro-5,5-dimethy 1-2,4-hexanedione） and Gd（bfa）3 · 2H2O （bfa = 1, 1, 1 -trifluoro-4-phenyl-2-4-butanedione） were reported. Though both of them were dihydrate and had distorted square antiprismatical structure, Gd（pta）3 · 2H2O crystallizes in the P 2 1/n （#14） monoclinic space group and its lattice parameters are a = 1.4141（6） nm, b = 1.0708（3） nm, c =2.2344（4） nm, β =952.4（2）°, and Gd（bfa）3· 2H2O crystallizes in P 212121 orthorhombic space group and its lattice parameters were a = 1.322 （1） nm, b = 2.295 （1） nm, c = 1. 0786（8） nm. In the meantime, the authors had finished a systematic investigation on the ^155Gd Mossbauer isomer shift （δ） of various Gd（Ⅲ） metal complexes having a different coordination number （C.N.） and different ratios coordinating oxygen to nitrogen. A tendency for the 6 value to decrease with an increase in the C.N, and the number of the nitrogen atom coordinating to Gd was confirmed. This indicated that the Gd-O and/or Gd-N bond in the investigated Gd（Ⅲ） metal complexes had a small covalent contribution, which was possible to be deduced from the O and/or N atoms of the lisands donating electrons to 6s, 5d, and 4f orbitals of Gd.
文摘Two new Gd Ⅲ complexes with nitrilotriacetic acid(nta) and trans-1,2-cyclohexanediaminetetraacetic acid(Cydta) ligands were synthesized. Their crystal structures were determined by single-crystal X-ray structure analyses. The crystal data are as follows: K 3[Gd Ⅲ(nta) 2·(H 2O)]·6H 2O, monoclinic system, C2/c space group, a=1.534 81(15) nm, b=1.292 05(12) nm, c=2.610 8(3) nm, β=96.244(2)°, V=5.146 7(9) nm 3, Z=8, M=776.87, D c=2.005 g/cm 3, μ= 3.149 mm -1 and \{F(000)=\}3 080, R=0.024 5, wR=0.064 3 for 4 455 unique reflections and R= 0.028 9, wR=0.067 2 for all 10 305 reflections. The Gd ⅢN 2O 7 part in the [Gd Ⅲ(nta) 2(H 2O)] 3- anion is a pseudo-monocapped square antiprismatic nine-coordination structure.(NH 4)[Gd Ⅲ(Cydta)(H 2O) 2]·5H 2O, triclinic system, P1 space group, a=0.866 2(3) nm, b=1.006 7(3) nm, c= 1.444 8(5) nm, α= 88.282(5)°, β=75\^190(5)°, γ=88.317(4)°, V=1.217 2(7) nm 3, Z=2, M=643.69, D c=1.756 g/cm 3, μ=2.798 mm -1 and F(000)=650, R=0.030 3, wR=0.080 9 for 4 273 unique reflections and R=0.033 2, wR=0.082 5 for all 5 062 reflections. The Gd ⅢN 2O 6 part in the [Gd Ⅲ(Cydta)(H 2O) 2] - anion has a pseudo-square antiprismatic eight-coordination structure.
文摘Diethylenetriaminepentaacetic dianhydride was co-polymerized with dodecyl ester and benzyl ester of lysine,and octodecyl ester and benzyl ester of lysine respectively to give two terpolymers. These two terpolymer ligands were reacted with GdCl 3 to afford amphiphilic oligomers of Gd(Ⅲ) complexes. These new ligands and Gd(Ⅲ) complexes were characterized by IR, 1H NMR and elemental analysis. The oligomeric complexes show a higher relaxivity as compared to that of Gd(DTPA) which is widely used in clinic diagnoses. The Gd(Ⅲ) complex derived from octodecyl ester demonstrated liver-selective enhancement for MR imaging of Wistar rat. The ratios of signal to noise ( S/N ) in the proton intensity imaging were enhanced,respectively,by 15%,27%,and 36% at the time of 5,30 and 45 min after injection of this complex.
文摘The title complex K [Gd~Ⅲ(edta)(H_2O)_3]·5H_2O was synthesized, where edta denotes ethylenediamine- tetraacetic acid. The crystal and molecular structure of the complex were determined by single-crystal X-ray structure analysis. The crystal belongs to an orthorhombic crystal system and an Fdd2 space group. The complex anion [Gd~Ⅲ(edta)(H_2O)_3] has a pseudo-monocapped square antiprismatic nine-coordinate structure in which six coordinate atoms (two N and four O) are from an edta ligand and three water molecules coordinate to Gd~Ⅲ ion directly. It can be predicted that Gd~Ⅲ ion can also form a nine-coordinate complex with ttha (triethylenetetraminehexaacetic acid) li- gand, so the GdⅢ complex anion [Gd~?é¨(r)(Httha)]~￡¨2-￡(c) can supply a free non-coordinate carboxyl group (-C-CH_2COOH) used for molecular embellishment in some biological molecules to form a contrast agent of Magnetic Resonance Imagine (MRI) with targeting function.
基金Supported by the Natural Science Foundation of Hebei Province(No.2 0 2 140 ) and Hebei Education Departm ent(No.2 0 0 112 1)
文摘The thermal behavior of [Tb_2( m -MBA)_6(phen)_2](H_2O)_2( m -MBA=C_8H_7O_2, methoxybenzoate; phen=C_ 12 H_8N_2, 1,10-phenanthroline) in static air atmosphere was investigated by means of TG-DTG and DTA methods. The thermal decomposition of the title compound takes place mainly in two steps. The intermediate and the residue for each decomposition were identified by the TG curve. By the kinetic method of processing thermal analysis data put forward by Malek et al ., it is defined that the kinetics model for the first-step thermal decomposition is SB( m,n ).
文摘A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these complexes were also studied.
