(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under...(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.展开更多
Efficiently converting CO_(2)and H_(2)O into value-added chemicals using solar energy is a viable approach to address global warming and the energy crisis.However,achieving artificial photocatalytic CO_(2)reduction us...Efficiently converting CO_(2)and H_(2)O into value-added chemicals using solar energy is a viable approach to address global warming and the energy crisis.However,achieving artificial photocatalytic CO_(2)reduction using H_(2)O as the reductant poses challenges is due to the difficulty in efficient cooperation among multiple functional moieties.Metal-organic frameworks(MOFs)are promising candidates for overall CO_(2)photoreduction due to their large surface area,diverse active sites,and excellent tailorability.In this study,we designed a metal-organic framework photocatalyst,named PCN-224(Zn)-Bpy(Ru),by integrating photoactive Zn(Ⅱ)-porphyrin and Ru(Ⅱ)-bipyridyl moieties.In comparison,two isostructural MOFs just with either Zn(Ⅱ)-porphyrin or Ru(Ⅱ)-bipyridyl moiety,namely PCN-224-Bpy(Ru)and PCN-224(Zn)-Bpy were also synthesized.As a result,PCN-224(Zn)-Bpy(Ru)exhibited the highest photocatalytic conversion rate of CO_(2)to CO,with a production rate of 7.6μmol·g^(-1)·h^(-1)in a mixed solvent of CH_(3)CN and H_(2)O,without the need for co-catalysts,photosensitizers,or sacrificial agents.Mass spectrometer analysis detected the signals of^(13)CO(m/z=29),^(13)C^(18)O(m/z=31),^(16)O^(18)O(m/z=34),and^(18)O_(2)(m/z=36),confirming that CO_(2)and H_(2)O acted as the carbon and oxygen sources for CO and O_(2),respectively,thereby confirming the coupling of photocatalytic CO_(2)reduction with H_(2)O oxidation.In contrast,using PCN-224-Bpy(Ru)or PCN-224(Zn)-Bpy as catalysts under the same conditions resulted in significantly lower CO production rates of only 1.5 and 0μmol·g^(-1)·h^(-1),respectively.Mechanistic studies revealed that the lowest unoccupied molecular orbital(LUMO)potential of PCN-224(Zn)-Bpy(Ru)is more negative than the redox potentials of CO_(2)/CO,and the highest occupied molecular orbital(HOMO)potential is more positive than that of H_(2)O/O_(2),satisfying the thermodynamic requirements for overall photocatalytic CO_(2)reduction.In comparison,the HOMO potential of PCN-224(Zn)-Bpy without Ru(II)-bipyridyl moieties is less positive than that of H_(2)O/O_(2),indicating that the Ru(II)-bipyridyl moiety is thermodynamically necessary for CO_(2)reduction coupled with H_(2)O oxidation.Additionally,photoluminescence spectroscopy revealed that the fluorescence of PCN-224(Zn)-Bpy(Ru)was almost completely quenched,and a longer average photoluminescence lifetime compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru)was observed.These suggest a low recombination rate of photogenerated carriers in PCN-224(Zn)-Bpy(Ru),which also supported by the higher photocurrent observed in PCN-224(Zn)-Bpy(Ru)compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru).In summary,the integrated Zn(II)-porphyrin and Ru(II)-bipyridyl moieties in PCN-224(Zn)-Bpy(Ru)play important roles of a photosensitizer and CO_(2)reduction as well as H_(2)O oxidation sites,and their efficient cooperation optimizes the band structure,thereby facilitating the coupling of CO_(2)reduction with H_(2)O oxidation and resulting in highperformance artificial photocatalytic CO_(2)reduction.展开更多
Consecutive reaction between two solids, CuCl2.2H2O and 2,2'-bipyridyl in 1:2 molar ratio proceed in tWo steps: the salt first converts to the mediate, then the mediate turns to the final product.
