An effective route to pyrrolo[1,2-a]pyrazines is described via reaction of ethylenediamine,acetylenic esters and nitrostyrene derivatives in the presence of 20 mol%of sulfamic acid.
Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis m...Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.展开更多
Two pyrazine-containing macrocyclic polyazomethines 2 and 3 were synthesized by direct [2 + 2] and [3 + 3] condensation reactions between 2,21-[pyrazine-2,3-diylbis(oxy)]dibenzaldehyde (1) and hydrazine. Both 2 ...Two pyrazine-containing macrocyclic polyazomethines 2 and 3 were synthesized by direct [2 + 2] and [3 + 3] condensation reactions between 2,21-[pyrazine-2,3-diylbis(oxy)]dibenzaldehyde (1) and hydrazine. Both 2 and 3 were characterized by NMR, HRMS, and their structures were determined via X-ray crystal diffraction studies.展开更多
1 Introduction In the last decades,the furazan fused ring compounds have been paid much more attention owing to their characteristics,such as high density,high specific volume and high nitrogen content.A novel energet...1 Introduction In the last decades,the furazan fused ring compounds have been paid much more attention owing to their characteristics,such as high density,high specific volume and high nitrogen content.A novel energetic compound based on furazan fused ring,6-nitroimino-4,8-dinitro-5,6,7,8-tetrahydro-4H-imidazo furazano pyrazine(NIFDNP),was firstly designed and its properties of physico-chemical and detonation were calculated by Gaussian 09 program[4] and VLW method[5].Using glyoxal展开更多
A novel 2-D lead-containing hybrid compound, [(PbCl2)(μ-Pyz)1/2], (Pyz = pyrazine) 1, has been synthesized by the hydrothermal assembly of pyrazine with lead chloride. Elemental analysis and X-ray crystal struc...A novel 2-D lead-containing hybrid compound, [(PbCl2)(μ-Pyz)1/2], (Pyz = pyrazine) 1, has been synthesized by the hydrothermal assembly of pyrazine with lead chloride. Elemental analysis and X-ray crystal structure analyses were carded out for the structural determination and characterization of the title compound. Compound 1 crystallizes in orthorhombic, space group lbam, with a = 19.5558(18), b = 7.1939(6), c = 7.5449(6) A, V = 1061.44(16) .A^3, C2H2Cl2NPb, Mr= 318.14, Z = 8, Dc= 3.982 g/cm^3, μ = 32.63 mm^-1, F(000) = 1096.0, R = 0.0368 and wR = 0.0901 for 623 observed reflections (I 〉 2σ(I)).展开更多
The title complex,[Ag 2 (L1) 2 (Pyr)·2.5H 2 O] 1 (L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in...The title complex,[Ag 2 (L1) 2 (Pyr)·2.5H 2 O] 1 (L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in triclinic,space group P1,with a=7.339(5),b=13.105(5),c=14.097(5),α=84.377(5),β=76.921(5),γ=79.628(5)°,V=1296.7(11) 3,C 48 H 50 Ag 4 N 8 O 17 S 4,M r=1570.68,Z=1,D c=2.011 g/cm 3,μ=1.732 mm-1,F(000)=782,S=1.148,the final R=0.0436 and wR=0.1181 for 4130 observer reflections (I 2σ(Ⅰ)).Compound 1 shows a rare one-dimensional (1D) double chain,and the chains are further connected through secondary bonding,hydrogen bonds,and π-π interactions to generate a three-dimensional (3D) supramolecular structure.The luminescent property of 1 was also studied in the solid state at room temperture.展开更多
The title compound,2,6-bis(2-pyridinylmethyl)-3,5-bis(2-hydroxyl-5-chlorophe nyl)-pyrazine(C26H12Cl2N4O2C2H8O2,Mr=551.41),has been synthesized and characterized by LC-ESIMS,NMR,UV and IR spectroscopy as well as ...The title compound,2,6-bis(2-pyridinylmethyl)-3,5-bis(2-hydroxyl-5-chlorophe nyl)-pyrazine(C26H12Cl2N4O2C2H8O2,Mr=551.41),has been synthesized and characterized by LC-ESIMS,NMR,UV and IR spectroscopy as well as by X-ray single-crystal diffraction.The compound behaves as a substituted pyrazine.The hydrogen atoms on C(2) and C(3) are substituted by 2-pyridinyl,whereas those on C(1) and C(4) are substituted by 2-hydroxyl-5-chlorophenyl.It crystallizes in the monoclinic system,space group P21/c with a=8.9433(12),b=32.003(4),c=10.5209(18),β=111.199(2)°,V=2807.5(7)3,Z=4,Dc=1.305 mg/m3,F(000)=1144 and μ=0.094 mm-1.A total of 13235 reflections were collected in the range of 2.17~25.01o by using a phi and omega scan mode,of which 4923 were unique(Rint=0.0692) and 2872 observed reflections with Ⅰ 〉2σ(Ⅰ) were used in the structure solution and refinement.展开更多
