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
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
Halfsandwich iron dicarbonyl complex [η 5-C5H3（t-Bu）2]Fe（CO）2Cl（1） reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10（2） to give a binuclear iron carborane complex [η 5-C5H3（t-Bu）2]2Fe2（CO）3&...Halfsandwich iron dicarbonyl complex [η 5-C5H3（t-Bu）2]Fe（CO）2Cl（1） reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10（2） to give a binuclear iron carborane complex [η 5-C5H3（t-Bu）2]2Fe2（CO）3·Se2C2B 10H 10（3）. The X-ray diffraction analysis of complex 3 reveals that one of the iron atoms is chiral.展开更多
The complex [Fe(C14H14NO2)3]2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl36H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted oc...The complex [Fe(C14H14NO2)3]2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl36H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted octahedral environment coordinated to the hydroxy and ketone oxygen atoms of three ligands in the mer configuration Mr=773.57(C42H46N3O8Fe). The crystal is hexagonal with space group P31c; a=15.943(2), c=17.612(4)? V=3877.0(12)?, Z=4, Dc=1.325g/cm3, m=0.445mm-1, F(000)=1634, R=0.0446, wR= 0.1154 for 3085 reflections with I >2s(I). The bond lengths from iron to oxygens are 1.980(1)?for the ketone oxygens and 2.071(1)?for the hydroxy oxygens. The molecule exhibits the expected propeller shape, and the angle of the trigonal twist is 48.37. The dihedral angles are 0.5(2)?between chelate ring plane and pyridine ring plane and 71.31(7)?between pyridine ring plane and benzene ring plane. The solvent H2O(O(3) and O(4)) molecules are linked with O(2) and O(1) by hydrogen bonds with bond lengths 2.900(1) and 2.999(1)? respectively.展开更多
Iron tetranitrosyl complex bearing the thiosulfate ligand (TNIC) is an efficient nitrogen monoxide donor (NO). He shows antitumor properties and may be used as an original drug for the therapy of acute coronary syndro...Iron tetranitrosyl complex bearing the thiosulfate ligand (TNIC) is an efficient nitrogen monoxide donor (NO). He shows antitumor properties and may be used as an original drug for the therapy of acute coronary syndrome. In this work, the reaction of the TNIC with adenosine triphosphoric acid (ATP) was studied. Formation of the products for the reaction of ATP with TNIC was shown by electronic microscopy. The kinetics of the reaction was controlled by spectrofluorometric method, and the complexation constant was measured. The mechanism of interaction of ATP with TNIC was proposed, and the relevant kinetic model satisfactorily described the experimental data, which permitted to calculate the rate constants for these process stages. NMR, IR, and M?ssbauer studies were used for determination of the reaction product structure. NMR study showed TNIC interaction only with adenine part of ATP. The method of IR spectroscopy identified both the absence NO in the reaction products and the occurrence of new Fe-S and Fe-N bonds. M?ssbauer study showed that iron in the reaction products was presented by two forms: Fe(II) and Fe(III). Thus, the structures for the [ATP-Fe2+S] and [ATP-Fe3+S] complexes were proposed.展开更多
A new compound of general formula {[(H2O)2K(μ-H2O)Sr]@[Cr(C2O4)3]}n (1) has been synthesized in water and characterized by elemental and thermal analyses, EDX, IR and UV-Vis spectroscopies and by single crystal X-ray...A new compound of general formula {[(H2O)2K(μ-H2O)Sr]@[Cr(C2O4)3]}n (1) has been synthesized in water and characterized by elemental and thermal analyses, EDX, IR and UV-Vis spectroscopies and by single crystal X-ray structure determination. Compound 1 crystallizes in the chiral space group Fdd2 of orthorhombic system with a = 14.110 (4) ?, b = 36.074 (11)?, c =11.034 (3)? and Z = 16. Compound 1 is a coordination polymer in which the three-dimensional lattice framework is realized by the interconnectivity between K+ cations, Sr2+ cations, aqua ligands and [Cr(C2O4)3]3– complex anions. The asymmetric unit of 1 consists of one cationic motif formally written [(H2O)2K(μ-H2O)Sr]3+ and one anionic entity, [Cr(C2O4)3]3–. The K+ and Sr2+ ions in the cationic motif are both eight-coordinate while the Cr3+ ions in the anionic complex are six-coordinate in a distorted octahedral geometry. Coulombic interactions between the ionic motifs and the three-dimensional H-bonding involving aqua ligands help to consolidate the bulk structure. Thermogra-vimetric analysis (TGA) shows that compound 1 is stable to heat up to ca. 80℃.展开更多