Two novel rhenium(I) 2, 2'-bipyridyl complexes, [(4,4'-di-COOEt-bipy) Re(CO)3 (NCCH3)PF6] and [(4,4'-di-COOEt-bipy) Re (CO)3 (NCS)], a model complex [(4,4'-di- COOEt-bipy) Re (CO)3 (pyridine)PF6], were...Two novel rhenium(I) 2, 2'-bipyridyl complexes, [(4,4'-di-COOEt-bipy) Re(CO)3 (NCCH3)PF6] and [(4,4'-di-COOEt-bipy) Re (CO)3 (NCS)], a model complex [(4,4'-di- COOEt-bipy) Re (CO)3 (pyridine)PF6], were synthesized. Their ground stat?electronic spectra and emission spectra were measured in acetonitrile. The MLCT absorption maximum of the complex exhibited a considerable red shift as the ligand changed from pyridine to CNCH3, or SCN.展开更多
Bipyridyl ruthenium dye N3 and N719 was synthesized, purified by the gel chromatogram method and characterized by the proton NMR and UV-Vis spectra. After the purification most of the impurities that decreased the pho...Bipyridyl ruthenium dye N3 and N719 was synthesized, purified by the gel chromatogram method and characterized by the proton NMR and UV-Vis spectra. After the purification most of the impurities that decreased the photoelectrochemical properties were removed and the open-circuit voltage （Voc）, short-circuit photocurrent density （Jsc） and overall photo-electric conversion efficiency （η） of the dye-sensitized solar cells （DSCs） increased dramatically. The standard curve of absorbance vs. concentration of N3 and N719 dye was achieved by using UV-Vis quantitative analytic spectrophotometry. This method was employed to determine the concentration of the dye solution after coating of TiO2 films. The linear concentration range of absorbance vs. concentration of N719 was between 6.25×10^-6 mol·L^-1 and 1×10^-4 mol·L^-1 with the molar extinction coefficient （ε） 1.58 ×10^4 L mol·L^-1·cm^-1 at a wavelength of 533 - 531 nm and 1.50 × 10^4 Lmol·L^-1·cm^-1 at a wavelength of 393 - 384 nm , accordingly. The linear concentration range of the N3 dye was 6.25 × 10^-6mol·L^-1 to 1.5× 10^-4 mol·L^-1 with ε of 1.47 × 10^4 L mol·L^-1· cm^-1 at a wavelength of 538 - 535 nm and 1.48 × 10^4 L ·mol·L^-1·cm^-1 at a wavelength of 399 - 393 nm.展开更多
The crystal structure of the ternary complex [Cu (L)(2, 2'-bipy)H2 O]·2H2O(L=phenylmalonate) has been determined by X-ray diffraction methods. The copperf(II) centerin five-coordinate Square-pyramidal structu...The crystal structure of the ternary complex [Cu (L)(2, 2'-bipy)H2 O]·2H2O(L=phenylmalonate) has been determined by X-ray diffraction methods. The copperf(II) centerin five-coordinate Square-pyramidal structure.It is of interest in this structure that the complexinvolves a metal ion bridge ligand-ligand aromatic ring stacking interaction展开更多
A series of novel rhenium(I) 2,2'-bipyridyl complexes [fac-Re(4,4'-di-COOEt-bpy) -(CO)3(Xpy)PF6], where bpy is 2,2'-bipyridine, py is pyridine and X is 3-methyl, 3-hydroxy, or 3-amino, were synthesized, th...A series of novel rhenium(I) 2,2'-bipyridyl complexes [fac-Re(4,4'-di-COOEt-bpy) -(CO)3(Xpy)PF6], where bpy is 2,2'-bipyridine, py is pyridine and X is 3-methyl, 3-hydroxy, or 3-amino, were synthesized, their photophysical and electrochemical properties were studied. The Re(II/I) oxidation potentials decreased as the X group becomes more electron donating from H to 3-methyl, 3-hydroxy, or 3-amino, which might be a very convenient ways for adjusting the electron transfer driving force.展开更多
