Transition metal possesses a unique d-orbital electronic structure,which imparts a diverse range of physical and chemical properties.These properties render them significant in fields such as chemistry and materials s...Transition metal possesses a unique d-orbital electronic structure,which imparts a diverse range of physical and chemical properties.These properties render them significant in fields such as chemistry and materials science.The distinctive optical,electrical,and magnetic properties of these complexes can be attributed to the variations in the quantity of d-orbital electrons,thereby influencing their spin and orbital characteristics.The d-orbitals facilitate the formation of stable multidirectional bonds with ligands,resulting in a variety of geometric structures and rich coordination chemistry.These interactions result in variations in energy levels,thereby producing diverse electrical properties,including low attenuation coefficients,high rectification ratios,and unique multichannel transmission.Moreover,the unpaired electrons inthe d-orbitals can give rise to diverse magnetic behaviors,leading to magnetic effects such as spin-related interfaces,switches,and magnetoresistance.This paves the way for extensive possibilities in the design and application of single-molecule devices.This review elaborates on singlemolecule physical properties of transition metal complexes,including length attenuation,rectification,multi-channel transmission,thermoelectric effect,and spin regulation,which are vital for the functionalization and regulation of molecular electronics.In addition,this review also explores the correlation between these physical properties and the electronic structure of transition metals,discussing the broad prospects of transition metal complexes in the fields of nanoelectronics,optoelectronics,and quantum technology.展开更多
Recent advancements have led to the synthesis of various new metal-containing explosives,particularly energetic metal-organic frameworks(EMOFs),which feature high-energy ligands within well-ordered crystalline structu...Recent advancements have led to the synthesis of various new metal-containing explosives,particularly energetic metal-organic frameworks(EMOFs),which feature high-energy ligands within well-ordered crystalline structures.These explosives exhibit significant advantages over traditional compounds,including higher density,greater heats of detonation,improved mechanical hardness,and excellent thermal stability.To effectively evaluate their detonation performance,it is crucial to have a reliable method for predicting detonation heat,velocity,and pressure.This study leverages experimental data and outputs from the leading commercial computer code to identify suitable decomposition pathways for different metal oxides,facilitating straightforward calculations for the detonation performance of alkali metal salts,and metal coordination compounds,along with EMOFs.The new model enhances predictive reliability for detonation velocities,aligning more closely with experimental results,as evi-denced by a root mean square error(RMSE)of 0.68 km/s compared to 1.12 km/s for existing methods.Furthermore,it accommodates a broader range of compounds,including those containing Sr,Cd,and Ag,and provides predictions for EMOFs that are more consistent with computer code outputs than previous predictive models.展开更多
Transition metal complexes of meso-tetra(4-myristyloxyphenyl)porphyrin TMPPM [M =Mn, Fe, Co, Ni, Cu, Zn; TMPP=mesotetra(4-myristyloxyphenyl)porphyrin] have been synthesized and characterized by means of elemental an...Transition metal complexes of meso-tetra(4-myristyloxyphenyl)porphyrin TMPPM [M =Mn, Fe, Co, Ni, Cu, Zn; TMPP=mesotetra(4-myristyloxyphenyl)porphyrin] have been synthesized and characterized by means of elemental analyses, UV-Vis spectra, infrared photoacoustic spectra, 1H NMR spectra, molar conductance and differential scanning calorimetry(DSC). The ligand and the Zn complex show liquid crystalline behavior. According to the DSC thermogram of the Zn complex, it exhibits a lower phase transition temperature -7.453 ℃ and a wide mesophase temperature span, 77 ℃.展开更多
The simultaneous removal of up to 92% of the surfactant template and chemical implantation of transition metal complexes into mesopores has been successfully achieved by treating as-synthesized pure siliceous MCM-41 w...The simultaneous removal of up to 92% of the surfactant template and chemical implantation of transition metal complexes into mesopores has been successfully achieved by treating as-synthesized pure siliceous MCM-41 with supercritical CO2 modified with CH2Cl2/MeOH mixture, resulting in the formation of functionalized material with uniform pore structure.展开更多
