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
Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of...Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of montmorillonite (MT) by ion exchange and coordination reaction of L with the Tb^3+ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL (NO3) ]^2+-MT and [TbL]^3+-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing (d001) approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.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
Four kinds of terbium containing monomers were synthesized by the reaction of Tb isoproxides with acrylic acid and β diketones. The composition and structure of these monomers were confirmed by FT IR, UV spectrosc...Four kinds of terbium containing monomers were synthesized by the reaction of Tb isoproxides with acrylic acid and β diketones. The composition and structure of these monomers were confirmed by FT IR, UV spectroscopy and elemental analysis. DTA and TG analyses reveal that the decomposition temperature of these monomers is in the range of 190~200 ℃. The fluorescence properties of these monomers were studied. Under the excitation of UV light, these monomers exhibit characteristic luminescence of terbium ion, the fluorescent intensity is affected by the polarity of solvent and triplet state of ligand. In solid state, the monochromatic index of luminescence is enhanced.展开更多
A novel rare earth complex of terbium ion with 2-benzoylbenzoic acid and 1, 10-phenathroline (Tb(o-BBA)3 (phen), o-BBA-2-benzoylbenzoic acid, phen = 1, 10-phenathroline) was used as an electroluminescent materia...A novel rare earth complex of terbium ion with 2-benzoylbenzoic acid and 1, 10-phenathroline (Tb(o-BBA)3 (phen), o-BBA-2-benzoylbenzoic acid, phen = 1, 10-phenathroline) was used as an electroluminescent material for the first time. The Tb complex was blended with poly(N-vinylcarbazole) (PVK) in different weight ratios and spinn to coated into films (noted as PVK :Tb films). The photoluminescence (PL) properties of films were investigated and the optimum weight ratio between PVK and Tb(o-BBA)3(phen) was found to be 3:1. Monolayer devices with the structure ITO/PVK: Tb/AI were fabricated and emitted green light, which was characteristic of Tb^3+ emission. The results show that mecha- nisms for PL and EL are different. The PL is considered to be caused because of energy transfer and direct excitation to the Tb(o-BBA)3(phen) molecule, while EL is mainly on charging trapping.展开更多
The surface pressure-area (pi -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TAl2)(3)), on pure water subphase was investigated. The m...The surface pressure-area (pi -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TAl2)(3)), on pure water subphase was investigated. The molecular area, 0.48 nm(2), is one-third of expected value that indicated the aggregation took place. The Langmuir-Blodgett (LB) films of Al(TAl2), was transferred and characterized. The AFM image confirmed the formation of aggregates.展开更多
It has first been reported that Tb(Ⅲ)is oxidated by K_2S_2O_8 in the heteropoly- tungstophosphate complex.The complex ion,[Tb(Ⅳ)(PW_(11)O_(39))_2]^(10-),is stable in aqueous solution only for hours,being graduately ...It has first been reported that Tb(Ⅲ)is oxidated by K_2S_2O_8 in the heteropoly- tungstophosphate complex.The complex ion,[Tb(Ⅳ)(PW_(11)O_(39))_2]^(10-),is stable in aqueous solution only for hours,being graduately reduced to[Tb(Ⅲ)(PW_(11)O_(39))_2]^(11-).It is red-brown,with absorption band at about 420 nm.展开更多
Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and...Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.展开更多