Three cobalt complexes bearing tunable,redox-active bipyridyl N-heterocyclic carbene(NHC)-based ligands have been studied for electrocatalytic hydrogen evolution from aqueous solutions.The effect of structural modific...Three cobalt complexes bearing tunable,redox-active bipyridyl N-heterocyclic carbene(NHC)-based ligands have been studied for electrocatalytic hydrogen evolution from aqueous solutions.The effect of structural modifications to the ligand framework is investigated across the catalyst series,which includes a non-macrocyclic derivative(1-Co)and 16-(2-Co)and 15-(3-Co)membered macrocycles.A structure-activity relationship is demonstrated,in which the macrocyclic complexes have greater activity compared to their non-macrocyclic counterpart with the most rigid catalyst,supported by the 15-membered macrocycle,performing best overall.Indeed,3-Co catalyzes H2 evolution from aqueous pH 4 acetate buffer with a Faradaic efficiency of 97%at a low overpotential of 330 mV.Mechanistic studies are consistent with formation of a cobalt-hydride species that is subsequently protonated to evolve H2 via a heterolytic pathway.展开更多
The interactions of 2,2'-bipyridyl with the lanthanide nitrates were studied and complexes of the formula Ln(NO_8)_8(bipy)_8 were isolated from water -ethanol mixed solvent.The complexes were characterized by elem...The interactions of 2,2'-bipyridyl with the lanthanide nitrates were studied and complexes of the formula Ln(NO_8)_8(bipy)_8 were isolated from water -ethanol mixed solvent.The complexes were characterized by elemental analysis, conductivity measurments,IR spectra and DAT-TG analysis.展开更多
Design and synthesis of organic chelating agents containing nitrogen and sulfur as donor atoms and their metal complexes is an interesting field of research for their different types of activities. The bi-dentate N,N ...Design and synthesis of organic chelating agents containing nitrogen and sulfur as donor atoms and their metal complexes is an interesting field of research for their different types of activities. The bi-dentate N,N chelating agent such as 2,2-Bipyridal has been playing a vital role in synthetic and medicinal chemistry. 2,2-Bipyridal has been used to prepare many mixed-ligand complexes. Different ligand complexes prepared from 2,2-Bipyridyl are used in different areas such as molecular catalysis, solar energy conversion, calorimetric analysis, herbicides, molecular recognition, self-assembly, antineoplastic agents, and nucleic acid probes. Another important property of these types of compounds is the triplet state photosensitizing character of bipyridyl nucleus, which is shown in metal complexes. It is also found that compounds containing O,S,N atoms have received considerable attention because of their pharmacological studies like anticancer, antibacterial, and antitumour activities. Therefore, it has been decided to synthesize Schiff bases derived from 2,2’- bipyridyl-5,5’-dicarbaldehyde compounds with O,S,N and F-containing amines and study their antibacterial properties. Several new Schiff bases have been synthesized and fully characterized by spectral data. This paper presents the synthesis and characterization of newly designed Schiff bases.展开更多
Eight novel Schiff Bases, from 6,6′-diformyl-2,2′-bipyridyl (1a, 43%)with O, N, S and F containing amines: Thiosemicarbazide (2a, 70%), 4-Ethyl-3-thiosemicabazide (2b, 75%), 4,4-Dimethyl-3-thio-semicarbazide (2c, 75...Eight novel Schiff Bases, from 6,6′-diformyl-2,2′-bipyridyl (1a, 43%)with O, N, S and F containing amines: Thiosemicarbazide (2a, 70%), 4-Ethyl-3-thiosemicabazide (2b, 75%), 4,4-Dimethyl-3-thio-semicarbazide (2c, 75%), S-benzyldithiocarbazide, SBDTC (2d, 80%), (Trifluromethyl) phenylhy-drazine (2e, 80%), 4-Phenyl-3-thiosemcarbazide (2f, 80%), Thiocarbazide (2g, 70%), 2-Amino-thiophenol (2h, 65%), have been synthesized. The conventional method of synthesis of the Schiff bases involves refluxing the reaction mixture containing the diformyls and amines for 1 hour. The solid products that had formed were filtered off using suction filtration. In few reactions, 2 - 3 drops of conc. sulfuric acid were used to obtain high yield. The structures of all eight novel synthesized compounds have fully been characterized by spectroscopic (IR, NMR, MS) methods.展开更多