With transition metal complex, a discrete cuprous iodide compound, namely, [Ni（phen）3]2Cu6I10（1, phen = 1,10-phenanthroline） has been solvothermally synthesized and structurally characterized. Single-crystal X-ray...With transition metal complex, a discrete cuprous iodide compound, namely, [Ni（phen）3]2Cu6I10（1, phen = 1,10-phenanthroline） has been solvothermally synthesized and structurally characterized. Single-crystal X-ray diffraction studies revealed that compound 1 crystallizes in triclinic space group P1（No. 2） with a = 11.2694（2）, b = 12.3699（3）, c = 15.0387（3） ？, α = 102.840（2）, β = 105.215（2）, γ = 96.388（2）°, V = 1940.04（7） ^3, Z = 1, Dc = 2.438 g·cm^-3, F（000） = 1324, R = 0.0256 and w R = 0.0555（I 〉 2σ（I））. Compound 1 features a discrete anionic moiety of [Cu6I10]^4- charge-balanced by two metal complexes of [Ni（phen）3]2＋. The optical absorption edge of compound 1 was estimated to be 2.24 eV. Interestingly, nearly 95% of contaminant（crystal violet aqueous solution（CV）, 50 m L, 1.0 × 10^-5 M） could be decolorized after exposure to visible light within 30 min, illustrating an impressive photocatalytic activity of compound 1. The thermal stability of 1 has also been studied.展开更多
Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,h...Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,how to extract the underlying electronicstructure information inevitably poses a major challenge to beginners,in particular for systems with S>1/2.In fact,the physical principles of transition metal EPR have long been well-established and since 1970s a series of dedicated voluminous monographs have been published already.Not surprisingly,they are not appropriate stating points for novices to grasp a panorama of the profound theory prior to scrutinizing in-depth references.The present review aims to fill this gap to provide a perspective of transition metal EPR and unveil some peculiar subtleties thereof on the basis of our recent work.展开更多
The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and ...The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.展开更多
In this study,the electronic transition properties and structural analysis of the metal complexes(Ni(Ⅱ),Co(Ⅱ),Cu(Ⅱ)and Mn(Ⅱ))of three different polymer ligands were performed by using XRF and X-ray diffraction(XRD...In this study,the electronic transition properties and structural analysis of the metal complexes(Ni(Ⅱ),Co(Ⅱ),Cu(Ⅱ)and Mn(Ⅱ))of three different polymer ligands were performed by using XRF and X-ray diffraction(XRD)techniques,respectively.The structural analysis of the polymers and their complexes were performed by XRD technique and some of the polymers were found to be in the face-centred cubic(fcc)structure.In addition,the values of the present K X-ray intensity ratios are significantly greater than the values reported in literature.展开更多
It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed hav...It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed have not been studied.Employing a new potential anticancer ligand 1,2-bis(thioacetic acid hydrazide)ethane prepared in our lab,along with ligands oxydiacetic hydrazide and 1,2-bis(oxyacetic acid hydrazide) ethane,a series of 11 new first-row transition metal(M=Zn^(2+),Cu^(2+),Co^(2+), Ni^(2+))complexes with each of the above three ligands have been synthesized and characterized by means of elemental analyses,IR,TG and X-ray powder diffraction.展开更多
The asymmetric alkylations of chiral transition metal complexes derived from (+)-camphor and 2-aminomethyl-6-methylpyridine were examined under mild conditions.The formation of the complexes 2 is conductive to the enh...The asymmetric alkylations of chiral transition metal complexes derived from (+)-camphor and 2-aminomethyl-6-methylpyridine were examined under mild conditions.The formation of the complexes 2 is conductive to the enhancement of di- astereoselectivity in the alkylations at room temperature.展开更多