A new copper(Ⅱ) complex of CuLCl_2, where L = N^1-(1-pyrazin-2-yl-ethylidene)-ethane-1,2-diamine, a tridentate Schiff base derived from 2-acetylpyrazine has been prepared. The complex has been characterized by FT-IR,...A new copper(Ⅱ) complex of CuLCl_2, where L = N^1-(1-pyrazin-2-yl-ethylidene)-ethane-1,2-diamine, a tridentate Schiff base derived from 2-acetylpyrazine has been prepared. The complex has been characterized by FT-IR, elemental analysis and single-crystal X-ray diffraction studies. Structural studies reveal that CuLCl_2 is a mononuclear copper(Ⅱ) complex with distorted square pyramidal geometry. Antifungal activity of CuLCl_2 was investigated by use of microcalorimetric measurement system and evaluated against S. pombe. It has high antifungal activity with IC_(50) = 213 μg/mL.展开更多
Two two-dimensional coordination polymers, [Cd(μ1,3-SCN-)2(μ1,6-L)]n 1 and [Co(μ1,3-SCN-)2(μ1,6-L)]n 2, have been synthesized with 2,3-dimethylpyrazine-1,4-dioxide (L) and thiocyanate as mixed bridging l...Two two-dimensional coordination polymers, [Cd(μ1,3-SCN-)2(μ1,6-L)]n 1 and [Co(μ1,3-SCN-)2(μ1,6-L)]n 2, have been synthesized with 2,3-dimethylpyrazine-1,4-dioxide (L) and thiocyanate as mixed bridging ligands, and their crystal structures were determined by X-ray crystallography. Both crystals belong to monoclinic system, space group C2/c. The other crystal parameters are as follows: for complex 1: α = 9.732(3), b =14.658(5), c = 8.811(3) A, β = 102.935(4)°, Z = 4, V= 1225.1(7) A^3, C8H8CdN4O2S2, Mr = 368.71, Dc = 1.999 g/cm^3, F(000) = 720 and μ= 2.117 mm^-1; for complex 2: α = 9.528(7), b = 14.563(11), c = 8.415(6) A, β= 102.195(9)°, V= 1141.3(14) A^3, Z = 4, C8H8CoN4O2S2, Mr = 315.23, Dc = 1.835 g/cm^3, F(000) = 636 and μ = 1.863 mm^-1. The two complexes show similar two-dimensional sheet structures. Along the c axis one-dimensional chains are constructed by the coordination of Cd(Ⅱ) (or Co(Ⅱ)) ions with μ1,6-L bridging ligand, and the μ1,3-SCN- bridging ligands make the chains connect to each other, resulting in the formation of a two-dimensional sheet on the ac plane.展开更多
The title compound, [Cu2(DMPz)2PMo12O40]·HDMPz (1, DMPz = 2,5-dimethyl pyrazine), has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group...The title compound, [Cu2(DMPz)2PMo12O40]·HDMPz (1, DMPz = 2,5-dimethyl pyrazine), has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1 with a = 11.075(2), b = 11.551(2), c = 11.886(2) A.α = 106.352(2), β = 109.862(3), γ = 109.504(1)°, V = 1206.8(3) A3, C18H26CU2Mo12N6O40P, Mr = 2275.78, Z = 1, Dc = 3.131 g/cm3, μ = 4.011 mm^-1, F(000) = 1073, S = 1.066, the final R = 0.0389 and wR = 0.1056 for 3739 observed reflections with I 〉 2σ(I). The structural analysis indicates that the title compound is composed of Keggin clusters [PMo12O40]3- connected by one-dimensional [CB(DMPz)]2n^2n+ chains to form a two-dimensional grid layer with holes occupied by monoprotonated DMPz molecules. In the solid of the title compound, the 2D grid layers are stacked together in an ABAB packing mode.展开更多
A novel coordination polymer, [Cd2Cl4(bpme)]n·n(H2O) (1, bpme=2,5-bis(be-nzoimidazol-2-yl)pyrazine), has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The ...A novel coordination polymer, [Cd2Cl4(bpme)]n·n(H2O) (1, bpme=2,5-bis(be-nzoimidazol-2-yl)pyrazine), has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal of the complex belongs to the triclinic system, space group P , with a=7.0737(9), b=8.7886(11), c=9.4561(12) , α=105.3580(10), β=94.981(2), γ=96.879(2)°, V=558.46(12) 3, Mr=714.97, Z=1, F(000)=346, Dc=2.126 g/cm3, μ=2.412 mm-1, T=296(2) K, S=1.057, R=0.0533 and wR=0.1480. According to the structural analysis, the Cd(Ⅱ) ion adopts a slightly distorted six-coordinated octahedral geometry. The Cd(Ⅱ) atoms are bridged by four Cl atoms along the a direction, forming infinite straight chains which are further constructed to generate 2D network layer structures through the μ4-N bpme ligand in the b direction, and such 2D network layer structures finally form a novel three-dimensional infinite supramolecular framework through weak π-π stacking between two network layers and hydrogen bonds.展开更多