The ternary Cu(II) complex with 2,2′-bipyridyl (bipy) and L-methioninate (L-Met) has been synthesized and characterized by elemental analysis, molar conductivity, UV-Vis spectra, IR spectra and pH-potentiometric titr...The ternary Cu(II) complex with 2,2′-bipyridyl (bipy) and L-methioninate (L-Met) has been synthesized and characterized by elemental analysis, molar conductivity, UV-Vis spectra, IR spectra and pH-potentiometric titration methods. The structure of the complex [Cu(L-Met)(bipy)(H_2O)]ClO_4·3/8H_2O was characterized by the X-ray diffraction analysis. It crystallizes in the triclinic system, space group P1 with four molecules in a unit cell of dimensions, a=0.7656(2) nm, b=1.3142(3) nm, c=2.0596(4) nm, α=97.70(3)°, β=97.96(3)°, γ=94.33(3)°, V=2.0244(8) nm 3, R_1=0.0441 and wR_2=0.0678. The crystal contains four crystallographically independent [Cu(L-Met)(bipy)(H_2O)] + complexes (Cu1-Cu4), having a distorted square-pyramidal geometry with the same coordinated atoms around each copper center. The base plane is occupied by two nitrogen atoms of one bipy, the amino nitrogen atom and one carboxylate oxygen atom from each independent L-Met moiety, and one water oxygen at an axial position. Cu1 and Cu3 are essentially enantiomers of Cu2 and Cu4. The four molecules are packed with each other by intermolecular hydrogen-bonding and aromatic-ring stacking interactions.展开更多
A novel coordination polymer, [Ag4(bpdc)(H2bpdc)(Hbpdc)2]n (bpdc=2,2'-bipyridyl-3,3'-dicarboxylate), was hydrothermally synthesized at 403 K and structurally characterized by single crystal X-ray diffraction ...A novel coordination polymer, [Ag4(bpdc)(H2bpdc)(Hbpdc)2]n (bpdc=2,2'-bipyridyl-3,3'-dicarboxylate), was hydrothermally synthesized at 403 K and structurally characterized by single crystal X-ray diffraction analysis. The compound crystalizes in the monoclinic space group C2/c with a=1.9516(4) nm, b=1.9503(4) nm, c=1.2566(3) nm, and β=112.48(3)°. In the two-dimensional crystal structure, AgI center is coordinated, in a scarce coordination environment, double-capped tetrahedron, by one bpdc ligand to form N—Ag—N chelate bond via two pyridyl N atoms, and other two bpdc ligands to form two O—Ag—O chelate bonds, respectively, via two carboxyl O atoms. The bpdc ligands are present in one non-protonated form, bpdc, and two protonated forms, Hbpdc and H2bpdc, which all act as μ3-ligand in a hexadentate fashion (N, N'; O, O'; O, O') to coordinate with three Ag centers, respec- tively, through the three chelate bonds. This coordinated fashion of bpdc ligand is first found in the title compound. UV-Vis-NIR reflectance spectroscopy study revealed insulator nature for the crystal with an optical energy gap of 3.1 eV.展开更多
A two-coordinate copper（Ⅰ） complex, Cu2（bipy）（H2L）2 （1） （H3L=cyanuric acid, bipy=4,4＇-bipyridyl）, which exhibits strong photoluminescence, has been synthesized under hydrothermal conditions and structurall...A two-coordinate copper（Ⅰ） complex, Cu2（bipy）（H2L）2 （1） （H3L=cyanuric acid, bipy=4,4＇-bipyridyl）, which exhibits strong photoluminescence, has been synthesized under hydrothermal conditions and structurally characterized by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n, with cell parameters： Mr= 539.42, a= 13.4806（5）A↑°, b=4.5234（2） A↑°, c= 15.4952（8）A↑°,β = 105.526（3）°, V=910.39（7）A↑°^3, Z=2 and μ=3.52 mm^ -1. In the structure the two Cu（Ⅰ） ions are bridged by bipy to form a two-coordinate copper（Ⅰ） dimer. The adjacent dimer units are connected by hydrogen bonding interactions, resulting in 1D zigzag chains along the c axis. 1 emits intense yellow light when excited with UV light.展开更多
文摘(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.