Seven transition metal complexes of Mn<sup>2+</sup>, Ni<sup>2+</sup>, Co<sup>2+</sup>, Cu<sup>2+</sup> and Zn<sup>2+</sup> with 3-aminopyridine (3-APy) as li...Seven transition metal complexes of Mn<sup>2+</sup>, Ni<sup>2+</sup>, Co<sup>2+</sup>, Cu<sup>2+</sup> and Zn<sup>2+</sup> with 3-aminopyridine (3-APy) as ligand have been synthesized, characterized by different techniques and their antibacterial activities were studied. Molecular modeling calculations were performed using DMOL<sup>3</sup> program in materials studio package which is designed for the realization of large scale density functional theory calculation (DFT). The quantum mechanical and chemical reactivity parameters such as chemical hardness, chemical potential, electronegativity, electrophilicity index and Homo-Lumo energy gap were obtained theoretically and were used to understand the biological activity of the prepared compounds. Some complexes were tested for their in-vitro cytotoxic activity in human lung cancer cell lines (A-549 cell line), and structureactivity relationships were established. In general, the coordination to Co<sup>2+</sup> increased the cytotoxicity while the Ni<sup>2+</sup> complexes show reduced cytotoxic activity compared to the metal-free 3-aminopyridine.展开更多
Some new Schiff bases were synthesized by the condensation of equimolar quantities of salicylaldehyde and 2-amino-5-phenylazo-pyridine or its derivatives in dry benzene(1):Metal complexes of the type ML_2and M'L_3...Some new Schiff bases were synthesized by the condensation of equimolar quantities of salicylaldehyde and 2-amino-5-phenylazo-pyridine or its derivatives in dry benzene(1):Metal complexes of the type ML_2and M'L_3 where M=Cu^(2+),Co^(2+),Ni^(2+),Mn^(2+)Pd^(2+),M'=Fe^(3+)and L=different newly synthesized monobasic Schiff bases were prepared in absolute ethanolic medium(2)and characterized by elementary analysis,conductance measurements,infrared spectra,electronic spectra,magnetic moments studies.展开更多
<div style="text-align:justify;"> <span style="font-family:Verdana;">The aim of this work is to synthesize, characterize and evaluate the biological activity of 2-acetyl and 2-formyl-3-...<div style="text-align:justify;"> <span style="font-family:Verdana;">The aim of this work is to synthesize, characterize and evaluate the biological activity of 2-acetyl and 2-formyl-3-amino-1,4-naphthoquinone (L<span style="white-space:nowrap;"><sup>1</sup> - L<span style="white-space:nowrap;"><sup>2</sup>) and their metal-Co(II), Ni(II) and Cu(II) chelates. The newly chelates were characterized by elemental analysis, IR, mass and <span style="white-space:nowrap;"><sup>1</sup>HNMR spectra, thermogravimetric analysis (TGA) and biological activity. The antibacterial and antifungal activities of the ligands and its metal complexes were screened against bacterial species (<span style="white-space:nowrap;">Staphylococcus aureus, Bacillus subtilis and Escherichia coli) and fungi (<span style="white-space:nowrap;">Candida albicans). Ampicillin and amphotericin were used as references for antibacterial and antifungal studies. The activity data show that the metal complexes have a promising biological activity comparable with parent free ligand against bacterial and fungal species.展开更多
The title complex M (mnt) (phen), M=Fe11, Co11. Ni11, Cu11. Zn11. was respectivelysynthesized by reaction of disodium maleionitriledithiolate (Na2 (mnt) ) with corresponding metalcomplex M (phen) Cl2. Charge transfer ...The title complex M (mnt) (phen), M=Fe11, Co11. Ni11, Cu11. Zn11. was respectivelysynthesized by reaction of disodium maleionitriledithiolate (Na2 (mnt) ) with corresponding metalcomplex M (phen) Cl2. Charge transfer transitions in the absorption and emission spectra have beenstuded.展开更多
Several new transition metal complexes using Schiff base containing pyridine and amide moieties (N, N'-bis(- salicylaliminoethyl)-2, 6-pyridinedicarboxylic amide, H4L) as the ligand have been prepared. Their compo...Several new transition metal complexes using Schiff base containing pyridine and amide moieties (N, N'-bis(- salicylaliminoethyl)-2, 6-pyridinedicarboxylic amide, H4L) as the ligand have been prepared. Their compositions and structures are corroborated by elemental analysis, IR, UV, 1H NMR, DTA-TG and molar conductivity data. Their anti-bacterial activities have been studied by microcalorimetry. The result shows that the ligand and all com-plexes are potential anti-bacteria reagent and their inhibitory capacities are concentration-depended. The Mn com-plex has the strongest inhibitory capacity.展开更多