Two new zinc(Ⅱ) compounds with dibenzoylmethane and N-donor ancillary ligands,[Zn(μ-pyz)(dbm)_2]_n(1) and [Zn(dbm)_2(μ-bpe)Zn(dbm)_2](2)(Hdbm = dibenzoylmethane,pyz = pyrazine and bpe = 1,2-bis(4-...Two new zinc(Ⅱ) compounds with dibenzoylmethane and N-donor ancillary ligands,[Zn(μ-pyz)(dbm)_2]_n(1) and [Zn(dbm)_2(μ-bpe)Zn(dbm)_2](2)(Hdbm = dibenzoylmethane,pyz = pyrazine and bpe = 1,2-bis(4-pyridyl)ethane),have been prepared and characterized using elemental analysis,IR,~1H NMR and 13 C NMR spectroscopy,and studied by thermal gravimetric analysis as well as single-crystal X-ray diffraction. The crystal and molecular structures of 1 and 2 have been solved by X-ray diffraction and they turned out to be a one-dimensional coordination polymer with linear dispositions of metal atoms and binuclear compound,respectively. These one-dimensional polymers are further connected to form a 3D supramolecular network by C–H···O(only in 2) and π-π interactions.展开更多
The merits of intrinsic electrical conductivity, high specific surface area, tunable chemical composition and tailor-made properties enable two-dimensional conductive metal-organic frameworks (2D c-MOFs) as promising ...The merits of intrinsic electrical conductivity, high specific surface area, tunable chemical composition and tailor-made properties enable two-dimensional conductive metal-organic frameworks (2D c-MOFs) as promising next-generation electrode materials in the field of energy storage and conversion. Herein, we have designed and synthesized a novel pyrazine-based 2D c-MOF (TPQG-Cu-MOF) bearing extended π-conjugated structure and abundant redox active sites. Thanks to the excellent redox reversibility of pyrazine units and CuO2 units, as well as the insolubility of the rigid framework skeleton, TPQG-Cu-MOF as the cathode material of lithium-ion battery exhibits a reversible specific capacity (150.2 mAh·g–1 at 20 mAh·g–1), good cycling stability (capacity retention of 82.6% after 500 cycles at 1 A·g–1) and excellent rate performance. Comprehensive ex-situ spectroscopic studies revealed the reversible redox activity of pyrazine units and CuO2 units of TPQG-Cu-MOF during the Li+ insertion/extraction process. The deepening fundamental understanding of the structure-property relationship was proposed, which might pave the way for further development of efficient MOF-based energy storage devices.展开更多
The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection.Metal organic frameworks(MOFs)have attracted the inter...The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection.Metal organic frameworks(MOFs)have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics,including adjustable structure,strong stability and porosity.Herein,pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions.Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal–organic frameworks.Furthermore,the material exhibits excellent adsorption capacity,with a theoretical maximum copper uptake of 247 mg/g.As proven by XPS and FT-IR analysis,the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66.This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions,and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.展开更多
The manipulation on turn-on fluorescence in solid state materials attracts increasing interests owing to their widespread applications.Herein we report how the nonradiative pathways of tetraphenylpyrazine(TPP)units in...The manipulation on turn-on fluorescence in solid state materials attracts increasing interests owing to their widespread applications.Herein we report how the nonradiative pathways of tetraphenylpyrazine(TPP)units in metal-organic frameworks(MOFs)systems could be hindered through a topological design approach.Two MOFs single crystals of different topology were constructed via the solvothermal reaction of a TPP-based 4,4',4",4"-(pyrazine-2,3,5,6-tetrayl)tetrabenzoic acid(H,TCPP)ligand and metal cations,and their mechanisms of formation have been explored.Compared with the innate lowfrequency vibrational modes of flu net Tb-TCPP-1,such