文摘Efficiently converting CO_(2)and H_(2)O into value-added chemicals using solar energy is a viable approach to address global warming and the energy crisis.However,achieving artificial photocatalytic CO_(2)reduction using H_(2)O as the reductant poses challenges is due to the difficulty in efficient cooperation among multiple functional moieties.Metal-organic frameworks(MOFs)are promising candidates for overall CO_(2)photoreduction due to their large surface area,diverse active sites,and excellent tailorability.In this study,we designed a metal-organic framework photocatalyst,named PCN-224(Zn)-Bpy(Ru),by integrating photoactive Zn(Ⅱ)-porphyrin and Ru(Ⅱ)-bipyridyl moieties.In comparison,two isostructural MOFs just with either Zn(Ⅱ)-porphyrin or Ru(Ⅱ)-bipyridyl moiety,namely PCN-224-Bpy(Ru)and PCN-224(Zn)-Bpy were also synthesized.As a result,PCN-224(Zn)-Bpy(Ru)exhibited the highest photocatalytic conversion rate of CO_(2)to CO,with a production rate of 7.6μmol·g^(-1)·h^(-1)in a mixed solvent of CH_(3)CN and H_(2)O,without the need for co-catalysts,photosensitizers,or sacrificial agents.Mass spectrometer analysis detected the signals of^(13)CO(m/z=29),^(13)C^(18)O(m/z=31),^(16)O^(18)O(m/z=34),and^(18)O_(2)(m/z=36),confirming that CO_(2)and H_(2)O acted as the carbon and oxygen sources for CO and O_(2),respectively,thereby confirming the coupling of photocatalytic CO_(2)reduction with H_(2)O oxidation.In contrast,using PCN-224-Bpy(Ru)or PCN-224(Zn)-Bpy as catalysts under the same conditions resulted in significantly lower CO production rates of only 1.5 and 0μmol·g^(-1)·h^(-1),respectively.Mechanistic studies revealed that the lowest unoccupied molecular orbital(LUMO)potential of PCN-224(Zn)-Bpy(Ru)is more negative than the redox potentials of CO_(2)/CO,and the highest occupied molecular orbital(HOMO)potential is more positive than that of H_(2)O/O_(2),satisfying the thermodynamic requirements for overall photocatalytic CO_(2)reduction.In comparison,the HOMO potential of PCN-224(Zn)-Bpy without Ru(II)-bipyridyl moieties is less positive than that of H_(2)O/O_(2),indicating that the Ru(II)-bipyridyl moiety is thermodynamically necessary for CO_(2)reduction coupled with H_(2)O oxidation.Additionally,photoluminescence spectroscopy revealed that the fluorescence of PCN-224(Zn)-Bpy(Ru)was almost completely quenched,and a longer average photoluminescence lifetime compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru)was observed.These suggest a low recombination rate of photogenerated carriers in PCN-224(Zn)-Bpy(Ru),which also supported by the higher photocurrent observed in PCN-224(Zn)-Bpy(Ru)compared to PCN-224(Zn)-Bpy and PCN-224-Bpy(Ru).In summary,the integrated Zn(II)-porphyrin and Ru(II)-bipyridyl moieties in PCN-224(Zn)-Bpy(Ru)play important roles of a photosensitizer and CO_(2)reduction as well as H_(2)O oxidation sites,and their efficient cooperation optimizes the band structure,thereby facilitating the coupling of CO_(2)reduction with H_(2)O oxidation and resulting in highperformance artificial photocatalytic CO_(2)reduction.
文摘Consecutive reaction between two solids, CuCl2.2H2O and 2,2'-bipyridyl in 1:2 molar ratio proceed in tWo steps: the salt first converts to the mediate, then the mediate turns to the final product.
文摘Two novel rhenium(I) 2, 2'-bipyridyl complexes, [(4,4'-di-COOEt-bipy) Re(CO)3 (NCCH3)PF6] and [(4,4'-di-COOEt-bipy) Re (CO)3 (NCS)], a model complex [(4,4'-di- COOEt-bipy) Re (CO)3 (pyridine)PF6], were synthesized. Their ground stat?electronic spectra and emission spectra were measured in acetonitrile. The MLCT absorption maximum of the complex exhibited a considerable red shift as the ligand changed from pyridine to CNCH3, or SCN.
基金supported by the National Basic Research Program of China (No. 2006CB202600)
文摘Bipyridyl ruthenium dye N3 and N719 was synthesized, purified by the gel chromatogram method and characterized by the proton NMR and UV-Vis spectra. After the purification most of the impurities that decreased the photoelectrochemical properties were removed and the open-circuit voltage （Voc）, short-circuit photocurrent density （Jsc） and overall photo-electric conversion efficiency （η） of the dye-sensitized solar cells （DSCs） increased dramatically. The standard curve of absorbance vs. concentration of N3 and N719 dye was achieved by using UV-Vis quantitative analytic spectrophotometry. This method was employed to determine the concentration of the dye solution after coating of TiO2 films. The linear concentration range of absorbance vs. concentration of N719 was between 6.25×10^-6 mol·L^-1 and 1×10^-4 mol·L^-1 with the molar extinction coefficient （ε） 1.58 ×10^4 L mol·L^-1·cm^-1 at a wavelength of 533 - 531 nm and 1.50 × 10^4 Lmol·L^-1·cm^-1 at a wavelength of 393 - 384 nm , accordingly. The linear concentration range of the N3 dye was 6.25 × 10^-6mol·L^-1 to 1.5× 10^-4 mol·L^-1 with ε of 1.47 × 10^4 L mol·L^-1· cm^-1 at a wavelength of 538 - 535 nm and 1.48 × 10^4 L ·mol·L^-1·cm^-1 at a wavelength of 399 - 393 nm.