The electrochemical properties of eight new divalent transition metal benzenesulphonate complexes with 1,10-phenanthroline in different solvents and supporting electrolytes were investigated by means of cyclic voltamm...The electrochemical properties of eight new divalent transition metal benzenesulphonate complexes with 1,10-phenanthroline in different solvents and supporting electrolytes were investigated by means of cyclic voltammetry(CV). Based on the CV data the influences of various coordination modes on the electrochemical behavior of the complexes were discussed. The diffusion coefficient D c and rate constant k s of those complexes in DMF systems were estimated according to CV and the results show that these processes were all quasi-reversible.展开更多
Charge transport through single molecular neutral mono- and di-cobalt（Ⅱ） complexes with re-conjugated macromolecular wire was investigated. Scanning tunnelling spectroscopy （STS） studies revealed that the mono-co...Charge transport through single molecular neutral mono- and di-cobalt（Ⅱ） complexes with re-conjugated macromolecular wire was investigated. Scanning tunnelling spectroscopy （STS） studies revealed that the mono-cobalt（Ⅱ） complex showed a pronounced rectifying effect with a large rectification ratio and finely featured NDR peaks, while the di-cobalt（Ⅱ） complex showed a relatively symmetric electron transport without clear NDR peaks. The results are explained based on the dipolar and electronic effects.展开更多
A nickel-1,10-phenanthroline complex supported on an octamolybdate, [{Ni(phen)2}2(ξ-Mo8O26)], has been hydrothermally synthesized with MoO3, H2MoO4, Ni(OAc)2 · 6H2O and 1,10-phenathroline (1,10-phen) as raw mate...A nickel-1,10-phenanthroline complex supported on an octamolybdate, [{Ni(phen)2}2(ξ-Mo8O26)], has been hydrothermally synthesized with MoO3, H2MoO4, Ni(OAc)2 · 6H2O and 1,10-phenathroline (1,10-phen) as raw materials. The crystals of the compound belong to mono-clinic P21/n space group, a= 1.2952(2), b = 1.6659(10), c= 1.3956(12) nm, β=106.273(8)°, V = 2.8906(5) nm3, Z = 2. 5604 observable reflections (/>2σ(/)) were used for structure resolution and refinements to converge to final R1 = 0.0414, wR2 = 0.0815. The result of structure determination shows that the compound contains octamolybdate possessing a novel structure type (named as ξ-isomer). The feature of ξ-[Mo8O26]4- is that it is composed of Mo6O6 ring and two MoO6 octa-hedra located at cap positions on opposite faces. The Mo6O6 ring contains two octahedral and four trigonal-bipyramidal MovI atoms. Each ξ-[Mo8O26]4- unit is bonded with two [Ni(phen)2]2+ through terminal oxygen atoms of octahedral and neighbouring trigonal-bipyramidal Mo atom in the Mo6O6 ring. IR and UV-Vis spectra of the compound were measured and its electronic structure was studied by EHMO method.展开更多
A series of new complexes{2,6-bis[1-((2-methyl-4-methoxyphenyl)imino)ethyl]pyri-dine}MCI2[M=Fe(Ⅱ)(2),Co(Ⅱ)(3),Ni(Ⅱ)(4),Cu(Ⅱ)(5),Zn(Ⅱ)(6)]have been synthesized.At 25℃,using 500 equiv of methylaluminoxane(MAO),the...A series of new complexes{2,6-bis[1-((2-methyl-4-methoxyphenyl)imino)ethyl]pyri-dine}MCI2[M=Fe(Ⅱ)(2),Co(Ⅱ)(3),Ni(Ⅱ)(4),Cu(Ⅱ)(5),Zn(Ⅱ)(6)]have been synthesized.At 25℃,using 500 equiv of methylaluminoxane(MAO),the activities of Fe(Ⅱ),Co(Ⅱ)catalysts can reach 4.02×106 g/mol-Fehatm for ethylene polymerization and 3.98×105 g/mol-Cohatm for ethylene oligomerization.The effects of polymerization conditions such as reaction temperature,Al/M molar ratio and time on the activity of catalyst have been explored.展开更多
A new azo Schiff-base ligand,(N^(1)Z,N^(2)Z)-N^(1),N^(2)-bis(4-((Z)4-hydroxy naphthalen-1-yl)diazenyl)-(1,5-dimethy-2-phenyl-^(1)H-pyrazol-3(2H)-ylidene)benzene-1,2-diamine,has been synthesized from coupling(N^(1)Z,N^...A new azo Schiff-base ligand,(N^(1)Z,N^(2)Z)-N^(1),N^(2)-bis(4-((Z)4-hydroxy naphthalen-1-yl)diazenyl)-(1,5-dimethy-2-phenyl-^(1)H-pyrazol-3(2H)-ylidene)benzene-1,2-diamine,has been synthesized from coupling(N^(1)Z,N^(2)Z)-N^(1),N^(2)-bis(4-amino-1,5-dimethyl-2-phenyl-^(1)H-pyrazol-3(2H)-ylidene)benzene-1,2-diamine with 1-naphthol.Fourier-transform infrared spectroscopy(FTIR),proton nuclear magnetic resonance(^(1)H-NMR),carbon nuclear magnetic resonance(^(13)C-NMR)technique,ultraviolet-visible spectroscopy(UV-Vis),mass analysis,molar conductance and magnetic susceptibility were used to characterize the structures of the new ligand and their transition metal complexes.The complexes were found to have the general formula(M)(L)Cl_(2) where M=Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ),Cd(Ⅱ)and Hg(Ⅱ),(M)(L)Cl_(3) where M=Au(Ⅲ),and(M)(L)Cl_(2)Cl where M=Fe(Ⅲ).The FTIR results demonstrated that the coordination sites were the azomethine nitrogen and azo nitrogen atoms of the azo Schiff-base ligand.The electronic spectral and magnetic measurement data indicated that the complexes exhibited octahedral geometry,except the Au(Ⅲ)complex suggested a square planar geometry around the central metal ion.The results showed the highest inhibitory effect for gold the complex.The effect of biological screening of the gold complex on human colon cancer cell line LS-174 was investigated.The gold complex was observed to have the highest inhibitory effect.展开更多