Novel dinuclear iron (III) complex [Fe2(HPTB) 1μ-O2P(OPh)2 O2P(OPh)2 2] (C1O4)2, where HPTB is the anion of N, N, N′, N′-tetrakis(2-benzimidawlylmethyl)-2-hydroxy-1, 3-diaminopropane, was prepared in order to provi...Novel dinuclear iron (III) complex [Fe2(HPTB) 1μ-O2P(OPh)2 O2P(OPh)2 2] (C1O4)2, where HPTB is the anion of N, N, N′, N′-tetrakis(2-benzimidawlylmethyl)-2-hydroxy-1, 3-diaminopropane, was prepared in order to provide a model for the active site of purple acid phosphatase (PAP). This compound has been characterized by X-ray crystallography. Crystal data: triclinic, space group $P \bar 1$ ,a = 1. 512 13(5), b = 1. 591 19(5),c = 1.890 90(5) nm, α = 69.925(1)°,β = 84. 358(1)°,γ = 65.712(1)°, Z = 2. Dinuclear iron (II1) centers are bridged by aμ-OR group from HPTB, a bidentate bridging diphenylphosphate and two terminal diphenylphosphates coordinate to Fe(III) centers.展开更多
A novel phenol-linked bis(imidazolium) salt,H3LCl2(L = O-4-C(CH3)3-C6H2-2,6-di[CH2{C(NCHCHNAr)}]2, Ar = 2,6-diisopropylphenyl, 1), was designed and used to prepare an ionic iron(III) complex [H2L][Fe Cl4](2).Complex 2...A novel phenol-linked bis(imidazolium) salt,H3LCl2(L = O-4-C(CH3)3-C6H2-2,6-di[CH2{C(NCHCHNAr)}]2, Ar = 2,6-diisopropylphenyl, 1), was designed and used to prepare an ionic iron(III) complex [H2L][Fe Cl4](2).Complex 2 was a highly efficient catalyst for aryl Grignard cross-coupling of alkyl chlorides bearing b-hydrogens.Furthermore, complex 2 was reusable and could be reused in at least eight times without significant loss in catalytic activity.展开更多
At room temperature(25 ℃), urea and ferric chloride hexahydrate(system Ⅰ) or f erric nitrate nonahydrate(system Ⅱ) in a mole ratio of 6∶1 were mixed and ground finely in an agate mortar for 6 hours, a direc t soli...At room temperature(25 ℃), urea and ferric chloride hexahydrate(system Ⅰ) or f erric nitrate nonahydrate(system Ⅱ) in a mole ratio of 6∶1 were mixed and ground finely in an agate mortar for 6 hours, a direc t solid state reaction occurred. IR and elemental analysis confirmed the products obtained are the com- plexes of urea with ir on(Ⅲ).展开更多
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.
基金Supported by the National Natural Science Foundation of China( No.2 99740 2 9,2 992 5 10 1) and Special Funds forMajor State Basic Research Projects of China( G19990 64 80 0)
文摘Halfsandwich iron dicarbonyl complex [η 5-C5H3（t-Bu）2]Fe（CO）2Cl（1） reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10（2） to give a binuclear iron carborane complex [η 5-C5H3（t-Bu）2]2Fe2（CO）3·Se2C2B 10H 10（3）. The X-ray diffraction analysis of complex 3 reveals that one of the iron atoms is chiral.
基金the Foundation of Returning Personal from Overseas Study of Jiangsu Education Department.
文摘The complex [Fe(C14H14NO2)3]2H2O has been prepared by reaction of N-p-methylphenyl-3-hydroxy-2-ethyl-4-pyridinone with FeCl36H2O. A single-crystal X-ray study shows that the iron atoms lie in a trigonally distorted octahedral environment coordinated to the hydroxy and ketone oxygen atoms of three ligands in the mer configuration Mr=773.57(C42H46N3O8Fe). The crystal is hexagonal with space group P31c; a=15.943(2), c=17.612(4)? V=3877.0(12)?, Z=4, Dc=1.325g/cm3, m=0.445mm-1, F(000)=1634, R=0.0446, wR= 0.1154 for 3085 reflections with I >2s(I). The bond lengths from iron to oxygens are 1.980(1)?for the ketone oxygens and 2.071(1)?for the hydroxy oxygens. The molecule exhibits the expected propeller shape, and the angle of the trigonal twist is 48.37. The dihedral angles are 0.5(2)?between chelate ring plane and pyridine ring plane and 71.31(7)?between pyridine ring plane and benzene ring plane. The solvent H2O(O(3) and O(4)) molecules are linked with O(2) and O(1) by hydrogen bonds with bond lengths 2.900(1) and 2.999(1)? respectively.