as phenyl ring torsions and pyrazine twists,Tb-TCPP-2 adopts a shp net,so the dihedral angle of pyrazine ring and phenyl arms is larger,and the center pyrazine ring in TPP unit is coplanar,which hinders the radiationless decay of TPP moieties in Tb-TCPP-2.Thereby Tb-TCPP-2 exhibits a larger blue-shifted fluorescence and a higher fluorescence quantum yield than Tb-TCPP-1,which is consistent with the reduced nonradiative pathways.Furthermore,Density functional theory(DFT)studies also confirmed aforementioned tunable turn-on fluorescence mechanism.Our work constructed TPP-type MOFs based on a deliberately topological design approach,and the precise design of turn-on fluorescence holds promise as a strategy for controlling nonradiative pathways.展开更多
Cu-TiO_2 catalysts supported onγ-Al_2O_3 are prepared and used in glycerol cyclization with 1,2-propanediamine to produce pyrazinyl compounds including 6-hydroxymethyl-2-methylpyrazine,5-hydroxymethyl -2-methyIpyrazi...Cu-TiO_2 catalysts supported onγ-Al_2O_3 are prepared and used in glycerol cyclization with 1,2-propanediamine to produce pyrazinyl compounds including 6-hydroxymethyl-2-methylpyrazine,5-hydroxymethyl -2-methyIpyrazine,2,6-dimethylpyrazine and 2,5-dimethylpyrazine in a fixed-bed system.It is found that glycerol cylclization with 1,2-propanediamine gave a high total yield of pyrazinyl compounds(〉80%) over Cu-Ti02/γ-Al_2O_3 catalyst,and cyclization was through the reactions between activated 1,2-propanediamine and the intermediates from glycerol dehydration and oxidation.In addition,the regioselectivity of the pyrazinyl compounds was mainly controlled by the steric hindrance of the substrates during the cyclization process.展开更多
Genomic alterations are commonly found in the signaling pathways of fibroblast growth factor receptors(FGFRs). Although there is no selective FGFR inhibitors in market, several promising inhibitors have been investiga...Genomic alterations are commonly found in the signaling pathways of fibroblast growth factor receptors(FGFRs). Although there is no selective FGFR inhibitors in market, several promising inhibitors have been investigated in clinical trials, and showed encouraging efficacies in patients. By designing a hybrid between the FGFR-selectivity-enhancing motif dimethoxybenzene group and our previously identified novel scaffold, we discovered a new series of potent FGFR inhibitors, with the best one showing sub-nanomolar enzymatic activity. After several round of optimization and with the solved crystal structure, detailed structure–activity relationship was elaborated. Together with in vitro metabolic stability tests and in vivo pharmacokinetic profiling, a representative compound(35) was selected and tested in xenograft mouse model, and the result demonstrated that inhibitor 35 was effective against tumors with FGFR genetic alterations, exhibiting potential for further development.展开更多
Novel 5,6,5,6-tetracyclic pyrazine/pyrrole-fused unsymmetric bis(BF2) fluorescent dyes(BOPYPYs) were obtained by reaction of pyrrole-2-carboxaldehyde with 1-(pyrazin-2-yl)hydrazine in the presence of Et3 N-BF3·Et...Novel 5,6,5,6-tetracyclic pyrazine/pyrrole-fused unsymmetric bis(BF2) fluorescent dyes(BOPYPYs) were obtained by reaction of pyrrole-2-carboxaldehyde with 1-(pyrazin-2-yl)hydrazine in the presence of Et3 N-BF3·Et2 O for the first time.The absorption maxima of pyrazine-fused BOPYPY are obviously bathochromic shifts,in contrast to those of the reported BOPPY,indicating that the discrepant substitute groups between pyridine and pyrazine result in the remarkable wavelength difference.The new series of BO PYPYs possess high molar extinction coefficients,high fluorescence quantum yields,and larger Stokes shifts.A Knoevenagel reaction of BOPYPY with 4-dimethylaminobenzaldehyde smoothly produced the dye with the extension of π-conjugation.Dimethylamino-containing BOPYPY as a pH-responsive fluorescent sensor could detect pH value.展开更多
文摘An effective route to pyrrolo[1,2-a]pyrazines is described via reaction of ethylenediamine,acetylenic esters and nitrostyrene derivatives in the presence of 20 mol%of sulfamic acid.