基金financially supported by the National Key R&D Program of China(Nos.2021YFA1200102,2021YFA1200101,2023YFF1205803,2022YFE0128700)the National Natural Science Foundation of China(Nos.22173050,22150013,21727806,21933001)+1 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202407)the Natural Science Foundation of Beijing(No.2222009)
文摘Transition metal possesses a unique d-orbital electronic structure,which imparts a diverse range of physical and chemical properties.These properties render them significant in fields such as chemistry and materials science.The distinctive optical,electrical,and magnetic properties of these complexes can be attributed to the variations in the quantity of d-orbital electrons,thereby influencing their spin and orbital characteristics.The d-orbitals facilitate the formation of stable multidirectional bonds with ligands,resulting in a variety of geometric structures and rich coordination chemistry.These interactions result in variations in energy levels,thereby producing diverse electrical properties,including low attenuation coefficients,high rectification ratios,and unique multichannel transmission.Moreover,the unpaired electrons inthe d-orbitals can give rise to diverse magnetic behaviors,leading to magnetic effects such as spin-related interfaces,switches,and magnetoresistance.This paves the way for extensive possibilities in the design and application of single-molecule devices.This review elaborates on singlemolecule physical properties of transition metal complexes,including length attenuation,rectification,multi-channel transmission,thermoelectric effect,and spin regulation,which are vital for the functionalization and regulation of molecular electronics.In addition,this review also explores the correlation between these physical properties and the electronic structure of transition metals,discussing the broad prospects of transition metal complexes in the fields of nanoelectronics,optoelectronics,and quantum technology.
基金the research committee at Malek Ashtar University of Technology (MUT) for their invaluable support of this project
文摘Recent advancements have led to the synthesis of various new metal-containing explosives,particularly energetic metal-organic frameworks(EMOFs),which feature high-energy ligands within well-ordered crystalline structures.These explosives exhibit significant advantages over traditional compounds,including higher density,greater heats of detonation,improved mechanical hardness,and excellent thermal stability.To effectively evaluate their detonation performance,it is crucial to have a reliable method for predicting detonation heat,velocity,and pressure.This study leverages experimental data and outputs from the leading commercial computer code to identify suitable decomposition pathways for different metal oxides,facilitating straightforward calculations for the detonation performance of alkali metal salts,and metal coordination compounds,along with EMOFs.The new model enhances predictive reliability for detonation velocities,aligning more closely with experimental results,as evi-denced by a root mean square error(RMSE)of 0.68 km/s compared to 1.12 km/s for existing methods.Furthermore,it accommodates a broader range of compounds,including those containing Sr,Cd,and Ag,and provides predictions for EMOFs that are more consistent with computer code outputs than previous predictive models.
文摘Transition metal complexes of meso-tetra(4-myristyloxyphenyl)porphyrin TMPPM [M =Mn, Fe, Co, Ni, Cu, Zn; TMPP=mesotetra(4-myristyloxyphenyl)porphyrin] have been synthesized and characterized by means of elemental analyses, UV-Vis spectra, infrared photoacoustic spectra, 1H NMR spectra, molar conductance and differential scanning calorimetry(DSC). The ligand and the Zn complex show liquid crystalline behavior. According to the DSC thermogram of the Zn complex, it exhibits a lower phase transition temperature -7.453 ℃ and a wide mesophase temperature span, 77 ℃.