A sensitive method based on the fluorescence quenching effect of the Tb^3+-Tiron complex is proposed for the determination of alkali-labile phosphoprotein phosphorus (ALP) released from fish plasma. The detection l...A sensitive method based on the fluorescence quenching effect of the Tb^3+-Tiron complex is proposed for the determination of alkali-labile phosphoprotein phosphorus (ALP) released from fish plasma. The detection limit was 5.4 ng/ml (S/N=2), and the relative standard deviation of the quenching effect (6 replicates) was 4.6%. The results obtained by the proposed method were in good agreement with those obtained by the colorimetric assay. The advantages of the present method are its relatively simple detection procedure, the lack of toxic organic solvents, and high sensitivity.展开更多
The syntheses, spec(?) complexes are of significance for understanding mechanisms of magnetic interaction between metal ions and the exploitation of the synthesis of molecular magnetic materials. There were a few work...The syntheses, spec(?) complexes are of significance for understanding mechanisms of magnetic interaction between metal ions and the exploitation of the synthesis of molecular magnetic materials. There were a few works reported previously on the syntheses and magnetic in-展开更多
Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only ...Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only a few complexes of Cu(I)have been published^(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Cl was prepared and characterized by elemental analyses,ICP,IR,and electronic spectra.Its conductivity,oxidation potential and reduction potential were measured.展开更多
The synthesis is and crystal structure are reported for the sheet-like compourd [CU2(oxpn)Fe(CN )5(NO)]. there oxpn is the dianion of M, M'-bis(3-aminopropyl)oxamide. This compound crustallizes in the orthogonal s...The synthesis is and crystal structure are reported for the sheet-like compourd [CU2(oxpn)Fe(CN )5(NO)]. there oxpn is the dianion of M, M'-bis(3-aminopropyl)oxamide. This compound crustallizes in the orthogonal space group Puma. with a=11 .413(4), b=22.242(5), c=7.736(2) A, and Z=4.The structure was refined to conventionat discrepancy factors R=0.047 and Pw=0.054. The Cu(II ) and Fe(III)centers are bridged by oxpn and cyanide, the formal behaves as a his-terdentate tigand bound to cooper(II)ion to form (II) dimers. whereas the latter bridges Cu(II) and Fe(III) centers in both symmetric and asymetric end- to-end bis-monodentate fashions, spreading out along be plane to form a 20 network. The Structure is made up of CuFe unit with Cu(II) and Fe(III) ions locating in a distorted square-based pyramid and a compressed octahedron, respectively.展开更多
It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help asses...It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help assess the mechanism by which these ligands may cause tumor cell death, iron binding and removal experiments have been considered. The close linkage between cell proliferation and intracellular iron concentrations suggest that iron deprivation strategies may be a mechanism involved in inhibiting tumor cell growth. With the creation of iron (III) phen complexes, the iron binding abilities of three polypyridal ligands [1,10-phenanthroline (phen), 2,9-dimethyl-1, 10-phenanthroline (methylphen), and 2,9-di-sec-butyl-1, 10-phenanthroline (sec-butylphen)] can be tested via a competition reaction with a known iron chelator. Therefore, iron (III) complexes possessing all three ligands were synthesized. Initial mass spectrometric and infrared absorption data indicate that iron (III) tetrachloride complex ions with protonated phen ligands (RphenH+) were formed: [phenH][FeCl4], [methylphenH][FeCl4], [sec-butylphenH][FeCl4]. UV-vis spectroscopy was used to monitor the stability of the complex ions, and it was found that the sec-butylpheniron complex was more stable than the phen and methylphen analogues. This was based on the observation that free ligand was observed immediately upon the addition of EDTA to the [phenH][FeCl4] and [methylphenH] [FeCl4] complex ions.展开更多