基金Supported by The Tackling-plan Project of Henan Department of Science and Technology (222102310388)Key Scientific Research Plan of Colleges in Henan Province (22B350002)Henan Provincial Medical Science and Technology Research Plan Joint Construction Project (LHGJ20191520).
文摘Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.
基金Shanghai Commission for Science and Technology(Nos.06Pj14034,06DZ19002,and 10ZR1409700)Ministry of Education(No.106078) for financial support
文摘Two pyrazine-containing macrocyclic polyazomethines 2 and 3 were synthesized by direct [2 + 2] and [3 + 3] condensation reactions between 2,21-[pyrazine-2,3-diylbis(oxy)]dibenzaldehyde (1) and hydrazine. Both 2 and 3 were characterized by NMR, HRMS, and their structures were determined via X-ray crystal diffraction studies.
基金Foundation Research Project of National defence(B0920110051)
文摘1 Introduction In the last decades,the furazan fused ring compounds have been paid much more attention owing to their characteristics,such as high density,high specific volume and high nitrogen content.A novel energetic compound based on furazan fused ring,6-nitroimino-4,8-dinitro-5,6,7,8-tetrahydro-4H-imidazo furazano pyrazine(NIFDNP),was firstly designed and its properties of physico-chemical and detonation were calculated by Gaussian 09 program[4] and VLW method[5].Using glyoxal
基金This work was supported by the National Natural Science Foundation of China (No. 20173063), the State Key Basic Research and Development Plan of China (001CB108906), and the NSF of Fujian Province (E0020001)
文摘A novel 2-D lead-containing hybrid compound, [(PbCl2)(μ-Pyz)1/2], (Pyz = pyrazine) 1, has been synthesized by the hydrothermal assembly of pyrazine with lead chloride. Elemental analysis and X-ray crystal structure analyses were carded out for the structural determination and characterization of the title compound. Compound 1 crystallizes in orthorhombic, space group lbam, with a = 19.5558(18), b = 7.1939(6), c = 7.5449(6) A, V = 1061.44(16) .A^3, C2H2Cl2NPb, Mr= 318.14, Z = 8, Dc= 3.982 g/cm^3, μ = 32.63 mm^-1, F(000) = 1096.0, R = 0.0368 and wR = 0.0901 for 623 observed reflections (I 〉 2σ(I)).
基金supported by the Science Foundation of Suihua University (K1001005)
文摘The title complex,[Ag 2 (L1) 2 (Pyr)·2.5H 2 O] 1 (L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in triclinic,space group P1,with a=7.339(5),b=13.105(5),c=14.097(5),α=84.377(5),β=76.921(5),γ=79.628(5)°,V=1296.7(11) 3,C 48 H 50 Ag 4 N 8 O 17 S 4,M r=1570.68,Z=1,D c=2.011 g/cm 3,μ=1.732 mm-1,F(000)=782,S=1.148,the final R=0.0436 and wR=0.1181 for 4130 observer reflections (I 2σ(Ⅰ)).Compound 1 shows a rare one-dimensional (1D) double chain,and the chains are further connected through secondary bonding,hydrogen bonds,and π-π interactions to generate a three-dimensional (3D) supramolecular structure.The luminescent property of 1 was also studied in the solid state at room temperture.
基金supported by the research grant of Phytochemistry Key Laboratory of Shaanxi Province (No. 02js40)
文摘The title compound,2,6-bis(2-pyridinylmethyl)-3,5-bis(2-hydroxyl-5-chlorophe nyl)-pyrazine(C26H12Cl2N4O2C2H8O2,Mr=551.41),has been synthesized and characterized by LC-ESIMS,NMR,UV and IR spectroscopy as well as by X-ray single-crystal diffraction.The compound behaves as a substituted pyrazine.The hydrogen atoms on C(2) and C(3) are substituted by 2-pyridinyl,whereas those on C(1) and C(4) are substituted by 2-hydroxyl-5-chlorophenyl.It crystallizes in the monoclinic system,space group P21/c with a=8.9433(12),b=32.003(4),c=10.5209(18),β=111.199(2)°,V=2807.5(7)3,Z=4,Dc=1.305 mg/m3,F(000)=1144 and μ=0.094 mm-1.A total of 13235 reflections were collected in the range of 2.17~25.01o by using a phi and omega scan mode,of which 4923 were unique(Rint=0.0692) and 2872 observed reflections with Ⅰ 〉2σ(Ⅰ) were used in the structure solution and refinement.