文摘The simultaneous removal of up to 92% of the surfactant template and chemical implantation of transition metal complexes into mesopores has been successfully achieved by treating as-synthesized pure siliceous MCM-41 with supercritical CO2 modified with CH2Cl2/MeOH mixture, resulting in the formation of functionalized material with uniform pore structure.
基金Supported by the NNSFC(No.21373223)Chunmiao project of Haixi Institute of Chinese Academy of Sciences(CMZX-2014-001)
文摘With transition metal complex, a discrete cuprous iodide compound, namely, [Ni（phen）3]2Cu6I10（1, phen = 1,10-phenanthroline） has been solvothermally synthesized and structurally characterized. Single-crystal X-ray diffraction studies revealed that compound 1 crystallizes in triclinic space group P1（No. 2） with a = 11.2694（2）, b = 12.3699（3）, c = 15.0387（3） ？, α = 102.840（2）, β = 105.215（2）, γ = 96.388（2）°, V = 1940.04（7） ^3, Z = 1, Dc = 2.438 g·cm^-3, F（000） = 1324, R = 0.0256 and w R = 0.0555（I 〉 2σ（I））. Compound 1 features a discrete anionic moiety of [Cu6I10]^4- charge-balanced by two metal complexes of [Ni（phen）3]2＋. The optical absorption edge of compound 1 was estimated to be 2.24 eV. Interestingly, nearly 95% of contaminant（crystal violet aqueous solution（CV）, 50 m L, 1.0 × 10^-5 M） could be decolorized after exposure to visible light within 30 min, illustrating an impressive photocatalytic activity of compound 1. The thermal stability of 1 has also been studied.
基金the financial support from Chinese Academy of Sciences,National Science Foundation of China(92161204)Max-Planck Society。
文摘Electron paramagnetic resonance(EPR)or electron spin resonance(ESR)has been widely employed to characterize transition metal complexes.However,because of the high degree of complexity of transition metal EPR spectra,how to extract the underlying electronicstructure information inevitably poses a major challenge to beginners,in particular for systems with S>1/2.In fact,the physical principles of transition metal EPR have long been well-established and since 1970s a series of dedicated voluminous monographs have been published already.Not surprisingly,they are not appropriate stating points for novices to grasp a panorama of the profound theory prior to scrutinizing in-depth references.The present review aims to fill this gap to provide a perspective of transition metal EPR and unveil some peculiar subtleties thereof on the basis of our recent work.
文摘The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.
基金Scientific Research Fund of Kahramanmaras Sutcu Imam University,Turkey(2012/3-7YLS)
文摘In this study,the electronic transition properties and structural analysis of the metal complexes(Ni(Ⅱ),Co(Ⅱ),Cu(Ⅱ)and Mn(Ⅱ))of three different polymer ligands were performed by using XRF and X-ray diffraction(XRD)techniques,respectively.The structural analysis of the polymers and their complexes were performed by XRD technique and some of the polymers were found to be in the face-centred cubic(fcc)structure.In addition,the values of the present K X-ray intensity ratios are significantly greater than the values reported in literature.
文摘It has been made certain that thio-and oxy-diacetic acid hydrazides are potential anticancer compounds.However,their ability to form complexes with transition metals and the properties of the complexes thus formed have not been studied.Employing a new potential anticancer ligand 1,2-bis(thioacetic acid hydrazide)ethane prepared in our lab,along with ligands oxydiacetic hydrazide and 1,2-bis(oxyacetic acid hydrazide) ethane,a series of 11 new first-row transition metal(M=Zn^(2+),Cu^(2+),Co^(2+), Ni^(2+))complexes with each of the above three ligands have been synthesized and characterized by means of elemental analyses,IR,TG and X-ray powder diffraction.
基金This work was supported by the National Natural Science Foundation of China.
文摘The asymmetric alkylations of chiral transition metal complexes derived from (+)-camphor and 2-aminomethyl-6-methylpyridine were examined under mild conditions.The formation of the complexes 2 is conductive to the enhancement of di- astereoselectivity in the alkylations at room temperature.