文摘The crystal structure of the ternary complex [Cu (L)(2, 2'-bipy)H2 O]·2H2O(L=phenylmalonate) has been determined by X-ray diffraction methods. The copperf(II) centerin five-coordinate Square-pyramidal structure.It is of interest in this structure that the complexinvolves a metal ion bridge ligand-ligand aromatic ring stacking interaction
基金The authors would like to thank the National Natural Science Foundation of China(project 20128005.20376010)the Ministry of Science&Technology and the Ministry of Education for financial suppot.
文摘A series of novel rhenium(I) 2,2'-bipyridyl complexes [fac-Re(4,4'-di-COOEt-bpy) -(CO)3(Xpy)PF6], where bpy is 2,2'-bipyridine, py is pyridine and X is 3-methyl, 3-hydroxy, or 3-amino, were synthesized, their photophysical and electrochemical properties were studied. The Re(II/I) oxidation potentials decreased as the X group becomes more electron donating from H to 3-methyl, 3-hydroxy, or 3-amino, which might be a very convenient ways for adjusting the electron transfer driving force.
文摘Three cobalt complexes bearing tunable,redox-active bipyridyl N-heterocyclic carbene(NHC)-based ligands have been studied for electrocatalytic hydrogen evolution from aqueous solutions.The effect of structural modifications to the ligand framework is investigated across the catalyst series,which includes a non-macrocyclic derivative(1-Co)and 16-(2-Co)and 15-(3-Co)membered macrocycles.A structure-activity relationship is demonstrated,in which the macrocyclic complexes have greater activity compared to their non-macrocyclic counterpart with the most rigid catalyst,supported by the 15-membered macrocycle,performing best overall.Indeed,3-Co catalyzes H2 evolution from aqueous pH 4 acetate buffer with a Faradaic efficiency of 97%at a low overpotential of 330 mV.Mechanistic studies are consistent with formation of a cobalt-hydride species that is subsequently protonated to evolve H2 via a heterolytic pathway.
文摘The interactions of 2,2'-bipyridyl with the lanthanide nitrates were studied and complexes of the formula Ln(NO_8)_8(bipy)_8 were isolated from water -ethanol mixed solvent.The complexes were characterized by elemental analysis, conductivity measurments,IR spectra and DAT-TG analysis.
文摘Design and synthesis of organic chelating agents containing nitrogen and sulfur as donor atoms and their metal complexes is an interesting field of research for their different types of activities. The bi-dentate N,N chelating agent such as 2,2-Bipyridal has been playing a vital role in synthetic and medicinal chemistry. 2,2-Bipyridal has been used to prepare many mixed-ligand complexes. Different ligand complexes prepared from 2,2-Bipyridyl are used in different areas such as molecular catalysis, solar energy conversion, calorimetric analysis, herbicides, molecular recognition, self-assembly, antineoplastic agents, and nucleic acid probes. Another important property of these types of compounds is the triplet state photosensitizing character of bipyridyl nucleus, which is shown in metal complexes. It is also found that compounds containing O,S,N atoms have received considerable attention because of their pharmacological studies like anticancer, antibacterial, and antitumour activities. Therefore, it has been decided to synthesize Schiff bases derived from 2,2’- bipyridyl-5,5’-dicarbaldehyde compounds with O,S,N and F-containing amines and study their antibacterial properties. Several new Schiff bases have been synthesized and fully characterized by spectral data. This paper presents the synthesis and characterization of newly designed Schiff bases.