The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35&...The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35°C under pseudo-first order conditions, >>?[complex]. Reaction obeyed first order dependence with respect to and [Cr(III)], and the rate of reaction increases with increasing of pH for the range 3.40 - 4.45. Experimentally, the mechanism of this reaction is found to be consistent with the rate law in which the hydroxo species, [CrIII(NTA)(Ala)(OH)]2- is considerably much more reactive than their conjugate acid. ΔH* and ΔS* have been calculated. It is proposed that electron transfer occurs through an inner-sphere mechanism via coordination of to chromium(III).展开更多
Three new heterotrinuclear complexes have been synthesized and characterized, namely {[Gd(L)(2)](2)[Cu(pbaOH)]}(ClO4)(4), where pbaOH denotes 2-hydroxy-1,3-propylenebis(oxamato), L stands for 1,10-phenanthroline (phen...Three new heterotrinuclear complexes have been synthesized and characterized, namely {[Gd(L)(2)](2)[Cu(pbaOH)]}(ClO4)(4), where pbaOH denotes 2-hydroxy-1,3-propylenebis(oxamato), L stands for 1,10-phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO2-phen) or 2,2'-bipyridyl (bpy). The temperature dependence of the magnetic susceptibility of ([Gd(phen)(2)(ClO4)](2)[Cu(pbaOH)])(ClO4)(2) has been studied in the 4-300K range, giving the exchange integral J = 6.69 cm(-1). This indicates a weak ferromagnetic interaction between the copper(II) and gadolinium(III) ions.展开更多
The crystal and molecular structures of the K[Tb^(III)(edta)(H_2O)_3].5 H_2O(edta = ethylenediaminetetraacetic acid) and K_4[Tb^(III)_2(Httha)_2].14 H_2O (ttha =triethylenetetraminehexaacetic acid) complexes have been...The crystal and molecular structures of the K[Tb^(III)(edta)(H_2O)_3].5 H_2O(edta = ethylenediaminetetraacetic acid) and K_4[Tb^(III)_2(Httha)_2].14 H_2O (ttha =triethylenetetraminehexaacetic acid) complexes have been determined by single-crystal X-raydiffraction analyses. The crystal of the K[Tb^(III)(edta)(H_2O)_3].5 H_2O complex belongs toorthorhombic crystal system and Fdd 2 space group. The crystal data are as follows: a = 1.9373(5)nm, b = 3.5429(10) nm, c = 1.2114(3) nm, V 8.315(4) nm^3, Z= 16, M= 630.35, Dc = 2.014 g cm^(-3), m= 3.683 mm^(-1) and F(000) = 5024. The final Rand wR values are 0.0224 and 0.0557 for 3189 [I> 2.0sigma(I)] unique reflections, and 0.0245 and 0.0567 for all 8206 reflections, respectively. The[Tb^(III)(edta)(H_2O)_3]^- complex anion has a nine-coordinated pseudo-monocapped squareantiprismatic structure in which the nine coordinate atoms, two N and seven O come from one edtaligand and three water molecules. The crystal of the K_4[Tb^(III)_2(Httha)_2].14 H_2O complexbelongs to monoclinic system and P 2(1)/n space group. The crystal data are as follows: a =1.1326(3) nm, b = 2.5675(7) nm, C =2.2076(6) nm, bate = 102.943(5) centre dot, V =6.256(3) nm^3, Z =4, M = 1705.26, Dc = 1.802 g cm^(-3), m = 2.611 mm^(-1) and F(000) = 3424. The final R and wR are0.0339 and 0.0667 for 10699 [I>2.0 sigma (I)] unique reflections, and 0.0543 and 0.0741 for all22190 reflections, respectively. The total complex molecule is composed of two close parts instructure.展开更多
A comparative thermal decomposition kinetic investigation on Fe(III) complexes of a antipyrine Schiff base ligand, 1,2-Bis(imino-4’-antipyrinyl)ethane (GA)), with varying counter anions viz. CIO4-, NO3-, SCN-, Cl-, a...A comparative thermal decomposition kinetic investigation on Fe(III) complexes of a antipyrine Schiff base ligand, 1,2-Bis(imino-4’-antipyrinyl)ethane (GA)), with varying counter anions viz. CIO4-, NO3-, SCN-, Cl-, and Br-, has been done by thermogravimetric analysis by using Coats-Redfern equation. The kinetic parameters like activation energy (E), pre-exponential factor (A) and entropy of activation (ΔS) were quantified. On comparing the various kinetic parameters, lower activation energy was observed in second stage as compared to first thermal decomposition stage. The same trend has been observed for pre-exponential factor (A) and entropy of activation (ΔS). The present results show that the starting materials having higher activation energy (E), are more stable than the intermediate products, however;the intermediate products possess well-ordered chemical structure due to their highly negative entropy of activation (ΔS) values. The present investigation proves that the counter anions play an important role on the thermal decomposition kinetics of the complexes.展开更多