文摘Seven transition metal complexes of Mn<sup>2+</sup>, Ni<sup>2+</sup>, Co<sup>2+</sup>, Cu<sup>2+</sup> and Zn<sup>2+</sup> with 3-aminopyridine (3-APy) as ligand have been synthesized, characterized by different techniques and their antibacterial activities were studied. Molecular modeling calculations were performed using DMOL<sup>3</sup> program in materials studio package which is designed for the realization of large scale density functional theory calculation (DFT). The quantum mechanical and chemical reactivity parameters such as chemical hardness, chemical potential, electronegativity, electrophilicity index and Homo-Lumo energy gap were obtained theoretically and were used to understand the biological activity of the prepared compounds. Some complexes were tested for their in-vitro cytotoxic activity in human lung cancer cell lines (A-549 cell line), and structureactivity relationships were established. In general, the coordination to Co<sup>2+</sup> increased the cytotoxicity while the Ni<sup>2+</sup> complexes show reduced cytotoxic activity compared to the metal-free 3-aminopyridine.
文摘Some new Schiff bases were synthesized by the condensation of equimolar quantities of salicylaldehyde and 2-amino-5-phenylazo-pyridine or its derivatives in dry benzene(1):Metal complexes of the type ML_2and M'L_3 where M=Cu^(2+),Co^(2+),Ni^(2+),Mn^(2+)Pd^(2+),M'=Fe^(3+)and L=different newly synthesized monobasic Schiff bases were prepared in absolute ethanolic medium(2)and characterized by elementary analysis,conductance measurements,infrared spectra,electronic spectra,magnetic moments studies.
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">The aim of this work is to synthesize, characterize and evaluate the biological activity of 2-acetyl and 2-formyl-3-amino-1,4-naphthoquinone (L<span style="white-space:nowrap;"><sup>1</sup> - L<span style="white-space:nowrap;"><sup>2</sup>) and their metal-Co(II), Ni(II) and Cu(II) chelates. The newly chelates were characterized by elemental analysis, IR, mass and <span style="white-space:nowrap;"><sup>1</sup>HNMR spectra, thermogravimetric analysis (TGA) and biological activity. The antibacterial and antifungal activities of the ligands and its metal complexes were screened against bacterial species (<span style="white-space:nowrap;">Staphylococcus aureus, Bacillus subtilis and Escherichia coli) and fungi (<span style="white-space:nowrap;">Candida albicans). Ampicillin and amphotericin were used as references for antibacterial and antifungal studies. The activity data show that the metal complexes have a promising biological activity comparable with parent free ligand against bacterial and fungal species.
文摘The title complex M (mnt) (phen), M=Fe11, Co11. Ni11, Cu11. Zn11. was respectivelysynthesized by reaction of disodium maleionitriledithiolate (Na2 (mnt) ) with corresponding metalcomplex M (phen) Cl2. Charge transfer transitions in the absorption and emission spectra have beenstuded.
基金Project supported by the National Natural Science Foundation of China (No. 20072029).
文摘Several new transition metal complexes using Schiff base containing pyridine and amide moieties (N, N'-bis(- salicylaliminoethyl)-2, 6-pyridinedicarboxylic amide, H4L) as the ligand have been prepared. Their compositions and structures are corroborated by elemental analysis, IR, UV, 1H NMR, DTA-TG and molar conductivity data. Their anti-bacterial activities have been studied by microcalorimetry. The result shows that the ligand and all com-plexes are potential anti-bacteria reagent and their inhibitory capacities are concentration-depended. The Mn com-plex has the strongest inhibitory capacity.
文摘The electrochemical properties of eight new divalent transition metal benzenesulphonate complexes with 1,10-phenanthroline in different solvents and supporting electrolytes were investigated by means of cyclic voltammetry(CV). Based on the CV data the influences of various coordination modes on the electrochemical behavior of the complexes were discussed. The diffusion coefficient D c and rate constant k s of those complexes in DMF systems were estimated according to CV and the results show that these processes were all quasi-reversible.
基金the financial supports of the National Science Foundationthe NSF MRSEC program at the University of Chicago
文摘Charge transport through single molecular neutral mono- and di-cobalt（Ⅱ） complexes with re-conjugated macromolecular wire was investigated. Scanning tunnelling spectroscopy （STS） studies revealed that the mono-cobalt（Ⅱ） complex showed a pronounced rectifying effect with a large rectification ratio and finely featured NDR peaks, while the di-cobalt（Ⅱ） complex showed a relatively symmetric electron transport without clear NDR peaks. The results are explained based on the dipolar and electronic effects.
