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
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
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
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
<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
By virtue of their rich photophysical and photochemical properties,transition metal complexes(TMCs)have been extensively studied in multidisciplinary research.In this review,recent studies on TMCs for biological appli...By virtue of their rich photophysical and photochemical properties,transition metal complexes(TMCs)have been extensively studied in multidisciplinary research.In this review,recent studies on TMCs for biological applications are described with a focus on the behaviour of TMCs as specific intracellular sensors and organelle-targeting imaging reagents.Some prominent examples of TMCs as photosensitisers for in vitro and in vivo phototherapies,such as photodynamic therapy and photoactivated chemotherapy,are highlighted.Also,future development of TMCs for new diagnostic and therapeutic applications is discussed.展开更多
The introduction of redox-active ligands into transition metal complexes can lead to novel redox behavior due to the ability of these ligands to serve as electron reservoirs.This feature is especially attractive in ea...The introduction of redox-active ligands into transition metal complexes can lead to novel redox behavior due to the ability of these ligands to serve as electron reservoirs.This feature is especially attractive in earth-abundant transition metal systems that typically favor one-electron redox processes and radical reactivity,as opposed to the two-electron redox cycles common with the noble metals.The redox flexibility afforded by redox-active ligands can enable substrate activation and/or bond forming and breaking processes that would otherwise be inaccessible with traditional redox-innocent ligands.This review discusses key examples of stoichiometric substrate activation and organic transformations facilitated by redox-active ligand-promoted multielectron reactivity at earth-abundant metal complexes.We highlight the electrochemical properties of these systems in relation to their substrate reactivity,where,in many cases,the complexes exhibit sequential one-electron redox events.Only a few examples have achieved electrocatalytic reactivity based on two-electron redox features,which underscores the untapped potential for further development of redox-active ligand systems to expand the capabilities of earth-abundant metal complexes in electrocatalysis.展开更多
A new class of photoactive and chelating ligands L1–3 has been designed and synthesized by incorporating arylazo-3,5-dimethylpyrazole units in the ligand frameworks.Significantly,they are designed in such a way that ...A new class of photoactive and chelating ligands L1–3 has been designed and synthesized by incorporating arylazo-3,5-dimethylpyrazole units in the ligand frameworks.Significantly,they are designed in such a way that azopyrazole units directly coordinate as neutral N-donor ligands.The resulting tri-and tetra-dentate chelating ligands have been complexed with a few transition metal ions(Ni^(2+),Cu^(2+),Co^(2+))to synthesize the complexes L1–Cu,L1–Ni,L2–Ni,L2–Co,L2–Cu,L3–Co and L3–Cu.展开更多
A new class of luminescent mechanochromic cyclometalated Ir(Ⅲ)complexes with pyridyl acyclic carbene ligands have been developed.These complexes shown predominant MLCT phosphorescence mixed with^(3)LC character.In th...A new class of luminescent mechanochromic cyclometalated Ir(Ⅲ)complexes with pyridyl acyclic carbene ligands have been developed.These complexes shown predominant MLCT phosphorescence mixed with^(3)LC character.In the solid state and neat film,the emission of these complexes show significant red-shift upon mechanical grinding.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
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 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
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
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<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.
基金funding support from the Hong Kong Research Grants Council(Project No.CityU 11300017,CityU 11300318,CityU 11300019,CityU 11302820 and T42-103/16-N)“Laboratory for Synthetic Chemistry and Chemical Biology”under the Health@InnoHK Program launched by Innovation and Technology Commission,The Government of Hong Kong Special Administrative Region of the People’s Republic of China+1 种基金the receipt of a Postgraduate Studentship administered by City University of Hong Kongthe receipt of a Hong Kong PhD Fellowship administered by the Research Grants Council of Hong Kong Special Administrative Region of the People’s Republic of China.
文摘By virtue of their rich photophysical and photochemical properties,transition metal complexes(TMCs)have been extensively studied in multidisciplinary research.In this review,recent studies on TMCs for biological applications are described with a focus on the behaviour of TMCs as specific intracellular sensors and organelle-targeting imaging reagents.Some prominent examples of TMCs as photosensitisers for in vitro and in vivo phototherapies,such as photodynamic therapy and photoactivated chemotherapy,are highlighted.Also,future development of TMCs for new diagnostic and therapeutic applications is discussed.
基金supported the ACS Petroleum Research Fund(65171-DNI3)Rutgers,The State University of New Jersey.
文摘The introduction of redox-active ligands into transition metal complexes can lead to novel redox behavior due to the ability of these ligands to serve as electron reservoirs.This feature is especially attractive in earth-abundant transition metal systems that typically favor one-electron redox processes and radical reactivity,as opposed to the two-electron redox cycles common with the noble metals.The redox flexibility afforded by redox-active ligands can enable substrate activation and/or bond forming and breaking processes that would otherwise be inaccessible with traditional redox-innocent ligands.This review discusses key examples of stoichiometric substrate activation and organic transformations facilitated by redox-active ligand-promoted multielectron reactivity at earth-abundant metal complexes.We highlight the electrochemical properties of these systems in relation to their substrate reactivity,where,in many cases,the complexes exhibit sequential one-electron redox events.Only a few examples have achieved electrocatalytic reactivity based on two-electron redox features,which underscores the untapped potential for further development of redox-active ligand systems to expand the capabilities of earth-abundant metal complexes in electrocatalysis.
基金DST Indo-Czech Republic Bilateral Scientific Research Cooperation,Ministry of Science and Technology,New Delhi,India(DST/INT/CZ/P-17/2019)S.V.thanks the Science and Engineering Research Board(SERB),New Delhi for CRG/2019/005744/OC.
文摘A new class of photoactive and chelating ligands L1–3 has been designed and synthesized by incorporating arylazo-3,5-dimethylpyrazole units in the ligand frameworks.Significantly,they are designed in such a way that azopyrazole units directly coordinate as neutral N-donor ligands.The resulting tri-and tetra-dentate chelating ligands have been complexed with a few transition metal ions(Ni^(2+),Cu^(2+),Co^(2+))to synthesize the complexes L1–Cu,L1–Ni,L2–Ni,L2–Co,L2–Cu,L3–Co and L3–Cu.
基金supported by the General Research Fund(Project No.CityU 11306217 and CityU 11303318).
文摘A new class of luminescent mechanochromic cyclometalated Ir(Ⅲ)complexes with pyridyl acyclic carbene ligands have been developed.These complexes shown predominant MLCT phosphorescence mixed with^(3)LC character.In the solid state and neat film,the emission of these complexes show significant red-shift upon mechanical grinding.
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.
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 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.
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.