Spectrophotometric method was used to evaluate the kinetic of the complex formation from the reaction between H[Ru(III)Cl2(H2EDTA)] and the modifier agent [3-(2-aminoethyl)aminopropyl] trimethoxysilane (AEATS) (μ = 0...Spectrophotometric method was used to evaluate the kinetic of the complex formation from the reaction between H[Ru(III)Cl2(H2EDTA)] and the modifier agent [3-(2-aminoethyl)aminopropyl] trimethoxysilane (AEATS) (μ = 0.50 mol.dm-3 with NaCF3COO, 298.15 K), in pseudo-first order conditions. These studies showed that the reactions are successives producing several species influenced by the concentrations ratio. The electronics spectrum of all solutions showed a band in 457 nm with variable molar absorptivity (ε).展开更多
Reaction of 2-pyridone, copper acetate and terbium(or yttrium) perchlorate in acetone with the mole ratio 6: 2: 1 results in the formation of heteronuclear complex Ln_2Cu_4L_8 (HL)_4 (OH)_2 (ClO_4)_4 (H_20)_(10) 2CH_3...Reaction of 2-pyridone, copper acetate and terbium(or yttrium) perchlorate in acetone with the mole ratio 6: 2: 1 results in the formation of heteronuclear complex Ln_2Cu_4L_8 (HL)_4 (OH)_2 (ClO_4)_4 (H_20)_(10) 2CH_3COCH_3(Ln = Tb (1), Y (2)). By recrystallizing (1) in CHCl_3 single crystals were obtained and the structure was determined by four-circle diffractometer. Data showed that the crystal is in space group C2/m with a=27. 454(9)A, b=13, 608A, c=30. 556(11)A, β=99. 89(3)°, v=11245. 7(7. 5)A^3. The structure was solved by a combination of Patterson method and Fourier technique. The final R value is 0. 103. In the structure, four copper and two terbium ions are bridged by 2-pyridone anions to form an essentially octahedral Cu_4Tb_2 core. The terbium atoms are each eight-coordinate and the copper atoms are five-coordinate.展开更多
A new complex Tb(IB)_3(phen)·2H_2O that gives off green fluorescence was synthesized. The results show that the strong fluorescence emitting of 490 and 545 nm for Tb 3+ in the Tb(IB)_3(phen)·2H_2O complex is...A new complex Tb(IB)_3(phen)·2H_2O that gives off green fluorescence was synthesized. The results show that the strong fluorescence emitting of 490 and 545 nm for Tb 3+ in the Tb(IB)_3(phen)·2H_2O complex is related to the transitions 5D_4-7F_6 and 5D_4-7F_5, respectively. The results indicate that the complex is concentrated on the nuclei regions in the section of onion toot tip tissues and the nuclei are high lighted under fluorescent microscope. It is possible that the Tb(IB)_3(phen)·2H_2O complex can be developed as a fluorescent dye in biological and pathological studies.展开更多
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Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of montmorillonite (MT) by ion exchange and coordination reaction of L with the Tb^3+ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL (NO3) ]^2+-MT and [TbL]^3+-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing (d001) approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.
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.
文摘Four kinds of terbium containing monomers were synthesized by the reaction of Tb isoproxides with acrylic acid and β diketones. The composition and structure of these monomers were confirmed by FT IR, UV spectroscopy and elemental analysis. DTA and TG analyses reveal that the decomposition temperature of these monomers is in the range of 190~200 ℃. The fluorescence properties of these monomers were studied. Under the excitation of UV light, these monomers exhibit characteristic luminescence of terbium ion, the fluorescent intensity is affected by the polarity of solvent and triplet state of ligand. In solid state, the monochromatic index of luminescence is enhanced.