文摘A nickel-1,10-phenanthroline complex supported on an octamolybdate, [{Ni(phen)2}2(ξ-Mo8O26)], has been hydrothermally synthesized with MoO3, H2MoO4, Ni(OAc)2 · 6H2O and 1,10-phenathroline (1,10-phen) as raw materials. The crystals of the compound belong to mono-clinic P21/n space group, a= 1.2952(2), b = 1.6659(10), c= 1.3956(12) nm, β=106.273(8)°, V = 2.8906(5) nm3, Z = 2. 5604 observable reflections (/>2σ(/)) were used for structure resolution and refinements to converge to final R1 = 0.0414, wR2 = 0.0815. The result of structure determination shows that the compound contains octamolybdate possessing a novel structure type (named as ξ-isomer). The feature of ξ-[Mo8O26]4- is that it is composed of Mo6O6 ring and two MoO6 octa-hedra located at cap positions on opposite faces. The Mo6O6 ring contains two octahedral and four trigonal-bipyramidal MovI atoms. Each ξ-[Mo8O26]4- unit is bonded with two [Ni(phen)2]2+ through terminal oxygen atoms of octahedral and neighbouring trigonal-bipyramidal Mo atom in the Mo6O6 ring. IR and UV-Vis spectra of the compound were measured and its electronic structure was studied by EHMO method.
基金supported by the Chinese Academy of Sciences,the National Natural Science Foundation of China(Grant No.20371039)National Basic Research Program(the 973 Program,No.2003CB214600)+1 种基金the Key Laboratory Research and Establishment Program of Shaanxi Education Section(No.03JS006)the Natural Science Foundation of Shaanxi Province(Grant No.04JK143).
文摘A series of new complexes{2,6-bis[1-((2-methyl-4-methoxyphenyl)imino)ethyl]pyri-dine}MCI2[M=Fe(Ⅱ)(2),Co(Ⅱ)(3),Ni(Ⅱ)(4),Cu(Ⅱ)(5),Zn(Ⅱ)(6)]have been synthesized.At 25℃,using 500 equiv of methylaluminoxane(MAO),the activities of Fe(Ⅱ),Co(Ⅱ)catalysts can reach 4.02×106 g/mol-Fehatm for ethylene polymerization and 3.98×105 g/mol-Cohatm for ethylene oligomerization.The effects of polymerization conditions such as reaction temperature,Al/M molar ratio and time on the activity of catalyst have been explored.
文摘A new azo Schiff-base ligand,(N^(1)Z,N^(2)Z)-N^(1),N^(2)-bis(4-((Z)4-hydroxy naphthalen-1-yl)diazenyl)-(1,5-dimethy-2-phenyl-^(1)H-pyrazol-3(2H)-ylidene)benzene-1,2-diamine,has been synthesized from coupling(N^(1)Z,N^(2)Z)-N^(1),N^(2)-bis(4-amino-1,5-dimethyl-2-phenyl-^(1)H-pyrazol-3(2H)-ylidene)benzene-1,2-diamine with 1-naphthol.Fourier-transform infrared spectroscopy(FTIR),proton nuclear magnetic resonance(^(1)H-NMR),carbon nuclear magnetic resonance(^(13)C-NMR)technique,ultraviolet-visible spectroscopy(UV-Vis),mass analysis,molar conductance and magnetic susceptibility were used to characterize the structures of the new ligand and their transition metal complexes.The complexes were found to have the general formula(M)(L)Cl_(2) where M=Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ),Cd(Ⅱ)and Hg(Ⅱ),(M)(L)Cl_(3) where M=Au(Ⅲ),and(M)(L)Cl_(2)Cl where M=Fe(Ⅲ).The FTIR results demonstrated that the coordination sites were the azomethine nitrogen and azo nitrogen atoms of the azo Schiff-base ligand.The electronic spectral and magnetic measurement data indicated that the complexes exhibited octahedral geometry,except the Au(Ⅲ)complex suggested a square planar geometry around the central metal ion.The results showed the highest inhibitory effect for gold the complex.The effect of biological screening of the gold complex on human colon cancer cell line LS-174 was investigated.The gold complex was observed to have the highest inhibitory effect.