基金supported by the National Natural Science Foundation of China(No.41701349)
文摘A new copper(Ⅱ) complex of CuLCl_2, where L = N^1-(1-pyrazin-2-yl-ethylidene)-ethane-1,2-diamine, a tridentate Schiff base derived from 2-acetylpyrazine has been prepared. The complex has been characterized by FT-IR, elemental analysis and single-crystal X-ray diffraction studies. Structural studies reveal that CuLCl_2 is a mononuclear copper(Ⅱ) complex with distorted square pyramidal geometry. Antifungal activity of CuLCl_2 was investigated by use of microcalorimetric measurement system and evaluated against S. pombe. It has high antifungal activity with IC_(50) = 213 μg/mL.
基金This work was supported by the National Natural Science Foundation of China (No. 20271043) and the Natural Science Foundation of Shandong Province (Y2005B25)
文摘Two two-dimensional coordination polymers, [Cd(μ1,3-SCN-)2(μ1,6-L)]n 1 and [Co(μ1,3-SCN-)2(μ1,6-L)]n 2, have been synthesized with 2,3-dimethylpyrazine-1,4-dioxide (L) and thiocyanate as mixed bridging ligands, and their crystal structures were determined by X-ray crystallography. Both crystals belong to monoclinic system, space group C2/c. The other crystal parameters are as follows: for complex 1: α = 9.732(3), b =14.658(5), c = 8.811(3) A, β = 102.935(4)°, Z = 4, V= 1225.1(7) A^3, C8H8CdN4O2S2, Mr = 368.71, Dc = 1.999 g/cm^3, F(000) = 720 and μ= 2.117 mm^-1; for complex 2: α = 9.528(7), b = 14.563(11), c = 8.415(6) A, β= 102.195(9)°, V= 1141.3(14) A^3, Z = 4, C8H8CoN4O2S2, Mr = 315.23, Dc = 1.835 g/cm^3, F(000) = 636 and μ = 1.863 mm^-1. The two complexes show similar two-dimensional sheet structures. Along the c axis one-dimensional chains are constructed by the coordination of Cd(Ⅱ) (or Co(Ⅱ)) ions with μ1,6-L bridging ligand, and the μ1,3-SCN- bridging ligands make the chains connect to each other, resulting in the formation of a two-dimensional sheet on the ac plane.
基金supported by the Natural Science Foundation of Fujian Province (2006F3135,2006F3141,2007HZ0001-1)the Fund of Fujian Key Laboratory of Nanomaterials (2006L2005)
文摘The title compound, [Cu2(DMPz)2PMo12O40]·HDMPz (1, DMPz = 2,5-dimethyl pyrazine), has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1 with a = 11.075(2), b = 11.551(2), c = 11.886(2) A.α = 106.352(2), β = 109.862(3), γ = 109.504(1)°, V = 1206.8(3) A3, C18H26CU2Mo12N6O40P, Mr = 2275.78, Z = 1, Dc = 3.131 g/cm3, μ = 4.011 mm^-1, F(000) = 1073, S = 1.066, the final R = 0.0389 and wR = 0.1056 for 3739 observed reflections with I 〉 2σ(I). The structural analysis indicates that the title compound is composed of Keggin clusters [PMo12O40]3- connected by one-dimensional [CB(DMPz)]2n^2n+ chains to form a two-dimensional grid layer with holes occupied by monoprotonated DMPz molecules. In the solid of the title compound, the 2D grid layers are stacked together in an ABAB packing mode.