文摘A novel rare earth complex of terbium ion with 2-benzoylbenzoic acid and 1, 10-phenathroline (Tb(o-BBA)3 (phen), o-BBA-2-benzoylbenzoic acid, phen = 1, 10-phenathroline) was used as an electroluminescent material for the first time. The Tb complex was blended with poly(N-vinylcarbazole) (PVK) in different weight ratios and spinn to coated into films (noted as PVK :Tb films). The photoluminescence (PL) properties of films were investigated and the optimum weight ratio between PVK and Tb(o-BBA)3(phen) was found to be 3:1. Monolayer devices with the structure ITO/PVK: Tb/AI were fabricated and emitted green light, which was characteristic of Tb^3+ emission. The results show that mecha- nisms for PL and EL are different. The PL is considered to be caused because of energy transfer and direct excitation to the Tb(o-BBA)3(phen) molecule, while EL is mainly on charging trapping.
基金the NSFC (29973026, 29773017) and Beijing Natural Science Foundation (2992007) for the provision of financial support.
文摘The surface pressure-area (pi -A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TAl2)(3)), on pure water subphase was investigated. The molecular area, 0.48 nm(2), is one-third of expected value that indicated the aggregation took place. The Langmuir-Blodgett (LB) films of Al(TAl2), was transferred and characterized. The AFM image confirmed the formation of aggregates.
文摘It has first been reported that Tb(Ⅲ)is oxidated by K_2S_2O_8 in the heteropoly- tungstophosphate complex.The complex ion,[Tb(Ⅳ)(PW_(11)O_(39))_2]^(10-),is stable in aqueous solution only for hours,being graduately reduced to[Tb(Ⅲ)(PW_(11)O_(39))_2]^(11-).It is red-brown,with absorption band at about 420 nm.
基金Project(20761002) supported by the National Natural Science Foundation of China
文摘Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.
基金Project supported by the Hi-Tech Research and Development Program (863) of China (No. 2006AA06Z424) the National Basic Research Program (973) of China (No. 2003CB415001)the Pilot Project of Knowledge Innovation Program of Chinese Academy of Sciences (No. KJCX2-SW-H06).
文摘A sensitive method based on the fluorescence quenching effect of the Tb^3+-Tiron complex is proposed for the determination of alkali-labile phosphoprotein phosphorus (ALP) released from fish plasma. The detection limit was 5.4 ng/ml (S/N=2), and the relative standard deviation of the quenching effect (6 replicates) was 4.6%. The results obtained by the proposed method were in good agreement with those obtained by the colorimetric assay. The advantages of the present method are its relatively simple detection procedure, the lack of toxic organic solvents, and high sensitivity.
基金Supported by the National Natural Science Foundation of China
文摘The syntheses, spec(?) complexes are of significance for understanding mechanisms of magnetic interaction between metal ions and the exploitation of the synthesis of molecular magnetic materials. There were a few works reported previously on the syntheses and magnetic in-
文摘Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only a few complexes of Cu(I)have been published^(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Cl was prepared and characterized by elemental analyses,ICP,IR,and electronic spectra.Its conductivity,oxidation potential and reduction potential were measured.
文摘The synthesis is and crystal structure are reported for the sheet-like compourd [CU2(oxpn)Fe(CN )5(NO)]. there oxpn is the dianion of M, M'-bis(3-aminopropyl)oxamide. This compound crustallizes in the orthogonal space group Puma. with a=11 .413(4), b=22.242(5), c=7.736(2) A, and Z=4.The structure was refined to conventionat discrepancy factors R=0.047 and Pw=0.054. The Cu(II ) and Fe(III)centers are bridged by oxpn and cyanide, the formal behaves as a his-terdentate tigand bound to cooper(II)ion to form (II) dimers. whereas the latter bridges Cu(II) and Fe(III) centers in both symmetric and asymetric end- to-end bis-monodentate fashions, spreading out along be plane to form a 20 network. The Structure is made up of CuFe unit with Cu(II) and Fe(III) ions locating in a distorted square-based pyramid and a compressed octahedron, respectively.