文摘Iron tetranitrosyl complex bearing the thiosulfate ligand (TNIC) is an efficient nitrogen monoxide donor (NO). He shows antitumor properties and may be used as an original drug for the therapy of acute coronary syndrome. In this work, the reaction of the TNIC with adenosine triphosphoric acid (ATP) was studied. Formation of the products for the reaction of ATP with TNIC was shown by electronic microscopy. The kinetics of the reaction was controlled by spectrofluorometric method, and the complexation constant was measured. The mechanism of interaction of ATP with TNIC was proposed, and the relevant kinetic model satisfactorily described the experimental data, which permitted to calculate the rate constants for these process stages. NMR, IR, and M?ssbauer studies were used for determination of the reaction product structure. NMR study showed TNIC interaction only with adenine part of ATP. The method of IR spectroscopy identified both the absence NO in the reaction products and the occurrence of new Fe-S and Fe-N bonds. M?ssbauer study showed that iron in the reaction products was presented by two forms: Fe(II) and Fe(III). Thus, the structures for the [ATP-Fe2+S] and [ATP-Fe3+S] complexes were proposed.
文摘A new compound of general formula {[(H2O)2K(μ-H2O)Sr]@[Cr(C2O4)3]}n (1) has been synthesized in water and characterized by elemental and thermal analyses, EDX, IR and UV-Vis spectroscopies and by single crystal X-ray structure determination. Compound 1 crystallizes in the chiral space group Fdd2 of orthorhombic system with a = 14.110 (4) ?, b = 36.074 (11)?, c =11.034 (3)? and Z = 16. Compound 1 is a coordination polymer in which the three-dimensional lattice framework is realized by the interconnectivity between K+ cations, Sr2+ cations, aqua ligands and [Cr(C2O4)3]3– complex anions. The asymmetric unit of 1 consists of one cationic motif formally written [(H2O)2K(μ-H2O)Sr]3+ and one anionic entity, [Cr(C2O4)3]3–. The K+ and Sr2+ ions in the cationic motif are both eight-coordinate while the Cr3+ ions in the anionic complex are six-coordinate in a distorted octahedral geometry. Coulombic interactions between the ionic motifs and the three-dimensional H-bonding involving aqua ligands help to consolidate the bulk structure. Thermogra-vimetric analysis (TGA) shows that compound 1 is stable to heat up to ca. 80℃.
文摘Novel dinuclear iron (III) complex [Fe2(HPTB) 1μ-O2P(OPh)2 O2P(OPh)2 2] (C1O4)2, where HPTB is the anion of N, N, N′, N′-tetrakis(2-benzimidawlylmethyl)-2-hydroxy-1, 3-diaminopropane, was prepared in order to provide a model for the active site of purple acid phosphatase (PAP). This compound has been characterized by X-ray crystallography. Crystal data: triclinic, space group $P \bar 1$ ,a = 1. 512 13(5), b = 1. 591 19(5),c = 1.890 90(5) nm, α = 69.925(1)°,β = 84. 358(1)°,γ = 65.712(1)°, Z = 2. Dinuclear iron (II1) centers are bridged by aμ-OR group from HPTB, a bidentate bridging diphenylphosphate and two terminal diphenylphosphates coordinate to Fe(III) centers.
基金supported by the National NaturalScience Foundation of China(21172164)the Key Laboratory of Organic Chemistry of Jiangsu Province,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Project of Scientific and Technologic Infrastructure of Suzhou(SZS201207)
文摘A novel phenol-linked bis(imidazolium) salt,H3LCl2(L = O-4-C(CH3)3-C6H2-2,6-di[CH2{C(NCHCHNAr)}]2, Ar = 2,6-diisopropylphenyl, 1), was designed and used to prepare an ionic iron(III) complex [H2L][Fe Cl4](2).Complex 2 was a highly efficient catalyst for aryl Grignard cross-coupling of alkyl chlorides bearing b-hydrogens.Furthermore, complex 2 was reusable and could be reused in at least eight times without significant loss in catalytic activity.
文摘At room temperature(25 ℃), urea and ferric chloride hexahydrate(system Ⅰ) or f erric nitrate nonahydrate(system Ⅱ) in a mole ratio of 6∶1 were mixed and ground finely in an agate mortar for 6 hours, a direc t solid state reaction occurred. IR and elemental analysis confirmed the products obtained are the com- plexes of urea with ir on(Ⅲ).
基金supported by the Jiangsu Province Science Foundation for Youths (Grant No.BK20150569)the National Natural Science Foundation of China (Grant No.201502088)+1 种基金the project of Scientific and Technological Support Program in Jiangsu province (Grant No.BE2014147-2)the Doctoral Fund of the Ministry of Education of China for financial support (Grant No.20120091130002)~~