基金supported by the Guangxi Natural Science Foundation (No. 2010GXNSFA013017, No. 2010GXNSFA013062, No. 0991293)the Science Research Foundation of Guangxi Normal University
文摘A novel coordination polymer, [Cd2Cl4(bpme)]n·n(H2O) (1, bpme=2,5-bis(be-nzoimidazol-2-yl)pyrazine), has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal of the complex belongs to the triclinic system, space group P , with a=7.0737(9), b=8.7886(11), c=9.4561(12) , α=105.3580(10), β=94.981(2), γ=96.879(2)°, V=558.46(12) 3, Mr=714.97, Z=1, F(000)=346, Dc=2.126 g/cm3, μ=2.412 mm-1, T=296(2) K, S=1.057, R=0.0533 and wR=0.1480. According to the structural analysis, the Cd(Ⅱ) ion adopts a slightly distorted six-coordinated octahedral geometry. The Cd(Ⅱ) atoms are bridged by four Cl atoms along the a direction, forming infinite straight chains which are further constructed to generate 2D network layer structures through the μ4-N bpme ligand in the b direction, and such 2D network layer structures finally form a novel three-dimensional infinite supramolecular framework through weak π-π stacking between two network layers and hydrogen bonds.
文摘Two new zinc(Ⅱ) compounds with dibenzoylmethane and N-donor ancillary ligands,[Zn(μ-pyz)(dbm)_2]_n(1) and [Zn(dbm)_2(μ-bpe)Zn(dbm)_2](2)(Hdbm = dibenzoylmethane,pyz = pyrazine and bpe = 1,2-bis(4-pyridyl)ethane),have been prepared and characterized using elemental analysis,IR,~1H NMR and 13 C NMR spectroscopy,and studied by thermal gravimetric analysis as well as single-crystal X-ray diffraction. The crystal and molecular structures of 1 and 2 have been solved by X-ray diffraction and they turned out to be a one-dimensional coordination polymer with linear dispositions of metal atoms and binuclear compound,respectively. These one-dimensional polymers are further connected to form a 3D supramolecular network by C–H···O(only in 2) and π-π interactions.
基金financially supported by the National Natural Science Foundation of China(Nos.51973153,22105144).
文摘The merits of intrinsic electrical conductivity, high specific surface area, tunable chemical composition and tailor-made properties enable two-dimensional conductive metal-organic frameworks (2D c-MOFs) as promising next-generation electrode materials in the field of energy storage and conversion. Herein, we have designed and synthesized a novel pyrazine-based 2D c-MOF (TPQG-Cu-MOF) bearing extended π-conjugated structure and abundant redox active sites. Thanks to the excellent redox reversibility of pyrazine units and CuO2 units, as well as the insolubility of the rigid framework skeleton, TPQG-Cu-MOF as the cathode material of lithium-ion battery exhibits a reversible specific capacity (150.2 mAh·g–1 at 20 mAh·g–1), good cycling stability (capacity retention of 82.6% after 500 cycles at 1 A·g–1) and excellent rate performance. Comprehensive ex-situ spectroscopic studies revealed the reversible redox activity of pyrazine units and CuO2 units of TPQG-Cu-MOF during the Li+ insertion/extraction process. The deepening fundamental understanding of the structure-property relationship was proposed, which might pave the way for further development of efficient MOF-based energy storage devices.
基金the National Natural Science Foundation of China(Nos.52125002 and 51908270)the Natural Science Foundation of Jiangxi Province(No.20212ACB213006),and the National Key Research and Development Program of China(No.2019YFC1907900).
文摘The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection.Metal organic frameworks(MOFs)have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics,including adjustable structure,strong stability and porosity.Herein,pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions.Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal–organic frameworks.Furthermore,the material exhibits excellent adsorption capacity,with a theoretical maximum copper uptake of 247 mg/g.As proven by XPS and FT-IR analysis,the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66.This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions,and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.
基金supported by the National Natural Science Foundation of China(Nos.52025131 and 61721005)Science Technology Department of Zhejiang Province(2022C01225).
文摘The manipulation on turn-on fluorescence in solid state materials attracts increasing interests owing to their widespread applications.Herein we report how the nonradiative pathways of tetraphenylpyrazine(TPP)units in metal-organic frameworks(MOFs)systems could be hindered through a topological design approach.Two MOFs single crystals of different topology were constructed via the solvothermal reaction of a TPP-based 4,4',4",4"-(pyrazine-2,3,5,6-tetrayl)tetrabenzoic acid(H,TCPP)ligand and metal cations,and their mechanisms of formation have been explored.Compared with the innate lowfrequency vibrational modes of flu net Tb-TCPP-1,such as phenyl ring torsions and pyrazine twists,Tb-TCPP-2 adopts a shp net,so the dihedral angle of pyrazine ring and phenyl arms is larger,and the center pyrazine ring in TPP unit is coplanar,which hinders the radiationless decay of TPP moieties in Tb-TCPP-2.Thereby Tb-TCPP-2 exhibits a larger blue-shifted fluorescence and a higher fluorescence quantum yield than Tb-TCPP-1,which is consistent with the reduced nonradiative pathways.Furthermore,Density functional theory(DFT)studies also confirmed aforementioned tunable turn-on fluorescence mechanism.Our work constructed TPP-type MOFs based on a deliberately topological design approach,and the precise design of turn-on fluorescence holds promise as a strategy for controlling nonradiative pathways.