文摘It has previously been demonstrated that phenanthroline-based ligands used to make gold metallotherapuetics have the ability to exhibit cytotoxicity when not coordinated to the metal center. In an effort to help assess the mechanism by which these ligands may cause tumor cell death, iron binding and removal experiments have been considered. The close linkage between cell proliferation and intracellular iron concentrations suggest that iron deprivation strategies may be a mechanism involved in inhibiting tumor cell growth. With the creation of iron (III) phen complexes, the iron binding abilities of three polypyridal ligands [1,10-phenanthroline (phen), 2,9-dimethyl-1, 10-phenanthroline (methylphen), and 2,9-di-sec-butyl-1, 10-phenanthroline (sec-butylphen)] can be tested via a competition reaction with a known iron chelator. Therefore, iron (III) complexes possessing all three ligands were synthesized. Initial mass spectrometric and infrared absorption data indicate that iron (III) tetrachloride complex ions with protonated phen ligands (RphenH+) were formed: [phenH][FeCl4], [methylphenH][FeCl4], [sec-butylphenH][FeCl4]. UV-vis spectroscopy was used to monitor the stability of the complex ions, and it was found that the sec-butylpheniron complex was more stable than the phen and methylphen analogues. This was based on the observation that free ligand was observed immediately upon the addition of EDTA to the [phenH][FeCl4] and [methylphenH] [FeCl4] complex ions.
文摘The kinetics of the periodate oxidation of chromium(III)-complex, [CrIII(NTA)(Ala)(H2O)]-(NTA = Nitrilotriacetate and Ala = ß-alanine) to Cr(VI) have been carried out for the temperature range 15°C - 35°C under pseudo-first order conditions, >>?[complex]. Reaction obeyed first order dependence with respect to and [Cr(III)], and the rate of reaction increases with increasing of pH for the range 3.40 - 4.45. Experimentally, the mechanism of this reaction is found to be consistent with the rate law in which the hydroxo species, [CrIII(NTA)(Ala)(OH)]2- is considerably much more reactive than their conjugate acid. ΔH* and ΔS* have been calculated. It is proposed that electron transfer occurs through an inner-sphere mechanism via coordination of to chromium(III).
文摘Three new heterotrinuclear complexes have been synthesized and characterized, namely {[Gd(L)(2)](2)[Cu(pbaOH)]}(ClO4)(4), where pbaOH denotes 2-hydroxy-1,3-propylenebis(oxamato), L stands for 1,10-phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO2-phen) or 2,2'-bipyridyl (bpy). The temperature dependence of the magnetic susceptibility of ([Gd(phen)(2)(ClO4)](2)[Cu(pbaOH)])(ClO4)(2) has been studied in the 4-300K range, giving the exchange integral J = 6.69 cm(-1). This indicates a weak ferromagnetic interaction between the copper(II) and gadolinium(III) ions.
文摘The crystal and molecular structures of the K[Tb^(III)(edta)(H_2O)_3].5 H_2O(edta = ethylenediaminetetraacetic acid) and K_4[Tb^(III)_2(Httha)_2].14 H_2O (ttha =triethylenetetraminehexaacetic acid) complexes have been determined by single-crystal X-raydiffraction analyses. The crystal of the K[Tb^(III)(edta)(H_2O)_3].5 H_2O complex belongs toorthorhombic crystal system and Fdd 2 space group. The crystal data are as follows: a = 1.9373(5)nm, b = 3.5429(10) nm, c = 1.2114(3) nm, V 8.315(4) nm^3, Z= 16, M= 630.35, Dc = 2.014 g cm^(-3), m= 3.683 mm^(-1) and F(000) = 5024. The final Rand wR values are 0.0224 and 0.0557 for 3189 [I> 2.0sigma(I)] unique reflections, and 0.0245 and 0.0567 for all 8206 reflections, respectively. The[Tb^(III)(edta)(H_2O)_3]^- complex anion has a nine-coordinated pseudo-monocapped squareantiprismatic structure in which the nine coordinate atoms, two N and seven O come from one edtaligand and three water molecules. The crystal of the K_4[Tb^(III)_2(Httha)_2].14 H_2O complexbelongs to monoclinic system and P 2(1)/n space group. The crystal data are as follows: a =1.1326(3) nm, b = 2.5675(7) nm, C =2.2076(6) nm, bate = 102.943(5) centre dot, V =6.256(3) nm^3, Z =4, M = 1705.26, Dc = 1.802 g cm^(-3), m = 2.611 mm^(-1) and F(000) = 3424. The final R and wR are0.0339 and 0.0667 for 10699 [I>2.0 sigma (I)] unique reflections, and 0.0543 and 0.0741 for all22190 reflections, respectively. The total complex molecule is composed of two close parts instructure.