文摘Eight novel Schiff Bases, from 6,6′-diformyl-2,2′-bipyridyl (1a, 43%)with O, N, S and F containing amines: Thiosemicarbazide (2a, 70%), 4-Ethyl-3-thiosemicabazide (2b, 75%), 4,4-Dimethyl-3-thio-semicarbazide (2c, 75%), S-benzyldithiocarbazide, SBDTC (2d, 80%), (Trifluromethyl) phenylhy-drazine (2e, 80%), 4-Phenyl-3-thiosemcarbazide (2f, 80%), Thiocarbazide (2g, 70%), 2-Amino-thiophenol (2h, 65%), have been synthesized. The conventional method of synthesis of the Schiff bases involves refluxing the reaction mixture containing the diformyls and amines for 1 hour. The solid products that had formed were filtered off using suction filtration. In few reactions, 2 - 3 drops of conc. sulfuric acid were used to obtain high yield. The structures of all eight novel synthesized compounds have fully been characterized by spectroscopic (IR, NMR, MS) methods.
基金ProjectsupportedbytheNaturalScienceFoundationofGuangdongProvince (No .0 10 338)andtheNaturalScienceFoundationofEducationDe partmentofGuangdongProvince (No .2 0 0 0 70 )
文摘The ternary Cu(II) complex with 2,2′-bipyridyl (bipy) and L-methioninate (L-Met) has been synthesized and characterized by elemental analysis, molar conductivity, UV-Vis spectra, IR spectra and pH-potentiometric titration methods. The structure of the complex [Cu(L-Met)(bipy)(H_2O)]ClO_4·3/8H_2O was characterized by the X-ray diffraction analysis. It crystallizes in the triclinic system, space group P1 with four molecules in a unit cell of dimensions, a=0.7656(2) nm, b=1.3142(3) nm, c=2.0596(4) nm, α=97.70(3)°, β=97.96(3)°, γ=94.33(3)°, V=2.0244(8) nm 3, R_1=0.0441 and wR_2=0.0678. The crystal contains four crystallographically independent [Cu(L-Met)(bipy)(H_2O)] + complexes (Cu1-Cu4), having a distorted square-pyramidal geometry with the same coordinated atoms around each copper center. The base plane is occupied by two nitrogen atoms of one bipy, the amino nitrogen atom and one carboxylate oxygen atom from each independent L-Met moiety, and one water oxygen at an axial position. Cu1 and Cu3 are essentially enantiomers of Cu2 and Cu4. The four molecules are packed with each other by intermolecular hydrogen-bonding and aromatic-ring stacking interactions.
基金Project supported by the State Key Laboratory of Structural Chemistry for Unstable and Stable Species China ( No. 200301).
文摘A novel coordination polymer, [Ag4(bpdc)(H2bpdc)(Hbpdc)2]n (bpdc=2,2'-bipyridyl-3,3'-dicarboxylate), was hydrothermally synthesized at 403 K and structurally characterized by single crystal X-ray diffraction analysis. The compound crystalizes in the monoclinic space group C2/c with a=1.9516(4) nm, b=1.9503(4) nm, c=1.2566(3) nm, and β=112.48(3)°. In the two-dimensional crystal structure, AgI center is coordinated, in a scarce coordination environment, double-capped tetrahedron, by one bpdc ligand to form N—Ag—N chelate bond via two pyridyl N atoms, and other two bpdc ligands to form two O—Ag—O chelate bonds, respectively, via two carboxyl O atoms. The bpdc ligands are present in one non-protonated form, bpdc, and two protonated forms, Hbpdc and H2bpdc, which all act as μ3-ligand in a hexadentate fashion (N, N'; O, O'; O, O') to coordinate with three Ag centers, respec- tively, through the three chelate bonds. This coordinated fashion of bpdc ligand is first found in the title compound. UV-Vis-NIR reflectance spectroscopy study revealed insulator nature for the crystal with an optical energy gap of 3.1 eV.
基金Project supported by the National Natural Science Foundation of China（No. 20331010）.
文摘A two-coordinate copper（Ⅰ） complex, Cu2（bipy）（H2L）2 （1） （H3L=cyanuric acid, bipy=4,4＇-bipyridyl）, which exhibits strong photoluminescence, has been synthesized under hydrothermal conditions and structurally characterized by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n, with cell parameters： Mr= 539.42, a= 13.4806（5）A↑°, b=4.5234（2） A↑°, c= 15.4952（8）A↑°,β = 105.526（3）°, V=910.39（7）A↑°^3, Z=2 and μ=3.52 mm^ -1. In the structure the two Cu（Ⅰ） ions are bridged by bipy to form a two-coordinate copper（Ⅰ） dimer. The adjacent dimer units are connected by hydrogen bonding interactions, resulting in 1D zigzag chains along the c axis. 1 emits intense yellow light when excited with UV light.