基金supported financially by the Youth Science & Technology Foundation of Sichuan Province in China(No. 2012JQ0047)Development foundation from Air Environmental Modeling and Pollution Controlling Key Laboratory of Sichuan Higher Education Institutes(No.ZZKT2012003)
文摘Cu-TiO_2 catalysts supported onγ-Al_2O_3 are prepared and used in glycerol cyclization with 1,2-propanediamine to produce pyrazinyl compounds including 6-hydroxymethyl-2-methylpyrazine,5-hydroxymethyl -2-methyIpyrazine,2,6-dimethylpyrazine and 2,5-dimethylpyrazine in a fixed-bed system.It is found that glycerol cylclization with 1,2-propanediamine gave a high total yield of pyrazinyl compounds(〉80%) over Cu-Ti02/γ-Al_2O_3 catalyst,and cyclization was through the reactions between activated 1,2-propanediamine and the intermediates from glycerol dehydration and oxidation.In addition,the regioselectivity of the pyrazinyl compounds was mainly controlled by the steric hindrance of the substrates during the cyclization process.
基金financial support from the National Natural Science Foundation of China(Grants No.81661148046 and81773762,China)the "Personalized Medicines-Molecular Signature-based Drug Discovery and Development",Strategic Priority Research Program of the Chinese Academy of Sciences(Grants No.XDA12020317,China)+1 种基金the program for Innovative Research Team of the Ministry of Education(China)the program for Liaoning Innovative Research Team at Shenyang Pharmaceutical University(China)
文摘Genomic alterations are commonly found in the signaling pathways of fibroblast growth factor receptors(FGFRs). Although there is no selective FGFR inhibitors in market, several promising inhibitors have been investigated in clinical trials, and showed encouraging efficacies in patients. By designing a hybrid between the FGFR-selectivity-enhancing motif dimethoxybenzene group and our previously identified novel scaffold, we discovered a new series of potent FGFR inhibitors, with the best one showing sub-nanomolar enzymatic activity. After several round of optimization and with the solved crystal structure, detailed structure–activity relationship was elaborated. Together with in vitro metabolic stability tests and in vivo pharmacokinetic profiling, a representative compound(35) was selected and tested in xenograft mouse model, and the result demonstrated that inhibitor 35 was effective against tumors with FGFR genetic alterations, exhibiting potential for further development.
基金supported by the National Natural Science Foundation of China (No.21542004)Young and Middle-aged Scientific and Technological Innovation Talents of Shenyang Science and Technology Bureau (No.RC170140)+4 种基金Natural Science Foundation of Liaoning Province (No.20170540721)Basic research on the application of Industrial Development of Shenyang Science and Technology Bureau (No.18013027)Liaoning BaiQianWan Talents Programthe Distinguished Professor Project of Liaoning province (No.20183532)the Chinese Scholarship Council (No.20183058) for financial support
文摘Novel 5,6,5,6-tetracyclic pyrazine/pyrrole-fused unsymmetric bis(BF2) fluorescent dyes(BOPYPYs) were obtained by reaction of pyrrole-2-carboxaldehyde with 1-(pyrazin-2-yl)hydrazine in the presence of Et3 N-BF3·Et2 O for the first time.The absorption maxima of pyrazine-fused BOPYPY are obviously bathochromic shifts,in contrast to those of the reported BOPPY,indicating that the discrepant substitute groups between pyridine and pyrazine result in the remarkable wavelength difference.The new series of BO PYPYs possess high molar extinction coefficients,high fluorescence quantum yields,and larger Stokes shifts.A Knoevenagel reaction of BOPYPY with 4-dimethylaminobenzaldehyde smoothly produced the dye with the extension of π-conjugation.Dimethylamino-containing BOPYPY as a pH-responsive fluorescent sensor could detect pH value.