文摘A comparative thermal decomposition kinetic investigation on Fe(III) complexes of a antipyrine Schiff base ligand, 1,2-Bis(imino-4’-antipyrinyl)ethane (GA)), with varying counter anions viz. CIO4-, NO3-, SCN-, Cl-, and Br-, has been done by thermogravimetric analysis by using Coats-Redfern equation. The kinetic parameters like activation energy (E), pre-exponential factor (A) and entropy of activation (ΔS) were quantified. On comparing the various kinetic parameters, lower activation energy was observed in second stage as compared to first thermal decomposition stage. The same trend has been observed for pre-exponential factor (A) and entropy of activation (ΔS). The present results show that the starting materials having higher activation energy (E), are more stable than the intermediate products, however;the intermediate products possess well-ordered chemical structure due to their highly negative entropy of activation (ΔS) values. The present investigation proves that the counter anions play an important role on the thermal decomposition kinetics of the complexes.
文摘Spectrophotometric method was used to evaluate the kinetic of the complex formation from the reaction between H[Ru(III)Cl2(H2EDTA)] and the modifier agent [3-(2-aminoethyl)aminopropyl] trimethoxysilane (AEATS) (μ = 0.50 mol.dm-3 with NaCF3COO, 298.15 K), in pseudo-first order conditions. These studies showed that the reactions are successives producing several species influenced by the concentrations ratio. The electronics spectrum of all solutions showed a band in 457 nm with variable molar absorptivity (ε).
基金Project supported by China National Climbing plan and National Nature Science Foundation
文摘Reaction of 2-pyridone, copper acetate and terbium(or yttrium) perchlorate in acetone with the mole ratio 6: 2: 1 results in the formation of heteronuclear complex Ln_2Cu_4L_8 (HL)_4 (OH)_2 (ClO_4)_4 (H_20)_(10) 2CH_3COCH_3(Ln = Tb (1), Y (2)). By recrystallizing (1) in CHCl_3 single crystals were obtained and the structure was determined by four-circle diffractometer. Data showed that the crystal is in space group C2/m with a=27. 454(9)A, b=13, 608A, c=30. 556(11)A, β=99. 89(3)°, v=11245. 7(7. 5)A^3. The structure was solved by a combination of Patterson method and Fourier technique. The final R value is 0. 103. In the structure, four copper and two terbium ions are bridged by 2-pyridone anions to form an essentially octahedral Cu_4Tb_2 core. The terbium atoms are each eight-coordinate and the copper atoms are five-coordinate.
文摘A new complex Tb(IB)_3(phen)·2H_2O that gives off green fluorescence was synthesized. The results show that the strong fluorescence emitting of 490 and 545 nm for Tb 3+ in the Tb(IB)_3(phen)·2H_2O complex is related to the transitions 5D_4-7F_6 and 5D_4-7F_5, respectively. The results indicate that the complex is concentrated on the nuclei regions in the section of onion toot tip tissues and the nuclei are high lighted under fluorescent microscope. It is possible that the Tb(IB)_3(phen)·2H_2O complex can be developed as a fluorescent dye in biological and pathological studies.